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  • 1451.
    Al, S.
    Linköping University, Department of Thematic Studies, The Department of Gender Studies.
    Women’s bodies and Men’s Honour: Supporting Middle eastern migrant women who have experienced honour violence2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is a study of gender and honour, focusing on NGO’s who work to support women in Sweden who have escaped honour violence. The purpose of this thesis is to find out and explain how they make sense of honour and more specifically, to investigate how does Swedish authorities can help the Middle Eastern women who are victims under this tradition.

    My focus through this thesis will be on the data analysis, moreover, using intersectionality as an analytical tool will help to explain the intersections which lead to the honour killings.

    The results show that the honour violence still exists in the Swedish society as well as the Middle East, in addition, some Middle Eastern people who moved to Sweden still believe and practice the honour culture in the Swedish society. More than that, I got the answers for all the research questions which helped me to clarify the relation between honour and its intersections which helped me to know the reasons why does the Honour violence/killings can happen. The answers agree that the honour violence is connected to the shame and guilt cultures. The meaning of honour is different in different cultures. Most of the honour related cases have women as victims. The honour has many intersections, most of them related to virginity, homosexuality, out marriage relations and rape. The Swedish organisations offer help for the victims of honour.

     More than that, reading my thesis will give the reader the understanding of the phenomena of Honour, its intersections and how it does exist in the Middle Eastern culture and its old traditions.

  • 1452.
    Al Taie, Salwan
    Linköping University, Department of Management and Engineering, Political Science.
    The 2003 war on Iraq: Purposes and Motivations, An Analytical View2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Iraqi war represents a form of coercive diplomacy between words and war in the enforcement of international norms and is considered as a new and old notion at the same time. This holds true ever since the days of the Desert Storm: the war waged to liberate Kuwait. This mechanism was launched in 1990 under the title of the war to liberate Iraq or the punitive war, the core idea of which would correspond to the purposes and motivations of the 2003 war. This study begins with a review of the literature, both for background information and for the identification of variables of the events and factors in this issue. This war is analysed in relation to the US objectives in the region when it comes to maintaining its interests, ensuring security for its allies and dominating the whole region.

    This study investigates the controversy surrounding the case of 2003 war on Iraq, which is embodied in the plural reasons for the war. The situation in Iraq is of course still a subject for debate, as the country has experienced a stalemate for some years now. The study focuses on one chosen central research question; What was the real reason behind that war? The methodological triangulation approach adopted is about using different research methods to complement one another, in order for the findings to have validity and credibility. Relying upon conceptual analysis, critical review of relevant literature and concepts, political discourses analysis and also on primary data in the form of interviews with Iraqi elite experts of intelligence service and weapons experts, including the former top administrators who are linked to this issue, this thesis provides both facts and opinions which could be used as qualitative data. The aim of the variegated sources and material used for this study is to exemplify contending perspectives on the subject under study.

    The findings of this study suggest that since the war lacks a strong moral base, it remains suspicious as a legitimate policy instrument to solve the problematic issue in Iraq. While the war came about during the reign of the Republicans and the foreign policy then adopted, as this study demonstrates, the repercussions are severe to this day. Coercive diplomacy can ultimately lead the region into enormous chaos, which may have dire consequences for the whole region, not only within Iraq.

  • 1453.
    Alabas, Oras A.
    et al.
    University of Leeds, England.
    Gale, Chris P.
    University of Leeds, England; York Teaching Hospital NHS Fdn Trust, England.
    Hall, Marlous
    University of Leeds, England.
    Rutherford, Mark J.
    University of Leicester, England.
    Szummer, Karolina
    Department Med, Sweden.
    Sederholm Lawesson, Sofia
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping. Linköping University, Faculty of Medicine and Health Sciences.
    Alfredsson, Joakim
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
    Lindahl, Bertil
    Uppsala University, Sweden; Uppsala University, Sweden.
    Jernberg, Tomas
    Karolinska Institute, Sweden.
    Sex Differences in Treatments, Relative Survival, and Excess Mortality Following Acute Myocardial Infarction: National Cohort Study Using the SWEDEHEART Registry2017In: Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease, ISSN 2047-9980, E-ISSN 2047-9980, Vol. 6, no 12, article id e007123Article in journal (Refereed)
    Abstract [en]

    Background-This study assessed sex differences in treatments, all-cause mortality, relative survival, and excess mortality following acute myocardial infarction. Methods and Results-A population-based cohort of all hospitals providing acute myocardial infarction care in Sweden (SWEDEHEART [Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies]) from 2003 to 2013 was included in the analysis. Excess mortality rate ratios (EMRRs), adjusted for clinical characteristics and guideline-indicated treatments after matching by age, sex, and year to background mortality data, were estimated. Although there were no sex differences in all-cause mortality adjusted for age, year of hospitalization, and comorbidities for ST-segment-elevation myocardial infarction (STEMI) and non-STEMI at 1 year (mortality rate ratio: 1.01 [95% confidence interval (CI), 0.96-1.05] and 0.97 [95% CI, 0.95-.99], respectively) and 5 years (mortality rate ratio: 1.03 [95% CI, 0.99-1.07] and 0.97 [95% CI, 0.95-.99], respectively), excess mortality was higher among women compared with men for STEMI and non-STEMI at 1 year (EMRR: 1.89 [95% CI, 1.66-2.16] and 1.20 [95% CI, 1.16-1.24], respectively) and 5 years (EMRR: 1.60 [95% CI, 1.48-1.72] and 1.26 [95% CI, 1.21-1.32], respectively). After further adjustment for the use of guideline-indicated treatments, excess mortality among women with non-STEMI was not significant at 1 year (EMRR: 1.01 [95% CI, 0.97-1.04]) and slightly higher at 5 years (EMRR: 1.07 [95% CI, 1.02-1.12]). For STEMI, adjustment for treatments attenuated the excess mortality for women at 1 year (EMRR: 1.43 [95% CI, 1.26-1.62]) and 5 years (EMRR: 1.31 [95% CI, 1.19-1.43]). Conclusions-Women with acute myocardial infarction did not have statistically different all-cause mortality, but had higher excess mortality compared with men that was attenuated after adjustment for the use of guideline-indicated treatments. This suggests that improved adherence to guideline recommendations for the treatment of acute myocardial infarction may reduce premature cardiovascular death among women.

  • 1454.
    Al-Absi, Thabit
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, The Institute of Technology.
    Efficient Characterization of Short Anelloviruses Fragments Found in Metagenomic Samples2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Some viral metagenomic serum samples contain a huge amount of Anellovirus, which is a genetically diverse family with a few conserved regions making it hard to efficiently characterize. Multiple sequence alignment of the Anelloviruses found in the sample must be constructed to get a clear picture of Anellovirus diversity and to identify stable regions. Using available multiple sequence alignment software directly on these fragments results in an MSA of a very poor quality due to their diversity, misaligned regions and low-quality regions present in the sequence.

    An efficient MSA must be constructed in order to characterize these Anellovirus present in the samples. Pairwise alignment is used to align one fragment to the database sequences at a time. The fragments are then aligned to the database sequences using the start and end position from the pairwise alignment results. The algorithm will also exclude non-aligned portions of the fragments, as these are very hard to handle properly and are often products of misassembly or chimeric sequenced fragments. Other tools to aid further analysis were developed, such as finding a non-overlapping window that contains the most fragments, find consensus of the alignment and extract any regions from the MSA for further analysis.

    An MSA was constructed with a high percent of correctly aligned bases compared to an MSA constructed using MSA softwares. The minimal number of genomes found in the sampled sequence was found as well as a distribution of the fragments along the database sequence. Moreover, highly conserved region and the window containing most fragments were extracted from the MSA and phylogenetic trees were constructed for these regions. 

  • 1455.
    Alagia, M.
    et al.
    ISMN-CNR, Sez. Roma1, P.le A. Moro 5, I-00185 Roma, Italy and TASC-CNR, Area Science Park, Basovizza, I-34012 Trieste, Italy.
    Lavollée, M.
    LIXAM-CNRS, F-91898 Orsay-Cedex, France.
    Richter, R.
    Sincrotrone Trieste, Area Science Park, I-34012 Basovizza, Trieste, Italy.
    Ekström, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics . Linköping University, The Institute of Technology.
    Carravetta, V.
    Institute of Chemical Physical Processes (CNR), Via Moruzzi 1, I-56124 Pisa, Italy.
    Stranges, D.
    Dipartimento di Chimica and INSTM, Universitá La Sapienza, P.le A. Moro 5, I-00185 Roma, Italy and ISMN-CNR, Sez. Roma1, P.le A. Moro 5, I-00185 Roma, Italy.
    Brunetti, B.
    ISMN-CNR, Sez. Roma1, P.le A. Moro 5, I-00185 Roma, Italy.
    Stranges, S.
    Dipartimento di Chimica and INSTM, Universitá La Sapienza, P.le A. Moro 5, I-00185 Roma, Italy; ISMN-CNR, Sez. Roma1, P.le A. Moro 5, I-00185 Roma, Italy; and TASC-CNR, Area Science Park, Basovizza, I-34012 Trieste, Italy.
    Probing the potential energy surface by highresolution x-ray absorption spectroscopy: The umbrella motion of the coreexcited CH3 free radical2007In: Physical Review. A, ISSN 1050-2947, Vol. 76, no 2, p. 124305-Article in journal (Refereed)
    Abstract [en]

    A detailed study of the umbrellalike vibration in inner-shell spectroscopy is presented. The high-resolution x-ray absorption spectrum for the lowest lying core excitation of the CH3 free radical was recorded. High quality potential energy surfaces (PES) for the initial and final states of the transition were calculated as a function of the symmetrical stretching and the umbrella deformation coordinates. The strong anharmonicity along the umbrella coordinate in the double-well region of the PES of the core excited state has a strong effect on the bending vibrational progressions. The excellent agreement between the experiment and theory allows an accurate spectroscopic characterization of the vibrational structure of the electronic transition, and the estimation of the umbrella inversion time of 149  fs.

  • 1456.
    Alagia, Michele
    et al.
    ISMN-CNR, Rom.
    Baldacchini, Chiara
    Università di Roma "La Sapienza" .
    Betti, Maria Grazia
    Università di Roma "La Sapienza" .
    Bussolotti, Fabio
    Università di Modena e Reggio Emilia.
    Carravetta, Vincenzo
    IPCF-CNR, Pisa.
    Ekström, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics . Linköping University, The Institute of Technology.
    Mariani, Carlo
    Università di Roma "La Sapienza" .
    Stranges, Stefano
    Università di Roma "La Sapienza" .
    Core-shell photoabsorption and photoelectron spectra of gas-phase pentacene: Experiment and theory2005In: Journal of chemical physics Online, ISSN 1089-7690, Vol. 122, no 12, p. 124305-Article in journal (Refereed)
    Abstract [en]

    The C K-edge photoabsorption and 1s core-level photoemission of pentacene (C22H14) free molecules are experimentally measured, and calculated by self-consistent-field and static-exchange approximation ab initio methods. Six nonequivalent C atoms present in the molecule contribute to the C 1s photoemission spectrum. The complex near-edge structures of the carbon K-edge absorption spectrum present two main groups of discrete transitions between 283 and 288  eV photon energy, due to absorption to * virtual orbitals, and broader structures at higher energy, involving * virtual orbitals. The sharp absorption structures to the * empty orbitals lay well below the thresholds for the C 1s ionizations, caused by strong excitonic and localization effects. We can definitely explain the C K-edge absorption spectrum as due to both final (virtual) and initial (core) orbital effects, mainly involving excitations to the two lowest-unoccupied molecular orbitals of * symmetry, from the six chemically shifted C 1s core orbitals. ©2005 American Institute of Physics

