检索结果-南通市图书馆

Optimization of Extrusion Process Parameters of Recycled High-Density Polyethylene-Thermoplastic Starch Composite for Fused Filament Fabrication

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Open journal of Composite Materials 2023年第4期13卷 69-86页

作者： Grace Njeri Wamuti james Wamai Mwangi Samuel Kabini Karanja Leif Micke henning Zeidler Pan African University Institute of Basic Sciences Technology and Innovation Nairobi Republic of Kenya Department of Mechatronic Engineering Jomo Kenyatta University of Agriculture and Technology Nairobi Republic of Kenya Chair of Additive Manufacturing Technische Universit&aumlt Bergakademie Freiberg Freiberg Germany

High-density poly-ethylene (HDPE) is a nonbiodegradable recyclable plastic which is widely utilized in single use packaging applications. Consequently, it constitutes a significant amount of plastic waste found in landfills. From literature, it has been shown that parts produced using composites of HDPE with carbohydrate-based polymers, such as thermoplastic starch (TPS), experience mechanical degradation through hydrolytic degradation process. The possible utilization of recycled-HDPE (rHDPE) and TPS composite in nonconventional manufacturing processes such as Fused filament fabrication (FFF) has however not been explored. This study explores the potential application of rHDPE and TPS composites in FFF and optimizes the extrusion process parameters used in rHDPE-TPS filament production process. Taguchi method was utilized to analyze the extrusion process. The extrusion process parameters studied were the spooling speed, extrusion speed and the extrusion temperatures. The response variable studied was the filament diameter. In this research, the maximum TPS content achieved during filament production was 40 wt%. This filament was however challenging to use in FFF printers due to frequent nozzle clogging. Printing was therefore done with filaments that contained 0 - 30 wt% TPS. The experimental results showed that the most significant parameter in extrusion process was the spooling speed, followed by extrusion speed. Extrusion temperature had the least significant influence on the filament diameter. It was observed that increase in TPS content resulted in reduced warping and increased rate of hydrolytic degradation. Mechanical properties of printed parts were investigated and the results showed that increasing TPS content resulted in reduction in tensile strength, reduction in compression strength and increase in stiffness. The findings of this research provide valuable insights to plastic recycling industries and researchers regarding the utilization of recycled HDP

关键词： Additive Manufacturing (AM) Fused Filament Fabrication (FFF) High Density Polyethylene (HDPE) Thermoplastic Starch (TPS) Bio-Composite

Chemically Induced and Light-Independent Cryptochrome Photoreceptor Activation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2008年第1期1卷 4-14页

作者： Gesa Rosenfeldt Rafael Munoz Viana henning D. Mootz Albrecht G. von Arnim Alfred Batschauera FB Biologie-pflanzenphysiologie Philipps-Universitat Karl-von-Frisch-Str. 8 35032 Marburg Germany Universitat Dortmund FB Chemie-Chemische Biologie Otto-Hahn-Str. 6 44227 Dortmund Germany University of Tennessee Department of Biochemistry Cellular and Molecular Biology Waiters Life Sciences M407 Knoxville TN 37996-0840 USA

The cryptochrome photoreceptors of higher plants are dimeric proteins. Their N-terminal photosensory domain mediates dimerization, and the unique C-terminal extension （CCT） mediates signaling. We made use of the human FK506binding protein （FKBP） that binds with high affinity to rapamycin or rapamycin analogs （rapalogs）. The FKBP-rapamycin complex is recognized by another protein, FRB, thus allowing rapamycin-induced dimerization of two target proteins. Here we demonstrate by bioluminescence resonance energy transfer （BRET） assays the applicability of this regulated dimer- ization system to plants. Furthermore, we show that fusion proteins consisting of the C-terminal domain of Arabidopsis cryptochrome 2 fused to FKBP and FRB and coexpressed in Arabidopsis cells specifically induce the expression of cryptochrome-controlled reporter and endogenous genes in darkness upon incubation with the rapalog. These results demonstrate that the activation of cryptochrome signal transduction can be chemically induced in a dose-dependent fashion and uncoupled from the light signal, and provide the groundwork for gain-of-function experiments to study specifically the role of photoreceptors in darkness or in signaling cross-talk even under light conditions that activate members of all photoreceptor families.

