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Neural Regeneration Research 2017年第9期12卷 1433-1434页

作者： bjorn spittau Institute for Anatomy and Cell Biology Department of Molecular Embryology Faculty of Medicine University of Freiburg Institute of Anatomy University of Rostock

Parkinson＇s disease （PD） has been described as one of the most common neurodegenerative diseases affecting up to 2% of the worldwide population over 60 years of age. The hallmarks of PD are progressive loss of midbrain dopaminergic （mDA） neurons and a decrease in striatal dopamine levels, which result in typ- ical clinical motor symptoms such as akinesia, resting tremor, rigidity, and gait impairments. Although the causes for PD are only partially understood and seem to be very heterogeneous, one of the common phenomenons observed in toxin-based an- imal models of PD as well as PD patients is a microglia-driven neuroinflammatory response,

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Impacts of CO2 and H2S on the risk of hydrate formation during pipeline transport of natural gas

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Frontiers of Chemical Science and Engineering 2019年第3期13卷 616-627页

作者： Solomon A. Aromada bjorn Kvamme Department of Physics and Technology University of Bergen5007 BergenNorway Strategic Carbon LLC Vestre Holbergsallmenningen 175011 BergenNorway

Evaluation of maximum content of water in natural gas before water condenses out at a given temperature and pressure is the initial step in hydrate risk analysis during pipeline transport of natural gas, The impacts of CO2 and ELS in natural gas on the maximum mole-fractions of water that can be tolerated during pipeline transport without the risk of hydrate nucleation has been studied using our novel thermodynamic scheme. Troll gas from the North Sea is used as a reference ease, it contains very negligible amount of CO2 and no H2S. Varying mole-fractions of CO2 and INS were introduced into the Troll gas, and the effects these inorganic impurities on the water tolerance of the system were evaluated. It is observed that CO2 does not cause any distinguishable impact on water tolerance of the system, but H2S does. Water tolerance decreases with increase in concentration of H2S. The impact of ethane on the system was also investigated. The maximum mole-fraction of water permitted in the gas to ensure prevention of hydrate formation also decreases with increase in the concentration of C2H6 like H2S. H2S has the most impact, it tolerates the least amount of water among the components studied.

关键词： hydrate hydrogen Sulphide CO2 dewpoint pipeline

Hierarchical approach for fatigue cracking performance evaluation in asphalt pavements

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Frontiers of Structural and Civil Engineering 2017年第3期11卷 257-269页

作者： Ibrahim ONIFADE Yared DINEGDAE bjorn BIRGISSON Department of Civil and Architectural Engineering KTH Royal Institute of Technology Stockholm Sweden School of Engineering and Applied Science Aston University Aston Triangle Birmingham B4 7ET United Kingdom

In this paper, a hierarchical approach is proposed for the evaluation of fatigue cracking in asphalt concrete pavements considering three different levels of complexities in the representation of the material behaviour, design parameters characterization and the determination of the pavement response as well as damage computation. Based on the developed hierarchical approach, three damage computation levels are identified and proposed. The levels of fatigue damage analysis provides pavement engineers a variety of tools that can be used for pavement analysis depending on the availability of data, required level of prediction accuracy and computational power at their disposal. The hierarchical approach also provides a systematic approach for the understanding of the fundamental mechanisms of pavement deterioration, the elimination of the empiricism associated with pavement design today and the transition towards the use of sound principles of mechanics in pavement analysis and design.

关键词： fatigue cracking energy based crack initiation mechanistic approach pavement analysis

Taking Comfort in Points:The Appeal of the Norwegian Model in Sweden

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Journal of Data and Information Science 2018年第4期3卷 85-95页

作者： bjorn Hammarfelt Swedish School of Library and In formation Science University of BorasSweden

Purpose: The "Norwegian model" has become widely used for assessment and resource allocation purposes. This paper investigates why this model has becomes so widespread and influential. Approach: A theoretical background is outlined in which the reduction of "uncertainty" is highlighted as a key feature of performance measurement systems. These theories are then drawn upon when revisiting previous studies of the Norwegian model, its use, and reactions to it, in ***: The empirical examples, which concern more formal use on the level of universities as well as responses from individual researchers, shows how particular parts—especially the "publication indicator"—are employed in Swedish academia. The discussion posits that the attractiveness of the Norwegian model largely can be explained by its ability to reduce complexity and uncertainty, even in fields where traditional bibliometric measurement is less applicable. Research limitations: The findings presented should be regarded as examples that can be used for discussion, but one should be careful to interpret these as representative for broader sentiments and ***: The sheer popularity of the Norwegian model, leading to its application in contexts for which it was not designed, can be seen as a major challenge for the ***: This paper offers a novel perspective on the Norwegian model by focusing on its general "appeal", rather than on its design, use or(mis)-use.

