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Effect of pre-twinning and heat treatment on formability of AZX311 Mg alloy

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Journal of Magnesium and Alloys 2024年第3期12卷 1154-1169页

作者： Mahesh Panchal lalit Kaushik Min-Seong Kim Ravi Kottan Renganayagalu Shi-Hoon Choi Jaiveer Singh Department of Mechanical Engineering Indian Institute of Technology JodhpurKarwarJodhpur 342030RajasthanIndia Department of Metallurgical and Materials Engineering Indian Institute of Technology JodhpurKarwarJodhpur 342030RajasthanIndia Energy Materials Research Center Korea Institute of Science and Technology(KIST)5 Hwarang-roSeongbuk-guSeoul 02792Republic of Korea Department of Advanced Components and Materials Engineering Sunchon National University255 Jungang-roSuncheonJeonnam 57922Republic of Korea

In this study,the effects of pre-strain-induced tensile twins(TTWs)and controlled heat treatment on the formability behavior of AZX311 Mg alloy sheets were investigated.A 4%compressive strain was applied to pre-strain the sheets using the in-plane compression(IPC)technique along the rolling direction(RD)to introduce *** pre-strained(PS)samples were subsequently heat-treated at 250℃,350℃,and 400℃ independently for 1 hr,and are termed as PSA1,PSA2,and PSA3,*** cupping tests were conducted to assess the formability of the sheet samples under different initial *** results showed that the PS sample heat-treated at 250℃ for 1hr exhibited a decrease in the Erichsen index(IE)compared to the as-rolled sample,whereas PSA2 and PSA3 samples showed an increase in IE *** analysis revealed that most of the TTWs generated through pre-twinning were stable at 250℃;however,the twin volume fraction reduced to 41%at 350℃ compared to the PS samples due to enhanced thermal activity at that ***,PSA2 samples showed severe grain coarsening in some areas of the sample,and the fraction of such grains increased in the PSA3 *** stretch formability(IE value)of PSA2 samples showed a 32.3%increase compared to the as-rolled ***,the analysis of the deformed specimen at failure under the Erichsen test indicated that considerable detwinning occurs in the PS and PSA1 samples,whereas dislocation slip activity dominates in the PSA2 and PSA3 samples during stretch *** from detwinning and dislocation slip,deformation twins were also observed in all samples after the Erichsen ***,this work highlights the importance of texture control and its underlying mechanisms via pre-twinning followed by heat treatment and their impact on the room temperature(RT)stretch formability of AZX311 Mg alloy sheets.

关键词： Mg alloys Pre-twinning Texture Formability EBSD.

Modelling Impacts of Climate Change on Maize (<i>Zea mays</i>L.) Growth and Productivity: A Review of Models, Outputs and Limitations

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Journal of Geoscience and Environment Protection 2019年第8期7卷 76-95页

作者： Benjamin Kipkemboi Kogo lalit kumar Richard Koech Philip Langat School of Environmental and Rural Science University of New England Armidale Australia School of Health Medical and Applied Sciences Central Queensland University Bundaberg Australia

The use of crop modelling in various cropping systems and environments to project and upscale agronomic decision-making under the facets of climate change has gained currency in recent years. This paper provides an evaluation of crop models that have been used by researchers to simulate maize growth and productivity. Through a systematic review approach, a comprehensive assessment of 186 published articles was carried out to establish the models and parameterization features, simulated impacts on maize yields and adaptation strategies in the last three decades. Of the 23 models identified, CERES-maize and APSIM models were the most dominant, representing 49.7% of the studies undertaken between 1990 and 2018. Current research shows projected decline in maize yields of between 8% - 38% under RCP4.5 and RCP8.5 scenarios by the end of the 21st century, and that adaptation is essential in alleviating the impacts of climate change. Major agro-adaptation options considered in most papers are changes in planting dates, cultivars and crop water management practices. The use of multiple crop models and multi-model ensembles from general circulation models (GCMs) is recommended. As interest in crop modelling grows, future work should focus more on suitability of agricultural lands for maize production under climate scenarios.

