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Optimization of Performance and Emission Characteristics of PPCCI Engine fuelled with Ethanol and Diesel blends Using Grey-Taguchi Method

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Journal of Thermal science 2018年第1期27卷 89-94页

作者： s.natarajan K.Pitchandi N.V.Mahalakshmi Department of Mechanical Engineering Sri Venkateswara College of EngineeringSriperumbudur-602117TamilnaduIndia. Department of Mechanical Engineering Sri Venkatcswara College of EngineeringSriperumbudur-602117TamilnaduIndia. Internal combustion Engineering Division Department of Mechanical EngineeringCollege of EngineeringAnna UniversityChennai-600025TamilnaduIndia.

The performance and emission characteristics of a PPCCI engine fuelled with ethanol and diesel blends were carried out on a single cylinder air cooled CI engine. In order to achieve the optimal process response with a limited number of experimental cycles, multi objective grey relational analysis had been applied for solving a multiple response optimization problem. Using grey relational grade and signal-to-noise ratio as a performance index, a combination of input parameters was prefigured so as to achieve optimum response characteristics. It was observed that 20% premixed ratio of blend was most suitable for use in a PPCCI engine without significantly affecting the engine performance and emissions characteristics.

关键词：排放特征优化问题柴油机引擎乙醇性能反应特征输入参数

Effect of Low Feed Rate FsP on Microstructure and Mechanical Properties of Extruded Cast 2285 Aluminum Alloy

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Journal of Materials science & Technology 2007年第5期23卷 614-618页

作者： L.Karthikeyan V.s.senthilkumar D.Viswanathan s.natarajan Department of Mechanical Engineering Panimalar Engineering CollegeChennai-103TamilNaduIndia Department of Mechanical Engineering College of EngineeringAnna UniversityChennai-025TamilNaduIndia

Friction stir processing （FsP）, a variation of FsW （friction stir welding） is an emerging surface engineering technology that can locally eliminate casting defects and refine microstructures, thereby improving the mechanical properties of material. FsP can also produce fine grained microstructures through the thickness to impart superplasticity. The technology involves plunging a rapidly rotating, non consumable tool, comprising a profiled pin and larger diameter shoulder, into the surface and then traversing the tool across the surface. The pin and the shoulder friction heat the surface which alters the grain structure in the processed area thereby improving the mechanical properties. This paper presents the effects of FsP on microstructure and mechanical properties of extruded cast 2285 aluminum alloy at three different feed rates viz. 10, 12 and 15 mm/min. With the increase in the feed speed the material was observed to have increased impact strength. FsP also increased the tensile and yield strengths with increases in hardness and ductility values also. The observation has been listed in detail and pictorially represented.

关键词： Friction stir processing Feed rate Fine grain microstructure

Phase transformation and crystal growth behavior of 8mol%(smO1.5, GdO1.5, and YO1.5) stabilized ZrO2 powders

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International Journal of Minerals,Metallurgy and Materials 2017年第7期24卷 842-849页

作者： R.Mahendran s.P.Kumaresh Babu s.natarajan s.Manivannan A.Vallimanalan Department of Metallurgical and Materials Engineering National Institute of Technology Tirchirappalli 620015 Tamil Nadu india

Nanocrystalline powders of ZrO_2–8mol%smO1.5（8sm sZ）, ZrO_2–8mol%GdO1.5（8Gd sZ）, and ZrO_2–8mol%YO1.5（8YsZ） were prepared by a simple reverse-coprecipitation technique. Differential thermal analysis/thermogravimetry（DTA/TG）, Fourier transform infrared spectroscopy（FTIR）, X-ray diffraction（XRD）, Raman spectroscopy, and high-resolution transmission electron microscopy（HRTEM） were used to study the phase transformation and crystal growth behavior. The DTA results showed that the ZrO_2 freeze-dried precipitates crystallized at 529, 465, and 467°C in the case of 8sm sZ, 8Gd sZ, and 8YsZ, respectively. The XRD and Raman results confirmed the presence of tetragonal ZrO_2 when the dried precipitates were calcined in the temperature range from 600 to 1000°C for 2 h. The crystallite size increased with increasing calcination temperature. The activation energies were calculated as 12.39, 12.45, and 16.59 k J/mol for 8sm sZ, 8Gd sZ, and 8YsZ respectively.

