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Promise of metformin for preventing age-related cognitive dysfunction

Neural Regeneration Research 2022年第3期17卷 503-507页

作者： Leelavathi N.madhu Maheedhar kodali Ashok k.Shetty Institute for Regenerative Medicine Department of Molecular and Cellular MedicineTexas A&M University College of MedicineCollege StationTXUSA

The expanded lifespan of people,while a positive advance,has also amplified the prevalence of age-related disorders,which include mild cognitive impairment,dementia,and Alzheimer's ***,competent therapies that could improve the healthspan of people have great *** of the dietary and pharmacological approaches that augment the lifespan could also preserve improved cognitive function in old ***,a drug widely used for treating diabetes,is one such candidate that could alleviate age-related cognitive ***,the possible use of metformin to alleviate age-related cognitive dysfunction has met with conflicting results in human and animal *** most clinical studies have suggested the promise of metformin to maintain better cognitive function and reduce the risk for developing dementia and Alzheimer's disease in aged diabetic people,its efficacy in the nondiabetic population is still ***,a previous animal model study implied that metformin could adversely affect cognitive function in the ***,a recent animal study using multiple behavioral tests has reported that metformin treatment in late middle age improved cognitive function in old *** study also revealed that cognitionenhancing effects of metformin in aged animals were associated with the activation of the energy regulator adenosine monophosphate-activated protein kinase,diminished neuroinflammation,inhibition of the mammalian target of rapamycin signaling,and augmented autophagy in the *** proficiency of metformin to facilitate these favorable modifications in the aged hippocampus likely underlies its positive effect on cognitive ***,additional studies probing the outcomes of different doses and durations of metformin treatment at specific windows in the middle and old age across sex in nondiabetic and non-obese prototypes are required to substantiate the promise of metformin to maintain better cognitive fun

关键词： activated microglia aging autophagy cognitive dysfunction memory metformin mTOR signaling neuroinflammation

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Numerical investigations on HCCI engine with increased induction induced swirl and engine speed

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Journal of Central South University 2015年第10期22卷 3837-3848页

作者： T.karthikeya Sharma G.Amba Prasad Rao k.madhu Murthy Department of Mechanical Engineering NIT

Homogeneous charge compression ignition(HCCI) mode of combustion is popularly known for achieving simultaneous reduction of NOx as well as soot emissions as it combines the compression ignition(CI) and spark ignition(SI) engine features. In this work, a CI engine was simulated to work in HCCI mode and was analyzed to study the effect of induction induced swirl under varying speeds using three-zone extended coherent flame combustion model(ECFM-3Z, compression ignition) of STAR-CD. The analysis was done considering speed ranging from 800 to 1600 r/min and swirl ratios from 1 to 4. The present study reveals that ECFM-3Z model has well predicted the performance and emissions of CI engine in HCCI mode. The simulation predicts reduced in-cylinder pressures, temperatures, wall heat transfer losses, and piston work with increase in swirl ratio irrespective of engine speed. Also, simultaneous reduction in CO2 and NOx emissions is realized with higher engine speeds and swirl ratios. Low speeds and swirl ratios are favorable for low CO2 emissions. It is observed that increase in engine speed causes a marginal reduction in in-cylinder pressures and temperatures. Also, higher turbulent energy and velocity magnitude levels are obtained with increase in swirl ratio, indicating efficient combustion necessitating no modifications in combustion chamber design. The investigations reveal a total decrease of 38.68% in CO2 emissions and 12.93% in NOx emissions when the engine speed increases from 800 to 1600 r/min at swirl ratio of 4. Also an increase of 14.16% in net work done is obtained with engine speed increasing from 800 to 1600 r/min at swirl ratio of 1. The simulation indicates that there is a tradeoff observed between the emissions and piston work. It is finally concluded that the HCCI combustion can be regarded as low temperature combustion as there is significant decrease in in-cylinder temperatures and pressures at higher speeds and higher swirl ratios.

