检索结果-南通市图书馆

Developments in Processing of Functionally Gradient Metals and Metal–Ceramic Composites:A Review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 825-838页

作者： T.P.D.rajan b.C.Pai Materials Science and Technology Division CSIR-National Institute for Interdisciplinary Science and TechnologyIndustrial Estate PO

Functionally gradient/graded materials （FGMs）, an emerging new class of materials, are the outcome of the recent innovative concepts in materials technology. FGMs are in their early stages of evolution and expected to have a strong impact on the design and development of new components and structures with better performance. FGMs exhibit gradual transitions in the microstructure and/or the composition in a specific direction, the presence of which leads to variation in the functional performance within a part. The presence of gradual transitions in material composition in FGMs can reduce or eliminate the deleterious stress concentrations and result in a wide gradation of physical and/or chemical properties within the material. Functionally graded metal-ceramic composites are also getting the attention of the researchers. Among the fabrication routes for FGMs such as chemical vapour deposition, physical vapour deposition, the sol-gel technique, plasma spraying, molten metal infiltration, self propagating high temperature synthesis, spray forming, centrifugal casting, etc., the ones based on solidification route are preferred for FGMs because of their economics and capability to make large size products. The present paper discusses and compares various solidification processing tech- niques available for the fabrication of functionally gradient metals and metal-ceramic composites and lists their properties and possible applications. The other processing methods are briefly described.

关键词： Functionally gradient materials Solidification Aluminium Centrifugal casting Infiltration

Mass Flow Prediction of the Coriolis Meter using C^0 Continuous beam Elements

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2015年第4期24卷 398-402页

作者： binulal b R Akash rajan Abhilash suryan R Jayaraj Kochupillai Heuy Dong Kim Research Scholar Department of Mechanical EngineeringCollege of Engineering Trivandrum Department of Mechanical Engineering College of Engineering Adoor Department of Mechanical Engineering College of Engineering Trivandrum Department of Mechanical Engineering Andong National University

A three node C^0 continuous isoparametric beam element is formulated to model the curved pipe conveying fluid in three dimensional *** equations of motion for the combined structure and fluid domain including added mass effect,Coriolis effect,centrifugal effect and the effect of pressure on the walls of pipe have been developed by *** equation is converted to finite element formulation using Galerkin technique and is validated with the results available from literature.

关键词： Coriolis mass flow meter Timoshenko beams finite element formulation Coriolis effect

Role of Ag microalloying on glass forming ability and crystallization kinetics of ZrCoAgAlNi amorphous alloy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics b 2021年第1期30卷 471-476页

作者： A Surendar K Geetha C rajan M Alaazim Department of Pharmacology Saveetha Dental College and HospitalSaveetha Institute of Medical and Technical SciencesChennaiIndia CSE Excel Engineering CollegePallakapalayamKomarapalayam637303India IT K S Rangasamy College of Technology TiruchengodeNamakkalTamil Nadu 637215India Faculty of Engineering Universitas Muhammadiyah Surakarta(UMS)Indonesia

bulk metallic glasses(bMGs) with new chemical compositions(ZrCoAgAlNi) were fabricated and the effects of Ag minor addition on the glass forming ability(GFA) and crystallization kinetics were studied. The x-ray diffraction(XRD) test was applied to identify the amorphousness of bMGs or possible crystalline phases. Using differential scanning calorimeter(DSC), the thermal stability and crystallization kinetics under a non-isothermal condition at the different heating rates were studied. Considering the heating rate dependency of glass transition and crystallization kinetics, the activation energy was evaluated and measured for the mentioned processes. It was revealed that the rise in Ag content led to the decrease in activation energy for glass transition, while the activation energy for crystallization increased. The thermal stability and GFA were also studied and it was found that the Ag addition strongly affected the inherent features of bMGs. With the increase in Ag content, the atomic mobility and structural rearrangement changed in the material and consequently, the GFA and thermal stability were significantly improved.

