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Journal of Magnesium and Alloys 2019年第4期7卷 661-671页

作者： prakash kumar sahu Nikhil P Vasudevan Bipul Das Sukhomay Pal Department of Mechanical Engineering and IDM Joint Lab Tsinghua UniversityBeijing 100084China Larsen and Toubro Limited HaziraSuratGujarat 394510India Department of Mechanical Engineering National Institute of Technology Silchar788010 AssamIndia Department of Mechanical Engineering Indian Institute of Technology Guwahati781039 AssamIndia

Research work presented in this study has the primary target of exploring joint attributes of AZ31 magnesium alloys using friction stir welding process with a modified tool referred as bobbin *** of inert and open atmosphere on mechanical properties are evaluated over a wide range of welding speed and tool rotation *** of the research findings from the inert atmosphere bobbin tool were made with the traditional process of friction stir *** results depicted improved joint properties for inert atmosphere *** and intermediate range of tool rotational speed is found to be favorable for bobbin tool friction stir welding without and with an inert medium,*** atmosphere due to inert medium leads to less oxidation of the AZ31 Mg alloy leading to superior joint *** investigations are also made with the aim of evaluating the impact of bobbin tool and inert medium on joint *** each aspect for joining of AZ31 Mg alloy,bobbin tool with inert medium is found to be an effective solution for joining with improved mechanical properties compared to without inert bobbin tool as well as conventional tool friction stir welding.

关键词： Mg FSW Bobbin tool Process parameters Mechanical properties Fractography Microstructural characterization

Multi-response optimization of process parameters in friction stir welded AM20 magnesium alloy by Taguchi grey relational analysis

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Journal of Magnesium and Alloys 2015年第1期3卷 36-46页

作者： prakash kumar sahu Sukhomay Pal Department of Mechanical Engineering Indian Institute of Technology Guwahati781039 AssamIndia

The purpose of this paper is to optimize the process parameter to get the better mechanical properties of friction stir welded AM20 magnesium alloy using Taguchi Grey relational analysis(GRA).The considered process parameters are welding speed,tool rotation speed,shoulder diameter and plunging *** experiments were carried out by using Taguchi's L18 factorial design of *** processes parameters were optimized and ranked the parameters based on the *** percentage influence of each process parameter on the weld quality was also quantified.A validation experimental run was conducted using optimal process condition,which was obtained from the analysis,to show the improvement in mechanical properties of the *** study also shows the feasibility of the GRA with Taguchi technique for improvement in welding quality of magnesium alloy.

关键词： Friction stir welding Magnesium alloy Tensile strength Bending strength Micro-hardness Optimization Taguchi Grey relational analysis

Hybrid fuzzy-grey-Taguchi based multi weld quality optimization of Al/Cu dissimilar friction stir welded joints

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Advances in Manufacturing 2016年第3期4卷 237-247页

作者： prakash kumar sahu Kanchan kumari Sukhomay Pal Surjya K. Pal Department of Mechanical Engineering Indian Institute of Technology Guwahati Guwahati Assam 781039 India Department of Mechanical Engineering Indian Institute of Technology Kharagpur Kharagpur West Bengal 721302India

Nowadays aluminum alloys substitute copper in various applications for weight reduction and cost savings. This paper presents fuzzy-grey Taguchi technique for optimization of friction stir welding condition with seven weld quality attributes of dissimilar A1/Cu joints with the minimum number of experiments for effective productivity and product quality. Taguchi＇s L16 orthogonal array was used to conduct the experiments. Fuzzy inference system was adapted to convert the multi quality characteristics into an equivalent single quality parameter which was opti- mized by Taguchi approach. Four parameters namely, rotational speed of the tool, welding speed, plunging depth and tool pin offset were varied in four levels for investi- gating the effects on the process output like tensile strength, compressive strength, percentage of elongation, bending angle, weld bead thickness and average hardness at the nugget zone. The hardness profile is consistent with the variation of the structure within the nugget zone （NZ）. Confirmation experiment was conducted using predicted optimum parameter setting and it showed that the proposed approach could efficiently optimize weld quality parame- ters. The microstructural analyses were also performed for all the zones of the joints at both Al and Cu sides. It revealed the finer grain size at the NZ compared to the base material due to dynamic recrystallization.

