检索结果-南通市图书馆

chinese Journal of Polymer Science 2017年第3期35卷 407-421页

作者： pradeepa prabakaran ramesh prabhu manimuthu sowmya gurusamy edwinraj sebasthiyan school of physics alagappa universityKaraikudi-630 004Tamil NaduIndia

Plasticized polymer electrolytes were prepared using poly（ethylene oxide）(PEO)/poly（vinylidene fluoridehexafluoro propylene）(PVd F-HFP) with lithium perchlorate（Li cl O4） and different plasticizers. XRD and FTIR spectroscopic techniques were used to characterize the structure and the complexation of plasticizer with the host polymer matrix. The role of interaction between polymer hosts and plasticizer on conductivity is discussed using the results of alternating current（a.c.） impedance studies. TG-DTA and SEM were used for thermal and physical characterizations. Maximum ionic conductivity(3.26 × 10;S·cm;) has been observed for ethylene carbonate（Ec）-based polymer electrolytes. Electrochemical performance of the plasticized polymer electrolyte is evaluated in LiFePO;/plasticized polymer electrolytes（PPEs）/Li coin cell. Good performance with low capacity fading on charge discharge cycling is demonstrated.

关键词： X-ray diffraction Impedance spectroscopy Atomic force microscopy Ionic conductivity Dielectrics

Scavenging Action of Zinc and Green Tea Polyphenol on cisplatin and Nickel Induced Nitric Oxide Generation and Lipid Peroxidation in Rats

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2004年第4期17卷 402-409页

作者： SEEMA JOSHI S. K. HASAN ramesh cHANDRA M. M. HUSAIN R. c. SRIVASTAVA Isabella Thoburn P. G. college Faizabad Road Lucknow 226 007 IndiaIndustrial Toxicology Research Centre P. O. Box. 80 M. G. Marg Lucknow 226 001 IndiaIndustrial Toxicology Research Centre P. O. Box. 80 M. G. Marg Lucknow 226 001 IndiaIndustrial Toxicology Research Centre P. O. Box. 80 M. G. Marg Lucknow 226 001 IndiaR.C.Srivastava Scientist 'F'and Area Coordinator Analytical Toxicology Industrial Toxicology Research Centre P.O.Box80M.G.Marg Lucknow226001UP.INDIA

Objective Toxic metal ions have been implicated in the generation of reactive oxygen species (ROS) and nitric oxide (NO). Metallothionines (MT) and plant flavonoids have been reported in the intervention against oxidative damage. We investigated the effect of zinc induced MT and green tea polyphenol (GTP) in reducing the oxidative responses induced by nickel and platinum. Methods Zinc (10 mg/kg b. wt, sc) was administered to rats twice at a gap of 24hrs and GTP (10 mg/100 mL in drinking water) was fed ad libitum for 8 days. Nickel chloride (150 umol/***, ip) and cisplatin (50 mmol/kg ***, sc) was administered to rats 24 h after Zn or GTP pre-treatment. Animals of all the groups were sacrificed 16 hrs after treatment and biochemical markers for toxicity were monitored. Results Zinc or GTP pre-treatment caused significant protection against nickel or cisplatin enhanced mortality in rats, and reduction in lipid peroxidation and NO. conclusion It is proposed that inhibition of ROS and NO by GTP and zinc may prove useful as a selective pharmacological agent in the amelioration of metal toxicity.

