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Load frequency control in deregulated power system with wind integrated system using fuzzy controller

Frontiers in Energy 2013年第2期7卷 245-254页

作者： Yajvender Pal verma Ashwani KUMAR Department of Electrical & Electronics Engineering UIET PanjabUniversity Chandigarh 160014 India Department of Electrical Engineering National Institute of TechnologyKurukshetra Haryana 132119 India

This paper presents the analysis of load frequency control （LFC） of a deregulated two-area hydro-thermal power system using fuzzy logic controller, with doubly fed induction generators （DFIGs） integrated into both the control areas. The deregulation of power sector has led to the formation of new companies for generation, transmission and distribution of power. The conventional two-area power system is modified to study the effects of the bilateral contracts of companies on the system dynamics. Deregulation creates highly competitive and distributed control environment, and the LFC becomes even more challenging when wind generators are also integrated into the system. The overall inertia of the system reduces, as the wind unit does not provide inertia and isolates from the grid during disturbances. The DFIGs integrated provide inertial support to the system through modified inertial control scheme, and arrests the initial fall in frequency after disturbance. The inertial control responds to frequency deviations, which takes out the kinetic energy of the wind turbine for improving the frequency response of the system. To enhance the participation of the doubly fed induction generator （DFIG） in the frequency control, optimal values of the speed control parameters of the DFIG-based wind turbine have been obtained using integral square error （ISE） technique. The dynamics of the system have been obtained for a small load perturbation, and for contract violation using fuzzy controller.

关键词： frequency regulation fuzzy controller deregulated power system doubly fed induction generator(DFIG) bilateral contract

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Multifunctional characteristics of 3D printed polymer nanocomposites under monotonic and cyclic compression

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Defence Technology（防务技术） 2023年第12期30卷 13-22页

作者： Pawan verma Jabir Ubaid Fahad Alam Suleyman Deveci S.Kumar Department of Mechanical Engineering Khalifa University of Science and TechnologyMasdar InstituteMasdar CityP.O.Box 54224Abu DhabiUnited Arab Emirates Borouge Pte.Ltd. Innovation CentreSas Al Nakhl6951Abu DhabiUnited Arab Emirates James Watt School of Engineering University of GlasgowGlasgowG128QQUK

This study presents the multifunctional characteristics of multi-walled carbon nanotube(MWCNT)/polypropylene random copolymer(PPR) composites enabled via fused filament fabrication(FFF) under monotonic and quasi-static cyclic compression. Utilizing in-house MWCNT-engineered PPR filament feedstocks, both bulk and cellular composites were realized. The morphological features of nanocomposites were examined via scanning electron microscopy, which reveals that MWCNTs are uniformly dispersed. The uniformly dispersed MWCNTs forms an electrically conductive network within the PPR matrix, and the resulting nanocomposite shows good electrical conductivity(~10^(-1)S/cm), improved mechanical performance(modulus increases by 125% and compressive strength increases by 25% for 8 wt% MWCNT loading) and pronounced piezoresistive response(gauge factor of 27.9-8.5 for bulk samples)under compression. The influence of strain rate on the piezoresistive response of bulk samples(4 wt% of MWCNT) under compression was also measured. Under repeated cyclic compression(2% constant strain amplitude), the nanocomposite exhibited stable piezoresistive performance up to 100 cycles. The piezoresistive response under repeated cyclic loading with increasing strain amplitude of was also *** gauge factor of BCC and FCC cellular composites(4 wt% of MWCNT) with a relative density of 30%was observed to be 46.4 and 30.2 respectively, under compression. The higher sensitivity of the BCC plate-lattice could be attributed to its higher degree of stretching-dominated deformation behavior than the FCC plate-lattice, which exhibits bending-dominated behavior. The 3D printed cellular PPR/MWCNT composites structures were found to show excellent piezoresistive self-sensing characteristics and open new avenues for in situ structural health monitoring in various applications.

关键词： Carbon nanotubes Nanoengineered polymer composites 3D printing Piezoresistive self-sensing Lattice structures

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Emerging trends in self-healable nanomaterials for triboelectric nanogenerators:A comprehensive review and roadmap

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Frontiers in Energy 2023年第6期17卷 727-750页

作者： Prabhakar YADAV Kuldeep SAHAY Malvika SRIVASTAVA Arpit verma Bal Chandra YADAV Department of Electrical Engineering Institute of Engineering and TechnologyA P J Kalam Technical UniversityLucknow 226031India Nanomaterials and Sensors Research Laboratory Department of PhysicsBabasaheb Bhimrao Ambedkar UniversityLucknow 226025India

A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an external power source to function. TENGs are developing into a viable choice for powering numerous applications as low-power electronics technology advances. Despite having less power than conventional energy sources, TENGs do not directly compete with these. TENGs, on the other hand, provide unique opportunities for future self-powered systems and might encourage advancements in energy and sensor technologies. Examining the many approaches used to improve nanogenerators by employing materials with shape memory and self-healable characteristics is the main goal of this review. The findings of this comprehensive review provide valuable information on the advancements and possibilities of TENGs, which opens the way for further research and advancement in this field. The discussion of life cycle evaluations of TENGs provides details on how well they perform in terms of the environment and identifies potential improvement areas. Additionally, the cost-effectiveness, social acceptability, and regulatory implications of self-healing TENGs are examined, as well as their economic and societal ramifications.

