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Influence of A-site cation disorder on structural and magnetocaloric properties of Nd_(0.7–x)La_xSr_(0.3)MnO_3(x=0.0, 0.1, 0.2 & 0.3)

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Journal of Rare Earths 2015年第10期33卷 1072-1080页

作者： Sudharshan Vadnala Prem Pal Saket Asthana Department of Physics Indian Institute of Technology Hyderabad

In the present research, the influence of A-site ionic size disorder on structural, magnetic and magnetocaloric properties of Ndo.7_xtaxSr0.3MnO3 （for x=0.0, 0.1, 0.2 ＆ 0.3） compounds were investigated. These compounds were synthesized by solid state reaction route and crystallized in orthorhombic structure with Pnma space group. An average ionic radius 〈rA〉 increased with La-substitution which influenced the physical properties such as the magnetic entropy varying from 4.78 J/kg.K （for x-=0.0） to 3.55 J/kg.K （for x=0.3） and the maximum magnetization at 5 K changing from 3.92 μB （for x=0.0） to 3.59 μB （for x=0.3）. The change in maximum magnetic entropy decreased with increase of A-site average ionic radius. The decrease in magnetic entropy indicated the suppression of lattice disorder that influenced the spin-lattice coupling. The ferromagnetic transition temperature shifted toward room temperature with La substitution. As 〈rA〉 increased, the phase transition changed from first order （for x-=0.0） to second order （for x≥ 0.1） and the refrigeration capacity increased to a significant level. The modest change in magnetic entropy over a wide range of transition temperature might be useful for future active magnetic refrigeration technology.

关键词： manganites magnetocaloric effect relative cooling Curie temperature rare earths

Investigation of structural,magnetic and optical properties of rare earth substituted bismuth ferrite

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Journal of Rare Earths 2013年第4期31卷 370-375页

作者： T.Durga Rao T.Karthik Saket Asthana Advanced Functional Materials Laboratory Department of PhysicsIndian Institute of Technology Hyderabad Department of Materials Science and Engineering Indian Institute of Technology Hyderabad

Polycrystalline BiFeO3 and rare earth substituted ***3 （BRFO, R=Y, Ho and Er） compounds were prepared by rapid solid state sintering technique. Structural phase analysis indicated that all the compounds stabilized in rhombohedral structure （R3c space group） and a small orthorhombic phase fraction was observed in BRFO compounds. From the Raman spectra results, the changes in the phonon frequencies （A1） and line widths suggested lattice distortion in the BRFO compounds as was evidenced in the XRD analysis. Compared to the linear variation of magnetization with magnetic field （M-H） shown by BFO, an obvious M-H loop was observed in BRFO compounds which could be due to the suppression of space modulated spin structure and was explained on the basis of weak ferromagnetism and field induced spin reorientation. UV-Vis spectroscopy evidenced a change in local FeO6 envi- ronment due to shift in the 6Alg→4T2g energy transition band. BRFO compounds with improved remnant magnetization and coercive field are applicable for magnetoelectric devices.

关键词： structural distortion spin-reorientation G-type antiferromagnet rare earths

CompactChain:an efficient stateless chain for UTXO-model blockchain

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Frontiers of Computer Science 2024年第2期18卷 167-179页

作者： B Swaroopa REDDY T Uday Kiran REDDY Department of Electrical Engineering Indian Institute of Technology HyderabadHyderabadTelangana 502285India

In this work,we propose a stateless blockchain called CompactChain,which compacts the entire state of the UTXO(Unspent Transaction Output)based blockchain systems into two RSA *** first accumulator is called Transaction Output(TXO)commitment which represents the TXO *** second one is called Spent Transaction Output(STXO)commitment which represents the STXO *** this work,we discuss three algorithms:(i)To update the TXO and STXO commitments by the *** miner also provides the proofs for the correctness of the updated commitments;(ii)To prove the transaction’s validity by providing a membership witness in TXO commitment and non-membership witness against STXO commitment for a coin being spent by a user;(iii)To update the witness for the coin that is not yet spent;The experimental results evaluate the performance of the CompactChain in terms of time taken by a miner to update the commitments and time taken by a validator to verify the commitments and validate the *** compare the performance of CompactChain with the existing state-of-the-art works on stateless *** shows a reduction in commitments update complexity and transaction witness size which inturn reduces the mempool size and propagation latency without compromising the system throughput(Transactions per second(TPS)).