关键词： bulk metallic glass materials design crystallization kinetics glass forming ability

Vanishing bile duct syndrome in human immunodeficiency virus: Nevirapine hepatotoxicity revisited

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第26期16卷 3335-3338页

作者： rajan Kochar Moises I Nevah Frank J Lukens Michael b Fallon Victor I Machicao Division of Gastroenterology Hepatology and Nutrition The University of Texas Health Science Center at Houston Houston TX 77030 United States

Vanishing bile duct syndrome (VbDS) refers to a group of disorders characterized by prolonged cholestasis as a result of destruction and disappearance ofintrahepatic bile ducts. Multiple etiologies have been indentifi ed including infections, neoplastic disorders, autoimmune conditions and drugs. The natural history of this condition is variable and may involve resolution of cholestasis or progression with irreversible damage. VbDS is extremely rare in human immunodeficiency virus (HIV)-infected patients and anti-retroviral therapy has never been implicated as a cause. We encountered a young pregnant female with HIV and VbDS secondary to anti-retroviral therapy. Here, we report her clinical course and outcome.

关键词： Vanishing bile duct syndrome Ductopenia Acquired immune deficiency syndrome Cholangiopathy Cholestasis Drug-induced liver injury

Immunotherapy in type 1 diabetes:Novel pathway to the future ahead

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Diabetes 2024年第10期15卷 2022-2035页

作者： Sayantan Ray rajan Palui Department of Endocrinology All India Institute of Medical SciencesBhubaneswar 751019India Department of Endocrinology The Mission HospitalDurgapur 713212India

Since the discovery of insulin over 100 years ago,the focus of research in the management of type 1 diabetes(T1D)has centered around glycemic control and management of complications rather than the prevention of autoimmune destruc-tion of pancreaticβ***,in recent years,there has been significant advancement in immune-targeted pharmacotherapy to halt the natural progres-sion of *** immune-targeted intervention aims to alter the underlying pa-thogenesis of T1D by targeting different aspects of the immune *** im-munotherapy can either antagonize the immune mediators like T cells,b cells or cytokines(antibody-based therapy),or reinduce self-tolerance to pancreaticβcells(antigen-based therapy)or stem-cell ***,the US Food and Drug Administration approved the first immunotherapy teplizumab to be used only in stage 2 of ***,the window of opportunity to practically implement this approved molecule in the selected target population is *** this Edito-rial,we briefly discuss the various promising recent developments in the field of immunotherapy research in ***,further studies of these newer thera-peutic agents are needed to explore their true potential for prevention or cure of T1D.

关键词： Type 1 diabetes Immunotherapy Teplizumab Antigen based therapy Stem cell immunotherapy

Physical,Mechanical,and Tribological Attributes of Stir-Cast AZ91/SiC_p Composite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 295-305页

作者： K.K.Ajith Kumar Abhilash Viswanath T.P.D.rajan U.T.S.Pillai b.C.Pai Material Science and Technology Division CSIR-National Institute for Interdisciplinary Science and Technology

In the present investigation, composites with silicon carbide particle （SiCp） as reinforcement and AZ91 magnesium alloy as matrix have been synthesized using liquid metal stir-casting technique with optimized processing conditions. The composites with good particle distribution in the matrix, and better grain refinement and good interfacial bonding between the matrix and reinforcement have been obtained. The effect of SiCp content on the physical, mechanical, and tribological properties of Mg-based metal matrix composite （MMC） is studied with respect to particle distribution, grain refinement, and particle/matrix interfacial reactions. The electrical conductivity, coefficient of thermal expansion, microas well as macro-hardness, tensile and compressive properties, and the fracture behavior of the composites along with dry sliding wear of the composites have been evaluated and compared with the base alloy.

关键词： Composite AZ91D alloy Casting alloy Mechanical properties Wear

Trend in Observed and Projected Maximum and Minimum Temperature over N-W Himalayan basin

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2015年第2期12卷 417-433页

作者： Dharmaveer SINGH Sanjay K JAIN rajan Dev GUPTA GIS Cell Motilal Nehru National Institute of Technology Allahabad Water Resources Systems Division National Institute of Hydrology Department of Civil Engineering Motilal Nehru National Institute of Technology Allahabad