关键词： triboelectric nanogenerator(TENG) self-healable nanomaterials self-powered devices energy

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Centration axis in refractive surgery

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Eye and Vision 2015年第1期2卷 28-43页

作者： Samuel Arba Mosquera Shwetabh verma Colm McAlinden SCHWIND eye-tech-solutions KleinostheimGermany Recognized Research Group in Optical Diagnostic Techniques University of ValladolidValladolidSpain Department of Ophthalmology and Sciences of Vision University of OviedoOviedoSpain Flinders University AdelaideSouth AustraliaAustralia Wenzhou Medical University WenzhouZhejiangChina.

The human eye is an asymmetric optical system and the real cornea is not a rotationally symmetrical *** optical element in the eye has its own optical and neural *** the optimum center for laser ablation is difficult with many available *** explain the various centration approaches(based on these reference axes)in refractive surgery and review their clinical *** line-of-sight(LOS)(the line joining the entrance pupil center with the fixation point)is often the recommended reference axis for representing wavefront aberrations of the whole eye(derived from the definition of chief ray in geometrical optics);however pupil centration can be unstable and change with the pupil *** corneal vertex(CV)represents a stable preferable morphologic reference which is the best approximate for alignment to the visual ***,the corneal light reflex can be considered as non-constant,but dependent on the direction of gaze of the eye with respect to the light source.A compromise between the pupil and CV centered ablations is seen in the form of an asymmetric offset where the manifest refraction is referenced to the CV while the higher order aberrations are referenced to the pupil *** is a need for a flexible choice of centration in excimer laser systems to design customized and non-customized treatments optimally.

关键词： Centration Refractive surgery Optical axis Neural axis Corneal vertex Pupil centration Corneal light reflex Line of sight Angle Kappa Alpha Lambda Asymmetric offset

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A New Approach on Mixed-Type Nondifferentiable Higher-Order Symmetric Duality

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Journal of the Operations Research Society of China 2019年第2期7卷 321-335页

作者： Khushboo verma Pankaj Mathur Tilak Raj Gulati Department of Mathematics and Astronomy University of LucknowLucknow 226001India Department of Mathematics Indian Institute of Technology RoorkeeRoorkee 247667India

In this paper,a new mixed-type higher-order symmetric duality in scalar-objective programming is *** the literature we have results either Wolfe or Mond–Weir-type dual or separately,while in this we have combined those results over one *** weak,strong and converse duality theorems are proved for these programs underη-invexity/η-pseudoinvexity ***-duality is also *** results generalize some existing dual formulations which were discussed by Agarwal et al.(Generalized second-order mixed symmetric duality in nondifferentiable mathematical ***://***/10.1155/2011/103597),Chen(Higher-order symmetric duality in nonlinear nondifferentiable programs),Gulati and Gupta(Wolfe type second order symmetric duality in nondifferentiable ***.310,247–253,2005,Higher order nondifferentiable symmetric duality with generalized ***.329,229–237,2007),Gulati and verma(Nondifferentiable higher order symmetric duality under invexity/generalized *** 28(8),1661–1674,2014),Hou andYang(On second-order symmetric duality in nondifferentiable programming.J Math Anal Appl.255,488–491,2001),verma and Gulati(Higher order symmetric duality using generalized ***:Proceeding of 3rd International Conference on Operations Research and Statistics(ORS).***://***/10.5176/2251-1938_ORS13.16,Wolfe type higher order symmetric duality under invexity.J Appl Math Inform.32,153–159,2014).

关键词： Higher-order dual model Symmetric duality Duality theorems Higher-order invexity/generalized invexity Self duality

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Dynamic contribution of variable-speed wind energy conversion system in system frequency regulation

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Frontiers in Energy 2012年第2期6卷 184-192页

作者： Yajvender Pal verma Ashwani KUMAR Department of Electrical&Electronics Engineering UIETPanjab UniversityChandigarh 160014India Department of Electrical Engineering National Institute of TechnologyKurukshetraHaryana 132119India

Frequency regulation in a generation mix having large wind power penetration is a critical issue, as wind units isolate from the grid during disturbances with advanced power electronics controllers and reduce equivalent system inertia. Thus, it is important that wind turbines also contribute to system frequency control. This paper examines the dynamic contribution of doubly fed induction generator （DFIG）-based wind turbine in system frequency regulation. The modified inertial support scheme is proposed which helps the DFIG to provide the short term transient active power support to the grid during transients and arrests the fall in frequency. The frequency deviation is considered by the controller to provide the inertial control. An additional reference power output is used which helps the DFIG to release kinetic energy stored in rotating masses of the turbine. The optimal speed control parameters have been used for the DFIG to increases its participation in frequency control. The simulations carried out in a two-area interconnected power system demonstrate the contribution of the DFIG in load frequency control.