关键词： C-terminal extension (CCT) FK506-binding protein (FKBP) bioluminescence resonance energy transfer (BRET)

固态锂金属电池中不均匀离子通量介导的正负极耦合失效机制

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2023年第8期68卷 813-825,M0004页

作者：郑越张舒马君孙富 Markus Osenberg AndréHilger henning Markötter Fabian Wilde Ingo Manke 胡中波崔光磊 Qingdao Industrial Energy Storage Research Institute Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijing 100049China Shandong Energy Institute Qingdao 266101China Institute of Applied Materials Helmholtz-Zentrum Berlin für Materialien und EnergieBerlin 14109Germany Department of Non-Destructive Testing Bundesanstalt für Materialforschung und-PrüfungBerlin 12205Germany Institute of Materials Physics Helmholtz-Zentrum HereonGeesthacht 21502Germany

本文通过联用无损三维同步辐射X射线断层扫描成像技术(SXCT)和其他非原位测试技术及有限元模拟,深入研究了LiNi0.8Co0.1Mn0.1O2|Li6PS5Cl|Li全固态电池的衰退机制.研究发现正极电化学-机械力学耦合失效诱导的反应异质性产生不均匀的锂... 详细信息

本文通过联用无损三维同步辐射X射线断层扫描成像技术(SXCT)和其他非原位测试技术及有限元模拟,深入研究了LiNi0.8Co0.1Mn0.1O2|Li6PS5Cl|Li全固态电池的衰退机制.研究发现正极电化学-机械力学耦合失效诱导的反应异质性产生不均匀的锂离子通量并传输到负极,进而导致不均匀的锂沉积、溶解行为及死锂的产生等.锂负极不均匀的电化学反应行为又反作用于正极并强化其反应异质性,形成一种正负极衰退互相促进的正强化机制.随着电池继续循环,正负极的不均匀反应加剧造成其结构破坏,同时正负极体积缩胀引起电解质巨大塑性变形,最终致使电池失效.对比实验表明采用LiZr_(2)(PO_(4))_(3)(LZP)对正极进行改性,不仅有效抑制了正极的电化学-机械力学耦合失效,而且显著提高了负极锂沉积-溶解均匀性和电解质的结构完整性.该研究首次提出了全固态金属锂电池正负极相互依赖、相互关联的失效机制,为提升全固态金属锂电池性能提供了新思路.

关键词： Current density distribution Lithium ion flux Solid-state lithium metal batteries Codependent failure mechanism Cathode deactivation

Evaluation of growth and reproduction as indicators of soil metal toxicity to the Collembolan, Sinella curviseta

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2009年第1期16卷 57-63页

作者： jie Xu Xin Ke Paul henning Krogh Yin Wang Yong-Ming Luo jing Song Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China Department of Terrestrial Ecology National Environmental Research Institute University of Aarhus Vejlsevej 25 DK-8600 Silkeborg Denmark Soil and Environment Bioremediation Research Centre Institute of Soil Sciences Chinese Academy of Sciences Nanjing China

