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Effects of stretching/shrinking on the thermal performance of a fully wetted convective-radiative longitudinal fin of exponential profile

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Applied mathematics and mechanics(English Edition) 2022年第3期43卷 389-402页

作者： B.j.gIREESHA m.L.KEERTHI g.SOWmYA Department of Pg Studies and Research in mathematics Kuvempu UniversityShankaraghatta 577451India Department of Pg mathematics The National College(Auto)Bangalore 560070India

The present investigation focuses on the thermal performance of a fully wet stretching/shrinking longitudinal fin of exponential profile coated with a mechanism like a conveyer *** modeled equation is non-dimensionalized and solved by applying the Runge-Kutta-Fehlberg(RKF)*** effects of parameters such as the wet parameter,the fin shape parameter,and the stretching/shrinking parameter on the heat transfer and thermal characteristics of the fin are graphically analyzed and *** is inferred that the negative effects of motion and internal heat generation on the fin heat transfer rate can be lessened by setting a shrinking mechanism on the fin *** current examination is inclined towards practical applications and is beneficial to the design of fins.

关键词： fully wet longitudinal fin convection exponential profile internal heat generation moving fin

Study on thermal stability of poled non-linear optical polymers

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Chinese journal of Chemistry 1996年第5期14卷 472-480页

作者： mhlmann g.R. vanderVorst C.P.j.m. AKZO NOBEL Research Laboratories Arnhem P.O.Box 93006800 SB ArnhemThe NetherlandsAKZO NOBEL Research Laboratories ArnhemP.O.Box 93006800 SB ArnhemThe NetherlandsAKZO NOBEL Research Laboratories ArnhemP.O.Box 93006800 SB ArnhemThe NetherlandsAKZO NOBEL Research Laboratories ArnhemP.O.Box 93006800 SB ArnhemThe Netherlands

A logarithmic expression is proposed to describe relaxation of the polar order in side chain polymers, together with a new way of plotting temperature dependent relaxation data. This results in a straight line extending even below the glass transition temperature in the case of poled nonlinear optics (NLO) side chain polymers. A simple procedure to determine the rotational diffusion constant D-r is given and D-r values of several polymer systems have been evaluated and compared with each other. It appears that, starting from the conventional and well known poled polymer system currently applied, a further lowering of D-r by about 3 orders of magnitude is necessary in order to reach an acceptable orientational stability or lifetime of poled polymers for practical applications. Attempts have been made to introduce electron push-pull substituents into high thermostable molecular frameworks and results of preliminary measurements are reported.

关键词： thermal stability poled polymer film organic nonlinear optical materials

Application and analysis of functionally graded piezoelectrical rotating cylinder as mechanical sensor subjected to pressure and thermal loads

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Applied mathematics and mechanics(English Edition) 2011年第8期32卷 997-1008页

作者： g.H.RAHImI m.AREFI m.j.KHOSHgOFTAR Department of mechanical Engineering Tarbiat modares University

The exact thermoelastic analysis of a functionally graded piezoelectrical （FgP） rotating cylinder is investigated analytically. The cylinder is subjected to a com- bination of electrical, thermal, and mechanical loads simultaneously. The structure is a simplified model of a rotational sensor or actuator. The basic governing differential equation of the system is obtained by using the energy method. A novel term, named as the additional energy, is introduced to exact the evaluation of the energy functional. The solution to the governing differential equation is presented for two types of boundary conditions including free rotating and rotating cylinders exposed to the inner pressure. The effect of the angular velocity is investigated on the radial distribution of various components. The mentioned structure can be considered as a sensor for measuring the angular velocity of the cylinder subjected to the pressure and temperature. The obtained results indicate that the electrical potential is proportional to the angular velocity.

