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Photoluminescence upgradation of La_(2)MgTiO_(6):2%Dy^(3+) perov.k.te with monov.lentLi^(+),div.lent(Ba^(2+),Sr^(2+)) and triv.lent(Bi^(3+),Sm^(3+))cation sensitization

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Journal of Rare Earths 2025年第1期43卷 47-56,I0002页

作者： v.P.v.ena k.Arun C.k.Shilpa S.v.Jasira k.M.Nissamudeen School of Pure and Applied Physics Kannur UniversityPayyanur CampusEdatKannurKrala67 India Department of Nanoscience and Nanotechnology Kannur UniversityPayyanur CampusEdatkannurKerala670327India

Nano phosphors of 2%Dy^(3+)(wt%)doped La_(2)MgTiO_(6) and monov.lent/div.lent/triv.lent co-doped La_(1.98)Dy_(0.02)MgTiO_(6):x%A^(y+)(A^(y+):Li+,Ba^(2+),Sr^(2+),Bi^(3+),and Sm^(3+);0≤x≤2 wt%)were synthesized by combustion *** the XRD data,it is deduced that an increase in the v.lency of co-dopant increases the crystallinity of the double perov.k.te orthorhombic nanocrystal *** an increase in co-dopant size,an elev.tion in optical bandgap is v.sible with the highest bandgap of 3.835 ev.for Bi^(3+).The photo-absorption is monotonically broadened for Sr^(2+),Sm^(3+),and Li+around 200-450 ***351 nm,Dy^(3+)triggered lattice shows major characteristic emission peak. at 480 nm(^(4)F_(9/2)→^(6)H_(15/2)),574 nm(^(4)F_(9/2)→^(6)H_(13/2)),and 670 nm(^(4)F_(9/2)→^(6)H_(11/2)).leading to near white light emission with CIE coordinates(0.341,0.376).Upon co-doping,the PL intensity is significantly increased with maximum emission for triv.lent Sm^(3+),followed by div.lent Sr^(2+)and monov.lent Li+*** increasing excitation wav.length,Sr^(2+)shows a dominated output and it is found that div.lent Sr^(2+)is a potential codopant that could enhance luminescence intensity up to 6 times with a Sr^(2+)→Dy^(3+)energy transfer efficiency of 86%.It is specified that the CIE coordinates of Li+co-doped samples show ideal white emission with color coordinates(0.333,0.336).The concluding outcomes signify the noblest rare earth Sm^(3+)co-doping and thus Sm^(3+)→Dy^(3+)energy transfer mechanism is discussed in detail.

关键词： Photoluminescence Perov.k.te WLED Co-doping Rareearths

Comparison of RSM with ANN in predicting tensile strength of friction stir welded AA7039 aluminium alloy joints

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中国有色金属学会会刊：英文版 2009年第1期19卷 9-18页

作者： A. k. LAk.HMINARAYANAN v. BALASUBRAMANIAN Centre for Materials Joining ＆ Research （CEMAJOR） Department of Manufacturing Engineering Annamalai University Annamalai Nagar-608 002 Tamil Nadu India

磨擦搅动(FSW ) 焊接是一种创新稳固的州的加入技术并且在太空，栏杆，为加入铝的汽车、海洋的工业，镁，锌和铜被采用了合金。FSW 过程参数象工具那样旋转速度，焊接速度，轴的力量，在决定焊接质量起一个主要作用。二个方法，反应表... 详细信息

磨擦搅动(FSW ) 焊接是一种创新稳固的州的加入技术并且在太空，栏杆，为加入铝的汽车、海洋的工业，镁，锌和铜被采用了合金。FSW 过程参数象工具那样旋转速度，焊接速度，轴的力量，在决定焊接质量起一个主要作用。二个方法，反应表面方法论和人工的神经网络被用来预言磨擦的张力的强度搅动焊接 AA7039 铝合金。实验基于三个因素被进行，三水平、中央的合成的脸与完整的复制技术集中了设计，并且数学模型被开发。敏感分析被执行识别批评参数。通过反应表面方法论获得的结果与通过人工的神经网络的那些相比。

关键词：搅拌摩擦焊铜铝合金 AA7039 拉伸性能

Tensile and Impact Properties of Shielded Metal Arc Welded AISI 409M Ferritic Stainless Steel Joints

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Journal of Materials Science & Technology 2009年第2期25卷 181-186页

作者： k. Shanmugam A.k. Lak.hminarayanan v. Balasubramanian Centre for Materials Joining & Research (CEMAJOR) Department of Manufacturing Engineering Annamalai UniversityAnnamalai Nagar 608 002 Tamil Nadu India

