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Effect of ZrSiO_4 on the Friction Performance of Automotive Brake Friction Materials

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journal of Materials Science & Technology 2007年第6期23卷 843-850页

作者： Mustafa BOZ Adem kurt Metallurgy Department Z.K.U.Karabük Technical Education Faculty78200 KarabükTurkey Metallurgy Department Gazi UniversityTechnical Education Faculty06500 AnkaraTurkey

Friction-wear properties of the ZrSiO4 reinforced samples were measured and compared with those of plain bronze based ones. For this purpose, density, hardness, friction coefficient wear behaviour of the samples were tested. Microstructures of samples before and after sintering and worn surfaces were also investigated by scanning electron microscopy （SEM）, and the wear types were determined. The optimum friction-wear behaviour was obtained in the sample compacted at 500 MPa and sintered at 820℃. Density of the final samples decreased with increasing the amount of reinforcing elements （ZrSiO4） before pre-sintering. However after sintering, there is no change in density of the samples including reinforcing elements （ZrSiO4）. With increasing friction surface temperature, a reduction in the friction coefficient of the samples was observed. However, the highest reductions in the friction coefficients were observed in the as-received samples containing 0. 5% reinforced ZrSiO4. The SEM images of the sample indicated that while bronze-based break lining material without ZrSiO4 showed abrasive wear behaviour, increasing the amount of ZrSiO4 resulted a change in abrasive to adhesive wear mechanism. All samples exhibited friction-wear values, which were within the values shown in SAE-j661 standard. With increasing the amount of reinforcing ZrSiO4, wear resistance of the samples was increased. However samples reinforced with 5% and 6% ZrSiO4 showed the best results.

关键词： Friction materials ZrSiO4 Wear Friction Brake lining

A regularization scheme for explicit level-set XFEM topology optimization

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Frontiers of Mechanical Engineering 2019年第2期14卷 153-170页

作者： Markus j.GEISS jorge L.BARRERA Narasimha BODDETI kurt MAUTE Ann and H.j.Smead Department of Aerospace Engineering Sciences University of Colorado at BoulderBoulderCO 80309-0429USA Singapore University of Technology and Design SUTD Digital Manufacturing and Design CentreSingapore 487372Singapore

Regularization of the level-set(LS)field is a critical part of LS-based topology optimization(TO)*** this is achieved by advancing the LS field through the solution of a Hamilton-jacobi equation combined with a reinitialization *** approach,however,may limit the maximum step size and introduces discontinuities in the design ***,energy functionals and intermediate LS value penalizations have been *** paper introduces a novel LS regularization approach based on a signed distance field(SDF)which is applicable to explicit LSbased *** SDF is obtained using the heat method(HM)and is reconstructed for every design in the optimization *** governing equations of the HM,as well as the ones describing the physical response of the system of interest,are discretized by the extended finite element method(XFEM).Numerical examples for pro?blems modeled by linear elasticity,nonlinear hyperelasticity and the incompressible Navier-Stokes equations in two and three dimensions are presented to show the applicability of the proposed scheme to a broad range of design optimization problems.

关键词： level-set regularization explicit level-sets XFEM CutFEM topology optimization heat method signed distance field nonlinear structural mechanics fluid mechanics

Cotton stomatal closure under varying temperature and vapor pressure deficit,correlation with the hydraulic conductance trait

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journal of Cotton Research 2022年第3期5卷 217-227页

作者： WEDEGAERTNER kurt SHEKOOFA Avat PURDOM Sam WALTERS Kellie DUNCAN Lori RAPER Tyson B Department of Plant Sciences University of Tennessee2505 E.J.Chapman Dr.KnoxvilleTN 37996USA Department of Biosystems Engineering and Soil Science University of Tennessee2506 EJ Chapman DriveKnoxvilleTN 37996USA.