关键词： Crop Modelling Climate Scenarios Maize Simulation GCM

Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

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Asian Journal of Andrology 2000年第2期2卷 103-109页

作者： Nirmal K Lohiya lalit K Kothari B Manivannan Pradyumna K Mishra Neelam Pathak Reproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India Reproductive Medicine Clinic 50 Gem Enclave Malviya Nagar Jaipur IndiaReproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India Reproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India Reproductive Physiology Section Department of Zoology University of Rajasthan Jaipur-302 004 India

Aim: To examine if the seed extracts of Carica papaya, which showed anfispermatogenic/sperm immobilizationproperties in animal models, could cause human sperm immobilization in vitro. Methods: Chloroform extract, ben-zene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolatedcompounds from the sub-fractions i. e., ECP 1 & 2 and MCP 1 & 2, of the seeds of Carica papaya were used at con-centrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and ev-ery 5 minutes thereafter for 30 minutes. Results: There were dose-dependent spermicidal effects showing an instantfall in the sperm motility to less than 20% at 2% concentration. Isolated compounds ECP 1 & 2 were more effective in-ducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motilitywas observed within 20-25 rain at all concentrations of all products. Scanning and transmission electron microscopyrevealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability testand the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were *** effects were spermicidal but not spermiostatic as revealed by the sperm revival test. Conclusion: The results re-veal spermicidal activity in vitro of the seed extracts of Carica papaya.

关键词： human sperm sperm immobilization spermicidal agents Carica papaya

Recent advances in the in-plane shear testing of Mg alloy sheets

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Journal of Magnesium and Alloys 2023年第2期11卷 405-424页

作者： Mahesh Panchal lalit Kaushik Ravi K.R Rajesh Khatirkar Shi-Hoon Choi Jaiveer Singh Department of Mechanical Engineering Indian Institute of Technology JodhpurKarwarJodhpur 342030RajasthanIndia Department of Advanced Components and Materials Engineering Sunchon National University255 Jungang-roSuncheonJeonnam 57922Republic of Korea Department of Metallurgical and Materials Engineering Indian Institute of Technology JodhpurKarwarJodhpur 342030RajasthanIndia Department of Metallurgical and Materials Engineering Visvesvaraya National Institute of Technology(VNIT)South Ambazari RoadNagpur 440010MaharashtraIndia

Sheet-metal products are integral parts of engineering industries and academia research. Various testing techniques have revealed the deformation behaviors of sheet metals under complex stress states. Information obtained from tensile and compression tests, however, are insufficient for the identification of material parameters relevant to modern constitutive laws, which require experimental setups capable of generating various loading conditions and applying great amounts of strain to sheet metals. In-plane shear testing has emerged as an important method to overcome the challenges associated with tension and compression tests and can provide additional information about deformation behaviors under large plastic strains. Materials such as Mg alloys with poor levels of both ductility and formability cannot accommodate large plastic strains. Therefore, tension and compression tests have limitations in explaining the material behaviors that occur during sheet metal forming where large plastic strains are introduced. Many studies have been conducted to explain the deformation behaviors of Mg alloys under shear deformation techniques. These include severe plastic deformation(SPD), especially the equal channel angular pressing(ECAP)and equal channel angular extrusion, rolling combined with shear deformation i.e. differential speed rolling(DSR), and also in-plane shear for sheet metals, particularly under large levels of plastic strain. These in-plane shear technique involves the Miyauchi shear test, ASTM shear test, and twin bridge shear tests. Moreover, many experimental results have revealed that the evolution of microstructure and texture during in-plane shear is closely related to the failure behavior of materials. Therefore, this review is focused on techniques for in-plane shear testing that have been reported thus far, on the effect of in-plane shear on the microstructure development of Mg alloy sheets, and on the usefulness of in-plane shear testing to evaluate t

关键词： Mg alloys In-plane shear Texture Formability EBSD

Protective effect of Ocimum sanctum Linn. leaf extract on ethanol withdrawal syndrome in Wistar rats

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Asian Pacific Journal of Tropical Medicine 2018年第8期11卷 467-472页