关键词： stateless blockchain RSA Accumulator STXO commitment TXO commitment UTXO Non-interactive Proof of Exponentiation(NI-PoE) Transactions per second(TPS)

Renewable energy based microgrid system sizing and energy management for green buildings

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Journal of Modern Power Systems and Clean Energy 2015年第1期3卷 1-13页

作者： Y.V.PAVAN KUMAR Ravikumar BHIMASINGU Department of Electrical Engineering Indian Institute of Technology Hyderabad(IITH)HyderabadIndia

The objective of this paper is to model a hybrid power system for buildings,which is technically feasible and economically *** a view to promote renewable energy sources,photovoltaics and wind turbines are integrated with the grid connected *** system is modeled and the optimal system configuration is estimated with the help of hybrid optimization model for electric renewables(HOMER).The logic is illustrated with a case study based on the practical data of a building located in southern *** building is associated with 3.4 MWh/day priority load(peak load as 422 kW),as well as 3.3 MWh/day deferrable load(peak load as 500 kW).Sensitivity analysis is performed to deal with uncertainties such as the increase in electricity consumption and grid tariff,environmental changes,*** the simulation result,it is observed that the designed system is cost effective and environment friendly,which leads to 6.18%annual cost savings and reduces CO_(2) emissions by 38.3%.Sensitivity results indicate that the system is optimal and adaptable in a certain range of unanticipated variances with respect to best estimated ***,an energy management strategy is developed for the optimal system to ensure reliable power during contingency and *** green and hybrid power system designed can be adaptable to any critical and large consumers of urban buildings.

关键词： Renewable energy sources(RES) Hybrid power systems(HPS) Photovoltaic(PV) Wind turbine(WT) Low-carbon electricity Energy management Total net present cost(TNPC)

Upper mantle anisotropy inferred from shear wave splitting beneath the Eastern indian Shield region

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Geoscience Frontiers 2018年第6期9卷 1911-1920页

作者： Kuntal Bhukta Prosanta K.Khan Prantik Mandal indian institute of Technology(indian School of Mines) DhanbadIndia National Geophysical Research institute HyderabadIndia

We estimate the shear wave splitting parameters vis-a-vis the thicknesses of the continental lithosphere beneath the two permanent seismic broadband stations located at Dhanbad(DHN) and Bokaro(BOKR) in the Eastern indian Shield region. Broadband seismic data of 146 and 131 teleseismic earthquake events recorded at DHN and BOKR stations during 2007-2014 were analyzed for the present *** study is carried out using rotation-correlation and transverse component minimization methods. We retain our "Good", "Fair" and "Null" measurements, and estimate the splitting parameters using 13 "Good" results for DHN and 10 "Good" results for BOKR stations. The average splitting parameters(φ,δt)for DHN and BOKR stations are found to be 50.76°±5.46° and 0.82±0.2 s and 56.30°±5.07° and0.95 ± 0.17 s, and the estimated average thicknesses of the anisotropic layers beneath these two stations are ～94 and ～109 km,respectively. The measured deviation of azimuth of the fast axis direction(0)from the absolute motion of the indian plate ranges from ～8° to 14°. The measured deviation of azimuth of the fast axis direction(0) from the absolute motion of the indian plate ranges from ～8° to 14°. The eastward deviation of the fast axis azimuths from absolute plate motion direction is interpreted to be caused by induced outflow from the asthenosphere. Further, the delay time found in the present analysis is close to the global average for continental shield areas, and also coherent with other studies for indian shield regions. The five "Null" results and the lower delay time of ～0.5-0.6 s might be indicating multilayer anisotropy existing in the mantle lithosphere beneath the study area.

关键词： Eastern indian shield Seismic anisotropy Splitting parameters Absolute plate motion

Occupational Exposure of healthcare Workers during COVID-19 Field Surveillance Activities in South India: A Cross-Sectional Qualitative Study

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Open Journal of Epidemiology 2021年第4期11卷 446-456页

作者： Surya Srinivasan Shailaja Tetali public health Foundation of India (indian institute of public health) Hyderabad India

Context: health Care Workers (HCWs) involved in field-level activities are exposed to COVID-19 which puts them under physical and psychological stress. Aim: The objective of this study was to understand the perception of the health care workers regarding their occupational exposure to COVID-19, including the safety measures used during field surveillance activities. Settings and Design: This cross-sectional study was conducted from June 2020 to July 2020 among the health care workers involved in COVID-19 field containment activities in two south indian states—Telangana and Tamil Nadu. Methods and Material: Respondents were purposively sampled based on their involvement in the COVID-19 field level activities. Sixteen In-Depth Interviewees (IDIs) were conducted telephonically with medical officers, district epidemiologists, community health workers, sanitary workers, emergency medical technicians, and ambulance coordinators. Statistical Analysis Used: IDIs were analyzed using manual thematic analysis. Results: Seven themes and sub-themes emerged: awareness and training, occupational exposure to COVID-19 and duration, safety measures, occupational burnout, social stigma, psychological violence, and facilitating factors. Respondents felt a high level of occupational exposure to COVID-19 in addition to increased workload and stress due to fear of infection, shortage of workforce, denial of week off, psychological violence, and social stigma which affected them deeply. Support from supervisors and family, and measures ensuring the safety of women were facilitating factors to cope with the situation. Conclusions: It is important to safeguard the general and mental health of field-level health workers involved in COVID-19 activities, to keep their morale high during the continuing pandemic.