  • 1457.
    Al-Ahmad, A.
    et al.
    Cardiac Arrhythmia Service, Stanford University Medical School, Stanford, CA, United States.
    Wigström, Lars
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sandner-Porkristl, D.
    Siemens AG, Medical Solutions, Forchheim, Germany.
    Wang, P.J.
    Cardiac Arrhythmia Service, Stanford University Medical School, Stanford, CA, United States.
    Zei, P.C.
    Cardiac Arrhythmia Service, Stanford University Medical School, Stanford, CA, United States.
    Boese, J.
    Siemens AG, Medical Solutions, Forchheim, Germany.
    Lauritsch, G.
    Siemens AG, Medical Solutions, Forchheim, Germany.
    Moore, T.
    Siemens AG, Medical Solutions, Forchheim, Germany.
    Chan, F.
    Department of Radiology, Stanford University Medical School, Stanford, CA, United States.
    Fahrig, R.
    Department of Radiology, Stanford University Medical School, Stanford, CA, United States.
    Time-resolved three-dimensional imaging of the left atrium and pulmonary veins in the interventional suite-A comparison between multisweep gated rotational three-dimensional reconstructed fluoroscopy and multislice computed tomography2008In: Heart Rhythm, ISSN 1547-5271, Vol. 5, no 4, p. 513-519Article in journal (Refereed)
    Abstract [en]

    Background: Cardiac computed tomography (CT) is commonly used to visualize left atrial (LA) anatomy for ablation of atrial fibrillation. We have developed a new imaging technique that allows acquisition and visualization of three-dimensional (3D) cardiac images in the catheter lab. Objective: We sought to compare LA and pulmonary vein (PV) dimensions acquired using gated multisweep rotational fluoroscopy (C-arm CT) system and multislice computed tomography (MSCT) in an in vivo porcine model. Methods: A Siemens AXIOM Artis dTA C-arm system (Siemens AG, Medical Solutions) was modified to allow acquisition of four bidirectional sweeps during synchronized acquisition of the electrocardiogram signal to allow retrospective gating. C-arm CT image volumes were then reconstructed. Gated MSCT (SOMATOM Sensation 16 and 64, Siemens AG, Medical Solutions) and C-arm CT images were acquired in six animals. The two main PV diameters were measured in orthogonal axes. LA volumes were calculated. C-arm CT measurements were compared with the MSCT measurements. Results: The average PV diameters using the C-arm CT were 2.24 × 1.35 cm, versus 2.27 × 1.38 cm for CT. The average difference was 0.034 cm (1.9%) between the C-arm CT and standard CT. The average LA volume using MSCT was 49.1 ± 12.7 cm3, as compared with 51.0 ± 8.7 cm3 obtained by the C-arm CT. The average difference between the C-arm CT and the MSCT was 1.9 cm3 (3.7%). There were no significant differences in either the PV or LA measurements. Conclusions: Visualization of 3D cardiac anatomy during ablation procedures is possible and highly accurate. The 3D cardiac reconstructions acquired during ablation procedures will be valuable for procedural planning and guidance. © 2008 Heart Rhythm Society.

  • 1458.
    Alakokkare, Marlene
    et al.
    Linköping University, Department of Social and Welfare Studies, Social Work.
    Andreasson, Cecilia
    Linköping University, Department of Social and Welfare Studies, Social Work.
    Våld i nära relationer: En diskursanalys kring framställningar om våld i nära relationer i tidskriften Socionomen2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna kvalitativa uppsats är att undersöka hur våld i nära relationer framställs i tidskriften Socionomen. Vår empiri består av 42 artiklar som berör våld i nära relationer. Artiklarna är publicerade mellan åren 1997 - 2013 i tidskriften Socionomen. Uppsatsens teoretiska utgångspunkt är ett socialkonstruktionistiskt perspektiv, som bidrar med att synliggöra sociala konstruktioner inom forskningsområdet. Som analysmetod används en form av diskursanalys för att urskilja subjektspositioner och kategorier i det empiriska materialet. Resultatet av analysen visar på fyra diskurser som handlar om skuld och skam, genus, det "rena" våldsoffret och dess motsats samt föräldraskap. Dessa diskurser manifesterar olika sätt att samtala om våld i nära relationer som i sin tur kan påverka det sociala arbetet utifrån hur problemet beskrivs. Olika framställningar av våld i nära relationer kan leda till olika bemötanden av klienter i socialt arbete.

  • 1459. Alam, MT
    et al.
    Yamada, T
    Carlsson, Uno
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biochemistry.
    Ikai, A
    The importance of being knotted: Effects of the C-terminal knot structure on enzymatic and mechanical properties of bovine carbonic anhydrase II2003In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 84, no 2, p. 159A-159AConference paper (Other academic)
  • 1460.
    Alam, M.T.
    et al.
    Laboratory of Biodynamics, Grad. Sch. of Biosci. and Biotech., Tokyo Inst. of Technol., 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
    Yamada, T.
    Laboratory of Biodynamics, Grad. Sch. of Biosci. and Biotech., Tokyo Inst. of Technol., 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
    Carlsson, Uno
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biochemistry.
    Ikai, A.
    Laboratory of Biodynamics, Grad. Sch. of Biosci. and Biotech., Tokyo Inst. of Technol., 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
    The importance of being knotted: Effects of the C-terminal knot structure on enzymatic and mechanical properties of bovine carbonic anhydrase II12002In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 519, no 1-3, p. 35-40Article in journal (Refereed)
    Abstract [en]

    In order to better understand the contribution of the knotted folding pattern to the enzymatic and mechanical properties of carbonic anhydrases, we replaced Gln-253 of bovine carbonic anhydrase II with Cys, which allowed us to measure the mechanical strength of the protein against tensile deformation by avoiding knot tightening. The expressed protein, to our surprise, turned out to contain two conformational isomers, one capable of binding an enzymatic inhibitor and the other not, which led to their separation through affinity chromatography. In near- and far-UV circular dichroism and fluorescence spectra, the separated conformers were very similar to each other and to the wild-type enzyme, indicating that they both had native-like conformations. We describe new evidence which supports the notion that the difference between the two conformers is likely to be related to the completeness of the C-terminal knot formation. © 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

  • 1461.
    Alam, Syed Asad
    Linköping University, Department of Electrical Engineering.
    Design Space Exploration of Time-Multiplexed FIRFilters on FPGAs2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    FIR (Finite-length Impulse Response) filters are the corner stone of many signalprocessing devices. A lot of research has gone into their development as wellas their effective implementation. With recent research focusing a lot on powerconsumption reduction specially with regards to FPGAs, it was found necessaryto explore FIR filters mapping on FPGAs.

    Time multiplexed FIR filters are also a good candidate for examination withrespect to power consumption and resource utilization, for example when implementedin Field Programmable Gate Arrays (FPGAs). This is motivated by thefact that the usable clock frequency often is higher compared to the required datarate. Current implementations by, e.g., Xilinx FIR Compiler suffer from highpower consumption when the time multiplexing factor is low. Further, it needs tobe investigated how exploiting coefficient symmetry, scaling the coefficients andincreasing the time-multiplexing factor influences the performance.

  • 1462.
    Alam, Syed Asad
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Techniques for Efficient Implementation of FIR and Particle Filtering2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    FIR filters occupy a central place many signal processing applications which either alter the shape, frequency or the sampling frequency of the signal. FIR filters are used because of their stability and possibility to have linear-phase but require a high filter order to achieve the same magnitude specifications as compared to IIR filters. Depending on the size of the required transition bandwidth the filter order can range from tens to hundreds to even thousands. Since the implementation of the filters in digital domain requires multipliers and adders, high filter orders translate to a large number of these arithmetic units for its implementation. Research towards reducing the complexity of FIR filters has been going on for decades and the techniques used can be roughly divided into two categories; reduction in the number of multipliers and simplification of the multiplier implementation. 

    One technique to reduce the number of multipliers is to use cascaded sub-filters with lower complexity to achieve the desired specification, known as FRM. One of the sub-filters is a upsampled model filter whose band edges are an integer multiple, termed as the period L, of the target filter's band edges. Other sub-filters may include complement and masking filters which filter different parts of the spectrum to achieve the desired response. From an implementation point-of-view, time-multiplexing is beneficial because generally the allowable maximum clock frequency supported by the current state-of-the-art semiconductor technology does not correspond to the application bound sample rate. A combination of these two techniques plays a significant role towards efficient implementation of FIR filters. Part of the work presented in this dissertation is architectures for time-multiplexed FRM filters that benefit from the inherent sparsity of the periodic model filters.

    These time-multiplexed FRM filters not only reduce the number of multipliers but lowers the memory usage. Although the FRM technique requires a higher number delay elements, it results in fewer memories and more energy efficient memory schemes when time-multiplexed. Different memory arrangements and memory access schemes have also been discussed and compared in terms of their efficiency when using both single and dual-port memories. An efficient pipelining scheme has been proposed which reduces the number of pipelining registers while achieving similar clock frequencies. The single optimal point where the number of multiplications is minimum for non-time-multiplexed FRM filters is shown to become a function of both the period, L and time-multiplexing factor, M. This means that the minimum number of multipliers does not always correspond to the minimum number of multiplications which also increases the flexibility of implementation. These filters are shown to achieve power reduction between 23% and 68% for the considered examples.

    To simplify the multiplier, alternate number systems like the LNS have been used to implement FIR filters, which reduces the multiplications to additions. FIR filters are realized by directly designing them using ILP in the LNS domain in the minimax sense using finite word length constraints. The branch and bound algorithm, a typical algorithm to implement ILP problems, is implemented based on LNS integers and several branching strategies are proposed and evaluated. The filter coefficients thus obtained are compared with the traditional finite word length coefficients obtained in the linear domain. It is shown that LNS FIR filters provide a better approximation  error compared to a standard FIR filter for a given coefficient word length.

    FIR filters also offer an opportunity in complexity reduction by implementing the multipliers using Booth or standard high-radix multiplication. Both of these multiplication schemes generate pre-computed multiples of the multiplicand which are then selected based on the encoded bits of the multiplier. In TDF FIR filters, one input data is multiplied with a number of coefficients and complexity can be reduced by sharing the pre-computation of the multiplies of the input data for all multiplications. Part of this work includes a systematic and unified approach to the design of such computation sharing multipliers and a comparison of the two forms of multiplication. It also gives closed form expressions for the cost of different parts of multiplication and gives an overview of various ways to implement the select unit with respect to the design of multiplexers.

    Particle filters are used to solve problems that require estimation of a system. Improved resampling schemes for reducing the latency of the resampling stage is proposed which uses a pre-fetch technique to reduce the latency between 50% to 95%  dependent on the number of pre-fetches. Generalized division-free architectures and compact memory structures are also proposed that map to different resampling algorithms and also help in reducing the complexity of the multinomial resampling algorithm and reduce the number of memories required by up to 50%.

    List of papers
    1. A unified approach to the design and implementation of computation sharing multipliers: Computation sharing multipliers
    Open this publication in new window or tab >>A unified approach to the design and implementation of computation sharing multipliers: Computation sharing multipliers
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    A unified approach to the design and implementation of computation sharing multiplier based on Booth and standard high-radix multiplication schemes is presented here. Both of these multiplication schemes have various building blocks and one of which is the pre-computer which can be shared across a number of multiplications if the multiplicand to the multipliers is same, like in a transposed direct form (TDF) finitelength impulse response (FIR) filter. Closed form expressions to estimate the cost of different building blocks based on different schemes have been developed and analyzed in different dimensions. Standalone multipliers and as part of computation sharing in FIR filters and complex multipliers have been realized in hardware and synthesized using standard cell library.

    It is shown that apart from word length and filter length, the ratio  between the cost of implementing adders and multiplexers has an effect on the choice of optimal radix. The higher the ratio, the lower is the cost of implementing multiplexers which will benefit high radix. Higher radix will also benefit from computation sharing if the cost of one multiplication for it is less than the lower radix and it is shown that radix-16 Booth multiplier achieves lower area complexity and power consumption by an average of 7% and 17%, respectively.

