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Impact of invasive Ageratina adenophora on relative performance of woody vegetation in different forest ecosystems of kumaun Himalaya,India

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Journal of Mountain Science 2023年第9期20卷 2557-2579页

作者： Bhawna NEGI kavita kHATrI Surendra S.BArGALI kiran BArGALI Archana FArTYAL r.k.chaturvedi Department of Botany D.S.B CampusKumaun UniversityNainital-263002UttarakhandIndia Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglun 666303China

Invasive plant Ageratina adenophora(Sprengel)***&*** has invaded majority of the temperate forests in kumaun,Central *** on *** invaded forest types,their structural attributes,population demography and regeneration status are still at rudimentary *** this,the present study was conducted to assess the impacts of *** on vegetational attributes and regeneration status of three forest types,viz.,Oak(Quercus oblongata ***),Pine(Pinus roxburghii Sarg.)and Cypress(Cupressus torulosa ***).We selected three sites for each forest type and each site was further purposively stratified into paired sampling plots of 1 ha each i.e.,*** invaded and uninvaded *** results showed large densities of cut stumps or felled trees throughout invaded sites,but with fewer fire signs in comparison to uninvaded *** uninvaded sites,total density and basal area calculated for woody species were relatively higher than those in invaded sites,although results were insignificant(p>0.05).With the exception for Cypress forests,vegetation indices showed low woody species richness and diversity in invaded Oak and Pine ***,regeneration of ***,*** and *** tree species did not differ significantly(p>0.05)between invaded and uninvaded *** insignificant differences clearly imply that ***'s presence has not entirely changed the perennial plant communities in terms of composition,structure and natural ***,tree species with poor or no regeneration status requires special attention and needs management strategies involving control of invasive species in forest ecosystems.

关键词： Ageratina adenophora Seedling density Forests Population structure regeneration

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Computer aided design and analysis of a tunable muzzle brake

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Defence Technology（防务技术） 2019年第1期15卷 89-94页

作者： Ekansh chaturvedi ravi k.Dwivedi Department of Mechanical Engineering Maulana Azad National Institute of Technology

This research work deals with the design of a tunable muzzle brake [10] for a rifle chambered in 5.56 x 45 NATO ammunition. It proposes to solve the problem of handling differences from shooter to shooter by incorporating the feature of tunability. Beside this, it also solves the problem of requirement of optimum recoil in short recoil weapons. This innovation gives this design an edge over its already existing counterparts in the market. The product is designed using the internal ballistics calculations and the investigations been performed using solidworks flow simulation tool and ANSYS static structural to check the parameters like velocity distribution, pressure growth, and muzzle brake force along the series of ports and comparison of the so found results with those devised by the authors of the documents mentioned in references. This assures the market adaptability of the product for satisfactory performance, when brought among its already existing counterpart, though with a slight edge over them due to tunability. The results so found shall be concluded satisfactory regarding the performance of muzzle brake.

关键词： Flow simulation Innovation Muzzle brake Tunability Set screws

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Effect of extrusion on properties of Al-based composite

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Transactions of Nonferrous Metals Society of China 2010年第12期20卷 2229-2233页

作者： r.DASGUPTA S.DAS S.chaturvedi A.k.JHA Advanced Materials and Processes research Institute CSIR Bhopal 462064Madhya PradeshIndia

An aluminium alloy and its composite with dispersed SiC particles made by liquid metallurgy route were extruded under optimized *** properties were characterized in terms of microstructure,hardness and sliding wear behaviour and then compared between the extruded and cast alloys and composites,in order to understand the benefits of composite and extrusion on the *** was observed that composites drastically increased the hardness and the extruded composites further increased this *** advantage of composites was realized in sliding wear tests.

关键词： extrusion Al-alloy composites microstructure wear

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Numerical investigation of dynamic interaction with projectile and harmonic behaviour for T-finned machine gun barrels

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Defence Technology（防务技术） 2020年第2期16卷 460-469页

作者： Ekansh chaturvedi Maulana Azad National Institute of Technology Bhopal 462003India

