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小型腐殖质湖泊的碳收支:湖泊对北方集水区有机物质循环重要性的一个实例

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AMBIO－人类环境杂志 2006年第8期35卷 461-467页

作者： sebastian sobek Bjrn Sderbck Sara Karlsson Eva Andersson Anna Kristina Brunberg 李四海瑞典乌普萨拉大学

由于通常是大范围的细菌呼吸作用和沉积物中有机碳的有效埋藏,湖泊在北方景观有机物质循环中发挥着重要作用。为了评估碳收支对与有机物有关的放射性核素在环境中迁移的潜在影响,我们基于一种质量平衡方法,计算了瑞典的一个小腐殖质湖... 详细信息

由于通常是大范围的细菌呼吸作用和沉积物中有机碳的有效埋藏,湖泊在北方景观有机物质循环中发挥着重要作用。为了评估碳收支对与有机物有关的放射性核素在环境中迁移的潜在影响,我们基于一种质量平衡方法,计算了瑞典的一个小腐殖质湖的碳收支,该湖位于一个放射性废料潜在最后埋藏点的附近。我们发现该湖是一个净异养的生态系统,从集水区和现有大型植物生产物中补充得到有机碳输入。有机碳最大的汇点是水生细菌的呼吸作用和随后向大气释放CO_2。虽然每年埋藏在沉积物中的有机碳是一个比较小的汇,但它却导致湖中最大碳库的形成。因此,湖泊也许同时分散和聚集从最后埋藏点中泄漏的有机伴生的放射性核素。

关键词：物质循环碳收支集水区腐殖质湖泊北方放射性核素实例

The German Energiewende and its roll-out of renewableenergies： An economic perspective

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Frontiers in Energy 2017年第2期11卷 126-134页

作者： sebastian KREUZ Felix MUSGENS Faculty of Mechanical Engineering Electrical and Energy SystemsBrandenburg University of Technology 03046 Cottbus Germany

This paper gives a short overview of the German Energiewende, i.e. the transition of a large and mostly thermal electricity system towards electricity generation from renewable energy source. It discusses both, the motivation of the transitions as future goals and current status. Furthermore, it gives an in-depth view into the changes in economic costs for society as well as electricity price effects, especially for average private households and industrial consumers. It also discusses the benefits of the promotion of renewable energies in Germany.

关键词： electricity system renewable energy cost-benefit analysis

Influence of Non-Uniform Temperature Distribution on Metallic Charge Length on Energy and Force Parameters During Groove-Rolling

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Journal of Iron and Steel Research International 2012年第8期19卷 17-24页

作者： Mróz sebastian Czestochowa University of Technology

Change in the temperature of band over its length, associated with the stock being non-uniformly heated in the furnace, influences the variations in the magnitudes of energy-force parameters. Using the FEM (Finite Element Model) programs for the computation of the values of the energy-force parameters can take into account the distribution of temperature over the band length. The mathematical model of the computer program Forge2008 was used to theoretically examine the energy-force parameters and plastic metal flow in the roughing stands of the continuous rolling mill. The results of experimental investigation of influence of the non-uniform temperature distribution were presented on the metallic charge length on the energy and force parameters and dimensions of the band during round bars rolling. Thermovision monitoring energy and force parameters monitoring were carried out in continuous rolling mill D350 in one of the Polish industrial plants. On the basis of obtained results, it could be stated that non-uniform distribution of temperatures along the charge length causes local increase of energy and force parameters values and also such distribution affects the local increase of the width of rolled band. The rolling process of charge with non-uniform distribution of temperature could lead to exceeding required dimensional tolerances of the final products.