关键词： Green tea polyphenol Zinc Nitric oxide Lipid Peroxidation Nickel cisplatin

Nitrogen Gas Heating and Supply System for SST-1 Tokamak

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2013年第2期15卷 157-160页

作者： Ziauddin KHAN Firozkhan PATHAN Yuvakiran PARAVASTU Siju GEORGE Gattu ramesh Hima BINDU Dilip c. RAVAL Prashant THANKEY KalpeshDHANANI Subrata PRADHAN Institute for Plasma Research Bhat Gandhinagar-382 428 India

Steady State Tokamak （SST-1） vacuum vessel baking as well as baking of the first wall components of SST-1 are essential to plasma physics experiments. Under a refurbishment spectrum of SST-1, the nitrogen gas heating and supply system has been fully refurbished. The SST-1 vacuum vessel consists of ultra-high vacuum （UHV） compatible eight modules and eight sectors. Rectangular baking channels are embedded on each of them. Similarly, the SST-1 plasma facing components （PFc） are comprised of modular graphite diverters and movable graphite based limiters. The nitrogen gas heating and supply system would bake the plasma facing components at 350 ~c and the SST-1 vacuum vessel at 150 ~c over an extended duration so as to remove water vapour and other absorbed gases. An efficient PLc based baking facility has been developed and implemented for monitoring and control purposes. This paper presents functional and operational aspects of a SST-1 nitrogen gas heating and supply system. Some of the experimental results obtained during the baking of SST-1 vacuum modules and sectors are also presented here.

关键词： SST-1 heating and supply system graphite based limiters PFc

Measurement of bit-rock interface temperature and wear rate of the tungsten carbide drill bit during rotary drilling

在线全文

学校读者我要写书评

暂无评论

Friction 2020年第6期8卷 1073-1082页

作者： Vijay Kumar SHANKAR Bijay Mihir KUNAR chivukula Suryanarayana MURTHY M R ramesh Department of Mining Engineering National Institute of Technology KarnatakaSurathkal 575025India Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkal 575025India

Rock drilling is an essential operation in mining *** at the bit-rock interface plays a major role in the wear rate of the drill *** paper primarily focuses on the wear rate of tungsten carbide(Wc)drill bit and the interrelationship between temperature and wear rate during rotary drilling operations conducted using a computer numerical control(cNc)*** interrelationship between the temperature and wear rate was studied with regard to three types of rock samples,i.e.,fine-grained sandstone(FG)of uniaxial compressive strength(UcS)that is 17.83 MPa,medium-grained sandstone(MG)of UcS that is 13.70 MPa,and fine-grained sandstone pink(FGP)of UcS that is 51.67 *** rate of the drill bit has been measured using controlled parameters,i.e.,drill bit diameter(6,8,10,12,and 16 mm),spindle speed(250,300,350,400,and 450 rpm),and penetration rate(2,4,6,8,and 10 mm/min),***,a fully instrumented laboratory drilling set-up was *** weight of each bit was measured after the bit reached 30 mm depth in each type of the rock ***,effects of the bit-rock interface temperature and operational parameters on wear rate of the drill bits were *** results show that the wear rate of drill bits increased with an increase in temperature for all the bit-rock combinations *** is due to the silica content of the rock sample,which leads to an increase in the frictional heat between the bit-rock ***,in case of medium-grained sandstone,the weight percentage(wt%)of SiO2 is around 7.23 wt%,which presents a very low wear rate coefficient of 6.33×10^–2 mg/(N?m).Moreover,the temperature rise during drilling is also minimum,i.e.,around 74℃,in comparison to that of fine-grained sandstone and fine-grained sandstone *** addition,this paper develops the relationship between temperature and wear rate characteristics by employing simple linear regression analysis.

关键词： temperature wear rate drilling simple linear regression

Preparation and characterization of ce_(1-x)Dy_(x-y)Sr_yO_(2-δ) system

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of china 2014年第2期24卷 393-400页

作者： S.ramesh K.c.JAMES RAJU c.VISHNUVARDHAN REDDY School of Physics University of Hyderabad Department of Physics Osmania University

The effect of dysprosium and strontium on the total ionic conductivity of ceria in the system ce1-xDyx-ySryO2-δ was studied. In this system, few compositions were prepared with x=0.15, y=0.015, 0.03 and 0.045 by modified sol-gel process using maltose and pectin as organic precursors. Rietveld refinement of XRD patterns confirms the cubic structure with space group Fm3m . SEM images show relatively uniform grains with clean and distinct grain boundaries. Four probe Ac impedance measurements were carried out to evaluate the total ionic conductivity in the temperature range of 150-500 ℃ and frequency range of 40 Hz-1 MHz. The composition ce0.85Dy0.12Sr0.03O2-δshows higher electrical conductivity than single-doped ceria samples.

