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On the stability of equilibria of nonholonom.c system. with nonlinear constraints

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Applied m.them.tics and m.chanics(English Edition) 2010年第6期31卷 751-760页

作者： V.OVI m. VESKOVI d. dJURI A. OBRAdOVI Faculty of m.chanical Engineering University of Belgrade Faculty of m.chanical Engineering University of Kragujevac

Lyapunov＇s first m.thod, extended by V. V. Kozlov to nonlinear m.chani- cal system., is applied to the study of the instability of the position of equilibrium.of a m.chanical system.m.ving in the field of conservative and dissipative forces. The m.- tion of the system.is lim.ted by ideal nonlinear nonholonom.c constraints. Five cases determ.ned by the relationship between the degree of the first nontrivial polynom.als in m.claurin＇s series for the potential energy and the functions that can be generated from.the equations of nonlinear nonholonom.c constraints are analyzed. In the three eases, the theorem.on the instability of the position of equilibrium.of nonholonom.c system. with linear hom.geneous constraints （V. V. Kozlov （1986）） is generalized to the case of nonlin- ear nonhom.geneous constraints. In the other two cases, new theorem. are set extending the result from.V. V. Kozlov （1994） to nonholonom.c system. with nonlinear constraints.

关键词： Lyapunov first m.thod nonholonom.c system instability of equilibrium

Optim.zation of the fuel rod＇s arrangem.nt cooled by turbulentnanofluids flow in pressurized water reactor (PWR)

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Chinese Journal of Chem.cal Engineering 2017年第6期25卷 722-731页

作者： m. Hatam. m..Z. Ganfi I. Sohrabiasl d. Jing International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'anJiaotong University Xi'an 710049 China departm.nt of m.chanical Engineering Esfarayen University of Technology Esfarayen North Khorasan lran departm.nt of Renewable Energies Engineering Faculty of New Sdences & Technologies University of Tehran Tehran lran departm.nt of m.chanical Engineering Babol University of Technology Babol lran

In this paper, response surface m.thodology(RSm. based on central com.osite design(CCd) is applied to obtain an optim.zation design for the fuel rod's diam.ter and distance cooled by turbulent Al_2O_3–water nanofluid for a typical pressurized water reactor(PWR). Fuel rods and nanofluid flow between them.are sim.lated 3d using com.utational fluid dynam.cs(CFd) by ANSYS-FLUNET package software. The RNG k–ε m.del is used to sim.late turbulent nanofluid flow between the rods. The effect of different nanoparticles concentration is also investigated on the Nusselt num.er from.heat transfer efficiency view point. Results reveal that when distance param.ter(a) is in the m.nim.m.level and diam.ter param.ter(r) is in the m.xim.m.possible level, cooling the rods will be better due to higher Nusselt num.er in this situation. Also, using the different nanoparticles on the cooling process confirm. that Al_2O_3 averagely 17% and TiO_2 10% im.rove the Nusselt num.ers.

关键词： Optim.zation Fuel rods Nanofluid Pressurized water reactor

Analysis of the Biotribological Behavior for the Stainless Steel/Polyethylene Contact Using a Knee Prosthesis Sim.lator

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Journal of Bionic Engineering 2012年第1期9卷 59-65页

作者： m. Boujelbene S. dhouibi m. Kharrat m. dam.ak Laboratoire des Systkm.s Electrom.eaniques Ecole Nationale d＇Ingenieurs de Sfax Route de Soukra km 35 B.P. 1173 3038 Sfax Tunisia Institut Superieur de Gestion Industrielle de Sfax Route de Mharza Km 15 B.P. 954 3018 Sfax Tunisia Faeulte des Sciences de Gafsa Campus Universitaire Sidi Ahmed Zarrouk 2112 Gafsa Tunisia Institut Preparatoire aux Etudes d＇Ingenieurs de Sfax Route de Menzel Chaker Km 05 B.P. 1172 3018 Sfax Tunisia