    Keywords
    Computation sharing multipliers, standard high-radix multiplier, Booth multiplier, FIR filter
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-124194 (URN)
    Available from: 2016-01-21 Created: 2016-01-21 Last updated: 2016-02-02Bibliographically approved
    2. On the implementation of time-multiplexed frequency-response masking filters
    Open this publication in new window or tab >>On the implementation of time-multiplexed frequency-response masking filters
    2016 (English)In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 64, no 15, p. 3933-3944Article in journal (Refereed) Published
    Abstract [en]

    The complexity of narrow transition band finite-length impulse response (FIR) filters is high and can be reduced by using frequency-response masking (FRM) techniques. These techniques use a combination of periodic model and, possibly periodic, masking filters. Time-multiplexing is in general beneficial since only rarely does the technology bound maximum obtainable clock frequency and the application determined required sample rate correspond. Therefore, architectures for time-multiplexed FRM filters that benefit from the inherent sparsity of theperiodic filters are introduced in this work.

    We show that FRM filters not only reduces the number of multipliers needed, but also have benefits in terms of memory usage. Despite the total amount of samples to be stored is larger for FRM, it results in fewer memory resources needed in FPGAs and more energy efficient memory schemes in ASICs. In total, the power consumption is significantly reduced compared to a single stage implementation. Furthermore, we show that the choice of the interpolation factor which gives the least complexity for the periodic model filter and subsequent masking filter(s) is a function of the time-multiplexing factor, meaning that the minimum number of multipliers not always correspond to the minimum number of multiplications. Both single-port and dual-port memories are considered and the involved trade-off in number of multipliers and memory complexity is illustrated. The results show that for FPGA implementation, the power reduction ranges from 23% to 68% for the considered examples.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2016
    Keywords
    Frequency-response masking, FIR filter, FPGA, ASIC, time-multiplexing, memories
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-124190 (URN)10.1109/TSP.2016.2557298 (DOI)000379699800009 ()
    Note

    Vid tiden för disputation förelåg publikationen som manuskript

    Available from: 2016-01-21 Created: 2016-01-21 Last updated: 2017-11-30Bibliographically approved
    3. Design of Finite Word Length Linear-Phase FIR Filters inthe Logarithmic Number System Domain
    Open this publication in new window or tab >>Design of Finite Word Length Linear-Phase FIR Filters inthe Logarithmic Number System Domain
    2014 (English)In: VLSI design (Print), ISSN 1065-514X, E-ISSN 1563-5171, Vol. 2014, no 217495Article in journal (Refereed) Published
    Abstract [en]

    Logarithmic number system (LNS) is an attractive alternative to realize finite-length impulse response filters because ofmultiplication in the linear domain being only addition in the logarithmic domain. In the literature, linear coefficients are directlyreplaced by the logarithmic equivalent. In this paper, an approach to directly optimize the finite word length coefficients in theLNS domain is proposed. This branch and bound algorithm is implemented based on LNS integers and several different branchingstrategies are proposed and evaluated. Optimal coefficients in the minimax sense are obtained and compared with the traditionalfinite word length representation in the linear domain as well as using rounding. Results show that the proposed method naturallyprovides smaller approximation error compared to rounding. Furthermore, they provide insights into finite word length propertiesof FIR filters coefficients in the LNS domain and show that LNS FIR filters typically provide a better approximation error comparedto a standard FIR filter.

    Place, publisher, year, edition, pages
    Egypt: Hindawi Publishing Corporation, 2014
    Keywords
    Logarithmic Number System, FIR Filter, Integer Linear Programming, Branch and Bound
    National Category
    Signal Processing
    Identifiers
    urn:nbn:se:liu:diva-105861 (URN)10.1155/2014/217495 (DOI)
    Available from: 2014-04-10 Created: 2014-04-10 Last updated: 2017-12-05Bibliographically approved
    4. Improved particle filter resampling architectures
    Open this publication in new window or tab >>Improved particle filter resampling architectures
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The most challenging aspect of particle filtering hardware implementation is the resampling step which replicates particles with large weights and discards those with small weights because it has a high latency and can only be partially executed in parallel with the other steps of particle filtering. To reduce the latency, an improved resampling scheme is proposed in this work which involves pre-fetching from the weight memory in parallel to the fetching of a value from a random function generator. Architectures for realizing the pre-fetch technique are also proposed. The trade-off between the latency reduction achieved by increasing the size of the pre-fetch memory and the architectural implementation complexity has been analyzed. Results show that a pre-fetch of five achieves the best area-latency trade-off while on average achieving an 85% reduction in the latency.

    We also propose a generic double multiplier architecture for resampling which avoids normalization divisions and makes the architecture equally efficient for non-powers-of-two number of particles as well as removes the need of explicitly ordering the random values for efficient multinomial resampling implementation. It is further improved by computing the cumulative sum of weights on-the-fly which helps in reducing the size of the weight memories by up to 50%.

    Keywords
    Particle filters, resampling algorithm, resampling architecture
    National Category
    Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-124193 (URN)
    Available from: 2016-01-21 Created: 2016-01-21 Last updated: 2016-02-02Bibliographically approved
  • 1463.
    Alam, Syed Asad
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    A unified approach to the design and implementation of computation sharing multipliers: Computation sharing multipliersManuscript (preprint) (Other academic)
    Abstract [en]

    A unified approach to the design and implementation of computation sharing multiplier based on Booth and standard high-radix multiplication schemes is presented here. Both of these multiplication schemes have various building blocks and one of which is the pre-computer which can be shared across a number of multiplications if the multiplicand to the multipliers is same, like in a transposed direct form (TDF) finitelength impulse response (FIR) filter. Closed form expressions to estimate the cost of different building blocks based on different schemes have been developed and analyzed in different dimensions. Standalone multipliers and as part of computation sharing in FIR filters and complex multipliers have been realized in hardware and synthesized using standard cell library.

    It is shown that apart from word length and filter length, the ratio  between the cost of implementing adders and multiplexers has an effect on the choice of optimal radix. The higher the ratio, the lower is the cost of implementing multiplexers which will benefit high radix. Higher radix will also benefit from computation sharing if the cost of one multiplication for it is less than the lower radix and it is shown that radix-16 Booth multiplier achieves lower area complexity and power consumption by an average of 7% and 17%, respectively.

  • 1464.
    Alam, Syed Asad
    et al.
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Design of Finite Word Length Linear-Phase FIR Filters inthe Logarithmic Number System Domain2014In: VLSI design (Print), ISSN 1065-514X, E-ISSN 1563-5171, Vol. 2014, no 217495Article in journal (Refereed)
    Abstract [en]

    Logarithmic number system (LNS) is an attractive alternative to realize finite-length impulse response filters because ofmultiplication in the linear domain being only addition in the logarithmic domain. In the literature, linear coefficients are directlyreplaced by the logarithmic equivalent. In this paper, an approach to directly optimize the finite word length coefficients in theLNS domain is proposed. This branch and bound algorithm is implemented based on LNS integers and several different branchingstrategies are proposed and evaluated. Optimal coefficients in the minimax sense are obtained and compared with the traditionalfinite word length representation in the linear domain as well as using rounding. Results show that the proposed method naturallyprovides smaller approximation error compared to rounding. Furthermore, they provide insights into finite word length propertiesof FIR filters coefficients in the LNS domain and show that LNS FIR filters typically provide a better approximation error comparedto a standard FIR filter.

  • 1465.
    Alam, Syed Asad
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Generalized Division-Free Architecture and Compact Memory Structure for Resampling in Particle Filters2015In: 2015 European Conference on Circuit Theory and Design (ECCTD), IEEE Press, 2015, p. 416-419Conference paper (Refereed)
    Abstract [en]

    The most challenging step of implementing particle filtering is the resampling step which replicates particles with large weights and discards those with small weights. In this paper, we propose a generic architecture for resampling which uses double multipliers to avoid normalization divisions and make the architecture  equally efficient for non-powers-of-two number of particles. Furthermore, the complexity of resampling is greatly affected by the size of memories used to store weights. We illustrate that by storing the original weights instead of their cumulative sum and calculating them online reduces the total complexity, in terms of area, ranging from 21% to 45%, while giving up to 50% reduction in memory usage.

  • 1466.
    Alam, Syed Asad
    et al.
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Implementation of Narrow-Band Frequency-Response Masking for Efficient Narrow Transition Band FIR Filters on FPGAs2011In: NORCHIP, 2011, IEEE conference proceedings, 2011, p. 1-4Conference paper (Refereed)
    Abstract [en]

    The complexity of narrow transition band FIR filters is highand can be reduced by using frequency response masking (FRM) techniques. Thesetechniques use a combination of periodic model filters and masking filters. Inthis paper, we show that time-multiplexed FRM filters achieve lowercomplexity, not only in terms of multipliers, but also logic elements compared to time-multiplexed singlestage filters. The reduced complexity also leads to a lower power consumption. Furthermore, we show that theoptimal period of the model filter is dependent on the time-multiplexing factor.

  • 1467.
    Alam, Syed Asad
    et al.
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Electronics System. Linköping University, The Institute of Technology.
    Implementation of Time-Multiplexed Sparse Periodic FIR Filters for FRM on FPGAs2011Conference paper (Refereed)
    Abstract [en]

    Frequency-response masking (FRM) is a set of techniques for lowering the computational complexity of narrow transition band FIR filters. These FRM use a combination of sparse periodic filters and non-sparse filters. In this work we consider the implementation of these filters in a time-multiplexed manner on FPGAs. It is shown that the proposed architectures produce lower complexity realizations compared to the vendor provided IP blocks, which do not take the sparseness into consideration. The designs are implemented on a Virtex-6 device utilizing the built-in DSP blocks.

  • 1468.
    Alam, Syed Asad
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Improved particle filter resampling architecturesManuscript (preprint) (Other academic)
    Abstract [en]

    The most challenging aspect of particle filtering hardware implementation is the resampling step which replicates particles with large weights and discards those with small weights because it has a high latency and can only be partially executed in parallel with the other steps of particle filtering. To reduce the latency, an improved resampling scheme is proposed in this work which involves pre-fetching from the weight memory in parallel to the fetching of a value from a random function generator. Architectures for realizing the pre-fetch technique are also proposed. The trade-off between the latency reduction achieved by increasing the size of the pre-fetch memory and the architectural implementation complexity has been analyzed. Results show that a pre-fetch of five achieves the best area-latency trade-off while on average achieving an 85% reduction in the latency.

    We also propose a generic double multiplier architecture for resampling which avoids normalization divisions and makes the architecture equally efficient for non-powers-of-two number of particles as well as removes the need of explicitly ordering the random values for efficient multinomial resampling implementation. It is further improved by computing the cumulative sum of weights on-the-fly which helps in reducing the size of the weight memories by up to 50%.

  • 1469.
    Alam, Syed Asad
    et al.
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Oscar
    Linköping University, Department of Electrical Engineering, Computer Engineering. Linköping University, Faculty of Science & Engineering.
    On the implementation of time-multiplexed frequency-response masking filters2016In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 64, no 15, p. 3933-3944Article in journal (Refereed)
    Abstract [en]

    The complexity of narrow transition band finite-length impulse response (FIR) filters is high and can be reduced by using frequency-response masking (FRM) techniques. These techniques use a combination of periodic model and, possibly periodic, masking filters. Time-multiplexing is in general beneficial since only rarely does the technology bound maximum obtainable clock frequency and the application determined required sample rate correspond. Therefore, architectures for time-multiplexed FRM filters that benefit from the inherent sparsity of theperiodic filters are introduced in this work.

    We show that FRM filters not only reduces the number of multipliers needed, but also have benefits in terms of memory usage. Despite the total amount of samples to be stored is larger for FRM, it results in fewer memory resources needed in FPGAs and more energy efficient memory schemes in ASICs. In total, the power consumption is significantly reduced compared to a single stage implementation. Furthermore, we show that the choice of the interpolation factor which gives the least complexity for the periodic model filter and subsequent masking filter(s) is a function of the time-multiplexing factor, meaning that the minimum number of multipliers not always correspond to the minimum number of multiplications. Both single-port and dual-port memories are considered and the involved trade-off in number of multipliers and memory complexity is illustrated. The results show that for FPGA implementation, the power reduction ranges from 23% to 68% for the considered examples.