关键词： electrolyte Sr-Dy doping impedance spectroscopy conductivity

Properties of Al_2O_3-Sm_2O_3-ceO_2 electrolyte

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of china 2012年第6期22卷 1486-1494页

作者： S.ramesh K.c.J.RAJU c.V.REDDY School of Physics University of HyderabadHyderabad 500046India Department of Physics Osmania UniversityHyderabad 500007India

cel-xSmxO2 （x=0, 0.1, 0.2 and 0.3） and Sm-doped ceria＋（2%-8%）Al2O3 were synthesized through sol-gel process followed by low temperature combustion. The synthesis, structure, densification, conductivity and thermal expansion were studied, and the structure and phase were confirmed by XRD. Dense ceramics were obtained through sintering the pellets at 1300 ℃. 2% and 4% Al2O3 were added into ce0.8Sm0.2O2 to promote the densification at 1250 ℃. The surface morphology of the sintered pellets was analyzed using SEM. A two-probe Ac impedance spectroscopy was used to study the total ionic conductivity.

关键词： sol-gel process XRD-rietveld impedance spectroscopy ionic conductivity electrolyte ceramics

closed-Form Solutions of Stress Intensity Factors for Semi-elliptical Surface cracks in a cylindrical Bar Under Pure Tension

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2022年第2期35卷 344-356页

作者： M.K.Ramezani S.ramesh J.Purbolaksono R.Das centre of Advanced Manufacturing and Materials Processing Department of Mechanical EngineeringFaculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Department of Mechanical Engineering University of PertaminaJakarta 12220Indonesia Sir Lawrence Wackett Aerospace Research centre School of EngineeringRMIT UniversityMelbourneVI 3000Australia

In this work,the stress intensity factors(SIFs)for a wide range of semi-elliptical surface cracks with different inclination angles in a cylindrical bar subjected to pure tension were investigated *** main parameters considered to evaluate the SIFs were the crack size ratio(a/d),the crack aspect ratio(a/c),and the crack inclination angle(0).The dual-boundary element met hod implemented in software BEASY was used to compute the SIF values for *** her more,the general closed-form solutions were proposed to evaluate the corresponding SIFs for Mode I,Mode II and Mode III types of fracture through curve fitting *** solutions can provide accurate and reliable values of stress intensity factors for a crack on a cylindrical bar under pure tension in a rapid way compared to those obtained using computational *** addition,these results can be used as inputs for failure studies and life evaluations of cracked cylinder under working conditions.

关键词： Stress intensity factor Surface crack Solid cylinder closed-form solution Dual-boundary element method

Recent advances in new-onset diabetes mellitus after kidney transplantation

维普期刊数据库评论

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 2021年第5期12卷 541-555页

作者： Tess Montada-Atin G V ramesh Prasad Kidney Transplant Program St.Michael's HospitalToronto M5C 2T2OntarioCanada Department of Medicine University of TorontoToronto M5C 2T2Canada