Machine gun barrels differ from their rifle counterparts in terms of *** support high rates of sustained fire,machine gun barrels are made thicker in order to dissipate more heat and maintain their flexural rigidity and thus accuracy,but on other hand they also contribute in weight addition to *** investigation deals with comparison between a conventional machine gun barrel and an improved innovative design having T-fins,both having same weight and chambered in 5.56×45 NATO ammunition,to compare their structural and harmonic characteristics which were parameterized by factors such as modal spectrum,directional deformation at muzzle ends during a single shot fire and harmonic behaviour at corresponding range of exciting *** solid models of both the barrels having same weight,were created using *** continuous input data functions were generated by MATLAB using the field tested discreet data *** generated velocity-distance functions were converted into time dependent functions using integration algorithms to calculate transient parameters such as time steps,excitation frequency range,angle of rotation of projectile and its angular *** dynamic condition simulated the varying nature of forces due to eccentricity in projectile and this data was fed to a time step study using ANSYS transient structural work bench followed by modal and harmonic *** results showed a significant reduction in muzzle end deformation which thus proved that the T-finned barrel,although had same weight as that of the conventional one,but had better structural and harmonic characteristics,and hence it would inherit better firing accuracy.

关键词： FSHP Machine guns Pseudo-I section Second order mesh Transient behaviour

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A high methionine,low folate and vitamin B_6/B_(12) containing diet can be associated with memory loss by epigenetic silencing of netrin-1

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Neural regeneration research 2019年第7期14卷 1247-1254页

作者： Anuradha kalani Pankaj chaturvedi komal kalani Pradip k.kamat Poonam chaturvedi Neetu Tyagi Department of Physiology School of MedicineUniversity of Louisville Medicinal Chemistry Department CSIR-Central Institute of Medicinal and Aromatic Plants Pharmacology Department and Toxicology Higuchi Biosciences CenterUniversity of Kansas Department of Neurology Dr.Ram Manohar Lohia Institute of Medical Sciences

Memory-epigenetics which is the loss of memory due to epigenetic modifications can be due to the silencing of genes involved in cognitive functions and this is the basis of the current *** hypothesize that a diet containing high methionine and low vitamins can lead to memory impairment by increasing global DNA methylation and therefore,silencing the netrin-1 gene,which encodes the glycoprotein involved in neurogenesis,axonal guidance and maintenance of the synaptic *** type(C57 BL/6 J) mice were fed with a diet containing excess methionine(1.2%),low-folate(0.08 mg/kg),vitamin B_6(0.01 mg/kg),and B_(12)(10.4 mg/kg) for 6 *** were examined weekly for the long-term memory function,using a passive avoidance test,which determined loss of fear-motivated long-term memory starting from the fourth week of ***,an increase in brain %5-methyl cytosine was observed starting from the 4 th week of diet in *** fed with a high methionine,low folate and vitamins containing diet showed a decrease in netrin-1 protein expression and an increase in netrin-1 gene promotor methylation,as determined by methylation-sensitive restriction enzyme-polymerase chain reaction *** increase in methylation of netrin-1 gene was validated by high-resolution melting and sequencing ***,the association of netrin-1 with memory was established by administering netrin that considerably restored long-term fear motivated *** together,these results suggest that a diet rich in methionine and lacking in folate and vitamin B_6/B_(12) can induce defects in learning and ***,the data indicates that decrease in netrin-1 expression due to hyper-methylation of its gene can be associated with memory *** animal procedures were approved by the Institutional Animal Care and Use Committee,University of Louisville,USA(No.A3586-01) on February 2,2018.

关键词： Alzheimer’s disease epigenetics memory methionine 5-methylcytosine methylation netrin-1

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Application of a probabilistic LHS-PAWN approach to assess building cooling energy demand uncertainties

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Building Simulation 2022年第3期15卷 373-387页

作者： Shobhit chaturvedi Elangovan rajasekar Department of Architecture and Planning Indian Institute of TechnologyRoorkeeIndia

A deterministic approach to building energy simulation risks the omission of real-world uncertainties leading to prediction *** paper highlights limitations of this approach by contrasting it with a probabilistic uncertainty/sensitivity simulation *** hypercube sampling(LHS)generates 15000 unique model configurations to assess the effects of weather,physical and operational uncertainties on the annual and peak cooling energy demands for a residential building which situated in a hot and dry climatic *** simulations predicted 0.22–2.17 and 0.45–1.62 times variation in annual and peak cooling energy demands,respectively,compared to deterministic simulation.A novel density-based global sensitivity analysis(SA),i.e.,PAWN,is adopted to identify dominant input *** traditional SA methods,PAWN allows simultaneous treatment of continuous and categorical inputs from a generic input-output *** is favourable when computational resources are limited and model outputs are skewed or *** annual and peak cooling demands,the effects of weather and operational parameters associated with airconditioner and window operation are much stronger than these of other parameters ***,these parameters warrant greater attention during modelling and simulation *** and convergence analysis also confirm the validity of these results.