  • 1470.
    Alami, J.
    et al.
    Sulzer Metaplas GmbH, Germany.
    Bolz, S.
    University of Aachen, Germany.
    Sarakinos, Kostas
    Institute of Physics (IA), RWTH Aachen University, Germany.
    High power pulsed magnetron sputtering: Fundamentals and applications2009In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 483, no 1-2, p. 530-534Article in journal (Refereed)
    Abstract [en]

    Direct current magnetron sputtering (dcMS) is a widely used technique for deposition of a large number of compound and metallic coatings with specified mechanical, electrical and optical properties. Although dcMS is a successful coating technique, it suffers from fundamental problems, such as low target utilization and target poisoning during reactive sputtering, which results in process instabilities and poor deposition rates. In order to alleviate some of these problems, alternative techniques, such as radio frequency magnetron sputtering, additional ionization by rf coils or microwaves, or increased magnetic confinement by a multipolar magnetic setup are used. High power unipolar pulsing of the target voltage is another approach that has been used of late, in order to increase the ionization fraction in the discharge. in this deposition technique, known as high power pulsed magnetron sputtering (HPPMS), the power supply operates at low (or zero) power level and pulses to a high voltage for a short time each cycle. Thus, high electron densities are generated leading to increased ionization of the sputtered material. With peak power densities typically of several kW cm(-2), ionization fractions of the sputtered material ranging from 4.5% for C to 70% for Cu are achieved. HPPMS has been used to grow metallic and compound coatings. In the present work, a summary over some of the important results related to this technique are presented. The mechanisms taking place in the discharge and at the coating surface during deposition are discussed and the benefits of using HPPMS are reviewed: tailoring of coating properties, control of the coating bombardment during deposition, enhancement of the coating mechanical properties and morphology. Finally, TiAlN coatings are deposited using an industrial coater, and the coatings properties are studied.

  • 1471.
    Alami, J.
    et al.
    University of Aachen, Germany.
    Sarakinos, Kostas
    Institute of Physics (IA), RWTH Aachen University, Germany.
    Mark, G.
    MELEC GmbH, Germany.
    Wuttig, M.
    University of Aachen, Germany.
    On the deposition rate in a high power pulsed magnetron sputtering discharge2006In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 89, no 15, p. 154104-Article in journal (Refereed)
    Abstract [en]

    The effect of the high pulse current and the duty cycle on the deposition rate in high power pulsed magnetron sputtering (HPPMS) is investigated. Using a Cr target and the same average target current, deposition rates are compared to dc magnetron sputtering (dcMS) rates. It is found that for a peak target current density I-Tpd of up to 570 mA cm(-2), HPPMS and dcMS deposition rates are equal. For I-Tpd greater than 570 mA cm(-2), optical emission spectroscopy shows a pronounced increase of the Cr+/Cr-0 signal ratio. In addition, a loss of deposition rate, which is attributed to self-sputtering, is observed.

  • 1472.
    Alami, J.
    et al.
    Sulzer Metaplas GmbH, Germany.
    Sarakinos, Kostas
    Institute of Physics (IA), RWTH Aachen University, Germany.
    Uslu, F.
    RWTH Aachen University, Germany.
    Klever, C.
    RWTH Aachen University, Germany.
    Dukwen, J.
    RWTH Aachen University, Germany.
    Wuttig, M.
    RWTH Aachen University, Germany.
    On the phase formation of titanium oxide films grown by reactive high power pulsed magnetron sputtering2009In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 42, no 11, p. 115204-Article in journal (Refereed)
    Abstract [en]

    High power pulsed magnetron sputtering is used for the growth of titanium dioxide (TiO(2)) films at different working pressures and orientations of the substrate with respect to the target surface. In the case of substrates oriented parallel to the target surface, the increase in the working pressure from 0.5 to 3 Pa results in the growth of crystalline TiO(2) films with phase compositions ranging from rutile to anatase/rutile mixtures. When depositions are performed on substrates placed perpendicularly to the target surface, rutile films that consist of TiO(2) nanocrystals embedded in an amorphous matrix are obtained at 0.5 Pa. Increase in the working pressure leads to the deposition of amorphous films. These findings are discussed in the light of the energetic bombardment provided to the growing film at the various deposition conditions.

  • 1473.
    Alami, J.
    et al.
    University of Aachen, Germany.
    Sarakinos, Kostas
    Institute of Physics (IA), RWTH Aachen University, Germany.
    Uslu, F.
    University of Aachen, Germany.
    Wuttig, M.
    University of Aachen, Germany.
    On the relationship between the peak target current and the morphology of chromium nitride thin films deposited by reactive high power pulsed magnetron sputtering2009In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 42, no 1, p. 015304-Article in journal (Refereed)
    Abstract [en]

    High power pulsed magnetron sputtering (HPPMS) is used to deposit CrN films without external heating at different peak target currents, while the average current is kept constant. Films are also grown by dc magnetron sputtering (dcMS), for reference. The plasma properties, the deposition rate and the morphology of the films are investigated. The plasma analysis reveals that HPPMS provides higher fluxes of ionized species (both gas and sputtered) to the growing film, as compared with dcMS. In addition, the ionic bombardment during HPPMS increases, when the peak target current is increased. The HPPMS films exhibit changes of the density and the surface roughness as the peak target current increased, while the deposition rate decreases drastically. Furthermore, it is found that different thin-film morphologies are obtained starting from a porous columnar morphology for the dcMS films, which turns to a dense columnar one at low peak target currents and ends up to a featureless morphology at high peak target currents for the films grown by HPPMS. A new structure zone model specific for high ionization sputtering is, therefore, outlined.

  • 1474.
    Alami, Jones
    Linköping University, Department of Physics, Measurement Technology, Biology and Chemistry. Linköping University, The Institute of Technology.
    Plasma characterisation in high power pulsed magnetron sputtering2003Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, plasma parameters including plasma and floating potentials, electron energy distribution function (EEDF) plasma density and electron temperature are studied in a high power pulsed magnetron (HPPM) discharge at different Argon (Ar) gas pressures and different magnetron powers. It is reported that the EEDF during and shortly after the pulse can be represented by a bi-Maxwellian distribution indicating two energy groups of electrons.

    Furthermore, we report on the variation of the plasma parameters and electron energy distribution function with gas pressure in the pressure range 0.5-20 mtorr. At a high pressure (> 10 mTorr) two density peaks are present, the second of which occurs hundreds of microseconds after the pulse is switched off. It shows that the second peaks occurrence depends on the target material used as well as the chamber pressure and the magnetron power. It is found that the electron density is very high (up to 1019 m-3, during the whole of the measured 2000 µs, indicating the importance of the second density peak in maintaining the high plasma density.

    Measurements on the electron temperature show that this does not exceed 3 eV while the pulse is on, and that it is no more than 0.5 after the pulse is off. A movie is constructed using Langmuir probe measurements data, showing the temporal evolution of the plasma at 20 mTorr argon pressure and 11 J pulse energy. Analysis shows the existence of a magnetic trap underneath the center of the target. Furthermore, the electron flux in the substrate vicinity 10 - 12 cm from the target is found to be homogeneous. Ti thin films are grown along the sidewalls of a hole, 1 cm2 in area and 2 cm in depth, using both de magnetron and HPPM sputtering. Secondary electron microscopy shows that the film grown by de magnetron sputtering shows clear columnar growth, while a dense and flat film was produced using the HPPM sputtering technique.

  • 1475.
    Alami, Jones
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Plasma Characterization & Thin Film Growth and Analysis in Highly Ionized Magnetron Sputtering2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The present thesis addresses two research areas related to film growth in a highly ionized magnetron sputtering system: plasma characterization, and thin film growth and analysis. The deposition technique used is called high power pulsed magnetron sputtering (HPPMS). Characteristic for this technique are high energy pulses (a few Joules) of length 50-100 µs that are applied to the target (cathode) with a duty time of less than 1 % of the total pulse time. This results in a high electron density in the discharge (>1x1019 m-3) and leads to an increase of the ionization fraction of the sputtered material reaching up to 70 % for Cu.

    In this work the spatial and temporal evolution of the plasma parameters, including the electron energy distribution function (EEDF), the electron density and the electron temperature are determined using electrostatic Langmuir probes. Electron temperature measurements reveal a low effective temperature of 2-3 eV. The degree of ionization in the HPPMS discharge is explained in light of the self-sputtering yield of the target material. A simple model is therefore provided in order to compare the sputtering yield in HPPMS and that in dc magnetron sputtering (dcMS) for the same average power.

    Thin Ta films are grown using HPPMS and dcMS and their properties are studied. It is shown that enhanced microstructure and morphology of the deposited films is achieved by HPPMS. The Ta films are also deposited at a number of substrate inclination angles ranging from 0o (i.e., facing the target surface) up to 180 o (i.e., facing away from the target). Deposition rate measurements performed at all inclination angles for both techniques, reveal that growth made using HPPMS resulted in an improved film thickness at higher inclination. Furthermore, the high ionization of the Ta atoms in HPPMS discharge is found to allow for phase tailoring of the deposited films at all inclination angles by applying a bias voltage to the substrate. Finally, highly ionized magnetron sputtering of a compound MAX-phase material (Ti3SiC2) is performed, demonstrating that the HPPMS discharge could also be used to tailor the composition of the growing Ti-Si-C films.

    List of papers
    1. Evolution of the electron energy distribution and plasma parameters in a pulsed magnetron discharge
    Open this publication in new window or tab >>Evolution of the electron energy distribution and plasma parameters in a pulsed magnetron discharge
    2001 (English)In: Applied Physics Letters, ISSN 0003-6951, Vol. 78, no 22, p. 3427-Article in journal (Refereed) Published
    Abstract [en]

    We demonstrate the creation of high-density plasma in a pulsed magnetron discharge. A 2.4 MW pulse, 100 µs wide, with a repetition frequency of 50 Hz is applied to a planar magnetron discharge to study the temporal behavior of the plasma parameters: the electron energy distribution function, the electron density, and the average electron energy. The electron density in the vicinity of the substrate, 20 cm below the cathode target, peaks at 8×1017 m–3, 127 µs after initiating the pulse. Towards the end of the pulse two energy groups of electrons are present with a corresponding peak in average electron energy. With the disapperance of the high-energy electron group, the electron density peaks, and the electron energy distribution appears to be Maxwellian like. Following the electron density peak, the plasma becomes more Druyvesteyn like with a higher average electron energy.

    Keywords
    sputter deposition
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13372 (URN)10.1063/1.1376150 (DOI)
    Available from: 2005-10-25 Created: 2005-10-25 Last updated: 2013-10-30
    2. Spatial and temporal behavior of the plasma parameters in a pulsed magnetron discharge
    Open this publication in new window or tab >>Spatial and temporal behavior of the plasma parameters in a pulsed magnetron discharge
    2002 (English)In: Surface and Coatings Technology, Vol. 161, no 2-3, p. 249-256Article in journal (Refereed) Published
    Abstract [en]

    We demonstrate the evolution of the electron, energy distribution and the plasma parameters in a high-density plasma in a pulsed magnetron discharge. The high-density plasma is created by applying a high power pulse (1–2.4 MW) with pulse length 100 μs and repetition frequency of 50 Hz to a planar magnetron discharge. The spatial and temporal behavior of the plasma parameters are investigated using a Langmuir probe; the electron energy distribution function, the electron density and the average electron energy. The electron energy distribution function during and shortly after the pulse can be represented by a bi-Maxwellian distribution indicating two energy groups of electrons. Furthermore, we report on the variation of the plasma parameters and electron energy distribution function with gas pressure in the pressure range 0.5–20 mtorr. We report electron density as high as 4×1018 m−3 at 10 mtorr and 9 cm below the target in a pulsed discharge with average power 300 W. We estimate the traveling speed of the electron density peak along the axis of the discharge. The traveling speed decreases with increased gas pressure from 4×105 cm/s at 0.5 mtorr to 0.87×105 cm s−1 at 10 mtorr. The effective electron temperature peaks at the same time independent of position in the discharge, which indicates a burst of high energy electrons at the end of the pulse.