关键词： Dissimilar friction stir welding - Grey relational analysis. Fuzzy inference system Multi-response optimization Mechanical properties Microstructural analysis

Comparative Studies of Different Organs of Nyctanthes arbortristis in Modulation of Cytokines in Murine Model of Arthritis

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Biomedical and Environmental Sciences 2007年第2期20卷 154-159页

作者： BRIJESH RATHORE BHOLANATH PAUL BHUSAN P CHAUDHURY ASHOK kumar SAXENA ANAND prakash sahu YOGENDRA kumar GUPTA Immunobiology Laboratory Central Pathology Laboratory Preventive Toxicology Laboratory Industrial Toxicology Research Centre M. G. MargLucknow 226001India

Objective To study the modulation effect of pro- and anti-inflammatory cytokines following long term use of water soluble ethanol extracts from different organs of Nyctanthes arbortristis （NAT） in mouse model of arthritis. Methods Arthritis was induced in mice by two injections of Freund＇s complete adjuvant on days 0 and 12 in the sub-planter surface of the right hind paw. Results Injection of adjuvant resulted in a maximum primary edema of the footpad with erythema, and edema and distortion of joints of the right hind paw after 24-48 hours. Second injection of FCA led to the formation of secondary swellings persisting more than four weeks that spread onto the other hind limb but to a lesser extent. Histological analysis of the ankle on day 47 showed marked evidence of cartilage destruction in association with pannus formation and moderate bone resorption. Proinfiammatory cytokine levels in the inflamed joint homogenate were elevated on days 2, 14, and 47. Oral administration of leaf and fruit extracts in arthritic mice reduced joint homogenate levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 on days 2, 14, and 47 in comparison to untreated arthritic mice. Intedeukin-10 level was elevated in the inflamed joint on days 2, 14, and 47 in comparisons to untreated arthritic mice. Confusion Evidence of lesser inflammation of the footpad and joint and associated histological observation support the therapeutic benefit of leaf and fruit extracts from Nyctanthes arbortristis. This study helps in understanding the mechanism of anti-inflammatory action of Nyctanthes arbortristis in the light of pro- and anti-inflammatory cytokine balance.

关键词： Nyctanthes arbortristis Arthritis TNF-α IL- 1β IL-6 IL-10

Silica Induced Early Fibrogenic Reaction in Lung of Mice Ameliorated by Nyctanthes arbortristis Extract

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Biomedical and Environmental Sciences 2002年第3期15卷 215-222页

作者： BHOLA NATH PAUL ANAND prakash SIRISH kumar AJAY KYADAV UMANI ASHOK KSAXENA ANAND prakash sahu KEWAL LAL KALYAN KDUTTA Immunobiology Laboratory Industrial Toxicology Research CentreM.G.MargLucknow 226001U.P.India Inhalation Toxicology Laboratory Industrial Toxicology Research CentreM.G.MargLucknow 226001U.P.India Preventive Toxicology Laboratory Industrial Toxicology Research CentreM.G.MargLucknow 226001U.P.India

Objective To investigate the pharmacological effect of Nyctanthes arbortristis (NAT) leaf extract in the prevention of lung injury induced by silica particles. Method Lung injury was induced in Swiss mice through inhalation exposure to silica particles (<5m) using a Flow Past Nose Only Inhalation Chamber at the rate of -10 mg/m3 respirable mass for 5 h. Lung bronchoalveolar lavage (BAL) fluid collected between 48 and 72 h was subjected to protein profiling by electrophoresis and cytokine evaluation by solid phase sandwich ELISA. Lung histopathology was performed to evaluate lung injury. Results Inhalation of silica increased the level of tumor necrosis factor-a (TNF-a), and of the 66 and 63 kDa peptides in the BAL fluid in comparison to sham-treated control. Pre-treatment of silica exposed mice with NAT leaf extract significantly prevented the accumulation of TNF-a in the BAL fluid, but the 66 and 63 kDa peptides remained unchanged. The extract was also effective in the prevention of silica-induced early fibrogenic reactions like congestion, edema and infiltration of nucleated cells in the interstitial alveolar spaces, and thickening of alveolar septa in mouse lung. Conclusion NAT leaf extract helps in bypassing silica induced initial lung injury in mice.