关键词： zirconia thermal analysis reverse coprecipitation activation energy

Implementing the Node Based smoothed Finite Element Method as User Element in Abaqus for Linear and Nonlinear Elasticity

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Computers, Materials & Continua 2019年第8期61卷 481-502页

作者： s.Kshrisagar A.Francis J.J.Yee s.natarajan C.K.Lee Integrated Modelling and simulation Lab Department of Mechanical EngineeringIndian Institute of Technology MadrasChennai600036India The Department of Architectural Engineering Dong-A UniversityS04-0302Engineering 237Nakdongdaero 550beon-gilSaha-guBusan49315Korea National Research Center for Disaster-free&safe Ocean City Dong-A UniversityS04-0311-3Engineering 237Nakdong-daero 550beon-gilSaha-guBusan49315Korea

In this paper,the node based smoothed-strain Abaqus user element(UEL)in the framework of finite element method is *** basic idea behind of the node based smoothed finite element(NsFEM)is that finite element cells are divided into subcells and subcells construct the smoothing domain associated with each node of a finite element cell[Liu,Dai and Nguyen-Thoi(2007)].Therefore,the numerical integration is globally performed over smoothing *** is demonstrated that the proposed UEL retains all the advantages of the NsFEM,i.e.,upper bound solution,overly soft stiffness and free from locking in compressible and nearly-incompressible *** this work,the constant strain triangular(CsT)elements are used to construct node based smoothing domains,since any complex two dimensional domains can be discretized using CsT *** additional challenge is successfully addressed in this *** efficacy and robustness of the proposed work is obtained by several benchmark problems in both linear and nonlinear *** developed UEL and the associated files can be downloaded from https://***/nsundar/NsFEM.

关键词： smoothed finite element method(sFEM) node based sFEM(NsFEM) linear and nonlinear elasticity Abaqus UEL(user elements) compressible and nearlyincompressible materials

Protist and Plant Growth-Promoting Bacterium Interaction Alters GH3-2 Expression and Enhances Nutrient Content in Rice

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Rice science 2024年第2期31卷 134-138,I0017-I0019页

作者： Komal A.CHANDARANA natarajan AMAREsAN C.G.Bhakta Institute of Biotechnology UkaTarsadia UniversityMaliba CampusBardoliSurat 394350GujaratIndia

The present study aimed to assess the interactive effects of four plant growth-promoting bacterium(PGPB)species[Providencia sp.(Pr),stenotrophomonas sp.(st),Morganella sp.(Mo),and Lysinibacillus sp.(Lb)]and six protist species[two amoebae Vermamoeba vermiformis(A9)and Acanthamoeba genotype T4(A34),and four ciliates Crytolophosis mucicola(C1),Tetrahymena sp.(C2),Colpoda elliotti(C12),and an unidentified genus of the family Kreyellidae(C5)]on the uptake of nutrients and the expression of auxin-responsive gene(GH3-2)in *** findings revealed that rice seedlings grew healthily,and a statistically significant difference was observed after 30 d of incubation in pots under greenhouse conditions treated with each PGPB and protist-PGPB consortia,compared with the untreated control ***,the protist-PGPB treatments were more significant than PGPB treatment *** greatest improvement in rice seedling growth was observed in *** with stenotrophomonas sp.(C12st)treatment,showing increased root and shoot length(88.57%and 79.69%).