    Keywords
    Pulsed magnetron sputtering, Time evolution, Ionized sputtering, High density plasma, Ionized metal plasma
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13373 (URN)10.1016/S0257-8972(02)00518-2 (DOI)
    Available from: 2005-10-25 Created: 2005-10-25 Last updated: 2013-10-30
    3. Plasma dynamics in a highly ionized pulsed magnetron discharge
    Open this publication in new window or tab >>Plasma dynamics in a highly ionized pulsed magnetron discharge
    Show others...
    2005 (English)In: Plasma sources science & technology (Print), ISSN 0963-0252, E-ISSN 1361-6595, Vol. 14, no 3, p. 525-531Article in journal (Refereed) Published
    Abstract [en]

    We report on electrostatic probe measurements of a high-power pulsed magnetron discharge. Space- and time-dependent characteristics of the plasma parameters are obtained as functions of the process parameters. By applying high-power pulses (peak power of ~0.5 MW), with a pulse-on time of ~100 µs and a repetition frequency of 20 ms, peak electron densities of the order of ~1019 m− 3, i.e. three orders of magnitude higher than for a conventional dc magnetron discharge, are achieved soon after the pulse is switched on. At high sputtering gas pressures (>5 mTorr), a second peak occurs in the electron density curve, hundreds of microseconds after the pulse is switched off. This second peak is mainly due to an ion acoustic wave in the plasma, reflecting off the chamber walls. This is concluded from the time delay between the two peaks in the electron and ion saturation currents, which is shown to be dependent on the chamber dimensions and the sputtering gas composition. Finally, the electron temperature is determined, initially very high but decreasing rapidly as the pulse is turned off. The reduction seen in the electron temperature, close to the etched area of the cathode, is due to cooling by the sputtered metal atoms.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-13374 (URN)10.1088/0963-0252/14/3/015 (DOI)
    Available from: 2005-10-25 Created: 2005-10-25 Last updated: 2017-12-13
    4. Ion-accoustic solitary waves in a high power pulsed magnetron sputtering discharge
    Open this publication in new window or tab >>Ion-accoustic solitary waves in a high power pulsed magnetron sputtering discharge
    2005 (English)In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 38, no 18, p. 3417-3421Article in journal (Refereed) Published
    Abstract [en]

    We report on the creation and propagation of ion-acoustic solitary waves in a high power pulsed magnetron sputtering discharge. A dense localized plasma is created by applying high energy pulses (4–12 J) of length 70 µs, at a repetition frequency of 50 pulses per second, to a planar magnetron sputtering source. The temporal behaviour of the electron density, measured by a Langmuir probe, shows solitary waves travelling away from the magnetron target. The velocity of the waves depends on the gas pressure but is roughly independent of the pulse energy.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-13375 (URN)10.1088/0022-3727/38/18/015 (DOI)
    Available from: 2005-10-25 Created: 2005-10-25 Last updated: 2017-12-13
    5. Ion-assisted Physical Vapor Deposition for enhanced film properties on non-flat surfaces
    Open this publication in new window or tab >>Ion-assisted Physical Vapor Deposition for enhanced film properties on non-flat surfaces
    Show others...
    2005 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 23, no 2, p. 278-280Article in journal (Refereed) Published
    Abstract [en]

    We have synthesized Ta thin films on Si substrates placed along a wall of a 2-cm-deep and 1-cm-wide trench, using both a mostly neutral Ta flux by conventional dc magnetron sputtering (dcMS) and a mostly ionized Ta flux by high-power pulsed magnetron sputtering (HPPMS). Structure of the grown films was evaluated by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The Ta thin film grown by HPPMS has a smooth surface and a dense crystalline structure with grains oriented perpendicular to the substrate surface, whereas the film grown by dcMS exhibits a rough surface, pores between the grains, and an inclined columnar structure. The improved homogeneity achieved by HPPMS is a direct consequence of the high ion fraction of sputtered species.

    Keywords
    tantalum, ion beam assisted deposition, sputter deposition, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, surface structure, surface roughness, porosity, metallic thin films
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-13376 (URN)10.1116/1.1861049 (DOI)
    Available from: 2005-10-25 Created: 2005-10-25 Last updated: 2017-12-13
    6. Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering
    Open this publication in new window or tab >>Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering
    Show others...
    2007 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 7-8, p. 3434-3438Article in journal (Refereed) Published
    Abstract [en]

    Ta thin films were grown on Si substrates at different inclination angles with respect to the sputter source using high power impulse magnetron sputtering (HIPIMS), an ionized physical vapor deposition technique. The ionization allowed for better control of the energy and directionality of the sputtered species, and consequently for improved properties of the deposited films. Depositions were made on Si substrates with the native oxide intact. The structure of the as deposited films was investigated using X-ray diffraction, while a four-point probe setup was used to measure the resistivity. A substrate bias process-window for growth of bcc-Ta was observed. However, the process-window position changed with changing inclination angles of the substrate. The formation of this low-resistivity bcc-phase could be understood in light of the high ion flux from the HIPIMS discharge.

    Place, publisher, year, edition, pages
    Elsevier, 2007
    Keywords
    HPPMS, Ionized PVD, IPVD, Pulsed sputtering
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:liu:diva-10442 (URN)10.1016/j.tsf.2006.10.013 (DOI)
    Note
    Original publication: J. Alamia, P. Eklunda, J.M. Anderssona, M. Lattemanna, E. Wallina, J. Bohlmarka, P. Perssona, and U. Helmersson, Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering, 2007, Thin Solid Films, (515), 7-8, 3434-3438. http://dx.doi.org/10.1016/j.tsf.2006.10.013. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2007-12-14 Created: 2007-12-14 Last updated: 2017-12-14Bibliographically approved
    7. High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target
    Open this publication in new window or tab >>High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target
    Show others...
    2006 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 4, p. 1731-1736Article in journal (Refereed) Published
    Abstract [en]

    We have deposited Ti-Si-C thin films using high-power impulse magnetron sputtering (HIPIMS) from a Ti3SiC2 compound target. The as-deposited films were composite materials with TiC as the main crystalline constituent. X-ray diffraction and photoelectron spectroscopy indicated that they also contained amorphous SiC, and for films deposited on inclined substrates, crystalline Ti5Si3Cx. The film morphology was dense and flat, while films deposited with dc magnetron sputtering under comparable conditions were rough and porous. Due to the high degree of ionization of the sputtered species obtained in HIPIMS, it is possible to control the film composition, in particular the C content, by tuning the substrate inclination angle, the Ar process pressure, and the bias voltage.

    Place, publisher, year, edition, pages
    Institutionen för fysik, kemi och biologi, 2006
    Keywords
    HIPIMS, Titanium silicon carbide
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:liu:diva-10437 (URN)10.1016/j.tsf.2006.06.015 (DOI)000242931900079 ()
    Note

    Original publication: J. Alami, P. Eklund, J. Emmerlich, O. Wilhelmsson, U. Jansson, H. Högberg, L. Hultman, & U. Helmersson, High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target, 2006, Thin Solid Films, (515), 4, 1731-1736. http://dx.doi.org/10.1016/j.tsf.2006.06.015. Copyright: Elsevier B.V., http://www.elsevier.com/.

    Available from: 2007-12-14 Created: 2007-12-14 Last updated: 2017-12-14Bibliographically approved
  • 1476.
    Alami, Jones
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Andersson, Jon M.
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Lattemann, Martina
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Wallin, Erik
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Böhlmark, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Persson, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering2007In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 7-8, p. 3434-3438Article in journal (Refereed)
    Abstract [en]

    Ta thin films were grown on Si substrates at different inclination angles with respect to the sputter source using high power impulse magnetron sputtering (HIPIMS), an ionized physical vapor deposition technique. The ionization allowed for better control of the energy and directionality of the sputtered species, and consequently for improved properties of the deposited films. Depositions were made on Si substrates with the native oxide intact. The structure of the as deposited films was investigated using X-ray diffraction, while a four-point probe setup was used to measure the resistivity. A substrate bias process-window for growth of bcc-Ta was observed. However, the process-window position changed with changing inclination angles of the substrate. The formation of this low-resistivity bcc-phase could be understood in light of the high ion flux from the HIPIMS discharge.

  • 1477.
    Alami, Jones
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, The Institute of Technology.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Emmerlich, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Wilhelmsson, O.
    Department of Materials Chemistry, The Ångström Laboratory, Uppsala University, Uppsala, Sweden.
    Jansson, U.
    Department of Materials Chemistry, The Ångström Laboratory, Uppsala University, Uppsala, Sweden.
    Högberg, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, The Institute of Technology.
    High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target2006In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 4, p. 1731-1736Article in journal (Refereed)
    Abstract [en]

    We have deposited Ti-Si-C thin films using high-power impulse magnetron sputtering (HIPIMS) from a Ti3SiC2 compound target. The as-deposited films were composite materials with TiC as the main crystalline constituent. X-ray diffraction and photoelectron spectroscopy indicated that they also contained amorphous SiC, and for films deposited on inclined substrates, crystalline Ti5Si3Cx. The film morphology was dense and flat, while films deposited with dc magnetron sputtering under comparable conditions were rough and porous. Due to the high degree of ionization of the sputtered species obtained in HIPIMS, it is possible to control the film composition, in particular the C content, by tuning the substrate inclination angle, the Ar process pressure, and the bias voltage.

  • 1478.
    Alami, Jones
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Gudmundsson, J. T.
    University of Iceland, Reykjavik.
    Böhlmark, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Birch, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Plasma dynamics in a highly ionized pulsed magnetron discharge2005In: Plasma sources science & technology (Print), ISSN 0963-0252, E-ISSN 1361-6595, Vol. 14, no 3, p. 525-531Article in journal (Refereed)
    Abstract [en]

    We report on electrostatic probe measurements of a high-power pulsed magnetron discharge. Space- and time-dependent characteristics of the plasma parameters are obtained as functions of the process parameters. By applying high-power pulses (peak power of ~0.5 MW), with a pulse-on time of ~100 µs and a repetition frequency of 20 ms, peak electron densities of the order of ~1019 m− 3, i.e. three orders of magnitude higher than for a conventional dc magnetron discharge, are achieved soon after the pulse is switched on. At high sputtering gas pressures (>5 mTorr), a second peak occurs in the electron density curve, hundreds of microseconds after the pulse is switched off. This second peak is mainly due to an ion acoustic wave in the plasma, reflecting off the chamber walls. This is concluded from the time delay between the two peaks in the electron and ion saturation currents, which is shown to be dependent on the chamber dimensions and the sputtering gas composition. Finally, the electron temperature is determined, initially very high but decreasing rapidly as the pulse is turned off. The reduction seen in the electron temperature, close to the etched area of the cathode, is due to cooling by the sputtered metal atoms.

  • 1479.
    Alami, Jones
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Persson, Per O. Å.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Music, Denis
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Gudmundsson, J. T.
    University of Iceland, Reykjavik.
    Böhlmark, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics . Linköping University, The Institute of Technology.
    Ion-assisted Physical Vapor Deposition for enhanced film properties on non-flat surfaces2005In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 23, no 2, p. 278-280Article in journal (Refereed)
    Abstract [en]

    We have synthesized Ta thin films on Si substrates placed along a wall of a 2-cm-deep and 1-cm-wide trench, using both a mostly neutral Ta flux by conventional dc magnetron sputtering (dcMS) and a mostly ionized Ta flux by high-power pulsed magnetron sputtering (HPPMS). Structure of the grown films was evaluated by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The Ta thin film grown by HPPMS has a smooth surface and a dense crystalline structure with grains oriented perpendicular to the substrate surface, whereas the film grown by dcMS exhibits a rough surface, pores between the grains, and an inclined columnar structure. The improved homogeneity achieved by HPPMS is a direct consequence of the high ion fraction of sputtered species.