关键词： The Norwegian model Sweden Uncertainty Bibliometric indicators Assessment systems

Evaluation of Turbulence Models in Predicting Hypersonic and Subsonic Base Flows Using Grid Adaptation Techniques

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Chinese Journal of Aeronautics 2012年第3期25卷 325-334页

作者： YOU Yancheng BUANGA bjorn HANNEMANN Volker LUDEKE Heinrich Institute of Aerodynamics and Flow Technology German Aerospace Center (DLR) Braunschweig 38108 Germam Institute of Aerodynamics and Flow Technology German Aerospace Center (DLR) Gottingen 37073 Germany Department of Aeronautics Xiamen University Xiamen 361005 China

The flows behind the base of a generic rocket, at both hypersonic and subsonic flow conditions, are numerically studied. The main concerns are addressed to the evaluation of turbulence models and the using of grid adaptation techniques. The investigation focuses on two configurations, related to hypersonic and subsonic experiments. The applicability tests of different turbu- lence models are conducted on the level of two-equation models calculating the steady state solution of the Reynolds-averaged Navier-Stokes（RANS） equations. All used models, the original Wilcox k-co, the Menter shear-stress transport （SST） and the ex- plicit algebraic Reynolds stress model（EARSM） formulation, predict an asymmetric base flow in both cases caused by the support of the models. A comparison with preliminary experimental results indicates a preference for the SST and EARSM results over the results from the older k-co model. Sensitivity studies show no significant influence of the grid topology or the location of the laminar to turbulent transition on the base flow field, but a strong influence of even small angles of attack is reported from the related experiments.

关键词： base flows turbulence models steady calculation grid adaptation numerical simulation

Environmentally Adapted Hydropower in Sweden

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Small Hydro Power News 2006年第1期23卷 19-24页

作者： bjorn Svensson SwedPower AB Sweden

IntroductionThe alteration of watercourses has been extensive in Sweden as well as in other industrialised countries. Since the end of the last century the water table of about 2500 lakes have been lowered in order to reclaim farmland. More than 600 of these have been completely drained. This particular activity came to a halt at the end of the 1950s whereas the ditching of wetlands and dredging and channelisation of watercourses for the benefit of forestry are still ongoing activities. The regulation of rivers for the purpose of meeting differential needs of hydroelectric power commenced in the beginning of this century, At that time, the floating of timber constituted the economically most important profit from exploitation of northern Swedish rivers.

关键词：瑞典小水电水电站水资源

Historical Bibliometrics Using Google Scholar: The Case of Roman Law, 1727–2016

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Journal of Data and Information Science 2020年第3期5卷 18-32页

作者： Janne Polonen bjorn Hammarfelt Federation of Finnish Learned Societies Snellmaninkatu 1300170 HelsinkiFinland Swedish School of Library and Information Science University of BorasAllegatan 1Boras50332Sweden

Purpose: The purpose of this study is to investigate the historical and linguistic coverage of Google Scholar, using publications in the field of Roman law as an ***/methodology/approach: To create a dataset of Roman law publications, we retrieved a total of 21,300 records of publications, published between years 1500 and 2016, with title including words denoting "Roman law" in English, French, German, Italian, and Spanish. Findings: We were able to find publications dating back to 1727. The largest number of publications and authors date to the late 19th century, and this peak might be explained by the role of Roman law in French legal education at the time. Furthermore, we found exceptionally skewed concentration of publications to authors, as well as of citations to publications. We speculate that this could be explained by the long time-frame of the study, and the importance of classic works. Research limitation: Major limitations, and potential future work, relate to data quality, and cleaning, disambiguation of publications and authors, as well as comparing coverage with other data sources. Practical implications: We find Google Scholar to be a promising data source for historical bibliometrics. This approach may help bridge the gap between bibliometrics and the "digital humanities".Originality/value: Earlier studies have focused mainly on Google Scholar's coverage of publications and citations in general, or in specific fields. The historical coverage has, however, received less attention.