关键词： Occupational Exposure COVID-19 Field Surveillance healthcare Workers

Prevalence of obesity,determinants,and its association with hyperglycaemia among community dwelling older adolescents in India

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World Journal of Clinical Pediatrics 2024年第4期13卷 37-47页

作者： Vansh Maheshwari Saurav Basu indian institute of public health-Delhi Public Health Foundation of IndiaGurugram 122102HaryanaIndia

BACKGROUND Globally,obesity and diabetes mellitus(DM)are emergent public health concerns in the adolescent ***,home to the largest adolescent population and the second largest diabetes cohort is experiencing rapid but unplanned urbanization,with accompanying unhealthy nutritional transition,and sedentary *** To determine prevalence and determinants of obesity and hyperglycaemia and their association among community-dwelling older adolescents(15-19 years)in *** This cross-sectional analysis from the national family health survey-5 included data of 258028 adolescents aged 15-19 across India(2019-2021).The survey employed stratified two-stage sampling,with systematic random sampling in rural and urban *** analysis included descriptive statistics,bivariate,and multivariable logistic regression,employing generalized linear *** The weighted prevalence of DM was 1.09%including 0.77%[95%confidence interval(CI):0.72-0.83]previously diagnosed and 0.32%(95%CI:0.29-0.35)newly diagnosed cases detected on survey *** adjusted analysis,increasing age,higher education levels,higher wealth index,and overweight/obesity were the factors significantly associated with presence of *** 61%of the adolescents with previously diagnosed DM were on anti-diabetes *** weighted prevalence of overweight/obesity among older adolescents was 6.9%with significantly higher odds in the male sex,having higher educational levels,urban residence,and those with a higher wealth *** Nearly one in hundred older adolescents in India have diabetes,with one in three *** DM screening and treatment access among adolescents through public health programs is urgently warranted.

关键词： Obesity Hyperglycaemia Adolescents Diabetes India

Phase evolution and mechanical properties of novel nanocrystalline Y_(2)(TiZrHfMoV)_(2)O_(7) high entropy pyrochlore

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Journal of Materials Science & Technology 2021年第23期82卷 214-226页

作者： G.Karthick Lavanya Raman B.S.Murty Department of Metallurgical and Materials Engineering Indian Institute of Technology MadrasChennai600036India indian institute of Technology hyderabad Kandi502285India

High entropy pyrochlores(HEP)are potential candidates as dispersoids in the oxide dispersed strengthened steels or alloys,which can be used in nuclear reactors and supercritical *** the first time,HEP oxides Y_(2)(TiZrHfMoV)_(2)O_(7) were synthesized with Y_(2)Ti_(2)O_(7) as a base structure with the B site(Ti)substituted with five cations through reverse co-precipitation technique in the nanocrystalline form at lowest synthesis *** synthesis parameters for Y_(2)(TiZrHfMoV)_(2)O_(7)(5C)and other derived compositions(five compositions of four cationic systems with each cation eliminated at B site from 5 C)are optimised to obtain lower crystallite and particle sizes.5C has a smaller crystallite size(27 nm)than other single-phase *** cation’s influence,oxidation state,and oxygen vacancy in the phase formation were analysed through *** single-phase HEPs are consolidated through spark plasma sintering.Y_(2)(TiZrHfMo)_(2)O_(7)(4 C-V)shows the highest hardness among the compositions reported so far due to its finer grain size,and Y_(2)(TiHfMoV)_(2)O_(7)(4 C-Zr)has a higher Young’s modulus compared to other single-phase composition due to its higher degree of order in the structure.

关键词： High entropy pyrochlores Reverse co-precipitation B site substitution Hardness Young’s modulus

Lepton and quark mixing patterns with generalized CP transformations

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Chinese Physics C 2022年第10期46卷 25-42页

作者： Joy Ganguly Raghavendra Srikanth Hundi Department of Physics Indian Institute of Technology HyderabadKandi-502284India

In this study,we modify a scenario,originally proposed by Grimus and Lavoura,in order to obtain maximal values for the atmospheric mixing angle and CP,violating the Dirac phase of the lepton *** achieve this,we employ CP and some discrete symmetries in a type Ⅱ seesaw *** make predictions about the neutrino mass ordering and smallness of the reactor angle,we establish some conditions on the elements of the neutrino mass matrix of our ***,we study the quark masses and mixing pattern within the framework of our model.

关键词： neutrino physics nuetrino mass and mixing model quark mass and mixing analysis of scalar potential