  • 1480.
    Alami, Mohsen
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Interval Based Parameter Identification for System Biology2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis studies the problem of parameter identification for system biology. Two methods have been studied. The method of interval analysis uses subpaving as a class of objects to manipulate and store inner and outer approximations of compact sets. This method works well with the model given as a system of differential equations, but has its limitations, since the analytical expression for the solution to the ODE is not always obtainable, which is needed for constructing the inclusion function. The other method, studied, is SDP-relaxation of a nonlinear and non-convex feasibility problem. This method, implemented in the toolbox bio.SDP, works with system of difference equations, obtained using the Euler discretization method. The discretization method is not exact, raising the need of bounding this discretization error. Several methods for bounding this error has been studied. The method of ∞-norm optimization, also called worst-case-∞-norm is applied on the one-step error estimation method.

    The methods have been illustrated solving two system biological problems and the resulting SCP have been compared.

  • 1481.
    Alander, Johanna
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management.
    Nylin, Adam
    Linköping University, Department of Management and Engineering, Environmental Technology and Management.
    Feasibility study for producing and using biogas in Chisinau, Moldova2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    More and more people live in cities, cities that both present opportunities, in terms of potential sustainable growth and challenges, for example regarding insufficient infrastructure and waste management. There are several examples on initiatives to make cities reach their sustainability potential; one is to turn municipal organic waste, MOW, and sewage sludge into biogas and use it to produce electricity and/or heat or to upgrade it to biomethane and use it as a fuel in for example public transport or feed it to a gas grid.

    This study has focused on the potential and feasibility of producing and using biogas/biomethane as well as the remains from the production process, called digestate, in Chisinau, the capital of Moldova. For the most feasible options an indication of the environmental improvement and economic performance was also estimated. The study included biogas produced from municipal organic waste, sewage sludge and methane collected at landfills. For the areas of use, electricity or heat produced from biogas was included as well as using biomethane in public transport or feeding it to the gas grid and to use the digestate as biofertilizer. Since multiple factors needs to be considered in order to adequately assess the potential and feasibility a multi-criteria approach was used for developing a framework based on an early assessment tool for biomethane solutions in the urban context.

    In summary it is indicated that there are good conditions for biogas production in Chisinau with biogas production from sewage sludge being included in the ongoing rehabilitation of the largest wastewater facility and methane collection from the largest landfill historically being part of the operations and planned (although not confirmed) to soon be part of these again. However, the largest potential is for municipal organic waste where the main impediments relates to financial issues and to some extent legislation that indirectly favour short term landfilling. When investigating the possible use of the digestate as biofertilizer the outlooks are considerably less promising than for the supply side. Despite the fact that the law explicitly allows the use of digestate (both from MOW and sewage sludge) the lack of knowledge within the farmer community result in a low or non-existent customer demand. Regarding the possible use of biogas/biomethane it was concluded that electricity production is the most feasible option and heat generation placing as the second most feasible. Feeding the gas to the grid appears more difficult and the least likely option is for the biogas to be used within public transport. Overall it is in general technically possible to use the gas in terms of infrastructure and there is some demand, especially for electricity and heat. The biggest inhibitory factors are rather institutional since biogas in general is overlooked or not prioritized in the strategies leading to a shortcoming in economical instruments or funds and to some extent in the legislation.

    This thesis is complemented by an executive summary with the same name, both in English and translated to Romanian.

  • 1482. Al-ani, Neeran
    et al.
    Boutros, Mireille
    Linköping University.
    Flerpatientbesök – ett förbättringsförslag baserat på en analys av den dagligaverksamheten vid vårdcentralen Cityhälsan Söder: En kartläggning på Blodtrycksmottagning och Astma/KOL- mottagning med hjälp av Lean2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Östergötland County Council has begun to implement “Lean-Thinking" in healthcare service. Staff at healthcare service has experienced new challenges. Health care quality cannot anymore be measured only by medical treatment results, other factors are of importance, for example accessibility.

    The management of the health centre “Cityhälsan Söder” wished to identify problems that affect patient flow and requested proposals for improvements which could increase the number of patients cared for at Blood Pressure-department and Asthma/COL- department.

    For the mapping of the activities performed by a nurse during a working day, two data collection methods were used: observation and survey. Collected data were analysed in relation to the frame of reference concerning theories of Lean healthcare and logistics. Focus in the identification of problems was to improve the utilization of nursing time to allow more patient visits. 

    In the analysis eight types of wastes are especially used: overproduction, waiting, transportation, extra-processing, inventory, motion, defects and non-utilised skills. From the healthcare logistics point of view, the cancelations problem, lack of resources and matching capacity with demand was also analysed.

    To increase staff knowledge of how service may work better it was suggested to take advantage of the staff's creativity by expanding the personnel’s perception of patient flow in order to match capacity with demand. Other proposals concerned waiting-list management, which aims to introduce direct time booking of upcoming patient visits at both departments, freeing administrative time that can be spent to accommodate more patients. To standardize medical examinations on Asthma/COL-departments is also a proposal.

    IT-solutions for both departments may also create opportunities for more patient visits. A film that prepares the patient by teaching the correct blowing technique for the visit on Asthma/COL-department may accelerate medical examinations and free time that can be used better.

  • 1483.
    Alanne, K.
    et al.
    Department of Mechanical Engineering, Laboratory of Heating, Ventilating and Air-Conditioning, P.O. Box 1100, 02015 TKK, Finland.
    Salo, A.
    Department of Engineering Physics and Mathematics, Systems Analysis Laboratory, Helsinki University of Technology, P.O. Box 1100, 02015 TKK, Finland.
    Saari, A.
    Department of Civil and Environmental Engineering, Laboratory of Construction Economics and Management, Helsinki University of Technology, P.O. Box 2100, 02015 TKK, Finland.
    Gustafsson, Stig-Inge
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Energy Systems.
    Multi-criteria evaluation of residential energy supply systems2007In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 39, no 12, p. 1218-1226Article in journal (Refereed)
    Abstract [en]

    In this paper, we consider the selection of a residential energy supply system as a multi-criteria decision-making problem, which involves both financial and environmental issues. Specifically, we compare micro-CHP (micro-cogeneration) heating with traditional heating systems through an evaluation that accounts for: (i) the decision-makers' subjective preferences, (ii) uncertainties in the performance of micro-CHP heating systems (which are partly caused by the lack of long-term operational experiences) and (iii) the context-dependency of life-cycle costs and environmental burdens of heating systems. Motivated by these considerations, we employ the PAIRS multi-criteria decision-making methodology that captures incomplete information by way of interval-valued parameters and provides support for sensitivity analyses, too. Our comparative analysis of alternative heating systems suggests that micro-CHP is a reasonable alternative to traditional systems, particularly from the environmental point of view. © 2007 Elsevier B.V. All rights reserved.

  • 1484.
    Alansari, Hayder
    Linköping University, Department of Computer and Information Science.
    Clustered Data Management in Virtual Docker Networks Spanning Geo-Redundant Data Centers: A Performance Evaluation Study of Docker Networking2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Software containers in general and Docker in particular is becoming more popular both in software development and deployment. Software containers are intended to be a lightweight virtualization that provides the isolation of virtual machines with a performance that is close to native. Docker does not only provide virtual isolation but also virtual networking to connect the isolated containers in the desired way. Many alternatives exist when it comes to the virtual networking provided by Docker such as Host, Macvlan, Bridge, and Overlay networks. Each of these networking solutions has its own advantages and disadvantages.

    One application that can be developed and deployed in software containers is data grid system. The purpose of this thesis is to measure the impact of various Docker networks on the performance of Oracle Coherence data grid system. Therefore, the performance metrics are measured and compared between native deployment and Docker built-in networking solutions. A scaled-down model of a data grid system is used along with benchmarking tools to measure the performance metrics.

    The obtained results show that changing the Docker networking has an impact on performance. In fact, some results suggested that some Docker networks can outperform native deployment. The conclusion of the thesis suggests that if performance is the only consideration, then Docker networks that showed high performance can be used. However, real applications require more aspects than performance such as security, availability, and simplicity. Therefore Docker network should be carefully selected based on the requirements of the application.

  • 1485.
    Alarcon, E I
    et al.
    Bio-nanomaterials Chemistry and Engineering Laboratory, Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Rm H5229, Ottawa, Canada.
    Vulesevic, B
    Bio-nanomaterials Chemistry and Engineering Laboratory, Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Rm H5229, Ottawa, Canada.
    Argawal, A
    Bio-nanomaterials Chemistry and Engineering Laboratory, Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Rm H5229, Ottawa, Canada.
    Ross, A
    Bio-nanomaterials Chemistry and Engineering Laboratory, Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Rm H5229, Ottawa, Canada.
    Bejjani, P
    Bio-nanomaterials Chemistry and Engineering Laboratory, Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Rm H5229, Ottawa, Canada.
    Podrebarac, J
    Bio-nanomaterials Chemistry and Engineering Laboratory, Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Rm H5229, Ottawa, Canada.
    Ravichandran, Ranjithkumar
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Phopase, Jaywant
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Suuronen, E J
    Bio-nanomaterials Chemistry and Engineering Laboratory, Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Rm H5229, Ottawa, Canada.
    Griffith, May
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Coloured cornea replacements with anti-infective properties: expanding the safe use of silver nanoparticles in regenerative medicine.2016In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 8, no 12, p. 6484-6489Article in journal (Refereed)
    Abstract [en]

    Despite the broad anti-microbial and anti-inflammatory properties of silver nanoparticles (AgNPs), their use in bioengineered corneal replacements or bandage contact lenses has been hindered due to their intense yellow coloration. In this communication, we report the development of a new strategy to pre-stabilize and incorporate AgNPs with different colours into collagen matrices for fabrication of corneal implants and lenses, and assessed their in vitro and in vivo activity.

  • 1486.
    Alarcon, Emilio I.
    et al.
    University of Ottawa, Canada; University of Ottawa, Canada; University of Ottawa, Canada.
    Udekwu, Klas I.
    Karolinska Institute, Sweden.
    Noel, Christopher W.
    University of Ottawa, Canada; .
    Gagnon, Luke B. -P.
    University of Ottawa, Canada.
    Taylor, Patrick K.
    University of Ottawa, Canada.
    Vulesevic, Branka
    University of Ottawa, Canada.
    Simpson, Madeline J.
    University of Ottawa, Canada.
    Gkotzis, Spyridon
    Karolinska Institute, Sweden.
    Islam, Mohammed Mirazul
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Karolinska Institute, Sweden.
    Lee, Chyan-Jang
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Richter-Dahlfors, Agneta
    Karolinska Institute, Sweden.
    Mah, Thien-Fah
    University of Ottawa, Canada.
    Suuronen, Erik J.
    University of Ottawa, Canada.
    Scaiano, Juan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. University of Ottawa, Canada.
    Griffith, May
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Karolinska Institute, Sweden.
    Safety and efficacy of composite collagen-silver nanoparticle hydrogels as tissue engineering scaffolds2015In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 7, no 44, p. 18789-18798Article in journal (Refereed)
    Abstract [en]

    The increasing number of multidrug resistant bacteria has revitalized interest in seeking alternative sources for controlling bacterial infection. Silver nanoparticles (AgNPs), are amongst the most promising candidates due to their wide microbial spectrum of action. In this work, we report on the safety and efficacy of the incorporation of collagen coated AgNPs into collagen hydrogels for tissue engineering. The resulting hybrid materials at [AgNPs] less than0.4 mu M retained the mechanical properties and biocompatibility for primary human skin fibroblasts and keratinocytes of collagen hydrogels; they also displayed remarkable anti-infective properties against S. aureus, S. epidermidis, E. coli and P. aeruginosa at considerably lower concentrations than silver nitrate. Further, subcutaneous implants of materials containing 0.2 mu M AgNPs in mice showed a reduction in the levels of IL-6 and other inflammation markers (CCL24, sTNFR-2, and TIMP1). Finally, an analysis of silver contents in implanted mice showed that silver accumulation primarily occurred within the tissue surrounding the implant.