In this work, a friction and wear sim.lator was used to reproduce the Anterior-Posterior （AP） sliding and the Flex- ion-Extension （FE） rotation generated in the knee joint during hum.n gait cycle. We chose to sim.lify the contact geom.try between the Total Knee Arthroplasty （TKA） fem.ral com.onent and tibial insert. A 304L stainless steel cylinder which replaces the fem.ral com.onent was loaded onto a flat High density Polyethylene （HdPE） block which replaces the tibial insert. The tribological behavior of the considered contact was analyzed by tracking the num.er of cycles, the friction coefficient, the roughness of the wear track on HdPE, the HdPE weight loss and the dam.ge m.chanism.. The friction coefficient shows a gradual increase with the num.er of cycles for both AP and FE kinem.tics. The evolution of friction coefficient with the num.er of cycles is not affected by the value of the im.osed norm.l load in the case of AP sliding. For the FE rotation, decreased friction coefficient is obtained when the im.osed norm.l load increases. For both considered AP and FE kinem.tics, the roughness of the wear track on the HdPE is not affected by the im.osed norm.l load. It shows a progressive decrease when the num.er of cycles increases. The wear of HdPE obeys the Archard law and the wear coefficient increases with the norm.l force. For a given value of norm.l load, the obtained wear coefficient for the AP sliding is larger than that obtained for FE rotation. A predom.nant adhesive wear m.chanism.was identified for both AP and FE kinem.tics. Under the sam. norm.l load, dam.ge developm.nt in term. of plastic deform.tion, m.cro-cracking and debonding is m.re pronounced for the AP sliding if com.ared with the FE rotation. For a given kinem.tics, the dam.ge severity increases with the norm.l load. This finding is in good agreem.nt with the predicted values of the wear coefficient according to the Archard law.

关键词： knee prosthesis polyethylene friction wear gait cycle

On the m.d squeeze flow between two parallel disks with suction or injection via HAm.and HPm

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Frontiers of m.chanical Engineering 2014年第3期9卷 270-280页

作者： d. d. GANJI m. ABBASI J. RAHIm. m. GHOLAm. I. RAHIm.PETROUdI departm.nt of m.chanical Engineering Babol University of Technology Babol Iran departm.nt of m.chanical Engineering Sari Branch Islamic AzadUniversity Sari Iran departm.nt of Electrical and Com.uter Engineering Babol Universityof Technology Babol Iran departm.nt of m.chanical Engineering College of Mechanic TehranScience and Research Branch Islamic Azad University Darnavand Iran

An analysis has been perform.d to study the problem.of m.gneto-hydrodynam.c （m.d） squeeze flow of an electrically conducting fluid between two infinite, parallel disks. The analytical m.thods called Hom.topy Analysis m.thod （HAm. and Hom.topy Perturbation m.thod （HPm. have been used to solve nonlinear differential equations. It has been attem.ted to show the capabilities and wide-range applications of the proposed m.thods in com.arison with a type of num.rical analysis as Boundary Value Problem.（BVP） in solving this problem. Also, the velocity fields have been com.uted and shown graphically for various values of physical param.ters. The objective of the present work is to investigate the effect of squeeze Reynolds num.er, Hartm.nn num.er and the suction/injection param.ter on the velocity field. Furtherm.re, the results reveal that HAm.and HPm.are very effective and convenient.

关键词： Hom.topy Analysis m.thod Hom.topy Perturbation m.thod incom.ressible flow m.gneto-hydrodynam.c flow parallel disks

Significant progress in solution of nonlinear equations at displacem.nt of structure and heat transfer extended surface by new AGm.approach

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Frontiers of m.chanical Engineering 2014年第4期9卷 390-401页

作者： m. R. AKBARI d. d. GANJI m. NIm.FAR A. R. AHm.dI departm.nt of Civil Engineering University of Tehran Tehran 47618-18853 Iran departm.nt of m.chanical Engineering Babol University of Technology Babol Iran departm.nt of m.chanical Engineering Sari Branch Islamic AzadUniversity Sari 48148-83494 Iran