关键词： functionally graded piezoelectric (FgP) material sensor rotating cylinder angular velocity pressure temperature

microstructures in a carburized steel after isothermal pearlitic treatment

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journal of materials Science & Technology 2023年第29期160卷 66-75页

作者： j.Abraham mathews H.Farahani j.Sietsma R.H.Petrov m.g.mecozzi m.j.Santofimia Department of materials Science and Engineering Delft University of TechnologyMekelweg 22628 CDDelftThe Netherlands Tata Steel Research&Development IJmuidenThe Netherlands Department of Electromechanical Systems and Metal EngineeringGhent UniversityTech Lane Ghent Science park-Campus A ZwijnaardeTechnologiepark 46Belgium

The influence of carbon concentration variations on pearlite formation(20 h at 600℃)in a case-carburized steel is *** resultant microstructure shows three distinct regions:carburized case,a transition region,and the original *** microstructural transition from the case to the core regions is observed to be relatively *** investigated region of the carburized case(0.9 wt.%C)con-tains two types of pearlite:ferrite+cementite and ferrite+m_(23)C_(6),where the pearlitic aggregate with m_(23)C_(6)shows faster formation *** kinetics of pearlite formation in the transition region(0.3 wt.%C)is very slow and is observed with only m_(23)C_(6)*** around 40%austenite decomposes into pearlite in the transition region,which,in comparison to the carburized case region of 0.9 wt.%C is a fraction that is lower by a factor of *** is absent in the investigated core region(0.16 wt.%C).The microstructure in this region is predominantly martensite and pro-eutectoid ferrite,with a fraction of ferrite well below the equilibrium *** formation in this region is limited by the redistribution of mainly Ni,mn,and Cr,and their resulting solute drag effect on the austenite/ferrite interface.A ther-modynamic and kinetic argumentation of these observations is provided with the help of thermodynamic data,precipitation simulations,and a general mixed-mode gibbs energy balance model.

关键词： Pearlite formation Carburized steel m 2_(3)C_(6)carbide Kinetics Solute drag

A comprehensive framework for exploratory spatial data analysis:moran location and variance scatterplots

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International journal of Digital Earth 2010年第2期3卷 157-186页

作者： j.g.Negreiros m.T.Painho F.j.Aguilar m.A.Aguilar Institute of Statistics and Information management New University of LisbonCampus de CampolideLisbon 1070-312Portugal Department of Agricultural Engineering Almerı´a UniversityAlmeria 04120Spain

A significant geographic Information Science(gIS)issue is closely related to spatial autocorrelation,a burning question in the phase of information extraction from the statistical analysis of georeferenced *** present,spatial autocorrelation presents two types of measures:continuous and *** it possible to use moran’s I and the moran scatterplot with continuous data?Is it possible to use the same methodology with discrete data?A particular and cumbersome problem is the choice of the spatial-neighborhood matrix(W)for points *** paper addresses these issues by introducing the concept of covariogram contiguity,where each weight is based on the variogram model for that particular dataset:(1)the variogram,whose range equals the distance with the highest moran I value,defines the weights for points separated by less than the estimated range and(2)weights equal zero for points widely separated from the variogram range *** the W matrix is computed,the moran location scatterplot is created in an iterative *** accordance with various lag distances,moran’s I is presented as a good search factor for the optimal neighborhood ***/transition regions are also *** the same time,a new Exploratory Spatial Data Analysis(ESDA)tool is developed,the moran variance scatterplot,since the conventional moran scatterplot is not sensitive to neighbor *** computer-mapping framework allows the study of spatial patterns,outliers,changeover areas,and trends in an ESDA *** these tools were implemented in a free web e-Learning program for quantitative geographers called SAKWeb#(or,in the near future,***).

关键词： geocomputation exploratory spatial data analysis spatial autocorrelation moran scatterplot moran’s I variography

Viscoelastic models revisited:characteristics and interconversion formulas for generalized Kelvin-Voigt and maxwell models

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Acta mechanica Sinica 2019年第6期35卷 1191-1209页

作者： A.Serra-Aguila j.m.Puigoriol-Forcada g.Reyes j.menacho Passive Safety Department Applus+IDIADA Spain Tarragona HQSanta OlivaL'AlbomarPO Box 2043710 TarragonaSpain IQS-School of Engineering Universitat Ramon LlullVia Augusta 39008017 BarcelonaSpain

generalized Kelvin-Voigt and maxwell models using Prony series are some of the most well-known models to characterize the behavior of *** simulation software for viscoelastic materials generally implement only some material ***,for the practice of the engineer,it is very useful to have formulas that establish the equivalence between different *** the existence of these relationships is a well-established fact,moving from one model to another involves a relatively long *** article presents a development of the relationships between generalized Kelvin-Voigt and maxwell models using the aforementioned series and their respective relaxation and creep coefficients for one and two *** relationship between the singular points(maximums,minimums and inflexion points)is also included.