Background:Cotton(Gossypium hirsutum L.)is often grown in locations characterized by high atmospheric evaporative *** has been hypothesized that plants which resist hydraulic flow under this condition will limit water use and conserve soil ***,in a series of controlled environment experiments ten cotton cultivars were exposed to two different temperature and vapor pressure deficit(VPD)conditions(i.e.,38℃,>3 kPa and 32℃,1∼1.5 kPa)as well as a progressive soil ***,individual differences in shoot hydraulic conductance(K_(shoot))was measured using a hydraulic conductance flow meter(HCFM).Physiological parameters were reported included leaf area,dry leaf weight,stomatal conductance(g_(s)),and water use efficiency coefficient(WUE_(k)).Results:Differences were observed in K_(shoot) among cultivars under the 38℃,>3 kPa but not the 32℃,1∼1.5 kPa *** the 38℃,>3 kPa environment,correlations were found between K_(shoot),stomatal conductance(gs),VPD breakpoint,WUEk,total leaf area,dry leaf weight,fraction transpirable soil water(FTSW)threshold,and slope of TR decline after FTSW ***:Results show that the ability of some cotton cultivars to restrict water loss under high evaporative demand through early stomatal closure is associated with the cultivars’K_(shoot).The K_(shoot) is influential in the limitation of TR trait under high temperature and VPD.

关键词： Cotton FTSW threshold Shoot hydraulic conductance Temperature Transpiration rate VPD

Multiphoton synthetic lattices in multiport waveguide arrays: synthetic atoms and Fock graphs

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Photonics Research 2020年第7期8卷 1161-1170页

作者： Konrad Tschernig Roberto de j.León-Montiel Armando Pérez-Leija kurt Busch Max-Born-Institut 12489 BerlinGermany Instituto de Ciencias Nucleares Universidad Nacional Autónoma de MéxicoApartado Postal 70-54304510 Cd.Mexico CityMexico Humboldt-Universität zu Berlin Institut für PhysikAG Theoretische Optik&Photonik12489 BerlinGermany

Activating transitions between internal states of physical systems has emerged as an appealing approach to create lattices and complex *** such a scheme,the internal states or modes of a physical system are regarded as lattice sites or network nodes in an abstract space whose dimensionality may exceed the systems’apparent(geometric)*** introduces the notion of synthetic dimensions,thus providing entirely novel pathways for fundamental research and ***,we analytically show that the propagation of multiphoton states through multiport waveguide arrays gives rise to synthetic dimensions where a single waveguide system generates a multitude of synthetic *** these synthetic lattices exist in photon-number space,we introduce the concept of pseudo-energy and demonstrate its utility for studying multiphoton interference ***,the spectrum of the associated pseudo-energy operator generates a unique ordering of the relevant *** with generalized pseudo-energy ladder operators,this allows for representing the dynamics of multiphoton states by way of pseudo-energy term diagrams that are associated with a synthetic *** a result,the pseudo-energy representation leads to concise analytical expressions for the eigensystem of N photons propagating through M nearest-neighbor coupled *** the regime where N≥2 and M≥3,nonlocal coupling in Fock space gives rise to hitherto unknown all-optical dark states that display intriguing nontrivial dynamics.

关键词： synthetic dimensions system

Constructing Statistical Intervals for Small Area Estimates Based on Generalized Linear Mixed Model in Health Surveys

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Open journal of Statistics 2022年第1期12卷 70-81页

作者： Yan Wang Xingyou Zhang Hua Lu janet B. Croft kurt j. Greenlund Division of Population Health National Center for Chronic Disease Prevention and Health Promotion Centers for Disease Control and Prevention Atlanta GA USA Office of Compensation and Working Conditions U.S. Bureau of Labor Statistics Washington DC USA

Generalized Linear Mixed Model (GLMM) has been widely used in small area estimation for health indicators. Bayesian estimation is usually used to construct statistical intervals, however, its computational intensity is a big challenge for large complex surveys. Frequentist approaches, such as bootstrapping, and Monte Carlo (MC) simulation, are also applied but not evaluated in terms of the interval magnitude, width, and the computational time consumed. The 2013 Florida Behavioral Risk Factor Surveillance System data was used as a case study. County-level estimated prevalence of three health-related outcomes was obtained through a GLMM;and their 95% confidence intervals (CIs) were generated from bootstrapping and MC simulation. The intervals were compared to 95% credential intervals through a hierarchial Bayesian model. The results showed that 95% CIs for county-level estimates of each outcome by using MC simulation were similar to the 95% credible intervals generated by Bayesian estimation and were the most computationally efficient. It could be a viable option for constructing statistical intervals for small area estimation in public health practice.