作者： lalit Sharma Aditi Sharma G.L.Gupta Gopal Singh Bisht Department of Pharmacy Jaypee University of Information Technology School of Pharmaceutical Sciences Sholini University Department of Pharmacology SPPSPTM SVKM'S NMIMS University Department of BT and BI Jaypee University of Information Technology

Objective: To evaluate the effects of Oscimum sanctum L(O. sanctum), an important medicinal herb, on alcohol withdrawal syndrome in Wistar rats. Methods: Liquid diet with 7.2%, v/v ethanol was administered to the rats for 21 d. Control group animals received sucrose as an isocaloric liquid diet. After alcohol withdrawal, rats were examined at 6 th and 24 th hour for major withdrawal signs that included anxiety and hyper locomotor activity. Ethanol withdrawal anxiety was tested using elevated plus maze, light and dark model; the hyper locomotor activity using actophotometer. O. sanctum leaf extract(100, 200 and 300 mg/kg, oral) and diazepam(2 mg/kg, i.p) were administered to the treatment group animals 30 min before alcohol withdrawal estimation. Drug treatment was also given 30 min before the second observation at 24 th hour. On the last day of the protocol, rats were sacrificed by cervical dislocation liver, kidney and brain were isolated and preserved in formalin for further histopathological examination. Results: Findings from the present study revealed that O. Sanctum leaf extract treatment at doses 100, 200 and 300 mg/kg, oral had a significant protective effect on signs and symptoms of ethanol withdrawal in alcohol-dependent rats. However, no remarkable pathological and microscopic alterations were observed in histopathological examination. Conclusions: O. sanctum seems to be an active drug for the treatment of alcohol abstinence syndrome.

关键词： Oscimum sanctum Ethanol withdrawal syndrome Anxiety Hyperlocomotor activity Histopathology

The Potential Contribution of Wildlife Sanctuary to Forest Conservation: A Case Study from Binsar Wildlife Sanctuary

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Journal of Mountain Science 2013年第5期10卷 854-865页

作者： Balwant RAWAT Vikram S.NEGI Janhvi MISHRA RAWAT lalit M.TEWARI Laxmi RAWAT G.B. Pant Institute of Himalayan Environment and Development Kosi-Katarmal Forest Research Institute DehradunMolecular TaxonomyBotany Division Department of Botany D.S.B. CampusKumaun University Forest Research Institute DehradunForest Ecology and Environment Division

Forest vegetation of a protected area （Binsar Wildlife Sanctuary） in Kumaun region （west Himalaya） was analysed for structure, composition and representativeness across three different altitudinal belts, lower （1,6oo-1,8oo m a.s.1.）, middle （1,900-2,100 m a.s.1.） and upper （2,200-2,400 m a.s.1.） during 2oo9-2011 using standard phytosociological methods. Four aspects （east, west, north and south） in each altitudinal belt were chosen for sampling to depict maximum representation of vegetation in the sanctuary. Population structure and regeneration behaviour was analysed seasonally for two years to show the establishment and growth of tree species. A total of 147 plant species were recorded from the entire region of which 27 tree species were selected for detailed study. Highest number was recorded at upper （18 species）, and lowest at lower altitudinal belt （15 species）. The relative proportion of species richness showed higher contribution of tree layer at each altitudinal belt. The population structure, based on the number of individuals, revealed a greater proportion of seedling layer at each altitudinal belt. The relative proportion of seedlings increases significantly along altitudinal belts （p〈0.05） while opposite trends were observed in sapling and tree layers. The density of sapling and seedling species varied non-significantly across seasons （p〉0.05）. The density values decreased in summer and increased during rainy season. As far as the regeneration status is concerned, middle and upper altitudinal belts showed maximum number of species with fair regeneration as compared to lower altitudinal belt. Overall density diameter distribution of tree species showed highest species density and richness in the smallest girth class and decreased in the succeeding girth classes. This study suggests that patterns of regeneration behaviour would determine future structural and compositional changes in the forest communities. It is suggested that the compositional changes v

关键词： Altitudinal gradient Populationstructure Regeneration status West Himalaya Wildlife Sanctuary.