Recently, study in past trends of climate variables gained significant consideration because of its contribution in adaptions and mitigation strategies for potential future changes in climate, primarily in the area of water resource management. Future interannual and inter-seasonal variations in maximum and minimum temperature may bring significant changes in hydrological systems and affect regional water resources. The present study has been performed to observe past(1970-2010) as well as future(2011-2100)spatial and temporal variability in temperature(maximum and minimum) over selected stations of Sutlej basin located in North-Western Himalayan region in India. The generation of future time series of temperature data at different stations is done using statistical downscaling technique. The nonparametric test methods, modified Mann-Kendall test and Cumulative Sum chart are used for detecting monotonic trend and sequential shift in time series of maximum and minimum temperature. Sen's slope estimator test is used to detect the magnitude of change over a period of time on annual and seasonal basis. The cooling experienced in annual TMax and TMin at Kasol in past(1970-2010) would be replaced by warming in future as increasing trends are detected in TMax during 2020 s and 2050 s and in TMin during 2020 s, 2050 s and 2080 s under A1 b and A2 scenarios. Similar results of warming are also predicted at Sunnifor annual TMin in future under both scenarios which witnessed cooling during 1970-2010. The rise in TMin at Rampur is predicted to be continued in future as increasing trends are obtained under both the scenarios. Seasonal trend analysis reveals large variability in trends of TMax and TMin over these stations for the future periods.

关键词： Statistical downscaling model Canadian Coupled Global Climate Model Temperature MannKendall test Sen’s slope estimator

Self-lubricating bidirectional carbon fiber reinforced smart aluminum composites by squeeze infiltration process

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第11期35卷 2559-2569页

作者： K.M.Sree Manu L.Ajay Raag T.P.D.rajan b.C.Pai Vijay Petley Shweta Namdeo Verma CSIR-National Institute for Interdisciplinary Science and Technology TrivandrumIndia Gas Turbine Research Establishment(GTRE) BangaloreIndia

Self-lubrication is one of the smart material properties required for producing components with enhanced wear resistance and low coefficient of ***(bD)satin weave polyacrylonitrile(PAN)based carbon fiber(Cf)fabric preform was successfully infiltrated with Al 6061 alloy by squeeze infiltration *** infiltrated composite shows uniform distribution of carbon fibers in the matrix with the elimination of porosities,fiber damage and close control on the formation of deleterious aluminum carbide(Al4C3)***/Al composite exhibits remarkable wear resistance compared to unreinforced alloy due to the formation of self-lubricating tribolayer on the pin surface,which intercepts the contact of matrix metal to counter *** bD carbon fiber enhanced the hardness and compressive strength of the composite by restraining the plastic flow behavior of *** resolution transmission electron microscopy shows the presence of Al2O3 and MgAl2O4 spinel,confirmed by EDS and SAD pattern,at the composite *** composite shows a lower density of 2.16 g/cm^3 which is a major ad vantage for weight reduction compared to the monolithic alloy(2.7 g/cm^3).

关键词： Metal matrix composites Squeeze infiltration Aluminum Carbon fiber fabric Tribology Microstructure

Anemia in cirrhosis:An underestimated entity

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第3期10卷 777-789页

作者： Manish Manrai Saurabh Dawra rajan Kapoor Sharad Srivastava Anupam Singh Department of Internal Medicine Armed Forces Medical CollegePune 411040India Department of Medicine and Gastroenterology Command HospitalPune 411040India Department of Medicine Command HospitalKolkata 70027India Department of Gastroenterology Post Graduate Institute of Medical Education and ResearchChandigarh 160012India

Anemia in a patient with cirrhosis is a clinically pertinent but often overlooked clinical *** guidelines highlight the algorithmic approach of managing a patient of cirrhosis presenting with acute variceal hemorrhage but day-to-day management in hospital and out-patient raises multiple dilemmas:Whether anemia is a disease complication or a part of the disease spectrum?Should iron,folic acid,and vitamin b complex supplementation and nutritional advice,suffice in those who can perform tasks of daily living but have persistently low *** does one investigate and manage anemia due to multifactorial etiologies in the same patient:Acute or chronic blood loss because of portal hypertension and bone marrow aplasia secondary to hepatitis b or C viremia?To add to the clinician’s woes the prevalence of anemia increases with increasing disease *** thus aim to critically analyze the various pathophysiological mechanisms complicating anemia in a patient with cirrhosis with an emphasis on the diagnostic flowchart in such patients and proposed management protocols thereafter.

关键词： Anemia Cirrhosis Iron deficiency anemia Macrocytic anemia Normocytic anemia