关键词： Nyctanthes arbortristis Lung-injury Silica Mice prevention

Assessment of long-term climate variability and its impact on the decadal growth of horticultural crops in central India

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Ecological Processes 2022年第1期11卷 862-889页

作者： Gaurav Sharma Amita Sharma Nishant kumar Sinha Om prakash Sharma Ashutosh Singh Ajai kumar Pandey Abhishek kumar Sudhir kumar Trivedi Bharti Sao Mukesh kumar sahu College of Horticulture and Forestry Rani Lakshmi Bai Central Agricultural UniversityJhansiUttar Pradesh 284003India Department of Environmental Science Rajmata Vijayaraje Scindia Krishi VishwavidyalayaGwaliorMadhya Pradesh 474002India Division of Soil Physics Indian Institute of Soil ScienceBhopalMadhya Pradesh 462038India Department of Floriculture and Landscape Architecture Indira Gandhi Krishi VishwavidyalayaRaipurChhattisgarh 492012India

Background:The impact of climate change on horticultural production is of utmost concern *** such vulnerable region of horticultural importance is the Madhya Pradesh state in the central part of *** is crucial to analyse the long-term trend in climatic variations and its effect on horticultural crop ***,this study focuses on detecting trends in mean annual precipitation and temperature of 115 years for the 15 districts covering all the regions of the state as well as projections of all the Representative Concentration Pathway(RCP)climatic scenarios for 2050 and 2080 of Madhya Pradesh *** decadal(2010–2020)insight into the area and production of horticultural crops is undertaken which will help forecasting the future growth *** a better insight,case study on four horticultural crops is undertaken to assess their decadal growth trend vis-à-vis climate parameters in these 15 ***:The Mann–Kendall test for 1901–2016 and Sen’s slope indicated a non-significant change in long-term trend for precipitation except for increasing change in Khargone and decreasing change in Rewa ***-cant increasing trend of average temperature is obtained for Hoshangabad,Jabalpur,Sagar and Rewa *** Sen’s slope indicated an increase of 0.005 to 0.009℃for maximum temperature and 0.005 to 0.012℃for minimum temperature *** projections of all the RCP climate scenarios for the years 2050 and 2080 indicated non-significant variation in precipitation but an increase in maximum(1.4 to 4.1℃)and minimum(1.45 to 4.65℃)annual *** increasing trend in area and production for horticultural crops is also observed in central India for the study *** is yield increase in all the crops selected in case study except for potato,which recorded a decreased yield between the years 2010–***:The Mann–Kendall test and projections indicate towards climate change with a temperature *** the decad

关键词： Climate change Horticulture Madhya Pradesh Precipitation Temperature Trend analysis

Adaptive Tracking Control of an Autonomous Underwater Vehicle

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International Journal of Automation and computing 2014年第3期11卷 299-307页

作者： Basant kumar sahu Bidyadhar Subudhi Centre for Industrial Electronics and Robotics Department of Electrical Engineering National Institute of Technology

This paper presents the trajectory tracking control of an autonomous underwater vehicle(AUV). To cope with parametric uncertainties owing to the hydrodynamic effect, an adaptive control law is developed for the AUV to track the desired trajectory. This desired state-dependent regressor matrix-based controller provides consistent results under hydrodynamic parametric *** of the developed controller is verified using the Lyapunov s direct method. Numerical simulations are carried out to study the efficacy of the proposed adaptive controller.