关键词： Bayesian Estimation Behavioral Risk Factor Surveillance System Bootstrapping Monte Carlo Simulation Small Area Estimation

Positioning of old and new biologicals and small molecules in the treatment of inflammatory bowel diseases

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World journal of Gastroenterology 2018年第32期24卷 3567-3582页

作者： jason Reinglas Lorant Gonczi Zsuzsanna kurt Talat Bessissow Peter L Lakatos Department of Gastroenterology McGill University Health CenterMontrealQuébec H4A 3J1Canada First Department of Medicine Semmelweis UniversityH-1083BudapestKoranyi S.2AHungary

The past decade has brought substantial advances in the management of inflammatory bowel diseases(IBD). The introduction of tumor necrosis factor(TNF) antagonists, evidence for the value of combination therapy, the recog-nition of targeting lymphocyte trafficking and activation as a viable treatment, and the need for early treatment of high-risk patients are all fundamental concepts for current modern IBD treatment algorithms. In this article, authors review the existing data on approved biologicals and small molecules as well as provide insight on the current positioning of approved therapies. Patient stratification for the selection of specific therapies, therapeutic targets and patient monitoring will be discussed as well. The thera-peutic armamentarium for IBD is expanding as novel and more targeted therapies become available. In the absence of comparative trials, positioning these agents is becoming difficult. Emerging concepts for the future will include an emphasis on the development of algorithms which will facilitate a greater understanding of the positioning of novel biological drugs and small molecules in order to best tailor therapy to the patient. In the interim, anti-TNF therapy remains an important component of IBD therapy with the most real-life evidence and should be considered as first-line therapy in patients with complicated Crohn's disease and in acute-severe ulcerative colitis. The safety and efficacy of these ‘older' anti-TNF therapies can be optimized by adhering to therapeutic algorithms which combine clinical and objective markers of disease severityand response to therapy.

关键词： Inflammatory bowel disease Small molecule Positioning Biologic Therapeutic

Controversies in the treatment of gastroesophageal reflux and achalasia

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World journal of Gastroenterology 2006年第20期12卷 3155-3161页

作者： kurt E Roberts Andrew j Duffy Robert L Bell Department of Surgery Yale University School of Medicine 40 Temple St. Suite 3 ANew HavenCT 06510United States

胃的食道的倒流疾病(GERD ) 和弛缓不能的有效治疗为这二作为标准答案建立了最小的侵略外科的 laparoscopic 外科的巨大的成功与更低的病态和死亡调节，更短的医院停留，更快的康复，和不太手术后的疼痛。在 GERD 的处理的一争吵作为比... 详细信息

胃的食道的倒流疾病(GERD ) 和弛缓不能的有效治疗为这二作为标准答案建立了最小的侵略外科的 laparoscopic 外科的巨大的成功与更低的病态和死亡调节，更短的医院停留，更快的康复，和不太手术后的疼痛。在 GERD 的处理的一争吵作为比较喜欢的处理在 laparoscopic 反倒流外科(LARS ) 附近演变让 Barrett 的食管和过程的潜力减少食管的腺癌的风险。GERD 也与呼吸症状，气喘和喉的损害被联系了，并且第二争吵推动全部或部分的 fundoplication 是否是为 GERD 的更适当的处理的讨论。在 GERD 的处理的一种新、有希望的选择是 endoluminal 治疗。这种新处理选择的三种类型将被讨论：送到更低的食道的括约肌的射频精力，在胃的食道的连接的一个机械障碍的创造，并且更低的食道的括约肌的直接内视镜的紧缩。Laparoscopic 外科为弛缓不能为 GERD 而且同样永久的痊愈作为很有效的治疗被讨论不仅。这评论为弛缓不能分析三种很重要的处理选择：药，灵魂膨胀，和外科的治疗。因为他们的短半衰期和可变吸收，在弛缓不能的处理的药同样唯一的真非侵略的选择由于穷人不象 LARS 一样有效食道的倒空。第二种处理选择，灵魂膨胀，包含拉长更低的食管并且是仍然为弛缓不能考虑了最有效的非外科的处理。最后，为弛缓不能的外科的治疗和有关这个 laparoscopic 处理的二主要争吵被讨论。第一包含肌切开术被扩大到到胃上的程度，并且第二使反倒流过程的必要性和类型担心在肌切开术以后阻止 GERD。LARS 和 laparoscopic Heller 肌切开术是同意了在之上作为为 GERD 和弛缓不能的外科疗法的标准答案分别地。在一位富有经验的 laparoscopic 外科医生的手里，两个是为有有至少 90% 耐心的满足的优秀主观、客观的长期的结果的病人的安全、有效的治疗。

