检索结果-南通市图书馆

Microstructure and mechanical properties of similar and dissimilar metal gas tungsten constricted arc welds:Maraging steel to 13-8 Mo stainless steel

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第1期15卷 111-121页

作者： c.v.S.Murthy A.Gopala krishna G.M.reddy Defence Research and Development Laboratory Jawaharlal Nehru Technological University Defence Metallurgical Research Laboratory

Maraging steel (250) and 13-8 Mo stainless steel plates were joined by gas tungsten constricted arc welding(GTcAW) process in similar and dissimilar metal combinations using 13-8 Mo stainless steel filler wire. The similar and dissimilar metal welds made in solutionized condition were subjected to standard post weld hardening treatments direct ageing at 485 ℃, soaking for 31/2 hours followed by air cooling(ageing treatment of maraging steel) and direct ageing at 510 ℃, soaking for 4 h followed by air cooling(ageing treatment of 13-8 Mo stainless steel). The joint characterization studies include microstructure examination, microhardness survey across the weldments and transverse weld tensile *** and dissimilar metal weldments responded to both the post weld ageing treatment. After post weld aging, increase in yield strength, UTS and slight reduction in % elongation of similar and dissimilar metal were observed. The observed tensile properties were correlated with microstructure and hardness distribution across the welds.

关键词： Maraging steel(250) 13-8 Mo stainless steel Mechanical properties Microstructure

Influence of Nano-Materials on Mechanical and Permeation characteristics of High Strength concrete

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2022年第3期37卷 416-422页

作者： K v S Gopala krishna Sastry M Srinivasula reddy A Ravitheja c.v.l Engineering G Pulla Reddy Engineering CollegeKurnoolAPIndia SvR Engineering college NandyalAndhra PradeshIndia

Efforts have been made to evaluate the influences of the addition of nanoparticles on the strength,durability and mineralogical changes of high strength concrete(HSc).Therefore,mixes were prepared for conventional concrete mix(ccM)of M80 ***,various mixes were prepared by replacing cementitious materials initially with 1%Nano-cacO_(3)(Nc),2%Nc,3%Nc in the ccM,and then 1%Nc and Nano-SiO_(2)(NS)NS,2%Nc and NS,3%Nc and NS(Nc and NS were in equal proportion)in the *** developed concretes were then evaluated for mechanical properties,permeation characteristics,and mineralogical *** the studies,it is found that the concrete at 2%NcS possesses superior mechanical and superior permeation characteristics of all the mixes.A clear variation in the mineralogical structure with the addition of nanoparticles has been observed.

关键词： high strength concrete nano silicon dioxide nano calcium carbonate mechanical properties permeation properties

camphor-derived thioureas: Synthesis and application in asymmetric Kabachnik-Fields reaction

在线全文

学校读者我要写书评

暂无评论

chinese chemical Letters 2016年第6期27卷 943-947页

作者： Pogula Sreekanth reddy Motakatla venkata krishna reddy Peddiahgari vasu Govardhana reddy Department of chemistry Yogi Vemana University

A series of camphor-derived thiourea organocatalysts 3a–f were designed and synthesized from（1R,3S）-camphoric acid 1 and applied to the one-pot three-component Kabachnik–Fields reaction. catalyst 3c was found to be an efficient organocatalyst for the reaction of 2-cyclopropylpyrimidin-4-carbaldehyde 4,various amines 5, and diphenylphosphite 6 to yield the corresponding enantioselective a-aminophosphonates 7a–e in 74%–82% yields and 14%–35% ee.