关键词： HCCI engine ECFM-3Z swirl ratio emissions and performance

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Control of peak pressures of an HCCI engine under varying swirl and operating parameters

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Frontiers in Energy 2016年第3期10卷 337-346页

作者： T. kARTHIkEYA SHARMA G. AMBA PRASAD RAO k. madhu MURTHY Department of Mechanical Engineering NIT Warangal Warangal506004 India

The major advantages of homogeneous charge compression ignition （HCCI） are high efficiency in combination with low NOx-emissions. However, one of the major challenges with HCCI is the control of higher peak pressures which may damage the engine, limiting the HCCI engine life period. In this paper, an attempt is made to analyze computationally the effect of induction swirl in controlling the peak pressures of an HCCI engine under various operating parameters. A single cylinder 1.6 L reentrant piston bowl diesel engine is chosen. For computational analysis, the ECFM-3Z model of STAR - CD is considered because it is suitable for analyzing the combustion processes in SI and CI engines. As an HCCI engine is a hybrid version of SI and CI engines, the ECFM- 3Z model with necessary modifications is used to analyze the peak pressures inside the combustion chamber. The ECFM-3Z model for HCCI mode of combustion is validated with the existing literature to make sure that the results obtained are accurate. Numerical experiments are performed to study the effect of varying properties like speed of the engine, piston bowl geometry, exhaust gas recirculation （EGR） and equivalence ratio under different swirl ratios in controlling the peak pressures inside the combustion chamber. The results show that the swirl ratio has a considerable impact on controlling the peak pressures of HCCI engine. A reduction in peak pressures are observed with a swirl ratio of 4 because of reduced in cylinder temperatures. The combined effect of four operating parameters, i.e., the speed of the engine, piston bowl geometry, EGR, and equivalence ratio with swirl ratios suggest that lower intake temperatures, reentrant piston bowl, higher engine speeds and higher swirl ratios are favorable in controlling the peak pressures.

关键词： HCCI engine ECFM-3Z Swirl ratio peak pressures engine speed piston bowl geometry

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An experimental investigation of wire electrical discharge machining of hot-pressed boron carbide

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Defence Technology（防务技术） 2015年第4期11卷 344-349页

作者： Ravindranadh BOBBILI V.madhu A.k.GOGIA Defence Metallurgical Research Laboratory

The present work discusses the experimental study on wire-cut electric discharge machining of hot-pressed boron *** effects of machining parameters,such as pulse on time(TON),peak current(IP),flushing pressure(FP) and spark voltage on material removal rate(MRR)and surface roughness(R_a) of the material,have been *** parameters are found to have an effect on the surface integrity of boron carbide machined *** rate of brass wire increases with rise in input energy in machining of hot-pressed boron *** surfaces of machined samples were examined using scanning electron microscopy(SEM).The influence of machining parameters on mechanism of MRR and R_a was *** was demonstrated that higher TON and peak current deteriorate the surface finish of boron carbide samples and result in the formation of large craters,debris and micro *** generation of spherical particles was noticed and it was attributed to surface tension of molten ***-ridges were also observed on the surface due to protrusion of molten material at higher discharge energy levels.

关键词：电火花加工碳化硼热压制实验扫描电子显微镜材料去除率表面粗糙度电火花线切割

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Design and development of self-cleaning PV sliding system

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Clean Energy 2022年第3期6卷 392-403页

作者： Vinay Gupta madhu Sharma Rupendra Pachauri k N Dinesh Babu Department of Electrical Engineering Manipal University Jaipur-303007India School of Engineering University of Petroleum and Energy StudiesDehradun-248007India Megger Group Ltd MylaporeChennai-600004India