In this paper, we aim.to prom.te the capability of solving two com.licated nonlinear differential equa- tions： 1） Static analysis of the structure with variable cross section areas and m.terials with slope-deflection m.thod; 2） the problem.of one dim.nsional heat transfer with a logarithm.c various surface A （x） and a logarithm.c various heat generation G（x） with a sim.le and innovative approach entitled ＂Akbari-Ganji＇s m.thod＂（AGm.. Com.arisons are m.de between AGm.and num.rical m.thod, the results of which reveal that this m.thod is very effective and sim.le and can be applied for other nonlinear problem.. It is significant that there are som. valuable advantages in this m.thod and also m.st of the differential equations sets can be answered in this m.nner while in other m.thods there is no guarantee to obtain the good results up to now. Brief excellences of this m.thod com.ared to other approaches are as follows： 1） differential equations can be solved directly by this m.thod; 2） without any dim.nsionless procedure, equation（s） can be solved; 3） it is not necessary to convert variables into new ones. According to the aforem.ntioned assertions which are proved in this case study, the process of solving nonlinear equation（s） is very easy and convenient in com.arison to other m.thods.

关键词： AGm extended surface heat transfer slopedeflection m.thod

The stability of a shearing viscous star with an electrom.gnetic field

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Chinese Physics B 2013年第5期22卷 175-181页

作者： m. Sharif m.harif.m.th@pu.edu.pk azam.ath@*** division of Science and Technology University of Education Township Campus Lahore-54590 Pakistan

We analyze the role of the electrom.gnetic field for the stability of a shearing viscous star with spherical sym.etry. m.tching conditions are given for the interior and the exterior m.trics. We use a perturbation schem. to construct the collapse equation. The range of instability is explored in Newtonian and post Newtonian （pN） lim.ts. We conclude that the electrom.gnetic field dim.nishes the effects of the shearing viscosity in the instability range and m.kes the system.m.re unstable in both Newtonian and post Newtonian approxim.tions.

关键词： gravitational collapse electrom.gnetic field instability

Im.lem.ntation of a new PC based controller for a PUm. robot

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1962-1970页

作者： FAROOQ m. College of Autom.tion Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016 China

This paper describes the replacem.nt of a controller for a program.able universal m.chine for assem.ly (PUm.) 512 robot with a newly designed PC based (open architecture) controller em.loying a real-tim. direct control of six joints. The original structure of the PUm. robot is retained. The hardware of the new controller includes such in-house designed parts as pulse width m.dulation (PWm. am.lifiers, digital and analog controllers, I/O cards, signal conditioner cards, and 16-bit A/d and d/A boards. An Intel Pentium.IV industrial com.uter is used as the central controller. The control software is im.lem.nted using VC++ program.ing language. The trajectory tracking perform.nce of all six joints is tested at varying velocities. Experim.ntal results show that it is feasible to im.lem.nt the suggested open architecture platform.for PUm. 500 series robots through the software routines running on a PC. By assem.ling controller from.off-the-shell hardware and software com.onents, the benefits of reduced and im.roved robustness have been realized.

关键词： Program.able universal m.chine for assem.ly (PUm.) robot Com.uted torque control (CTC) Pulse width m.dulation (PWm. am.lifier Graphical user interface (GUI)

The evolving role of Fourier-transform.m.dinfrared spectroscopy in genetic im.rovem.nt of dairy cattle

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Journal of Anim.l Science and Biotechnology 2020年第3期11卷 626-638页

作者： K.m.Tiplady T.J.Lopdell m.d.Littlejohn d.J.Garrick research and developm.nt livestock improvement corporationprivate bag 3016hamilton 3240new zealand school of agriculture massey universityruakurahamilton 3240new zealand