Laboratory studies evaluated the sensitivity of Sinella curviseta Brook （Collembola： Entomobryidae） to selected heavy metals （Cu, Pb and Zn）. Survival, reproduction and growth of S. curviseta were determined in a 4-week exposure test in an agricultural soil amended with metals to concentrations of 100, 200, 400, 800, 1 600 and 3 200 mg/kg. Results showed reduction in adult survival and reproductive failure at the highest concentrations （3 200 mg/kg） of Cu and Zn. EC50reproduction values for Cu and Zn were approximately 442 and 2 760 mg/kg, respectively. Application of Pb at all levels resulted in large numbers of progeny and no significant mortality compared to controls. Adult growth rate decreased for all metal treatments compared to the controls, suggesting that metals affect S. curviseta metabolism and result in slower growth. We showed that reproduction is a slightly more sensitive parameter than growth. Since a growth test needs fewer juveniles and takes less time than a reproduction test, we conclude that the two parameters are complementary and could be used for a better ecotoxicological evaluation of contaminant levels. However, relative growth and reproduction sensitivities should be tested with more chemicals before a growth test is accepted as a faster sublethal test than a reproduction test.

关键词： Collembolan copper growth lead reproduction Sinella curviseta soil pollution toxicity testing zinc

Social Choice Meets Graph Drawing: How to Get Subexponential Time Algorithms for Ranking and Drawing Problems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2014年第4期19卷 374-386页

作者： henning Fernau Fedor V.Fomin Daniel Lokshtanov Matthias Mnich Geevarghese Philip Saket Saurabh FB 4-Abteilung Informatikwissenschaften Universitt Trier D-54286 TrierGermany the Department of Informatics University of Bergen N-5020 Bergen Norway Max-Planck-Institut fr Informatik D-66123 Saarbrcken Germany the Institute of Mathematical Sciences Chennai - 600113 India

We analyze a common feature of p-Kemeny AGGregation（p-KAGG） and p-One-Sided Crossing Minimization（p-OSCM） to provide new insights and findings of interest to both the graph drawing community and the social choice community. We obtain parameterized subexponential-time algorithms for p-KAGG—a problem in social choice theory—and for p-OSCM—a problem in graph drawing. These algorithms run in time O＊（2O（√k log k））,where k is the parameter, and significantly improve the previous best algorithms with running times O.1.403k/and O.1.4656k/, respectively. We also study natural ＂above-guarantee＂ versions of these problems and show them to be fixed parameter tractable. In fact, we show that the above-guarantee versions of these problems are equivalent to a weighted variant of p-directed feedback arc set. Our results for the above-guarantee version of p-KAGG reveal an interesting contrast. We show that when the number of ＂votes＂ in the input to p-KAGG is odd the above guarantee version can still be solved in time O＊（2O（√k log k））, while if it is even then the problem cannot have a subexponential time algorithm unless the exponential time hypothesis fails（equivalently, unless FPT D M[1]）.

关键词： Kemeny aggregation one-sided crossing minimization parameterized complexity subexponential-time algorithms social choice theory graph drawing directed feedback arc set

Simplified modeling of electromagnets for dynamic simulation of transient effects for a synchronous electric motor

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International journal of Mechanical System Dynamics 2021年第1期1卷 89-95页

作者： Florian Bechler julius Kesten Florian Wittemann Frank henning Martin Doppelbauer Peter Eberhard Institute of Engineering and Computational Mechanics University of StuttgartStuttgartGermany Institute of Electrical Engineering Karlsruhe Institute of Technology(KIT)KarlsruheGermany Institute of Vehicle System Technology Karlsruhe Institute of Technology(KIT)KarlsruheGermany

This study aims to show an approach for the dynamic simulation of a synchro-nous *** magnetic forces in the air gap are calculated efficiently using simplified approaches without neglecting important *** the modeling of the magnetic forces,an equivalent magnetic circuit is constructed in which the magnetic saturation and the leakage flux are taken into account and coupled with the electrical circuit at the *** calculated magnetic forces are then passed to a mechanical model of the *** with a predefinable load torque,the resulting motor rotation and the forces in the bearings are *** presented model is then investigated in a small *** novel ap-proach is intended to provide a method of calculating dynamically the forces transmitted from the shaft to the motor housing and to create the basis for evaluating electric motors for vibrations,noise,and harshness under varying loads and input voltages.