关键词： Historical bibliometrics Google Scholar Roman law

Shear assessment of compression flanges of structural concrete T-beams

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Frontiers of Structural and Civil Engineering 2014年第4期8卷 354-361页

作者： bjorn SCHUTTE Viktor SIGRIST Institute of Concrete Structures Hamburg University of Technology Hamburg 21073 Germany

In T-beams the force transfer from the web into the flange has to be studied. The general design procedure is based on a strut-and-tie （or a stress field） model which comprises spreading compressive and transverse tensile forces. As is known, strut-and-tie models represent the force flow within a structural member at ultimate. This procedure is sufficient for design purposes and in general, leads to safe results. For the assessment of a structure it may be worthwhile to improve the accuracy. For this purpose both web and flange have to be looked at more in detail. An advanced method for the analysis of webs in shear is the Generalized Stress Field Approach [1]. This approach can be utilized for treating flanges, where the classical assumptions have to be adapted; in particular by considering the strain dependence of the concrete compressive strength and thus, defining a representative strain value. In the present contribution background and details of these aspects are given, and the corresponding calculation procedure is described. Theoretical results are compared with experimental data and show a reasonably good agreement. However, as the number of sufficiently documented tests is very limited no concluding findings are attained.

关键词： concrete structures structural assessment stress field analysis shear

Neutron Diffraction Study of Low-Cycle Fatigue Behavior in an Austenitic–Ferritic Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2015年第10期28卷 1247-1256页

作者： Ming-Wei Zhu Nan Jia Feng Shi bjorn Clausen School of Materials Science and Engineering Shenyang Aerospace University Key Laboratory for Anisotropy and Texture of Materials(ATM) Northeastern University School of Science Northeastern University Los Alamos National Laboratory Los Alamos Neutron Science Center

By performing in situ neutron diffraction experiments on an austenitic-ferritic stainless steel subjected to lowcycle fatigue loading, the deformation heterogeneity of the material at microscopic level has been revealed. Based on the in situ neutron diffraction data collected from a single specimen together with the mechanical properties learned from the ex situ micro-hardness, a correlation has been found. The performance versus diffraction-profile correlation agrees with the cyclic-deformation-induced dislocation evolution characterized by ex situ TEM observation. Moreover, based on the refined neutron diffraction-profile data, evident strain anisotropy is found in the austenite. The high anisotropy in this phase is induced by the increase in dislocation density and hence contributes to the hardening of the steel at the first 10 *** 10 fatigue cycles, the annihilation and the rearrangement of the dislocations in both austenitic and ferritic phases softens the plastically deformed specimen. The study suggests that the evolution of strain anisotropy among the differently oriented grains and micro-strain induced by lattice distortion in the respective phases mostly affect the cyclic-deformationinduced mechanical behavior of the steel at different stages of fatigue cycles. The stress discrepancy between phases is not the dominant mechanism for the deformation of the steel.

关键词： Duplex steel Neutron diffraction Fatigue Plastic deformation Microstructure

A Cartesian Embedded Boundary Method for Hyperbolic Conservation Laws

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Communications in Computational Physics 2007年第6期2卷 1199-1219页

作者： bjorn Sjogreen N.Anders Petersson Center for Applied Scientific Computing Lawrence Livermore National LaboratoryLivermoreCA 94551USA.

We develop an embedded boundary finite difference technique for solving the compressible two-or three-dimensional Euler equations in complex geometries on a Cartesian *** method is second order accurate with an explicit time step determined by the grid size away from the *** limiters are used on the embedded boundary to avoid non-physical oscillations near shock *** show computed examples of supersonic flow past a cylinder and compare with results computed on a body fitted ***,we discuss the implementation of the method for thin geometries,and show computed examples of transonic flow past an airfoil.

关键词： Embedded boundary hyperbolic conservation law finite difference scheme shock wave.