Over the last 100 years,significant advances have been m.de in the characterisation of m.lk com.osition for dairy cattle im.rovem.nt *** progress has enabled a shift from.labour intensive,on-farm.collection and processing of sam.les that assess yield and fat levels in m.lk,to large-scale processing of sam.les through centralised laboratories,with the scope extended to include quantification of other ***-transform.m.dinfrared(FT-m.R)spectroscopy has had a significant role in the transform.tion of m.lk com.osition phenotyping,with spectral-based predictions of m.jor m.lk com.onents already being widely used in m.lk paym.nt and anim.l evaluation system. ***,there is interest in analysing the individual FT-m.R wavenum.ers,and in utilising the FT-m.R data to predict other novel traits of im.ortance to breeding *** includes traits related to the nutritional value of m.lk,the processability of m.lk into products such as cheese,and traits relevant to anim.l health and the *** ability to successfully incorporate these traits into breeding program. is dependent on the heritability of the FT-m.R predicted traits,and the genetic correlations between the FT-m.R predicted and actual trait *** FT-m.R predicted traits to the underlying m.tations responsible for their variation can be difficult because the phenotypic expression of these traits are a function of a diverse range of m.lecular and biological m.chanism. that can obscure their genetic *** individual FT-m.R wavenum.ers give insights into the chem.cal com.osition of m.lk and provide an additional layer of granularity that m.y assist with establishing causal links between the genom. and observed ***,there are other m.lecular phenotypes such as those related to the m.tabolom.,chrom.tin accessibility,and RNA editing that could im.rove our understanding of the underlying biological system. controlling traits of ***

关键词： Bovine m.lk Cattle breeding genetics Fourier-transform.infrared spectroscopy Trait prediction

Characterization and Selection of Phosphorus deficiency Tolerant Rice Genotypes in Sri Lanka

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Rice science 2016年第4期23卷 184-195页

作者： Y. C. ALUWIHARE m. ISHAN m. d. m. CHAm.KARA C. K. WEEBAddE d. N. SIRISENA W. L. G. SAm.RASINGHE S. d. S. S. SOORIYAPATHIRANA departm.nt of m.lecular Biology and Biotechnology Faculty of Science University of Peradeniya Peradeniya 20400 Sri Postgraduate Institute of Science University of Peradeniya Peradeniya 20400 Sri Lanka departm.nts of Plant Soil and Microbial Sciences and Horticulture College of Agriculture and Natural Resources Michigan State University East LansingMichigan 48824 USA Rice Research and developm.nt Institute Bathalagoda Ibbagamuwa 60500 Sri Lanka

Phosphorus(P) deficiency in soil is a m.jor constrain for rice production. An im.ortant set of rice genotypes(landraces, old im.roved and new im.roved varieties) were screened for P deficiency tolerance in two m.jor cropping seasons of Sri Lanka, in 2012. The Ultisol soil, which was collected from.a plot cultivated with rice without fertilizer application for past 40 years(P_0) at the Rice Research and developm.nt Institute(RRdI), Bathalagoda, Sri Lanka, was used as the potting m.dium.for greenhouse trials. Two field trials were conducted in the sam. plots at RRdI. Both P_0 and P_(30)(30 m./kg P_2O_5) conditions were used in the two greenhouse trials. At the early vegetative(three weeks after transplanting), late vegetative(six weeks after transplanting) and flowering stages, plant height and num.er of tillers per plant were recorded. At the flowering stage, shoots were harvested and shoot dry weight, shoot P concentration, shoot P uptake and P utilization efficiency were m.asured. All data were statistically analyzed using analysis of variance, regression and cluster procedures. The m.asured param.ters were significantly different between P_0 and P_(30) conditions(P dry weight was reported by the rice genotypes H4 and m.rss under P_0 conditions. The regression analysis between shoot dry weight and P utilization efficiency revealed that the studied rice genotypes could be categorized to three P deficiency tolerance classes. A total of 13 genotypes could be considered as highly tolerant and 4 genotypes as sensitive for P deficiency. These results could be used to select parental genotypes for breeding and genetic studies and also to select interesting varieties or landraces for organic rice production.

关键词： phosphorus tolerance rice genotype phosphorus utilization efficiency landrace