检索结果-南通市图书馆

Compliant Mechanism Synthesis by Using Elastic Similitude

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2015年第4期28卷 769-775页

作者： HANKE Uwe HAMPEL Peter COMSA andrei MODLER Niels MODLER Karl-Heinz Institute of Solid Mechanics TU Dresden 01069 Dresden Germany Institute of Lightweight Engineering and Polymer Technology TU Dresden 01307 Dresden Germany

Compliant mechanisms have several advantages, especially smaller number of elements and therefore less movable joints. The flexural members furthermore allow an integration of special functions like balancing or locking. Especially fiber reinforced materials exhibit a wide range of function integration considering their compliance in passive as well active applications. To take advantage of compliant elements in applications a robust synthesis tool is needed. The synthesis based on topology optimization method or the pseudo rigid body approach leads to complex structures. Considering the use of fiber reinforced material a synthesis approach which leads to less complex structures is more suitable. For building up simple structures, with only one cantilever beam as compliant element（B） a graphical approach using the elastic similitude is the most efficient method. A step-by-step synthesis procedure is presented to synthesize compliant mechanisms with rotatory joints（R） and prismatic joints（P） to develop RRB/PRB- and RPB-linkages. Using the elastic similitude to implement these results into a graphical synthesis algorithm is the innovation part of this paper. It can be shown that this approach leads to a comfortable handling of beam elements during the synthesis, where the two free parameters can be directly coupled to scale and fix the orientation of the beam element. This advantage inherently shortens the development process. In giving an example the focus lies of the experimental approach, which also shows that the simple BERNOULLI beam model is valid and so the synthesis by using the elastic similitude. The method is presented and discussed by using an application for a cup holder mechanism made of fiber reinforced material.

关键词： Compliant mechanism synthesis elastic similitude

Stress states of thawed soil subgrade

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2015年第4期7卷 348-353页

作者： andrei Petriaev Construction of Roads Transport Complex Department St.Petersburg State Transport University

The article presents the field measurement results of the stress states of roadbed thawed soil subgrade during the passage of trains. The dependences of the vertical and horizontal stresses on the velocity of the roll... 详细信息

关键词： dynamic vibration impact vertical and horizontal stresses thawing subgrade stress rise rate

Modeling and cyclic behavior of segmental bridge column connected with shape memory alloy bars

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2012年第3期11卷 375-389页

作者： Hwasung Roh andrei M.Reinhorn Jong Seh Lee Dept.of Civil and Environmental Engineering Hanyang University Dept.of Civil Structural and Environmental EngineeringUniversity at Buffalo The State University of New York

This paper examines the quasi-static cyclic behavior, lateral strength and equivalent damping capacities of a system of post-tensioned segmental bridge columns tied with large diameter martensitic Shape Memory Alloy （SMA） link-bars. Moment-curvature constitutive relationships are formulated and analysis tools are developed for the PT column, including a modified four-spring model prepared for the SMA bars. The suggested system is exemplified using a column with an aspect ratio of 7.5 and twelve 36.5 mm diameter NiTi martensitic SMA bars. A post-tensioning force of 40% to 60% of the tendon yield strength is applied in order to obtain a self re-centering system, considering the residual stress of the martensitie SMA bars. The cyclic response results show that the lateral strength remains consistently around 10% of the total vertical load and the equivalent viscous damping ratios reach 10%-12% of critical. When large diameter NiTi superelastic SMA bars are incorporated into the column system, the cyclic response varies substantially. The creep behavior of the superelastic SMA bar is accounted for since it affects the re-centering capability of the column. Two examples are presented to emphasize the modeling sensitivities for these special bars and quantify their cyclic behavior effects within the column assembly.

关键词： segmental rocking columns shape memory alloy bars cyclic response energy dissipation damping recentering

Seminal biomarkers for the evaluation of male infertility

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2016年第3期18卷 426-433,I0009页

作者： Jared M Bieniek andrei P Drabovich Kirk C Lo Department of Urology Hartford Hospital Hartford CT USA Department of Clinical Biochemistry University Health Network Toronto ON Canada Department ofLaboratory Medicine and Pathobiology University of Toronto Toronto ON Canada Department of Surgery Division of Urology Mount Sinai Hospital Toronto ONCanada.