关键词： building energy code(BEC) cooling energy demand uncertainty analysis PAWN sensitivity analysis

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ESTIMATION OF A SUBSET OF rEGrESSION COEFFICIENTS OF INTErEST IN A MODEL WITH NON-SPHErICAL DISTUrBANCES

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Journal of Systems Science & Complexity 2013年第2期26卷 209-231页

作者： chaturvedi Anoop kESArWANI Suchita Department of Statistics University of Allahabad

This paper considers the estimation of a subset of regression coefficients in a linear regression model with non-spherical disturbances,when other regression coefficients are of no interest.A family of estimators is considered and its asymptotic distribution is *** proposed family of improved estimators is compared with the usual unrestricted FGLS estimator,and dominance conditions are obtained with respect to risk under quadratic loss as well as the Pitman nearness *** results of a numerical simulation are presented to illustrate the risk performance of various estimators.

关键词： Large sample asymptotic minimum mean square error non-spherical disturbances pitman nearness criterion quadratic loss risk.

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A comprehensive review of the effect of different kinetic promoters on methane hydrate formation

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Chinese Journal of Chemical Engineering 2021年第4期34卷 1-16页

作者： Ekta chaturvedi Sukumar Laik Ajay Mandal Gas Hydrates Laboratory Petroleum Engineering DepartmentIndian Institute of Technology(ISM)DhanbadIndia

Gas hydrates have recently emerged as a better alternative for the production,storage,and transportation of natural ***,factors like slow formation rate and limited storage capacity obstruct the possible industrial application of this *** types of promoters and synergists have been developed that can improve the kinetics and storage capacity of gas *** review focuses on different kinetic promoters and synergists that can be utilized to enhance the storage capacity of *** main characteristics,structure and the possible limitations of the use of these promoters are likewise portrayed in *** relationship between structure and storage capacity of hydrates have also been discussed in the *** status of production of gas from hydrates,their restrictions,and future difficulties have additionally been addressed in the ensuing areas of the review.

关键词： Gas hydrates Structure Storage capacity kinetic promoters Nano-materials Surfactants

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Machine Learning Techniques in Predicting Hot Deformation Behavior of Metallic Materials

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 713-732页

作者： Petr Opela Josef Walek Jaromír kopecek Department of Metallurgical Technologies Faculty of Materials Science and TechnologyVSB–Technical University of OstravaOstrava70800Czech Republic FZU—Institute of Physics of the Czech Academy of Sciences Prague18200Czech Republic

In engineering practice,it is often necessary to determine functional relationships between dependent and independent *** relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable ***,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely *** study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic *** ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree regression(DTr),and Gaussian Process regression(GPr)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon *** the GPr method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.

关键词： Machine learning Gaussian process regression artificial neural networks support vector machine hot deformation behavior

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Analysis and simulation of a single-phase seven-level inverter controlled by modified sinusoidal PWM technique

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第4期12卷 120-139页

作者： V.Srinath Man Mohan Agarwal D.k.chaturvedi Department of Electrical Engineering Faculty of Engineering Dayalbagh Educational InstituteAgraIndia

In this paper,a modified sinusoidal pulse width modulation(MSPWM)technique and a modified single-phase H-bridge seven-level inverter is *** switching pulses for the proposed seven-level inverter are generated using a single triangular carrier waveform,a fully rectified sinusoidal signal,and three stepped reference signals(Uref1,Uref2 and Uref3).Using optimization technique,the magnitude of the stepped reference signal is determined so that the total harmonic distortion(THD)of the output voltage waveform is minimum and the fundamental component,rMS value of the voltage is improved for a given modulation index Ma as compared to the sinusoidal pulse width modulation(SPWM).By the implementation of the new scheme,the seven-level of the inverter output voltage level(+Vdc,+2Vdc/3,+Vdc/3,0,−Vdc,−2Vdc/3,−Vdc)is obtained for any given modulation ***,if only two stepped reference signals are used then the inverter will act as a five-level inverter for any modulating index *** proposed MSPWM and seven-level inverter are simulated on MATLAB/SIMULINk for r,r-L load and on a single-phase capacitor-start and capacitor-start-run Induction Motor.

关键词： Induction motor MATLAB/SIMULINk Seven-level inverter single triangular carrier SPWM stepped reference signals THD

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