关键词： Asymmetric organocatalysis (1R 3S)-camphoric acid camphor-derived thioureas chiral a-aminophosphonates Enantioselective Kabachnik-Fields reaction

Paleo-Mesoarchean sedimentary record in the Dharwar craton,India:Implications for Archean ocean oxygenation

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第1期15卷 126-154页

作者： G.Harshitha c.Manikyamba M.Santosh cheng-Xue Yang A.Keshav krishna v.v.Sesha Sai I.Panduranga reddy cSIR-National Geophysical Research Institute(NGRI) Uppal RoadHyderabad 500007India Department of Geology Osmania UniversityHyderabad 500007India School of Earth Science and Resources China University of GeosciencesBeijing 100083China Department of Earth Science University of AdelaideAdelaide SA5005Australia Yonsei Frontier Lab Yonsei UniversitySeoul 03722Republic of Korea Geological Survey of India State UnitNagpurIndia

The early Archean oceans were marked by significant redox changes which have subsequently shaped the Earth’s *** chemical sediments of banded Iron and Manganese formations provide important geochemical proxies for these historical shifts in the redox conditions and to trace the ancient sedimentation patterns and *** this study,we investigate the proto-ore of the Archean Mn-formations of the Sandur,chitradurga and Shimoga greenstone belts of Dharwar craton of southern Peninsular India,which is geochemically characterised as quartz arenites,Mn-arenites,Fe-arenites,Mn-argillites and *** geochemical systematics suggest their deposition in shallow to deeper shelf in the Archean *** detrital zircon U-Pb systematics of Mn arenites and argillites indicate their maximum depositional age of 3230±52 Ma representing the oldest onset of sedimentation during the Paleo-Mesoarchean timeframe in the chitradurga Group of Dharwar *** detrital influx proxies suggest variations in sedimentation rates associated with the Archean transgressive-regressive cycles and fluctuating hydrodynamic conditions,together reflecting an increasing trend in the contributions of recycled sediment from Sandur to chitradurga and Shimoga greenstone *** available detrital zircon ages of the Mn arenites and argillites from these greenstone belts indicate a~600 Ma prolonged period of Mn deposition for which high-T hydrothermal fluids from Archean mid-oceanic ridges supplied the *** trace element compositions of the concordant detrital zircons suggest 3.3-3.1 Ga Dharwar basement TTG/granitoid source which is corroborated by the zircon crystallization temperatures of 690-820℃.The source-normalisedα-dose rates of the detrital zircons signify greater degrees of sediment transport and multi-cycle nature which correspond to the earliest episode of crustal growth in the Indian sub-continent associated with the Mesoarchean Ur supercontinent.T

关键词： Mn-arenites-argillites Dharwar craton Zircon U-Pb geochronology Passive margin sediments Ocean oxygenation

Importance of etiologies of secondary diabetes:How often do we think off in clinical practice?

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 clinical cases 2025年第5期13卷 49-51页

作者： Kotha Sugunakar reddy Arvind Kumar Morya Archana Gaur Sakthivadivel varatharajan Department of General Medicine All India Institute of Medical SciencesHyderabad 508126TelanganaIndia Department of Ophthalmology All India Institute of Medical SciencesHyderabad 508126TelanganaIndia Department of Physiology All India Institute of Medical SciencesHyderabad 508126TelanganaIndia

The article"Secondary diabetes due to different etiologies:Four case reports"by Song et al,published in the World Journal of clinical cases,delves into the identi-fication of rare causes of secondary diabetes and emphasizes the necessity for healthcare professionals to recognize these *** to do so can result in treatment delays and compromised patient *** article discusses spe-cific types of diabetes,including maturity onset of diabetes in young,pancreas-related diseases,endocrinopathies,drug-induced diabetes,infections,and con-genital genetic syndromes associated with diabetes *** summaries highlight how patients with secondary diabetes,stemming from conditions such as Williams-Beuren syndrome and pituitary adenoma,often exhibit distinct characteristics overlooked in clinical *** authors stress the importance of a holistic diagnostic approach and advocate for proactive management through early intervention,including genetic tests and antibody *** awa-reness and education are crucial for timely identification and proper management,ultimately improving patient *** findings prompt a call to action for healthcare professionals to consider rare causes of secondary diabetes,facili-tating better glycemic control and overall patient care.