关键词： Viscoelasticity Dynamic mechanical analysis mechanical vibrations

Recrystallization and grain growth in Austenitic Stainless Steels: a Statistical Approach

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journal of materials Science & Technology 2003年第z1期19卷 119-121页

作者： A.Di Schino g.Abbruzzese j.m. Kenny materials Engineering Center University of Perugia Loc. Pentima Bassa TERNI Italy Centro Sviluppo Materiali Italy Materials Engineering Center University of Perugia Loc. Pentima Bassa TERNI Italy

A mathematical model, able to describe the recrystallization and grain growth in metals, has been developed. Taking into account the classical constitutive equations of the Taylor′s theory, the model involves only two free parameters (the dislocation density and the initial number of nuclei). Results from the model are here discussed in comparison with measurements performed on an AISI 304 stainless steel. The predictions of the model are in good agreement with experimental results. As cross check of the model prediction, the independent parameter "dislocation density"was found to properly correlate to the mechanical properties of the steel and to X-ray diffraction measurements,according to Taylor′s and Debye′s relations respectively.

关键词： Recrystallization, grain growth, Stainless steels

Recycling of spent lithium-ion batteries as a sustainable solution to obtain raw materials for different applications

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journal of Energy Chemistry 2023年第4期79卷 118-134页

作者： V.m.Leal j.S.Ribeiro E.L.D.Coelho m.B.j.g.Freitas Federal University of Espírito Santo Department of ChemistryLaboratory of Electrochemistry and ElectrochemistryAv.Fernando Ferrari514VitóriaES 29075-910Brazil

Lithium-ion batteries(LIBs)containing graphite as anode material and LiCoO_(2),Limn_(2)O_(4),and LiNi_(x)mn_(y)Co_(z)O_(2) as cathode materials are the most used worldwide because of their high energy density,capacitance,durability,and ***,such widespread use implies the generation of large amounts of electronic *** is estimated that more than 11 million ton of LIBs waste will have been generated by *** recycling can contribute to minimizing environmental contamination and reducing production costs through the recovery of high-value raw materials such as lithium,cobalt,and *** most common processes used to recycle spent LIBs are pyrometallurgical,biometallurgical,and *** the current scenario,it is necessary to develop environmentally friendly methods to recycle batteries and synthesize materials with multiple technological *** study presents a review of industrial and laboratory processes for recycling spent LIBs and producing materials that can be used in new batteries,energy storage devices,electrochemical sensors,and photocatalytic reactions.

关键词： Li-ion batteries Recycling Cathode Battery Hydrometallurgical Pyrometallurgical

Polymer Sensitized Quasi Solid-State Photovoltaic Cells Using Derivatives of Polythiophene

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journal of materials Science & Technology 2006年第6期22卷 811-816页

作者： g.K.R.Senadeera j.m.R.C.Fernando Institute of Fundamental Studies Hantane RoadKandySri Lanka Institute of Fundamental Studies Hantane RoadKandySri Lanka Postgraduate Institute of ScienceUniversity of PeradeniyaPeradeniyaSri Lanka

Substituted thiophene sensitized, nanocrystalline TiO2-based quasi solid-state solar cells were fabricated by using either poly （3-thiophene acetic acid）（P3TAA） or a copolymer with poly （3-thiophene acetic acid）-poly （hexyl thiophene）（P3TAA-PHT） polymers and copper iodide （Cul） as a hole conducting material together with an ionic liquid 1-ethyl-3-methylimidazolium bis （trifluoromethylsulfonyl） amide and lithium bis （triflu- oromethanesulfone） imide as additives for charge transport promotion. Dramatic enhancements in the cell performances were observed with the additives in Cul. While the cell sensitized with P3TAA generated a short-circuit photocurrent of -1.45 ***^-2, an open-circuit photovoltage of -345 mV with a total power conversion efficiency of -0.3% under simulated full sunlight of 100 mW-cm^-2 （air mass： 1.5）, the cell sensitized with copolymer P3TAA-PHT delivered -0.25% efficiency under the same conditions with -1.23 mA-cm^-2 as photocurrent and -371 mV as photovoltage.

关键词： Solar cells Polymers Titanium dioxide