  • 1487.
    Alarcon, Emilio I
    et al.
    University of Ottawa.
    Udekwu, Klas
    Karolinska Institute.
    Skog, Mårten
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Pacioni, NataliL
    University of Ottawa.
    Stamplecoskie, Kevin G
    University of Ottawa.
    Gonzalez-Bejar, Maria
    University of Ottawa.
    Polisetti, Naresh
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Wickham, Abeni
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Richter-Dahlfors, Agneta
    Karolinska Institute.
    Griffith, May
    Linköping University, Department of Clinical and Experimental Medicine, Ophthalmology. Linköping University, Faculty of Health Sciences.
    Scaiano, Juan C
    University of Ottawa.
    The biocompatibility and antibacterial properties of collagen-stabilized, photochemically prepared silver nanoparticles2012In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 33, no 19, p. 4947-4956Article in journal (Refereed)
    Abstract [en]

    Spherical 3.5 nm diameter silver nanoparticles (AgNP) stabilized in type I collagen (AgNP@collagen) were prepared in minutes (5-15 min) at room temperature by a photochemical method initiated by UVA irradiation of a water-soluble non-toxic benzoin. This biocomposite was examined to evaluate its biocompatibility and its anti-bacterial properties and showed remarkable properties. Thus, while keratinocytes and fibroblasts were not affected by AgNP@collagen, it was bactericidal against Bacillus megaterium and E. coli but only bacteriostatic against S. epidermidis. In particular, the bactericidal properties displayed by AgNP@collagen were proven to be due to AgNP in AgNP@collagen, rather than to released silver ions, since equimolar concentrations of Ag are about four times less active than AgNP@collagen based on total Ag content. This new biocomposite was stable over a remarkable range of NaCl, phosphate, and 2-(N-morpholino)ethanesulfonic acid concentrations and for over one month at 4 degrees C. Circular dichroism studies show that the conformation of collagen in AgNP@collagen remains intact. Finally, we have compared the properties of AgNP@collagen with a similar biocomposite prepared using alpha-poly-L-Lysine and also with citrate stabilized AgNP; neither of these materials showed comparable biocompatibility, stability, or anti-bacterial activity.

  • 1488.
    Alasuutari, Maarit
    et al.
    Jyväskylä University, Finland.
    Markström, Ann-Marie
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Vallberg-Roth, Ann-Christin
    Malmö högskola.
    Assessment and Documentation in Early Childhood Education2014 (ed. 1)Book (Other academic)
    Abstract [en]

    Documentation in early childhood education is typically seen as a means to enhance the quality of care and education, and as a way to take account of the child’s view.

    Assessment and Documentation in Early Childhood Education considers the increasing trend towards systematic child documentation especially in early childhood institutions. The authors present ways in which assessment and evaluation is done sometimes explicitly but more often implicitly in these practices, and explore its means, aims, forms, and functions. They also examine the rationalities of child documentation from the perspective of professional practice and professionalism and suggest that documentation and assessment practices can weaken and constrain but also empower and strengthen teachers, children and parents. Topics explored include:

    • Different forms of documentation and assessment
    • Documentation and listening to the children
    • Dilemmas of assessment and documentation
    • Participation by children
    • Involvement of parents

    This timely bookwill be appealing for those studying in the field of early childhood education, teacher education, special education, general education, social work, counselling, psychology, sociology, childhood studies, and family studies.

  • 1489.
    Alavian, S.M.
    et al.
    Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Tehran.
    Ande, S.R.
    University of Manitoba.
    Coombs, K.M.
    University of Manitoba.
    Yeganeh, B.
    University of Manitoba.
    Davoodpour, Padideh
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    Hashemi, M.
    Zahedan University of Medical Sceince, Iran.
    Los, Marek Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Cell Biology.
    Ghavami, S.
    University of Manitoba.
    Virus-triggered autophagy in viral hepatitis - possible novel strategies for drug development2011In: Journal of Viral Hepatitis, ISSN 1352-0504, E-ISSN 1365-2893, Vol. 18, no 12, p. 821-830Article, review/survey (Refereed)
    Abstract [en]

    . Autophagy is a very tightly regulated process that is important in many cellular processes including development, differentiation, survival and homoeostasis. The importance of this process has already been proven in numerous common diseases such as cancer and neurodegenerative disorders. Emerging data indicate that autophagy plays an important role in some liver diseases including liver injury induced by ischaemia reperfusion and alpha-1 antitrypsin Z allele-dependent liver disease. Autophagy may also occur in viral infection, and it may play a crucial role in antimicrobial host defence against pathogens, while supporting cellular homoeostasis processes. Here, the latest findings on the role of autophagy in viral hepatitis B and C infection, which are both serious health threats, will be reviewed.

  • 1490.
    Al-Ayoubi, Fawzi
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Eriksson, Helene
    Linköping University, Department of Social and Welfare Studies, Division of Health, Activity and Care. Linköping University, Faculty of Health Sciences.
    Myrelid, Pär
    Linköping University, Department of Clinical and Experimental Medicine, Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Wallon, Conny
    Linköping University, Department of Clinical and Experimental Medicine, Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Andersson, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Uneven distribution of emergency operations and lack of trauma: a call for reorganization of acute surgical care?2012In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 20Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Subspecialisation within general surgery has today reached further than ever. However, on-call time, an unchanged need for broad surgical skills are required to meet the demands of acute surgical disease and trauma. The introduction of a new subspecialty in North America that deals solely with acute care surgery and trauma is an attempt to offer properly trained surgeons also during on-call time. To find out whether such a subspecialty could be helpful in Sweden we analyzed our workload for emergency surgery and trauma. METHODS: Linkoping University Hospital serves a population of 257 000. Data from 2010 for all patients, diagnoses, times and types of operations, surgeons involved, duration of stay, types of injury and deaths regarding emergency procedures were extracted from a prospectively-collected database and analyzed. RESULTS: There were 2362 admissions, 1559 emergency interventions; 835 were mainly abdominal operations, and 724 diagnostic or therapeutic endoscopies. Of the 1559 emergency interventions, 641 (41.1%) were made outside office hours, and of 453 minor or intermediate procedures (including appendicectomy, cholecystectomy, or proctological procedures) 276 (60.9%) were done during the evenings or at night. Two hundred and fifty-four patients were admitted with trauma and 29 (11.4%) required operation, of whom general surgeons operated on eight (3.1%). Thirteen consultants and 11 senior registrars were involved in 138 bowel resections and 164 cholecystectomies chosen as index operations for standard emergency surgery. The median (range) number of such operations done by each consultant was 6 (3--17) and 6 (1--22). Corresponding figures for senior registrars were 7 (0--11) and 8 (1--39). CONCLUSION: There was an uneven distribution of exposure to acute surgical problems and trauma among general surgeons. Some were exposed to only a few standard emergency interventions and most surgeons did not operate on a single patient with trauma. Further centralization of trauma care, long-term positions at units for emergency surgery and trauma, and subspecialisation in the fields of emergency surgery and trauma, might be options to solve problems of low volumes.

  • 1491.
    Alayón González, Claudia Juliana
    Linköping University, Department of Management and Engineering, Quality Technology and Management.
    Research Trends in Quality Management over the years 2010-20112012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In current globalized and highly demanding markets, Quality does not constitute any more a competitive advantage for organizations. Instead, Quality represents a basic market entry requirement for organizations indistinguishable from the country or economic sector they belong to.

    Being conscious of the importance of Quality for all type of organizations, the purpose of this thesis is to contribute to the identification and better understanding of current trends in academic research on Quality Management. By analyzing a sample of 612 academic papers collected from five international Quality journals and two QMOD international conferences over 2010 and 2011, the author will study and reflect on the current trends of global academic research related to Quality Management.

    Literature review was used as research methodology for the thesis. Academic papers were categorized, classified and analyzed in order to identify current research trends on Quality Management.

    This work provides a snapshot of the current research trends on Quality Management. It benefits the educational sector, researchers, industry and practitioners by presenting an overview of the current research needs as well as potential future research topics.

    As a result of this study, five main trending research topics on Quality Management were identified: management systems standards, total quality management, service quality, customer related processes after delivering product/service and excellence models.

    China, India, USA, Sweden and UK were identified as the countries that have published the highest number of academic papers in international Quality journals during the studied period. Additionally, it was found a marked predominance of academic research on Quality Management towards the service sector.

    These results and the answers to five proposed research questions were discussed and solved in this report.

  • 1492.
    Alazawi, Salah
    et al.
    ISY, DATORSYSTEM, DI.
    Alilovic, Bojan
    ISY, DATORSSYTEM, DI.
    Konstruktion av Ethernet-baserad Qbussförlängare2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

     

    Syftet med var att konstruera ett bussförlängartkort till Qbussen som gör Ethernet-baserad kommunikation med I/O:t möjlig. Kortet ska kunna anslutas till standard 100 Mbits nätverksutrustning och klara autoförhandling och låsning av hastighet och duplex. Detta minskar på många ställen kabeldragningen väsentligt och det är därför önskvärt att SSAB:s egna I/O ska kunna köras så över Ethernet, antingen över vanliga nätverket eller på dedikerad kabel.

  • 1493.
    Albahari, Alberto
    et al.
    Universidad de Malaga, Spain.
    Klofsten, Magnus
    Linköping University, Department of Management and Engineering, Project Innovations and Entrepreneurship. Linköping University, Faculty of Science & Engineering. Linköping University, HELIX Competence Centre.
    Rubio-Romero, Juan Carlos
    Universidad de Malaga, Spain.
    Science and Technology Parks: A study of value creation for park tenants2019In: Journal of Technology Transfer, ISSN 0892-9912, E-ISSN 1573-7047, Vol. 44, no 4, p. 1256-1272Article in journal (Refereed)
    Abstract [en]

    The literature on Science and Technology Parks (STPs) is growing rapidly and, despite the positive impact of STPs on firms found by many studies, it remains unclear how STPs create value for tenants. In this paper, we study the STP supply side through a case study in a Swedish region. We identify two components of the business support provided by parks: a configuration-oriented component, and a process-oriented component. The former refers to the static design of the business support, and the latter to the active, hands-on support provided by parks’ management. Both components must be planned carefully in order to deliver value to tenants. We also discuss some implications for policy and managers.

  • 1494.
    Albani, Giorgia
    et al.
    University of Milano Bicocca, Italy; Ist Nazl Fis Nucl, Italy.
    Perelli Cippo, Enrico
    CNR, Italy.
    Croci, Gabriele
    University of Milano Bicocca, Italy; Ist Nazl Fis Nucl, Italy.
    Muraro, Andrea
    CNR, Italy.
    Schooneveld, Erik
    Rutherford Appleton Lab, England.
    Scherillo, Antonella
    Rutherford Appleton Lab, England.
    Hall-Wilton, Richard
    European Spallat Source ERIC, Sweden; Mittuniversitetet, Sweden.
    Kanaki, Kalliopi
    European Spallat Source ERIC, Sweden.
    Höglund, Carina
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. European Spallat Source ERIC, Sweden.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Birch, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Claps, Gerardo
    Ist Nazl Fis Nucl, Italy.
    Murtas, Fabrizio
    Ist Nazl Fis Nucl, Italy.
    Rebai, Marica
    University of Milano Bicocca, Italy; Ist Nazl Fis Nucl, Italy.
    Tardocchi, Marco
    CNR, Italy.
    Gorini, Giuseppe
    University of Milano Bicocca, Italy; CNR, Italy; Ist Nazl Fis Nucl, Italy.
    Evolution in boron-based GEM detectors for diffraction measurements: from planar to 3D converters2016In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 27, no 11, article id 115902Article in journal (Refereed)
    Abstract [en]

    The so-called He-3-crisis has motivated the neutron detector community to undertake an intense Ramp;D programme in order to develop technologies alternative to standard He-3 tubes and suitable for neutron detection systems in future spallation sources such as the European spallation source (ESS). Boron-based GEM (gas electron multiplier) detectors are a promising He-3-free technology for thermal neutron detection in neutron scattering experiments. In this paper the evolution of boron-based GEM detectors from planar to 3D converters with an application in diffraction measurements is presented. The use of 3D converters coupled with GEMs allows for an optimization of the detector performances. Three different detectors were used for diffraction measurements on the INES instrument at the ISIS spallation source. The performances of the GEM-detectors are compared with those of conventional He-3 tubes installed on the INES instrument. The conceptual detector with the 3D converter used in this paper reached a count rate per unit area of about 25% relative to the currently installed He-3 tube. Its timing resolution is similar and the signal-to-background ratio (S/B) is 2 times lower.