For men struggling to conceive with their partners, diagnostic tools are limited and often consist of only a standard semen analysis. This baseline test serves as a crude estimation of male fertility, leaving patients and clinicians in need of additional diagnostic biomarkers. Seminal fluid contains the highest concentration of molecules from the male reproductive glands, therefore, this review focuses on current and novel seminal biomarkers in certain male infertility scenarios, including natural fertility, differentiating azoospermia etiologies, and predicting assisted reproductive technique success. Currently available tests include antisperm antibody assays, DNA fragmentation index, sperm fluorescence in situ hybridization, and other historical sperm functional tests. The poor diagnostic ability of current assays has led to continued efforts to find more predictive biomarkers. Emerging research in the fields of genomics, epigenetics, proteomics, transcriptomics, and metabolomics holds promise for the development of novel male infertility biomarkers. Seminal protein-based assays of TEXI01, ECM 1, and ACRV1 are already available or under final development for clinical use. Additional panels of DNA, RNA, proteins, or metabolites are being explored as we attempt to understand the pathophysiologic processes of male infertility. Future ventures will need to continue data integration and validation for the development of clinically useful infertility biomarkers to aid in male infertility diagnosis, treatment, and counseling.

关键词： assisted reproductive techniques diagnosis male infertility, semen

It is Time for a Change： oPetri Dishes Weaken Cells

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2012年第3期9卷 353-357页

作者： andrei P. Sommer Mike Kh. Haddad Hans-Joerg Fecht Institute of Micro and Nanomaterials University of Ulm 89081 Ulm Germany Institute for Nanotechnology Karlsruhe Institute for Technology 76344 Eggenstein-Leopoldshafen Germany

We wish to draw the attention to a potential deficiency in the biocompatibility of polystyrene cell culture dishes which is caused by a softening of the material under relevant culture conditions. The finding confirms the central hypothesis of our previous model study. In it we assumed a local increase in pH at the interface between the hydrophilic polymer and liquid. The finding is of considerable biological interest. Polystyrene tissue culture dishes are now in use for 50 years. To the best of our knowledge their biocompatibility has never been challenged. Here we report the first experimental proof that exposure to water softens the surface of polystyrene Petri dishes. We expect that our results will stimulate the development of a new generation of cell culture devices, including Petri dishes and culture flasks, and the establishment of improved biomimetic settings for tissue engineering and stem cell research. New non-swelling biomaterials or nanocoatings designed to reduce the swelling of polymer ct, lture dishes could improve cell performance. The need for further study is clear.

关键词： Petri dish polystyrene biomimetic triangle nanoindentation stem cells diamond

Reply to "Discussion 1 on 'Introspection on improper seismic retrofit of Basilica Santa Maria di Collemaggio after 2009 Italian earthquake' by ***,*** and *** Stefano" by Vincenzo Ciampi

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2012年第2期11卷 283-288页

作者： Gian Paolo Cimellaro andrei M.Reinhorn Alessandro De Stefano Department of Structural Geotechnical & Building Engineering(DISEG)Politecnico di TorinoCorso Duca degli Abruzzi 2410129 TurinItaly Department of Civil Structural & Environmental EngineeringUniversity at Buffalothe State University of New York135 Ketter HallBuffalo NYUSA

The authors thank the discusser for his interest and careful review of the paper and his valuable comments. They also welcome this discussion,because it gives the authors the opportunity to clarify several points whic... 详细信息

关键词： Introspection on improper seismic retrofit of Basilica Santa Maria di Collemaggio after 2009 Italian earthquake by Vincenzo Ciampi Discussion 1 on Reply to De