关键词： groove-rolling energy parameter force parameter numerical technique FEM

Towards a Local-Level Resilience Composite Index: Introducing Different Degrees of Indicator Quantification

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International Journal of Disaster Risk Science 2017年第1期8卷 91-99页

作者： sebastian Jlich Regional Economics and Development Economics and Social SciencesSwiss Federal Research Institute WSL8903 BirmensdorfSwitzerland

Within disaster resilience research there is a trend of developing quantitative metrics for resilience analysis. Quantitative indicators can be useful for decision makers in the field of resilience building to prioritize preventive actions to target the least resilient. This study explores possibilities and constraints in quantifying disaster resilience at the local level. While national or regionallevel indicators mostly employ existing secondary source data, at the local level it is necessary to collect new data in most cases. The main aim of this study is to investigate how resilience indicators with different stages of operationalization can be developed at the local level. Using the example of the Swiss canton of Grisons, three local-level partial indicators for community resilience against natural hazard are developed. In this process qualitative research is the necessary basis to construct quantitative indicators. For each partial indicator different stages of quantification are offered to illustrate how quantitatively operationalized indicators can be developed and to examine their strengths and weaknesses. For this purpose a classification of different indicator operationalization stages is proposed,ranging from vague qualitative criteria to fully quantified criteria.

关键词： Disaster resilience Indicator development Resilience index Risk and loss perception Switzerland

Active protection of work area against explosion of dust-gas mixture

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International Journal of Coal Science & Technology 2021年第4期8卷 674-684页

作者： Zbigniew Szkudlarek sebastian Janas KOMAG Institute of Mining Technology 44-101 GliwicePoland

Potentially explosive atmosphere can occur not only in the production systems of the food,energy,chemical and petrochemical industries but also in the production processes of the mining ***,vapours,mists and dusts arise can escape in an uncontrolled way during production,processing,transportation and storage of flammable *** combination with oxygen,they create explosive atmospheres that,if ignited,lead to an explosion causing catastrophic damage to peopled lives and *** protect against the results of hazardous dust-gas mixtures explosions in a confined work space,where employees can stay,various control and protection mechanisms are used in the form of an active explosion-proof *** article presents the results of tests on an active system for limiting the effects of ignition of gas and/or dust based on a highly efficient explosion suppression system-equipped with an ignition detection system,high-pressure fire extinguisher and a power supply and trigger *** powder was used as the explosive charge and sodium bicarbonate as the suppressive *** of the effectiveness of the active explosion suppression system were carried out on two devices:a small-size dry dust collector and a zone extinguishing system adapted for direct explosion suppression in closed working *** both cases,the explosion suppression process took place through the action of extinguishing powder blown out of the fire extinguisher after membrane perforation by compressed combustion products.

关键词： Gas hazard Explosive dust Suppression of explosion Safety of work area

Micro-Task Processing in Heterogeneous Reconfigurable Systems

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Journal of Computer Science & Technology 2005年第5期20卷 624-634页

作者： sebastian Wallner Department of Distributed Systems Technical University of Hamburg-Harburg Schwarzenbergstrasse 95 D-21073 Hambur9 Germany

New reconfigurable computing architectures are introduced to overcome some of the limitations of conventional microprocessors and fine-grained reconfigurable devices （e.g., FPGAs）. One of the new promising architectures axe Configurable System-on-Chip （CSoC） solutions. They were designed to offer high computational performance for real-time signal processing and for a wide range of applications exhibiting high degrees of parallelism. The programming of such systems is an inherently challenging problem due to the lack of an programming model. This paper describes a novel heterogeneous system architecture for signal processing and data streaming applications. It offers high computational performance and a high degree of flexibility and adaptability by employing a micro Task Controller （mTC） unit in conjunction with programmable and configurable hardware. The hierarchically organized architecture provides a programming model, allows an efficient mapping of applications and is shown to be easy scalable to future VLSI technologies. Several mappings of commonly used digital signal processing algorithms for future telecommunication and multimedia systems and implementation results axe given for a standard-cell ASIC design realization in 0.18 micron 6-layer UMC CMOS technology.