关键词： seedling Plant GH3

Mesenchymal stem cell-based TRAIL delivery inhibits the metastatic state of clinical therapy-resistant progressive neuroblastoma

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World Journal of Pediatrics 2024年第3期20卷 287-293页

作者： Dinesh Babu somasundaram Andrew Maher sheeja Aravindan Zhongxin Yu Brian MBesch natarajan Aravindan Department of Radiation Oncology University of Oklahoma Health Sciences CenterOklahoma CityOKUSA stephenson Cancer Center Oklahoma CityOKUSA Department of Pathology University of Oklahoma Health Sciences CenterOklahoma CityOKUSA Radiation Biology Laboratory University of Oklahoma Health Sciences CenterBSEB 302F941 Stanton L.Young BoulevardOklahoma CityOK 73104USA

Progressive neuroblastomas(pNBs)that defy current intensive multimodal clinical therapy(IMCT)are a significant contributor to overall childhood cancer deaths[l].Neuroblastomas(NBs)that survive first-line IMCT actively evolve to acquire genetic and molecular rearrangements and display unparalleled plasticity and evolution,which causes frequent relapses in a rapidly accelerating timeline[2-4].

关键词： neuroblastoma clinical evolve

基于自适应双相场模型的纤维增强复合材料单层板断裂性能

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复合材料学报 2024年第3期41卷 1505-1515页

作者：郭雯马玉娥 sundar natarajan 陈鹏程彭帆西北工业大学航空学院西安710072 Indian Institute of Technology Madras School of Mechanical EngineeringChennai 600036 长安大学理学院西安710064

相场法可以自动捕捉裂纹的萌生和演化,因此在模拟复合材料的复杂失效行为时具有明显优势。为区分纤维增强复合材料(Fiber-reinforced composites,FRC)中存在的不同断裂模式,采用双相场断裂模型来分别表征基体和纤维的损伤演化。同时采... 详细信息

相场法可以自动捕捉裂纹的萌生和演化,因此在模拟复合材料的复杂失效行为时具有明显优势。为区分纤维增强复合材料(Fiber-reinforced composites,FRC)中存在的不同断裂模式,采用双相场断裂模型来分别表征基体和纤维的损伤演化。同时采用相场变量作为误差指标,在各向异性的双相场模型中引入了基于四叉树分解的网格自适应细化策略。设计并开发了相应的Matlab程序,研究了单向及变刚度纤维增强复合材料单层板在拉伸位移载荷下的断裂行为。计算结果表明:采用基于自适应算法的各向异性双相场模型所得到的数值计算结果与试验结果吻合良好;自适应双相场模型能在保证较高计算精度的同时,配合序参量的演化准确地在裂纹路径上进行网格自动加密,简化网格前处理过程,减少网格数量,降低计算成本,提高计算效率。

关键词：纤维增强复合材料双相场各向异性自适应有限元

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Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

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Journal of Rare Earths 2024年第1期42卷 66-75页

作者： s.W.Wi Y.s.Lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of Li + Photoluminescence sensitizer Rare earths

Tribological behavior of lubricant-impregnated porous polyimide

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Friction 2024年第4期12卷 711-725页

作者： Jinbang LI Ningning ZHOU Janet s.s.WONG school of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100029China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Porous materials impregnated with lubricants can be used in conditions where limited lubricant is *** this work,three porous polyimides(PPI)with different densities were ***(PAO)impregnated PPI(iPPI)discs were rubbed against steel and sapphire *** operando observations of the iPPI-sapphire contacts show that oil is released under an applied load,forming a meniscus around *** at the outlet is created at high sliding *** amount of released oil increases with increasing PPI *** moduli,E*,estimated based on the actual contact size show that trapped oil in iPPIs contributes to load *** higher speeds,tribological rehydration of the contact occurs in low density iPPI,with that E*rises with *** high density PPIs,high speeds give a constantly high E*which is limited by the viscoelastic properties of the PPI network and possibly the rate of oil *** of iPPI-steel contacts is governed by the mechanical properties of the PPI,the flow of the lubricant,and the roughness of the PPI *** low-and medium-density(highly porous,high roughness)PPIs,large amount of oil is released,and lubrication is mainly via lubricant restricted in the contact in the pores and possibly tribological *** high density(low porosity)PPI,with lower roughness,hydrodynamic lubrication is achieved which gives the lowest *** results show that polymeric porous materials for effective lubrication require the optimization of its surface roughness,stiffness,oil flow,and oil retentions.

关键词： polyimide porous material friction mechanism polymer limited lubrication