关键词：胃食管反流疾病弛缓不能治疗方法胃底折叠术

Evolution of surgical skills training

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World journal of Gastroenterology 2006年第20期12卷 3219-3224页

作者： kurt E Roberts Robert L Bell Andrew j Duffy Department of Surgery Yale University School of Medicine 40 Temple StreetSuite 3ANew HavenCT 06510United Staets

外科的训练正在变化：100 年传统被法律、道德的担心为耐心的安全，工作小时限制，手术室时间的费用，和复杂并发症正在质问。训练的外科的模拟和技巧提供一个机会在在生活病人上尝试他们前在手术室环境外面教并且练习先进技巧。当使用... 详细信息

外科的训练正在变化：100 年传统被法律、道德的担心为耐心的安全，工作小时限制，手术室时间的费用，和复杂并发症正在质问。训练的外科的模拟和技巧提供一个机会在在生活病人上尝试他们前在手术室环境外面教并且练习先进技巧。当使用真实仪器和录像设备操作在一个盒子训练员模仿了“织物”，模拟训练能向前是同样直的。更先进的、虚拟现实模拟器现在为普遍使用可得到、准备好了。早系统表明了他们的有效性和歧视的能力。更新的系统启用全面课程和完整的程序的模拟的开发。医药教育是的毕业生的认证委员会(ACGME ) 要求了训练和评估的新奇方法的发展。外科的组织正在打电话让方法保证技巧的维护，并且，进展 surgical 训练信任外科医生作为技术上能干。在他们的当前的形式的模拟器被表明了改进外科的居民的手术室表演。训练课程标准化的开发仍然是一个迫切、重要的议程，特别地为最小的侵略外科。一条创新、进步的途径，从航空的域借经验，能为外科的训练的下一个世纪提供基础，保证产品的质量。当技术发展，我们练习的方法将继续演变，到医生和病人的利益。

关键词：手术治疗技术培训模拟技术课程设置

Testicular expression of survivin and human telomerase reverse transcriptase(hTERT)associated with spermatogenic function in infertile patients

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Asian journal of Andrology 2006年第1期8卷 95-100页

作者： Steffen Weikert Frank Christoph Wolfgang Schulze Hans Krause Carsten Kempkensteffen Martin Schostak kurt Miller Mark Schrader Department of Urology Charité-Universittsmedizin BerlinCampus B.FranklinD-12200 BerlinGermany Department of Andrology University of HamburgD-20246 HamburgGermany

Aim： To characterize the coexpression of survivin, an inhibitor of apoptosis （IAF）, and human telomerase reverse transcriptase （hTERT） in human testes with varying spermatogenic function. Methods： Transcript levels of survivin mRNA and hTERT mRNA were determined in normal testes （n = 11） and testes with defective spermatogenesis （n = 28） using real-time reverse-transcription polymerase chain reaction （RT-PCR）. The histological work-up was performed according to a modified johnsen score. Results： Expressions of both survivin and hTERT were highest at median levels of 96.8 and 709 in normal spermatogenesis and dropped to 53.3 and 534 in testes with postmeiotic spermatogenic arrest （n = 10）. In severe spermatogenic failure （n = 18）, survivin expression was lacking in most specimens （n = 16）, whereas at least low levels of testicular hTERT expression were largely detectable with a normalized expression of 73 in premeiotic spermatogenic arrest （n = 7） and 45 in patients with Sertoli cell-only syndrome （SCOS）（n = 3）. Both survivin and hTERT expressions increased with a progressing johnsen score （P for trend = 0.001）. Conclusion： Although both survivin and hTERT are correlated with spermatogenic function, they show different expression patterns in testes of infertile patients. These findings substantiate results from studies in the rodent testis suggesting a predominant expression of survivin in meiotically dividing germ cells. （Asian j Andro12006 jan; 8： 95-100）

关键词： survivin human telomerase reverse transcriptase apoptosis azoospermia male infertility spermatogenesis