Swarm-LSTM: Condition Monitoring of Gearbox Fault Diagnosis Based on Hybrid LSTM Deep Neural Network Optimized by Swarm Intelligence Algorithms

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Computers, Materials & Continua 2021年第2期66卷 2041-2059页

作者： Gopi Krishna Durbhaka Barani Selvaraj Mamta Mittal Tanzila Saba Amjad Rehman lalit Mohan Goyal School of Electrical and Electronics Sathyabama Institute of Science and TechnologyChennai600119India Department of Computer Science and Engineering G.B.Pant Government Engineering CollegeNew Delhi110020India Artificial Intelligence and Data Analytics(AIDA)Laboratory CCISPrince Sultan UniversityRiyadh11586Saudi Arabia Department of Computer Engineering J.C.Bose University of Science and TechnologyFaridabad121006India

Nowadays,renewable energy has been emerging as the major source of energy and is driven by its aggressive expansion and falling *** of the renewable energy sources involve turbines and their operation and maintenance are vital and a difficult *** monitoring and fault diagnosis have seen remarkable and revolutionary up-gradation in approaches,practices and technology during the last *** mostly do use a rotating type of machinery and analysis of those signals has been challenging to localize the *** paper proposes a new hybrid model wherein multiple swarm intelligence models have been evaluated to optimize the conventional Long Short-Term Memory(LSTM)model in classifying the faults from the vibration signals data acquired from the *** helps to analyze the performance and behavioral patterns of the system more effectively and efficiently which helps to suggest for replacement of the unit with higher *** results have demonstrated that the proposed hybrid modeling approach is effective in classifying the faults of the gearbox from the time series data and achieve higher diagnostic accuracy in comparison to the conventional LSTM methods.

关键词： Gearbox long short term memory fault classification swarm intelligence optimization condition monitoring

A Distributed Weighted Cluster Based Routing Protocol for MANETs

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Wireless Sensor Network 2011年第2期3卷 54-60页

作者： Naveen Chauhan lalit kumar Awasthi Narottam Chand Vivek Katiyar Ankit Chugh 不详

Mobile ad-hoc networks (MANETs) are a form of wireless networks which do not require a base station for providing network connectivity. Many MANETs’ characteristics that distinguish MANETs from other wireless networks also make routing a challenging task. Cluster based routing is a MANET routing schemes in which various clusters of mobile nodes are formed with each cluster having its own clusterhead which is responsible for routing among clusters. In this paper we propose and implement a distributed weighted clustering algorithm for MANETs. This approach is based on combined weight metric that takes into account several system parameters like the node degree, transmission range, energy and mobility of the nodes. We have evaluated the performance of the proposed scheme through simulation in various network situations. Simulation results show that improved distributed weighted clustering algorithm (DWCAIMP) outperforms the original distributed weighted clustering algorithm (DWCA).

关键词： MANETs Clustering Routing Wireless Communication Distributed Clustering

Subacute posttraumatic ascending myelopathy： A case report and review of literature

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Chinese Journal of Traumatology 2015年第1期18卷 48-50页

作者： Mukul Mohindra V.K. Gautam lalit Maini Santosh kumar Saurabh Verma Department of Orthopaedics Maulana Azad Medical College and Associated Hospitals New Delhi India

Subacute posttraumatic ascending myelopathy is a rare disorder, unrelated to syrinx formation or mechanical instability, which may gradually emerge within the first 1-2 weeks after a spinal cord injury and may lead to diagnostic and prognostic dilemmas. We present a case of 24-year-old female with unstable wedge compression fracture of Ll vertebrae with signal changes in the upper lumbar cord causing complete paraplegia below D9 with bladder and bowel involvement. In the subsequent week, she developed a delayed progressively increasing neurological deficit with cord signal abnormality on MRI extending cephalad from the injury site to the upper dorsal cord. The patient had no initial clinical improvement initially but showed a delayed recovery over months.

关键词： Posttraumatic ascending myelopathy Spinal cord injury Wedge compression fracture