关键词： Autonomous underwater vehicle(AUV) adaptive control law regressor matrix Lyapunovs stability path following

DYNAMICAL BEHAVIOR OF AN INNOVATION DIFFUSION MODEL WITH INTRA-SPECIFIC COMPETITION BETWEEN COMPETING ADOPTERS

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Acta Mathematica Scientia 2022年第1期42卷 364-386页

作者： Rakesh kumar Anuj kumar SHARMA Govind Prasad sahu Department of Applied Sciences Shaheed Bhagat Singh State UniversityFerozepurPunjab 152004India Department of Mathematics L.R.D.A.V.CollegeJagraonLudhianaPunjab 142026India Center for Basic Sciences Pt Ravishankar Shukla UniversityRaipur(Chhattisgarh).India

In this paper,we proposed an innovation diffusion model with three compartments to investigate the diffusion of an innovation(product)in a particular *** model exhibits two equilibria,namely,the adopter-free and an interior *** existence and local stability of the adopter-free and interior equilibria are explored in terms of the effective Basic Influence Number(BIN)R_(A).It is investigated that the adopter free steady-state is stable if R_(A)<*** consideringτ(the adoption experience of the adopters)as the bifurcation parameter,we have been able to obtain the critical value ofτresponsible for the periodic solutions due to Hopf *** direction and stability analysis of bifurcating periodic solutions has been performed by using the arguments of normal form theory and the center manifold *** numerical simulations in the support of analytical results have been presented.

关键词： intra-specific competition basic influence number local stability Hopf-bifurcation normal form theory center manifold theorem

Maize gets an iron boost:Biofortification breakthrough holds promise to combat iron deficiency

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Journal of Integrative Plant Biology 2024年第4期66卷 635-637页

作者： Sunil kumar sahu State Key Laboratory of Agricultural Genomics Key Laboratory of GenomicsMinistry of AgricultureBGI ResearchShenzhen 518083China BGI Research Wuhan 430074China

Micronutrient deficiencies affect more than two billion people worldwide,resulting in poor health,developmental issues,and even *** deficiency is one of the most prevalent micronutrient deficiencies worldwide and impa... 详细信息

关键词： population breakthrough holds

Structural Tuning of Low Band Gap Intermolecular Push/Pull Side-chain Polymers for Organic Photovoltaic Applications

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Chinese Journal of Polymer Science 2017年第9期35卷 1073-1085页

作者： Ansuman Nayak P.S. Rama Sreekanth Santosh kumar sahu Duryodhan sahu Department of Chemistry National Institute of Science and Technology Palur Hills Berhampur Odisha India 761008 Department of Chemistry Gandhi Institute of Engineering and Technology Gunpur Odisha India Department of Mechanical Engineering National Institute of Science and Technology Palur Hills Berhampur Odisha India 761008

A series of novel low band gap donor-acceptor （D-A） type organic co-polymers （BT-F-TPA, BT-CZ-TPA and BT-SI-TPA） consisting of electron-deficient acceptor blocks both in main chains （M1） and at the pendant （M2） were polymerized with different electron rich donor （M3-M5） blocks, i.e., 9,9-dihexyl-9H-fluorene, N-alkyl-2,7-carbazole, and 2,6-dithinosilole, respectively, via Suzuki method. These polymers exhibited relatively low band gaps （1.65-1.88 eV） and broad absorption ranges （680-740 nm）. Bulk heterojunction （BHJ） solar cells incorporating these polymers as electron donors, blended with [6,6]-phenyl-C61-butyric acid methyl ester （PC61BM） or [6,6]-phenyl-Cvl-butyric acid methyl ester （PC71BM） as electron-acceptors in different weight ratios were fabricated and tested under 100 mW/cm2 of AM 1.5 with white-light illumination. The photovoltaic device containing donor BT-SI-TPA and acceptor PC71BM in 1：2 weight ratio showed the best power conversion efficiency （PCE） value of 1.88%, with open circuit voltage （Voc） = 0.75 V, short circuit current density （Jsc） = 7.60 mA/cm2, and fill factor （FF） = 33.0%.

关键词： Polymer solar cells Low band gap Conducting polymers Charge transfer Donor-acceptor Bulk heterojunctionsolar cell