关键词： doubly fed induction generator (DFIG) load frequency control inertial control wind energy conversion system (WECS)

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The use of Lactobacillus as an alternative of antibiotic growth promoters in pigs:A review

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Animal Nutrition 2017年第1期3卷 1-6页

作者： Runjun Dowarah A.K.verma Neeta Agarwal CAFT in Animal Nutrition Indian Veterinary Research Institute

Antibiotics, often supplemented in feed, used as a growth promoter, may cause their residual effect in animal produce and also trigger antibiotic resistance in bacteria, which is of serious concern among swine farming entrepreneurs. As an alternative, supplementing probiotics gained interest in recent *** being the most commonly used probiotic agent improves growth performance, feed conversion efficiency, nutrient utilization, intestinal microbiota, gut health and regulates immune system in pigs. The characteristics of Lactobacillus spp. and their probiotic effects in swine production are reviewed here under.

关键词： Diarrhea score Gut microbiota Lactobacilli Probiotics

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Multi-agent communication-based train control system for Indian railways： the behavioural analysis

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Journal of Modern Transportation 2015年第4期23卷 272-286页

作者： Anshul verma K. K. Pattanaik Information and Communication Technology Atal BihariVajpayee - Indian Institute of Information Technology andManagement Gwalior 474015 India

Multi-agent technology has been used in many complex distributed and concurrent systems. A railway system is such a safety critical system and careful inves- tigation of the functional components is very important. Study of the various functional components in communi- cation-based train control （CBTC） system necessitates a good structural design followed by its validation and ver- ification through a formal modelling technique. The work presented here is the follow up of our multi-agent-based CBTC system for Indian railway designed using the methodology for engineering system of software agents. Behavioural analysis of the designed system involves several operating scenarios that arise during train run, and helps in understanding the reaction of the system to such situations. This validation and verification are very important as it allows the system designer to critically evaluate the desired function of the system and to correct the design errors, if any, before its actual implementation. Modelling, validation and verification of the structural design through Coloured petri net （CPN） are central to this paper. Analysis of simulation results validates the efficacy of the design.

关键词： CBTC Multi-agent Fault resolution Modelling Validation and verification CPN

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Effect of papaya seed extract on microenvironment of cauda epididymis

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Asian Journal of Andrology 2001年第2期3卷 143-146页

作者： R.J.verma N.J.Chinoy Department of Zoology University School of Sciences Gujarat University Ahmedabad 380009 IndiaDepartment of Zoology University School of Sciences Gujarat University Ahmedabad 380009 India

Aim: To evaluate the effect of aqueous Carica papaya seed extract on microenvironment of cauda ***: Adult male albino rats were intramuscularly administered with 0 (control) or 0.5 mg papaya seed ex-tract/kg body weight for 7 days. Cauda epididymal tubular content was collected by micropuncture technique; epididy-mal luminal fluid and sperm pellets were separately analyzed. Results: The results revealed that the extract treat-ment caused significant reduction, as compared with control, in total protein and sialic acid contents in both epididymalfluid and sperm pellet. As compared with control, significantly lowered acid phosphatase activity was recorded in spermpellet but was higher in epididymal fluid after the treatment. The extract treatment also caused significant reduction inlevel of inorganic phosphorus in the epididymal fluid. Conclusion: It is concluded that the aqueous papaya seed ex-tract alters cauda epididymal microenvironment.

关键词： Carica papaya microenvironment epididymis spermatozoa protein sialic acid

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Some Formulas Involving Hypergeometric Functions in Four Variables

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Computer Modeling in Engineering & Sciences 2022年第2期130卷 887-902页

作者： Hassen Aydi Ashish verma Jihad Younis Jung Rye Lee Universit´e de Sousse Institut Sup´erieur D’Informatique etDes Techniques de CommunicationH.Sousse4000Tunisia Department of Mathematics and Applied Mathematics Sefako Makgatho Health Sciences UniversityGa-RankuwaSouth Africa ChinaMedical University Hospital ChinaMedical UniversityTaichung40402Taiwan Department of Mathematics V.B.S.Purvanchal UniversityJaunpur222003India Department of Mathematics Aden UniversityKhormaksarP.o.Box 6014Yemen Department of Data Science Daejin UniversityKyunggi11159Korea

Several(generalized)hypergeometric functions and a variety of their extensions have been presented and investigated in the literature by many *** the present paper,we investigate four new hypergeometric functions in four variables and then establish several recursion formulas for these new ***,some interesting particular cases and consequences of our results are discussed.

关键词： Recursion formula quadruple hypergeometric functions pascal identity

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