关键词： Diabetes mellitus Etiologies viral infections Syndromes Pathophysiology,Secondary diabetes mellitus,clinical practice

ETP-AKEP: enhanced three-party authenticated key exchange protocols for data integrity in cloud environments

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

Journal of control and Decision 2023年第1期10卷 126-133页

作者： Kalluri Rama krishna c.v.Guru Rao Faculty of Informatics Osmania UniversityHyderabadIndia School of computer Science&Artificial Intelligence S.R.UniversityWarangalIndia

With key exchange protocols, a secure session key is generated between two remote users, andservers and exchanged between them. It is generally used to prevent unauthorised users fromgaining access to sensitive data. This article presents an enhanced three-party authenticated keyexchange protocols (ETP-AKE) protocol that does not depend on symmetric key encryption andinstead uses asymmetric key encryption. A key component of the proposed ETP-AKE protocol isusing elliptic curve encryption in conjunction with a one-way hash function. Its integrity certificationwas confirmed via the usage of the AvISPA tool package. Our proposed protocol is intendedto protect against various security threats, including the man-in-the-middle assault, the parallelattack, and the key-compromise attack, among others.

关键词： Ecc hash function cloud integrity third party key exchange

Flash X-ray radiography technique to study the high velocity impact of soft projectile on E-glass/epoxy composite material

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

Defence Technology（防务技术） 2019年第2期15卷 216-226页

作者： B.venkata Ramudu c.Jayarami reddy v.Madhu Armour Design and Development Division Defence Metallurgical Research Laboratory

In the present paper, the high velocity impact of 9 mm soft lead projectile on 10 mm and 30 mm thick Eglass/epoxy composites was studied using a 450 kv Flash X-ray radiography(FXR) system. The basic parameters of FXR imaging, such as effect of ratio of target to film(TF) and source to target(ST) distances and X-ray penetration thickness of the composite material were optimized based on clarity and the actual dimensions of the objects. The optimized parameters were used in the FXR imaging of the ballistic event of 9 mm soft projectile on E-glass/epoxy composite. The real time deformation patterns of both the projectile and composite target during the ballistic impact were captured and studied at different time intervals. The notable failure modes of the 10 mm thick target with time include fibre breakage, bulging on the back side, delamination, rec.v.ry of the bulging, reverse bulging and its rec.v.ry. However, with increase in thickness of the target to 30 mm the only failure mechanism observed is the breaking of fibres. The ballistic impact event was also numerically simulated using commercially available LS-DYNA software. The numerically simulated deformation patterns of the projectile and target at different time intervals are closely matching with the corresponding radiographic images.

关键词： Flash X-ray radiography E-Glass/epoxy composite Ballistic impact Numerical simulation

KOH activated carbon derived from biomass-banana fibers as an efficient negative electrode in high performance asymmetric supercapacitor

在线全文

学校读者我要写书评

暂无评论

Journal of Energy chemistry 2017年第1期26卷 56-62页

作者： chaitraK vinny R T Sivaraman P Narendra reddy chunyan Hu krishna venkatesh vivek c S Nagaraju N Kathyayini N Department of Nanobiosciences Centre for Emerging TechnologiesJain Global CampusJain UniversityJakkasandra postKanakapura TalukRamanagara DistrictBangalore Rural 562112 KarnatakaIndia Naval Materials Research Laboratory DRDOAmbernathThane 421506India Department of chemistry St.Joseph’s College P.G.Centre.46Langford RoadShanthinagarBangaloreKarnataka 560027India Research Resource centre Visveswaraya Technological UniversityBelagaviIndia college of chemistry Chemical Engineering and BiotechnologyDonghua UniversityShanghai 201620China National Engineering Research center for Dyeing and Finishing of Textiles Donghua UniversityShanghai 201620China