This study describes the designing steps of the proposed self-cleaning system for the photovoltaic(PV)system and experimentally investigates the effectiveness of the proposed self-cleaning PV sliding system for solar power plants under all Indian climate *** investigate the performance of the proposed self-cleaning PV sliding system,we used three PV panels of 20 W with a sliding structure and another set of three PV panels of 20 W with a traditional(fixed)technique,and recorded the output power for the period of December 2019 to April *** experimental results show that the proposed self-cleaning PV sliding system improved efficiency by 18.3%,13.3%and 6.4%,respectively,in the summer,winter and post-monsoon seasons when compared to the fixed PV *** results also revealed that energy consumption was very low when compared to the amount of energy *** proposed system not only cleans the PV system,but also protects it from *** results of this study show that there is a significant improvement in PV efficiency and thus an increase in electricity production under all climate conditions.

关键词： solar energy photovoltaics cleaning soiling hailstorm protection sliding PV system

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A novel inductive technique for microcantilever displacement detection

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Theoretical & Applied Mechanics Letters 2011年第3期1卷 30-35页

作者： madhu Santosh k Mutyala kody Varahramyan Institute for Micromanufacturing Louisiana Tech University Indiana University-Purdue University Indianapolis

A novel inductive technique for the detection of microcantilever displacement for sensing applications was *** highlight the basic structure and evaluate its characteristics with the aid of modeling and *** generated by numerical simulations using ANSOFT are compared with those obtained from an equivalent circuit model using *** are indications that the sensitivity of the inductive cantilever is about one order of magnitude higher as compared to piezoresistive silicon cantilevers of the same dimension under the same cantilever bending.

关键词： inductance magnetic field coupling coefficient

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Ionic liquid-assisted hydrothermal synthesis of SnS nanoparticles:Electrode materials for lithium batteries,photoluminescence and photocatalytic activities

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Journal of Energy Chemistry 2018年第3期27卷 806-812页

作者： k.N.Manukumar G.Nagaraju Brij kishore C.madhu N.Munichandraiah Department of Chemistry Siddaganga Institute of TechnologyTumkurKarnatakaIndia Department of Inorganic and Physical Chemistry Indian Institute of ScienceBangaloreKarnatakaIndiac Department of Physics.Siddaganga Institute of Technology.Tumkur KarnatakaIndia

Tin mono-sulphide（Sn S） nanoparticles（Nps） have been successfully synthesised through ionic liquid assisted hydrothermal method using hydrated tin（II） chloride as a precursor, thiourea as sulphur source precursors using 2-Methoxy ethyl methyl imidazolium methane sulfonate ionic liquid as co-solvent. The Reitveld refinement on powder X-ray diffraction（PXRD） confirmed the presence of orthorhombic Sn S structure as major phase along with traces amount of Sn S2 and Sn2 S3. Diffuse reflectance spectrum studies revealed the energy band gap around 1.38 e V. TEM images confirmed the Sn S Nps with average particle size of 40 nm and HRTEM suggest good crystallinity. The electrochemical property for lithium storage behaviour shows an initial discharge capacity of 658 m Ah/g and it retains discharge capacity of 426 m Ah/g for 16 cycles, at current density 100 m A/g. The obtained results indicate that Sn S Nps to be one of the possible promising anode materials for next generation Lithium batteries. Photoluminescence study of Sn S Nps shows a strong green emission at 530 nm. Sn S Nps were also tested for the photocatalytic adsorption of methylene blue and Rhodamine B.