关键词： dynamic simulation electromagnet electromagnet modeling magnetomotive forces

Abdominal cocoon in children: A case report and review of literature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2021年第37期27卷 6332-6344页

作者： Daniel Keese Andrea Schmedding Kerstin Saalabian Georgy Lakshin henning Fiegel Udo Rolle Goethe-University Frankfurt Department of Paediatric Surgery and Paediatric UrologyUniversity HospitalFrankfurt 60590Germany

BACKGROUND Abdominal cocoon or“encapsulating peritoneal sclerosis”(EPS)is an uncommon and rare cause of intestinal *** a few cases have been reported in paediatric ***,EPS is described as the primary form in young adolescent girls from tropical and subtropical countries because of viral peritonitis due to retrograde menstruation or a history of peritoneal *** patients are asymptomatic or present with abdominal pain,which is likely to occur secondary to subacute bowel *** at imaging,such as ultrasound,computed tomography,and magnetic resonance imaging,are often *** diagnosed,EPS is characterized by total or partial encasement of the bowel within a thick fibrocollagenous membrane that envelopes the small intestine in the form of a cocoon because of chronic intraabdominal fibroinflammatory *** membrane forms a fibrous tissue sheet that covers,fixes,and finely constricts the gut,compromising its *** SUMMARY We present a case of EPS in a 12-year-old boy 8 wk after primary surgery for resection of symptomatic jejunal *** was no history of peritoneal dialysis or drug *** In this report,we sought to highlight the diagnostic,surgical,and histopathological characteristics and review the current literature on EPS in paediatric patients.

关键词： Abdominal cocoon Peritoneal encapsulation Encapsulating peritoneal sclerosis Intestinal obstruction Children Case report

Comparison of outcomes between complete and incomplete congenital duodenal obstruction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2019年第28期25卷 3787-3797页

作者： Stefan Gfroerer Till-Martin Theilen henning C Fiegel Anoosh Esmaeili Udo Rolle Department of Pediatric Surgery and Pediatric Urology University Hospital Frankfurt Frankfurt 60590 Germany Department of Pediatric Cardiology University Hospital Frankfurt Frankfurt 60590 Germany

BACKGROUND Congenital duodenal obstruction (CDO) can be complete (CCDO) or incomplete (ICDO). To date there is no outcome analysis available that compares both subtypes. AIM To quantify and compare the association between CCDO and ICDO with outcome parameters. METHODS We retrospectively reviewed all patients who underwent operative repair of CCDO or ICDO in our tertiary care institution between january 2004 and january 2017. The demographics, clinical presentation, preoperative diagnostics and postoperative outcomes of 50 patients were compared between CCDO (n = 27;atresia type 1-3, annular pancreas) and ICDO (n=23;annular pancreas, web, Ladd′s bands). RESULTS In total, 50 patients who underwent CDO repair were enrolled and followed for a median of 5.2 and 3.9 years (CCDO and ICDO, resp.). CCDO was associated with a significantly higher prenatal ultrasonographic detection rate (88% versus 4%;CCDO vs ICDO, P<0.01), lower gestational age at birth, lower age and weight at operation, higher rate of associated congenital heart disease (CHD), more extensive preoperative radiologic diagnostics, higher morbidity according to Clavien-Dindo classification and comprehensive complication index (all P≤0.01). The subgroup analysis of patients without CHD and prematurity showed a longer time from operation to the initiation of enteral feeds in the CCDO group (P<0.01). CONCLUSION CCDO and ICDO differ with regard to prenatal detection rate, gestational age, age and weight at operation, rate of associated CHD, preoperative diagnostics and morbidity. The degree of CDO in mature patients without CHD influences the postoperative initiation of enteral feeding.

关键词： Congenital duodenal obstruction Duodenal atresia Duodenal stenosis Prenatal ultrasonographic detection rate Clinical presentation Preoperative diagnostics Adverse events Outcome

The ethics of creativity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The ethics of creativity