关键词： system-on-chip reconfigurable heterogeneous architectures configuration instructions descriptors parallel processing system signal processing

Does pressure cause liver cirrhosis? The sinusoidal pressure hypothesis

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World Journal of Gastroenterology 2016年第48期22卷 10482-10501页

作者： sebastian Mueller Department of Medicine and Center for Alcohol Research Salem Medical CenterUniversity of Heidelberg

Independent of their etiology, all chronic liver diseases ultimately lead to liver cirrhosis, which is a majorhealth problem worldwide. The underlying molecular mechanisms are still poorly understood and no efficient treatment strategies are available. This paper introduces the sinusoidal pressure hypothesis(SPH), which identifies an elevated sinusoidal pressure(SP) as cause of fibrosis. SPH has been mainly derived from recent studies on liver stiffness. So far, pressure changes have been exclusively seen as a consequ-ence of cirrhosis. According to the SPH, however, an elevated SP is the major upstream event that initiates fibrosis via biomechanic signaling by stretching of perisinusoidal cells such as hepatic stellate cells or fibroblasts(SPH part?Ⅰ: initiation). Fibrosis progression is determined by the degree and time of elevated SP. The SPH predicts that the degree of extracellular matrix eventually matches SP with critical thresholds > 12 mmH g and > 4 wk. Elevated arterial flow and final arterialization of the cirrhotic liver represents the self-perpetuating key event exposing the low-pressure-organ to pathologically high pressures(SPH part?Ⅱ: perpetuation). It also defines the "point of no return" where fibrosis progression becomes irreversible. The SPH is able to explain the macroscopic changes of cirrhotic livers and the uniform fibrotic response to various etiologies. It also opens up new views on the role of fat and disease mechanisms in other organs. The novel concept will hopefully stimulate the search for new treatment strategies.

关键词： liver stiffness Stretch force Sinusoidal pressure hypothesis liver cirrhosis Hepatic arterial buffer response biomechanics Arterialization Hepatic stellate cells Fibroblasts cellular and intercellular mechano-signaling

UNIFORM SUPERCONVERGENCE OF A FINITE ELEMENT METHOD WITH EDGE STABILIZATION FOR CONVECTION-DIFFUSION PROBLEMS

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Journal of Computational Mathematics 2010年第1期28卷 32-44页

作者： sebastian Franz Torsten Linβ Hans-Grg Roos sebastian Schiller Department of Mathematics and Statistics University of Limerick Institut für Numerische Mathematik Technische Universitt Dresden

In the present paper the edge stabilization technique is applied to a convection-diffusion problem with exponential boundary layers on the unit square, using a Shishkin mesh with bilinear finite elements in the layer regions and linear elements on the coarse part of the mesh. An error bound is proved for ‖πu-u^h‖Е, where πu is some interpolant of the solution u and uh the discrete solution. This supercloseness result implies an optimal error estimate with respect to the L2 norm and opens the door to the application of postprocessing for improving the discrete solution.

关键词： Convection-diffusion problems Edge stabilization FEM Uniform convergence Shishkin mesh.

Interplay between microstructural evolution and tribo-chemistry during dry sliding of metals

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Friction 2019年第6期7卷 637-650页

作者： Philipp GGRÜTZMACHER sebastian RAMMACHER Dominic RATHMANN Christian MOTZ FrankMÜCKLICH sebastian SUAREZ Chair of Functional Materials Saarland UniversityCampus D3.3Saarbrücken 66123Germany Chair of Experimental Methodology of Material Science Saarland UniversityCampus D2.2Saarbrücken 66123Germany

Understanding the microstructural and tribo-chemical processes during tribological loading is of utmost importance to further improve the tribological behavior of metals. In this study, the friction, wear and tribo-chemical behavior of Ni with different initial microstructures(nanocrystalline, bi-modal, coarse-grained) is investigated under dry sliding conditions. In particular, the interplay be-tween frictional response, microstructural evolution and tribo-oxidation is considered. Friction tests are carried out using ball-on-disk experiments with alumina balls as counter-bodies, varying the load between 1 and 5 N. The microstructural evolution as well as the chemical reactions beneath the samples’ surface is investigated by means of cross-sections. The samples with finer microstructures show a faster run-in and lower maximum values of the coefficient of friction(COF) which can be attributed to higher oxidation kinetics and a higher hardness. It is observed that with increasing sliding cycles, a stable oxide layer is formed. Furthermore, initially coarse-grained samples show grain refinement, whereas initially finer microstructures undergo grain coarsening converging towards the same superficial grain size after 2,000 sliding cycles. Consequently, the experimental evidence supports that, irrespective of the initial microstructure, after a certain deformation almost identical steady-state COF values for all samples are achieved.

关键词： dry sliding microstructural analysis tribo‐oxidation wear