  • 1495.
    Albarracín, Lluís
    et al.
    Universitat Autònoma de Barcelona.
    Bergman Ärlebäck, Jonas
    Linköping University, Department of Mathematics, Mathematics and Applied Mathematics. Linköping University, Faculty of Science & Engineering.
    Civil, Elisabeth
    Universitat Autònoma de Barcelona.
    Gorgorió, Núria
    Universitat Autònoma de Barcelona.
    Extending Modelling Activity Diagrams as a tool to characterise mathematical modelling processes2019In: The Montana Mathematics Enthusiast, ISSN 1551-3440, E-ISSN 1551-3440, Vol. 16, no 1-2, article id 10Article in journal (Refereed)
    Abstract [en]

    In this paper, we present a qualitative study in which we analyse the video-recordings of four groups of students solving Fermi Problems. Previous studies show that Secondary School students solve this type of problems using complex problem solving processes and developing mathematical models. In order to analyse the students’ problem solving processes, so-called Modelling Activity Diagrams were used. The results of the present study demonstrate that solving Fermi problems is a complex matter, and that some of the theoretical tools used in the field of Mathematical Education fail to adequately reflect this level of complexity. In addition, Modelling Activity Diagrams are presented as a more detailed analysis tool to characterise student choices and actions, as well as to make the structure of the Fermi problem addressed more visible.

  • 1496.
    Albers, WM
    et al.
    LEIDEN UNIV,LEIDEN INST CHEM,GORLAEUS LABS,NL-2300 RA LEIDEN,NETHERLANDS; CRANFIELD UNIV,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    Lekkala, JO
    LEIDEN UNIV,LEIDEN INST CHEM,GORLAEUS LABS,NL-2300 RA LEIDEN,NETHERLANDS; CRANFIELD UNIV,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    Jeuken, L
    LEIDEN UNIV,LEIDEN INST CHEM,GORLAEUS LABS,NL-2300 RA LEIDEN,NETHERLANDS; CRANFIELD UNIV,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    Canters, GW
    LEIDEN UNIV,LEIDEN INST CHEM,GORLAEUS LABS,NL-2300 RA LEIDEN,NETHERLANDS; CRANFIELD UNIV,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    Turner, APF
    Cranfield University, UK.
    Design of novel molecular wires for realizing long-distance electron transfer1997In: Bioelectrochemistry and bioenergetics (Print), ISSN 0302-4598, E-ISSN 1872-8049, Vol. 42, no 1, p. 25-33Article in journal (Refereed)
    Abstract [en]

    Novel heteroarene oligomers, consisting of two pyridinium groups, linked by thiophene units of variable length, thienoviologens, are described as promising candidates for molecular wires. Two representative thienoviologens were coated by adsorption from micromolar concentrations in ethanol onto octadecylmercaptan (ODM)-coated gold electrodes and induced a gradual restoration of the electrochemistry with hexacyanoferrate as a function of molecular wire concentration. Glucose oxidase and choline oxidase showed strong adsorption to these conductive layers, but showed striking differences in adsorption to the different thienoviologen layers. The measurements support the hypothesis that the molecules are incorporated in the ODM layer in a different fashion. Also the complex formation of an engineered azurin redox protein with water-soluble pyridyl ligands is presented in relation to a possible application of the thienoviologens as conductive spacers, in which the contact with the redox protein is achieved via complex formation with a free pyridine nitrogen. (C) 1997 Elsevier Science S.A.

  • 1497.
    Albert, Frank W.
    et al.
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, and Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America,.
    Somel, Mehmet
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, CAS–MPG Partner Institute for Computational Biology SIBS, Shanghai, China.
    Carneiro, Miguel
    CIBIO, Centro de Investigac¸a˜o em Biodiversidade e Recursos Gene´ ticos, Vaira˜o, Portugal, and Departamento de Zoologia e Antropologia–Faculdade de Cieˆncias da Universidade do Porto, Porto, Po.
    Aximu-Petri, Ayinuer
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
    Halbwax, Michael
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany and Fernan Vaz Gorilla Project, Port-Gentil, Gabon.
    Thalmann, Olaf
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany and Department of Biology, University of Turku, Turku, Finland.
    Blanco-Aguiar, Jose A.
    CIBIO, Centro de Investigac¸a˜o em Biodiversidade e Recursos Gene´ ticos, Vaira˜o, Portugal, 5 Departamento de Zoologia e Antropologia–Faculdade de Cieˆncias da Universidade do Porto, Porto, Portugal and Instituto de Investigacio´n en Recursos Cinege´ticos, IREC (CSIC, UCLM, JCCM), Ciudad Real, Spain.
    Plyusnina, Irina Z.
    Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
    Trut, Lyudmila
    Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
    Villafuerte, Rafael
    Instituto de Investigacio´n en Recursos Cinege´ticos, IREC (CSIC, UCLM, JCCM), Ciudad Real, Spain.
    Ferrand, Nuno
    CIBIO, Centro de Investigac¸a˜o em Biodiversidade e Recursos Gene´ ticos, Vaira˜o, Portugal, and Departamento de Zoologia e Antropologia–Faculdade de Cieˆncias da Universidade do Porto, Porto, Portugal.
    Kaiser, Sylvia
    Department of Behavioural Biology, University of Mu¨ nster, Mu¨ nster, Germany.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Zoology. Linköping University, The Institute of Technology.
    Pääbo, Svante
    Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
    A Comparison of Brain Gene Expression Levels in Domesticated and Wild Animals2012In: PLOS Genetics, ISSN 1553-7390, Vol. 8, no 9, p. e1002962-Article in journal (Refereed)
    Abstract [en]

    Domestication has led to similar changes in morphology and behavior in several animal species, raising the questionwhether similarities between different domestication events also exist at the molecular level. We used mRNA sequencing toanalyze genome-wide gene expression patterns in brain frontal cortex in three pairs of domesticated and wild species (dogsand wolves, pigs and wild boars, and domesticated and wild rabbits). We compared the expression differences with thosebetween domesticated guinea pigs and a distant wild relative (Cavia aperea) as well as between two lines of rats selectedfor tameness or aggression towards humans. There were few gene expression differences between domesticated and wilddogs, pigs, and rabbits (30–75 genes (less than 1%) of expressed genes were differentially expressed), while guinea pigs andC. aperea differed more strongly. Almost no overlap was found between the genes with differential expression in thedifferent domestication events. In addition, joint analyses of all domesticated and wild samples provided only suggestiveevidence for the existence of a small group of genes that changed their expression in a similar fashion in differentdomesticated species. The most extreme of these shared expression changes include up-regulation in domesticates of SOX6and PROM1, two modulators of brain development. There was almost no overlap between gene expression in domesticatedanimals and the tame and aggressive rats. However, two of the genes with the strongest expression differences betweenthe rats (DLL3 and DHDH) were located in a genomic region associated with tameness and aggression, suggesting a role ininfluencing tameness. In summary, the majority of brain gene expression changes in domesticated animals are specific tothe given domestication event, suggesting that the causative variants of behavioral domestication traits may likewise bedifferent.

  • 1498.
    Albert, Jörg G
    et al.
    First Department of Medicine, Martin-Luther-University Halle-Wittenberg, Germany.
    Gimm, Oliver
    General Surgery, Martin-Luther-University Halle-Wittenberg, Germany.
    Stock, Karsten
    Department of Radiology, Martin-Luther-University Halle-Wittenberg, Germany.
    Bilkenroth, Udo
    Department of Pathology, Martin-Luther-University Halle-Wittenberg, Germany.
    Marsch, Wolfgang C H
    Department of Dermatology, Martin-Luther-University Halle-Wittenberg, Germany.
    Helmbold, Peter
    Department of Dermatology, University of Heidelberg, Germany.
    Small-bowel endoscopy is crucial for diagnosis of melanoma metastases to the small bowel: a case of metachronous small-bowel metastases and review of the literature.2007In: Melanoma research, ISSN 0960-8931, E-ISSN 1473-5636, Vol. 17, no 5, p. 335-8Article in journal (Refereed)
  • 1499.
    Alberth, Gunnar
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology.
    Kettissen, Johan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology. Östergötlands Läns Landsting, MKC - Medicin och kirurgicentrum, Anestesi.
    Lisander, Björn
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology. Östergötlands Läns Landsting, MKC - Medicin och kirurgicentrum, Anestesi.
    Blood loss in prosthetic hip replacement is not influenced by the AB0 blood group2001In: European Journal of Surgery, ISSN 1102-4151, E-ISSN 1741-9271, Vol. 167, no 9, p. 652-655Article in journal (Refereed)
    Abstract [en]

    Objective: To find out if there is a correlation between AB0 type and the amount of blood lost at operation. Design: Retrospective study. Setting: One county and one university hospital, Sweden. Subjects: 540 patients who underwent primary prosthetic hip replacement under regional anaesthesia. Albumin (n = 298) or dextran (n = 242) were used as plasma substitutes. Main outcome measures: Estimated blood loss and number of units of red cell concentrates transfused. Results: The characteristics of the study groups were similar. In patients given albumin, the mean (SD) intraoperative loss with blood group 0 (n = 100) was 718 (413) ml and 2.7 (1.9) red cell units were given. Those with other blood groups (n = 198) lost 713 (469) ml and were given 2.5 (2.0) units. In patients given dextran with blood group 0 (n = 82), the intraoperative blood loss was 650 (337) ml, the postoperative loss 480 (222) ml and they received 2.1 (2.1) units. The corresponding values in the patients with other blood groups (n = 160) were 665 (351), 498 (208) and 2.5 (2.1) units. Conclusion: Blood group 0 was not associated with increased blood loss.

  • 1500.
    Alberti, Esteban
    et al.
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    Los, Marek Jan
    Interfaculty Institute for Biochemistry, University of Tübingen, Germany; BioApplications Enterprises, Winnipeg, MB, Canada.
    Garcia, Rocio
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    Fraga, JL
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    Serrano, T.
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    Hernandez, E.
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    Klonisch, Thomas
    Department of Human Anatomy and Cell Sciences, and Manitoba Institute of Child Health, Winnipeg, Canada.
    Macías, R.
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    Martinez, L.
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    Castillo, L.
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba..
    de la Cuétara, K.
    Department of Neurobiology, International Center of Neurological Restoration, CIREN, Havana, Cuba.
    Prolonged Survival and expression of neural markers by bone marrow-derived stem cells transplanted into brain lesions2009In: Medical Science Monitor, ISSN 1234-1010, E-ISSN 1643-3750, Vol. 15, no 2, p. BR47-BR54Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Bone marrow-derived stem cell transplantation is a potentially viable therapeutic option for the treatment of neurodegenerative disease. MATERIAL/METHODS: We have isolated bone marrow stem cells by standard method. We then evaluated the survival of rats' bone marrow mononuclear cells implanted in rats' brain. The cells were extracted from rats' femurs, and marked for monitoring purposes by adenoviral transduction with Green Fluorescent Protein (GFP). Labeled cells were implanted within the area of rats' striatum lesions that were induced a month earlier employing quinolinic acid-based method. The implants were phenotyped by monitoring CD34; CD38; CD45 and CD90 expression. Bone marrow stromal cells were extracted from rats' femurs and cultivated until monolayer bone marrow stromal cells were obtained. The ability of bone marrow stromal cells to express NGF and GDNF was evaluated by RT-PCR. RESULTS: Implanted cells survived for at least one month after transplantation and dispersed from the area of injection towards corpus callosum and brain cortex. Interestingly, passaged rat bone marrow stromal cells expressed NGF and GDNF mRNA. CONCLUSIONS: The bone marrow cells could be successfully transplanted to the brain either for the purpose of trans-differentiation, or for the expression of desired growth factors.

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