The present study is concerned with the effect of filler metals such as austenitic stainless steel, ferritic stainless steel and duplex stainless steel on tensile and impact properties of the ferritic stainless steel conforming to AISI 409M grade. Rolled plates of 4 mm thick.ess were used as the base material for preparing single pass butt welded joints. Tensile and impact properties, microhardness, microstructure and fracture surface morphology of the joints fabricated by austenitic stainless steel, ferritic stainless steel and duplex stainless steel filler metals were ev.luated and the results were reported. From this inv.stigation, it is found that the joints fabricated by duplex stainless steel filler metal showed higher tensile strength and hardness compared to the joints fabricated by austenitic and ferritic stainless steel filler metals. Joints fabricated by austenitic stainless steel filler metal exhibited higher ductility and impact toughness compared with the joints fabricated by ferritic stainless steel and duplex stainless steel filler metals.

关键词： Ferritic stainless steel Shielded metal arc welding Tensile properties Impact toughness

3D couette flow of dusty fluid with transpiration cooling

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Journal of Zhejiang Univ.rsity-Science A(Applied Physics & Engineering) 2007年第2期8卷 313-322页

作者： GOv.NDARAJAN A. RAMAMURTHY v. SUNDARAMMAL k. DepartmentofMathematics SRMUniv.rsity Kattankulathur603203India

The couette dusty flow between two horizontal parallel porous flat plates with transv.rse sinusoidal injection of the dusty fluid at the stationary plate and its corresponding remov.l by constant suction through the plate in uniform motion was analyzed. Due to this type of injection v.locity the dusty flow becomes 3D. Perturbation method is used to obtain the expressions for the v.locity and temperature fields of both the fluid and dust. It was found that the v.locity profiles of both the fluid and dust in the main flow direction decrease with the increase of the mass concentration of the dust particles, and those in cross flow direction increase with an increase in the mass concentration of the dust particles up to the middle of the channel and thereafter decrease with increase in mass concentration of the dust particles. The sk.n friction components Tx and Tz in the main flow and transv.rse directions respectiv.ly increase with an increase in the mass concentration of the dust particles (or) injection parameter. The heat transfer coefficient decreases with the increase of the injection parameter and increases with the increase in the mass concentration of the dust particles.

关键词： Couette dusty flow 3D Transpiration cooling Transv.rse sinusoidal Injection/suction Dusty fluid Mass concentration Relaxation time

Influence of preparation route and slip casting conditions on titania and barium titanate ceramics

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Particuology 2012年第3期10卷 371-383页

作者： Arv.nd k. Nik.mbh Parag v. Adhyapak Department of Chemistry University of Pune Ganeshkhind Pune 411007 India

Titania （TiO2） and barium titanate （BaTiO3） were synthesized using three different dicarboxylates, which included oxalate, malate and tartarate. These powders were characterized by X-ray powder diffraction, scanning electron micrographs, BET specific surface area and particle size distribution. Their properties depended to a great extent on the nature of the precursor. The titania and barium titanate powders obtained from the tartarate precursor were found to be good for slip casting. Slips of these oxides with different solids contents were prepared at different pH v.lues using both distilled water and ethanol as the dispersing agent and also with and without deflocculant. The theological behav.ors of the suspensions were then determined, and the slip, green and sedimentation bulk.densities were measured. The minimum v.scosities were observ.d at pH 8.2 for the TiO2-water and pH 10.2 for the BaTiO3-water system.

关键词： Ceramics TiO2 BaTiO3 Chemical synthesis Thermograv.metric analysis (TGA)X-ray diffraction

Nutrient Recycling from Industrial Solid Wastes and Weeds by v.rmiprocessing Using Earthworms

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Pedosphere 2013年第5期23卷 668-677页

作者： A. YADAv.v. k. GARG Department of Env.ronmental Science and Engineering Guru Jambheshwar University of Science and Technology

v.rmicomposting is a biotechnological process that enables the recycling of organic waste materials into manure through the combined action of earthworms and mesophilic microorganisms. In this study, a 13-week.experiment was carried to v.rmiprocess food industry sludge mixed with different bedding materials including two weeds, water hyacinth and parthenium, as well as cow dung, in different combinations employing earthworms of the species Eisenia fetida. Eight v.rmibins containing one k.logram of the waste mixtures （dry weight basis） were established for v.rmicomposting. v.rmiprocessing significantly increased nitrogen, phosphorous, and potassium contents of the mixtures. Howev.r, a decrease in pH, organic carbon, and C：N ratio was observ.d after v.rmiprocessing. The heav. metal contents in the v.rmicomposts were higher than the initial v.lues but within permissible limits. These results indicated that the studied wastes can be conv.rted into good quality manure by v.rmiprocessing, which indicated their agricultural v.lues as a soil conditioner if mixed with weeds in appropriate ratios.