Here we demonstrate the fabrication, electrochemical performance and application of an asymmetric supercapacitor (AS) device constructed with ss-Ni(OH)(2)/MWcNTs as positive electrode and KOH activated honeycomb-like porous carbon (K-Pc) derived from banana fibers as negative electrode. Initially, the electrochemical performance of hydrothermally synthesized ss-Ni(OH)(2)/MWcNTs nanocomposite and K-Pc was studied in a three-electrode system using 1 M KOH. These materials exhibited a specific capacitance (cs) of 1327 Fig and 324 F/g respectively at a scan rate of 10 mv/s. Further, the AS device i.e., ss-Ni(OH)(2)/MWcNTs// K-Pc in 1 M KOH solution, demonstrated a cs of 156 F/g at scan rate of 10 mv/s in a broad cell voltage of 0-2.2 v. The device demonstrated a good rate capability by maintaining a cs of 59 F/g even at high current density (25 A/g). The device also offered high energy density of 63 Wh/kg with maximum power density of 5.2 kW/kg. The AS device exhibited excellent cycle life with 100% capacitance retention at 5000th cycle at a high current density of 25 A/g. Two AS devices connected in series were employed for powering a pair of LEDs of different colors and also a mini fan. (c) 2016 Science Press and Dalian Institute of chemical Physics, chinese Academy of Sciences. Published by Elsevier B.v. and Science Press. All rights reserved.

关键词： Asymmetric supercapacitor device Activated porous carbon High energy density cyclability Power source

Perturbations in Earth’s Atmosphere over An Indian Region during the Total Solar Eclipse on 22 July 2009

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2019年第4期33卷 784-796页

作者： S.B.Surendra PRASAD vinay KUMAR K.krishna reddy S.K.DHAKA Shristy MALIK M.venkatarami reddy U.Murali krishna Semi-arid-zone Atmospheric Research centre(SARc) Department of PhysicsYogi Vemana UniversityKadapaAndhra Pradesh 516003India Radio and Atmospheric Physics Lab Rajdhani CollegeUniversity of DelhiDelhi 110015India Department of Applied Physics Delhi Technical UniversityDelhi 110042India

During a total solar eclipse(TSE)on 22 July 2009,atmospheric perturbations were monitored from the surface to thermosphere to understand TSE’s impact on the meteorological(temperature,relative humidity,wind speed,and wind direction)and chemical(O3 and NOx)parameters around Kadapa(14.28°N,78.42°E),a tropical semi-arid region of *** this purpose,an experiment was conducted at Yogi vemana University campus,Kadapa,India,to measure the temperature,wind speed,wind direction,and concentrations of ozone(O3),NO,NO2,and NOx by using the automatic weather station(AWS)and O3 *** the eclipse day(22 July 2009),the surface observations at Kadapa showed a reduction in temperature(about 1.1℃)because of the solar *** of the thermal,dynamical(wind),and chemical parameters on the TSE day with control days[preceding(21 July 2009)and succeeding(23 July 2009)the TSE]illustrated the influence of solar *** the eclipse period,the O3 mixing ratio decreased,while NO2 and NOx increased;however,NO remained *** addition,radio occultation(RO)temperature profiles from constellation Observing System for Meteorology,Ionosphere,and climate(cOSMIc)/Formosat Satellite Mission(FORMOSAT-3)and Thermosphere,Ionosphere,and Mesosphere Energetics and Dynamics(TIMED)satellites were utilized to understand the impact of TSE on dynamics of the middle and upper atmosphere from tropopause to the *** vertical resolution cOSMIc observations revealed that during the solar eclipse,tropopause was cooler with twin peaks(double tropopause).The lower thermosphere between 110 and 130 km became warmer during the TSE,which might be caused by the dynamical response of the atmosphere in this region to the solar *** experimental data have provided very fine-scale variations of the atmospheric parameters both in time and height and also constituted a new set of results on TSE for further research.

关键词： total solar eclipse (TSE) atmospheric perturbations tropopause dynamics cOSMIc/FORMOSAT-3satellite radio occultation (RO) observations