Natural and Eco-Friendly Materials for Triboelectric Energy Harvesting

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2020年第3期12卷 179-196页

作者： Vladislav Slabov Svitlana Kopyl Marco PSoares dos Santos andrei L.Kholkin Department of Physics and CICECO‑Aveiro Institute of Materials University of Aveiro3810‑193 AveiroPortugal Centre for Mechanical Technology and Automation(TEMA) University of Aveiro3810‑193 AveiroPortugal Department of Mechanical Engineering University of Aveiro3810‑193 AveiroPortugal School of Natural Sciences and Mathematics Ural Federal UniversityEkaterinburgRussia 620000 Laboratory of Functional Low‑Dimensional Structures National University of Science and Technology MISiSMoscowRussia 119049

Triboelectric nanogenerators(TENGs)are promising electric energy harvesting devices as they can produce renewable clean energy using mechanical excitations from the *** designs of triboelectric energy harvesters relying on biocompatible and eco-friendly natural materials have been introduced in recent *** ability to provide customizable self-powering for a wide range of applications,including biomedical devices,pressure and chemical sensors,and battery charging appliances,has been *** review summarizes major advances already achieved in the field of triboelectric energy harvesting using biocompatible and eco-friendly natural materials.A rigorous,comparative,and critical analysis of preparation and testing methods is also *** power up to 14 mW was already achieved for the dry leaf/polyvinylidene fluoride-based TENG *** findings highlight the potential of eco-friendly self-powering systems and demonstrate the unique properties of the plants to generate electric energy for multiple applications.

关键词： Natural and eco-friendly materials Energy harvesting Triboelectric nanogenerators Biocompatibility

Comparison of fusion methods based on DST and DBN in human activity recognition

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2011年第1期9卷 18-27页

作者： andrei TOLSTIKOV Jit BISWAS Chris NUGENT Guido PARENTE Institute for Infocomm Research Networking Protocols Department1 Fusionopolis Way#21-01Singapore 138632 School of Computing and Mathematics University of UlsterShore RoadNewtownabbeyBT37 0QBU.K.

Ambient assistive living environments require sophisticated information fusion and reasoning techniques to accurately identify activities of a person under care. In this paper, we explain, compare and discuss the application of two powerful fusion methods, namely dynamic Bayesian networks (DBN) and Dempster-Shafer theory (DST), for human activity recognition. Both methods are described, the implementation of activity recognition based on these methods is explained, and model acquisition and composition are suggested. We also provide functional comparison of both methods as well as performance comparison based on the publicly available activity dataset. Our findings show that in performance and applicability, both DST and DBN are very similar; however, significant differences exist in the ways the models are obtained. DST being top-down and knowledge-based, differs significantly in qualitative terms, when compared with DBN, which is data-driven. These qualitative differences between DST and DBN should therefore dictate the selection of the appropriate model to use, given a particular activity recognition application.

关键词： Dynamic Bayesian networks Dempster-Shafer theory Healthcare monitoring Ambient assisted living Activity recognition

The Top of the Biomimetic Triangle

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2008年第2期5卷 91-94页

作者： andrei P. Sommer Dan Zhu Matthias Wiora Hans-Joerg Fecht Institute of Micro and Nanomaterials University of Ulm Ulm 89081 Germany Institute for Nanotechnology Forschungszentrum Karlsruhe Karlsruhe 76021 Germany

There is increasing observational evidence indicating that crystalline interfacial water layers play a central role in evolution and biology. For instance in cellular recognition processes, in particular during first contact events, where cells decide upon survival or entering apoptosis. Understanding water layers is thus crucial in biomedical engineering, specifically in the design of biomaterials inspired by biomimetic principles. Whereas there is ample experimental evidence for crystalline interfacial water layers on surfaces in air, their subaquatic presence could not be verified directly, so far. Analysing a polarity dependent asym- metry in the surface conductivity on hydrogenated nanocrystalline diamond, we show that crystalline interfacial water layers persist subaquatically. Nanoscopic interfacial water layers with an order different from that of bulk water have been identified at room temperature on both hydrophilic and hydrophobic model surfaces - in air and subaquatically. Their generalization and systematic inclusion into the catalogue of physical and chemical determinants of biocompatibility complete the biomimetic triangle.

关键词： biomimetic triangle crystalline interfacial water layers nanobionics diamond