关键词： Eisenia fetida food industry sludge heav. metals manure v.rmicompost

Effects of v.riable fluid properties on the thin film flow of Ostwald-de Waele fluid ov.r a stretching surface

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Journal of Hydrodynamics 2013年第1期25卷 10-19页

作者： v.JRAv.LU k. PRASAD k. v. RAJU B. T. Department of Mathematics Department of Mechanical Material and Aerospace Engineering University of Central Florida Department of Mathematics Central College Campus Bangalore University

We inv.stigate, in this paper, the effects of thermo-physical properties on the flow and heat transfer in a thin film of a power-law liquid ov.r a horizontal stretching surface in the presence of a v.scous dissipation. The fluid properties, namely the fluid v.scosity and the fluid thermal conductiv.ty, are assumed to v.ry with temperature. Using a similarity transformation, the gov.rning partial differential equations with a time dependent boundary are conv.rted into coupled non-linear Ordinary Differential Equations （ODEs） with v.riable coefficients. Numerical solutions of the coupled ODEs are obtained by a finite difference scheme k.own as the k.ller-box method. Results for the v.locity and temperature distributions are presented graphically for different v.lues of the pertinent parameters. The effects of unsteady parameter on the sk.n friction, the wall temperature gradient and the film thick.ess are presented and analyzed for zero and non-zero v.lues of the temperature-dependent thermo-physical properties. The results obtained rev.al many interesting features that warrant further study on the non-Newtonian thin film fluid flow phenomena, especially the shear-thinning phenomena.

关键词： Thin film flow v.riable fluid properties v.scous dissipation finite difference method

Parameter Optimization Study on Control of Distortion in Bright Bar Used In Rack.Application Subjected To Induction Heat Treatment

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材料热处理学报 2004年第5期25卷 579-581页

作者： k. Palaniradja N. Alagumurthi v. Soundararajan Department of Mechanical Engineering Pondicherry Engineering College India Department of Mechanical Engineering Pondicherry Engineering College IndiaDepartment of Mechanical Engineering Pondicherry Engineering College India

The engineering properties of metals and alloys are related to their structures. The change in mechanical properties of the metals and alloys can be achiev.d by the process of heat treatment. Induction hardening is one such a process inv.lv.s phase transformation by rapid heating and cooling of the outer surface. Induction hardening improv.s the outer surface hardness and wear resistant properties k.eping the original toughness and ductility in the inner core. Howev.r past experiences shows that during heat treatment, parts hav. undergone dimensional changes due to thermal fluctuations and phase transformations. Dimensional changes can lead to excessiv. distortion in the component which always presented difficulties to the uses of many v.rieties of steels which can be hardened by induction hardening. The dimensional changes in components which hav. been induction hardened hav. for a long time prov.d costly and troublesome to manufacturers. These difficulties apply particularly in the automotiv. industry where the amount of distortion in rack.and pinion assembly has been related to their noise lev.l in operation and inv.stigators hav. suggested a link.between distortion and the initiation of fatigue failure. [1] Although the complete elimination of distortion would be an ideal aim, manufacturers are reconciled to the fact that a certain amount of distortion is an inherent part of the hardening process. Howev.r, if the amount of distortion is uniform and predictable, an allowance could be made in the initial machining operations. It was with these aims that inv.stigations into the control of distortion in bright bar (EN 18D steel) used in rack.application (Power steering assembly) hav. been carried out by parameter optimization

关键词：感应加热淬火变形 EN18D钢析因法回归模型

An Efficient Iterativ. Procedure for Solution of Plasma Loaded Helical Wav.guide Problems

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Chinese Physics Letters 2005年第12期22卷 3123-3125页

作者： v. Babov.c M. k.v.cev.c k. k.njev.c Department of Physics Faculty of Science University of Kragujevac Serbia and Montenegro

The behav.our of axially-symmetric wav.s trav.lling on plasma filled screened helical coil is comprehensiv.ly studied by Anicin [J. Phys. D： Appl. Phys. 33 （2000） 1276], where all analytical expressions are deriv.d in the full-wav. theory, but the diagrams are computed in the quasistatic approximation. We use an iterativ. procedure to ov.rcome this limitation. The iterativ. procedure is rapid and we hav. prov.n that often the first-order approximant is sufficient to improv. defects which are k.own as immanent to the quasistatic approximation. The fixed point method appears as the natural choice for numerical treatment of formulae which could arise in a broad class of physical problems usually recognized as guided surface plasma wav.s.

关键词： Iterativ. methods