关键词： Nanoparticles Lithium-ion batteries Ionic liquids Ionothermal

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N-policy for M^(x)/G/1 Unreliable Retrial G-Queue with Preemptive Resume and Multi-services

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Journal of the Operations Research Society of China 2016年第4期4卷 437-459页

作者： Amita Bhagat madhu Jain Department of Applied Sciences The Northcap UniversityGurgaon 122017India Department of Mathematics Indian Institute of Technology RoorkeeRoorkee 247667India

Bulk arrival retrial G-queue with impatient customers and multi-servicessubject to server breakdowns has been analyzed. The system allows the arrival oftwo types of customers: positive customers and negative customers in the *** negative customers make the server fail if they find the server in busy state,whereas positive customers are served if the server is idle otherwise they join thevirtual pool of customers called orbit. The customers from the retrial orbit try theirchance again for the service. The customers have the option of obtaining more than oneservice. Moreover, the customers are impatient and may renege from the system withprobability (1−r ). The server is sent for repair as soon as it breakdowns;after repair,the service process starts again. Also, the server has the provision to initiate the servicewhen there areN customers accumulated in the system. Using supplementary variablestechnique and generating functions, various performance measures like reliabilityindices and long run probabilities have been obtained.

关键词： Retrial queue N-policy vacation Negative customers Reneging Bulk arrival Breakdowns Preemptive resume Multi-services

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An efficient approach for anti-jamming in IRNSS receivers using improved PSO based parametric wavelet packet thresholding

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Satellite Navigation 2022年第3期3卷 51-70,I0003页

作者： Jacob Silva Lorraine kambham madhu Ramarakula Department of ECE University College of EngineeringJNTUKKakinadaAndhra Pradesh533003India

The Indian Regional Navigation Satellite System provides accurate positioning service to the users within and around India,extending up to 1500 ***,when a receiver encounters a Continuous Wave Interference,its positioning accuracy degrades,or sometimes it even fails to *** Packet Transform(WPT)is the most widely used technique for anti-jamming in Global Navigation Satellite System *** the conventional method suffers from threshold drifting and employs inflexible thresholding ***,to address these issues,an efficient approach using Improved Particle Swarm Optimization based Parametric Wavelet Packet Thresholding(IPSO-PWPT)is ***,a new parameter adaptive thresholding function is ***,a new form of inertia weight is presented to enhance the performance of ***,IPSO is used to optimize the key parameters of ***,the implementation of the IPSO-PWPT anti-jamming algorithm is *** performance of the proposed technique is evaluated for various performance metrics in four jamming *** evaluation results manifest the proposed method’s efficacy compared to the conventional WPT in terms of anti-jamming ***,the results show the ability of the new thresholding function to process various signals ***,the findings reveal that the improved PSO outperforms the variants of PSO.

关键词： Continuous wave interference(CWI) IRNSS Particle swarm optimization(PSO) Wavelet packet transform(WPT)

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Reliability Enhanced Multi-objective Economic Dispatch Strategy for Hybrid Renewable Energy System with Storage

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Journal of the Operations Research Society of China 2023年第1期11卷 51-81页

作者： Anongpun Man-Im Weerakorn Ongsakul Nimal madhu Department of Energy Environment and Climate ChangeSchool of EnvironmentResources and DevelopmentAsian Institute of TechnologyKlong LuangPathumthani12120Thailand

An optimal dispatch strategy for the economic operation of hybrid renewable energy system with storage is presented in this paper. Solar photovoltaic (PV), Wind and Battery Storage are the prime components of interest constituting the hybrid system. In addition to the economic aspect of the systems, the formulation focuses on renewable prioritized operation, system reliability and environmental sustainability enhancement. Being a multi-objective (MO) problem, a modified non-dominated sorting particle swarm optimization is used for solving the problem, considering operational cost, pollutant emission, and expected energy not served as operational objectives. The non-dominated sorting particle swarm optimization (NSPSO) is augmented with crowding distance technique, stochastic weight trade-off and chaotic mutation approaches, to control the exploration of global and particle bests, alleviating premature convergence, and enhancing solution search capability. A two-stage approach is used to derive the best solution. A modified IEEE 30-bus test system is used to demonstrate the results. By using the proposed approach, a lower and wider Pareto front is obtained, in comparison with prominent optimization approaches.

关键词： Multi-objective economic dispatch Emission reduction Particle swarm optimization Hybrid energy system Expected energy not served Battery energy storage

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