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Phlorotannins from brown Algae as a Sustainable Aquatic Feedstock for Epoxy Resins

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Journal of Materials Science and Chemical Engineering 2024年第11期12卷 94-106页

作者： Andreas Winkel Martin Kahlmeyer stefan böhm Thomas Fuhrmann-Lieker Maximilian Heiko burk Department for Cutting and Joining Manufacturing Processes University of Kassel Kassel Germany Physical Chemistry of Nanomaterials University of Kassel Kassel Germany

bisphenol A (bPA) is the primary chemical used in the production of epoxy resins but as of today is not widely available in a bio-based form. bPA is also classified as a substance of very high concern due to its reproductive toxicity and endocrine-disrupting effects. Phlorotannins, a type of polyphenols, offer a promising structural alternative to bisphenol A as a more sustainable option. They are found in high quantities in brown algae, which are already harvested for alginate production. As a result, phlorotannins present an under-researched yet promising marine resource for the chemical industry, particularly in the area of epoxy resin formulation. In this study, a model epoxy resin compound based on phloroglucinol, the simplest phlorotannin, was chosen to explore its reactivity and the thermo-mechanical properties of epoxy resins based thereof. As hardeners well-established systems like isophorone diamine for ambient temperature cure as well as heat-curing anhydrides and dicyandiamide were used. Across all cases, thermosets with glass transition temperatures above 100?C were achieved under cross-linking conditions similar to those used today. One phthalic anhydride derivative yielded a glass transition temperature of 198?C, highlighting the significant potential of these algae-based epoxy resins for industrial uses, such as impregnating resins for fiber-reinforced plastics.

关键词： Epoxy Resins Algae Phlorotannins

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智能联合收获机——提高性能和效率

农业装备与车辆工程 2013年第6期51卷 15-16,42页

作者： stefan bTTINGER 霍恩海姆大学

从简单的信息系统到部分自动化操作,联系收割机减轻了机手的作业强度,提高了机具的应用潜力。将来的发展更将实现机组的自动化作业。

关键词：联合收获机传感器多功能手柄控制系统

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抗衰抗敏新手段抗炎皮肤护理

中国化妆品 2014年第7期 44-45页

作者： stefan b nziger 关小苏化妆品活性研发部门

Rahn集团的stefan banziger博士本期向我们展示了Defensil Plus——一种能舒缓发炎过程的活性抗炎成分——不仅能舒敏止痒,还能帮助发炎的肌肤恢复天然抵抗的屏障.

关键词：皮肤护理抗炎抗敏抗衰 Plus 止痒

用于分布式电源的高集成度DC/DC转换电路

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电子设计技术 2002年第10期 94-94页

作者： stefan burle Power Integrations GmbH

电信和数据通信设备中需要高效率的低压大电流电源,直流48V输出的分布式供电方案则可满足这一要求。如今,用户不仅要求高效率,还要求尺寸更小、更加灵活、系统成本更低并且更快地上市。

关键词： DC/DC 高集成度

Wash water in waterworks:contaminants and process options for reclamation

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Journal of Environmental Sciences 2008年第11期20卷 1300-1305页

作者： C b Chidambara Raj Tan Ee Kwong Soh Hoo Tiong Paul stefan Klose Centre for Advanced Water Technology Singapore Utilities International Pte Ltd.82 Toh Guan Road East # C4-03Singapore 608575 Public Utilities board Water Supply (Plants) Department40 Scotts Road #14-00Singapore 228231

Reclamation of clean water from filter backwash water was studied through pilot-scale *** pilot plant consisted of clarification,sand-filtration,and ultrafiltration modules in sequence,with a provision to bypass the sand *** water that conformed to World Health Organization (WHO) guidelines on Potable Quality was ***,aluminum and iron were found to be critical contaminants in process selection and ***,followed by sand filtration,was found to be the minim...

关键词： filter backwash clarification water treatment aluminium Giardia

Numerical analysis of synthetic granulate deposition in a physical model study

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International Journal of Sediment Research 2014年第1期29卷 110-117页

作者： Gabriele HARb stefan HAUN Joséf SCHNEIDER Nils Reidar b.OLSEN Institute of Hydraulic Engineering and Water Resources Management Graz University of Technology Department of Hydraulic and Environmental Engineering The Norwegian University of Science and Technology

The current study focuses on the application of a three-dimensional numerical model for the prediction of morphological bed *** sediment deposition in a reservoir during a 10-year-fiood was investigated and the results of the simulation were validated with data derived from a physical model *** of the small grain sizes in the prototype,synthetic granulate was used in the physical *** numerical computation domain was a reproduction of the physical model,including the grain sizes and the density of the particles,in order to ensure *** CFD code SSIIM,which solves the RANS-equations in three-dimensions,was used for the *** sediment transport in SSIIM is divided into suspended sediment transport,computed by solving the convection-diffusion equation,and bed-load transport,calculated by an empirical *** results of the numerical simulation correspond well to the results of the physical model *** simulated location and the pattern of the sediment deposition in the reservoir are an accurate representation of the observed distribution in the physical model.