A common challenge in managing kidney transplant recipients(KTR)is posttransplant diabetes mellitus(PTDM)or diabetes mellitus(DM)newly diagnosed after transplantation,in addition to known pre-existing *** is an important risk factor for post-transplant cardiovascular(cV)disease,which adversely affects patient survival and quality of *** disease in KTR may manifest as ischemic heart disease,heart failure,and/or left ventricular *** therapies for PTDM include most agents currently used to treat type 2 *** recently,the use of sodium glucose co-transporter 2 inhibitors(SGLT2i),glucagon-like peptide-1 receptor agonists(GLP-1 RA),and dipeptidyl peptidase 4 inhibitors(DPP4i)has cautiously extended to KTR with PTDM,even though KTR are typically excluded from large general population clinical *** evidence from observational studies seems to indicate that SGLT2i,GLP-1 RA,and DPP4i may be safe and effective for glycemic control in KTR,but their benefit in reducing cV events in this otherwise high-risk population remains *** newer drugs must still be used with care due to the increased propensity of KTR for intravascular volume depletion and acute kidney injury due to diarrhea and their single-kidney status,pre-existing burden of peripheral vascular disease,urinary tract infections due to immunosuppression and a surgically altered urinary tract,erythrocytosis from calcineurin inhibitors,and reduced kidney function from acute or chronic rejection.

关键词： cardiovascular disease Glucagon-like peptide-1 receptor agonists Kidney transplantation Oral antihyperglycemic drugs Post-transplant diabetes mellitus Sodium glucose co-transporter 2 inhibitors Dipeptidyl peptidase-4 inhibitors

Ultra-thin polarization independent broadband terahertz metamaterial absorber

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2021年第3期14卷 288-297页

作者： c.GANDHI P.ramesh BABU K.SENTHILNATHAN Department of Physics School of Advanced SciencesVellore Institute of TechnologyVellore 632014India

In this work,we present the design of a polarization independent broadband absorber in the terahertz(THz)frequency range using a metasurface *** absorber comprises of three layers,of which,the top layer is made of a vanadium dioxide(VO_(2))resonator with an electrical conductivity of a=200000 S/m;the bottom layer consists of a planar layer made of gold metal,and a dielectric layer is sandwiched between these two *** optimized absorber exhibits absorption greater than 90%from 2.54-5.54 ***,the corresponding bandwidth of the designed absorber is 3 ***,the thermal tunable absorption and reflection spectra have been analyzed by varying the electrical conductivity of VO_(2).The impact of the various geometrical parameters on the absorption characteristics has also been *** physics of generation of broadband absorption of the proposed device has been explored using field ***,the absorption characteristics of the unit cell has been studied for various incident and polarization angles.

关键词： terahertz(THz) metasurface tunable absorber

Managing cardiovascular disease risk in South Asian kidney transplant recipients

在线全文

学校读者我要写书评

暂无评论

World Journal of Transplantation 2021年第6期11卷 147-160页

作者： G V ramesh Prasad Vaishnavi Bhamidi Kidney Transplant Program St.Michael's HospitalToronto M5C 2T2ONCanada

South Asians(SA)are at higher cardiovascular risk than other ethnic groups,and SA kidney transplant recipients(SA KTR)are no *** KTR experience increased major adverse cardiovascular events both early and late *** risk management should therefore begin well before *** candidates may require aggressive screening for pretransplant cardiovascular disease(cVD)due to their ethnicity and *** SA ethnicity during the pre-transplant evaluation may enable programs to better assess cardiovascular risk,thus allowing for earlier targeted periand post-transplant intervention to improve cardiovascular *** remains the most prominent post-transplant cardiovascular risk factor in SA *** also clusters with other metabolic syndrome components including lower high-density lipoprotein cholesterol,higher triglycerides,hypertension,and central obesity in this ***,metabolic syndrome,and obesity are all significant cVD risk factors in SA KTR,and contribute to increased insulin *** biomarkers such as adiponectin,apolipoprotein B,and lipoprotein(a)may be especially important to study in SA *** interventions to improve health behaviors involving diet and exercise may especially benefit SA ***,there are few interventional clinical trials specific to the SA population,and none are specific to SA *** all cases,understanding the nuances of managing SA KTR as a distinct post-transplant group,while still screening for and managing each cVD risk factor individually in all patients may help improve the long-term success of all kidney transplant programs catering to multi-ethnic populations.

关键词： cardiovascular risk South Asians Diabetes Dyslipidemia Metabolic syndrome Health behavior Novel cardiovascular risk factors