关键词： Physical modeling Numerical modeling RANS-equations Reservoir management Sediment

The Psb32 Protein Aids in Repairing Photodamaged Photosystem II in the Cyanobacterium Synechocystis 6803

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Molecular Plant 2011年第6期4卷 1052-1061页

作者： Kimberly M. Wegener stefan bennewitz Ralf Oelmuller Himadri b. Pakrasi Department of biology Washington University St Louis MO 63130 USA Present address： Division of biological Sciences University of Missouri Columbia MO 65211 USA Institute of Plant Physiology Friedrich-Schiller-University Jena Dornburger Str. 159 D-07743 Jena Germany

Photosystem II （PSII）, a membrane protein complex, catalyzes the photochemical oxidation of water to molecular oxygen. This enzyme complex consists of approximately 20 stoichiometric protein components. However, due to the highly energetic reactions it catalyzes as part of its normal activity, PSII is continuously damaged and repaired. With advances in protein detection technologies, an increasing number of sub-stoichiometric PSII proteins have been identified, many of which aid in the biogenesis and assembly of this protein complex. Psb32 （SII1390） has previously been identified as a protein associated with highly active purified PSII preparations from the cyanobacterium Synechocystis sp. PCC 6803. To investigate its function, the subcellular localization of Psb32 and the impact of deletion of the psb32 gene on PSII were analyzed. Here, we show that Psb32 is an integral membrane protein, primarily located in the thylakoid membranes. Al- though not required for cell viability, Psb32 protects cells from oxidative stress and additionally confers a selective fitness advantage in mixed culture experiments. Specifically, Psb32 protects PSII from photodamage and accelerates its repair. Thus, the data suggest that Psb32 plays an important role in minimizing the effect of photoinhibition on PSII.

关键词： Photosynthesis reactive oxygen species photoinhibition photodamage.

Influence of sample preparation on nanoindentation results of twinninginduced plasticity steel

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International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 877-887页

作者： Jiali Zhang stefan Zaefferer Institute for Materials Applications in Mechanical Engineering RWTH Aachen UniversityAachen 52062Germany Max-Planck-Institut für Eisenforschung Düsseldorf 40237Germany

Nanoindentation is an attractive characterization technique,as it not only measures the local properties of a material but also facilitates understanding of deformation mechanisms at submicron ***,because of the complex stress-strain field and the small scale of the deformation under the nanoindenter,the results can be easily influenced by artifacts induced during sample *** this work,a systematic study was conducted to better understand the influence of sample preparation methods on the nanoindentation results of ductile *** experiments were conducted on a steel(Fe-22Mn-0.65C,wt%)with twinning-induced plasticity(TWIP),which was selected for its large grain size and sensitivity to different surface preparation *** grouping the results obtained from each nanoindent,chemical polishing was found to be the best sample preparation method with respect to the resulting mechanical properties of the *** contrast,the presence of a deformation layer left by mechanical polishing and surface damage induced by focused ion beam(FIb)scanning were confirmed by the dislocation-nucleation-induced pop-in events of nanoindentation.

关键词： TWIP steels nanoindentation mechanical polishing chemical polishing pop-in

Correlation between the results of three physical fitness tests(endurance,strength,speed) and the output measured during a bicycle ergometer test in a cohort of military servicemen

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Journal of Medical Colleges of PLA(China) 2016年第3期31卷 134-139页

作者： stefan Sammito Nils Gundlach Irina b?ckelmann bundeswehr Medical Service Headquarters Section Health PromotionSports and Nutrition Medicine Otto von Guericke University Magdeburg Medical FacultyDepartment of Occupational Medicine bundeswehr Medical Clinic Rotenburg

background: Physical fitness tests are widely used to assess endurance,sprint ability,coordination and/or *** objective of the present study was to analyze the degree to which the results of the bundeswehr basis Fitness Test(bFT)–a physical fitness test comprising a sprint test(11×10-m shuttle test),a flexed-arm hang test and a 1000-m run–are consistent with the output measured during a bicycle ergometer *** number of false-positive and falsenegative results with regard to the assessment of physical fitness were also ***: As part of a retrospective study,health assessments from 323 reenlistment examinations were evaluated regarding the output measured during a bicycle ergometer test and compared with the bFT results of the ***: Overall,a good correlation was shown between the bicycle ergometer test results and the results achieved in the bFT *** three disciplines of the bFT showed a highly significant correlation with the relative output achieved during the bicycle ergometer test(PbFT score was highly significantly correlated(PbFT results measured in the three physical fitness test items were highly correlated with the output measured during the bicycle ergometer *** rate of false-positive and false-negative results was *** test items thus represent an appropriate measurement instrument because the test items require few equipment and less ***,a large number of subjects can be *** suggest that it would be more useful to assess the physical fitness of this special group exclusively on the basis of the bFT instead of using the bicycle ergometer test.

关键词： Physical fitness Military Ergometer test bicycle Treadmill