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A novel control solution for improved trajectory tracking and LVRT performance in DFIG-based wind turbines

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Control Theory and Technology 2020年第1期18卷 43-55页

作者： Ahmad HASHEMI Christian CONFICONI andrea TILLI The Center of Complex Automated Systems(CASY)at the Department of Electrical Electronic and Information Engineering(DEI)University of BolognaRisorgimento240136 BolognaItaly Sama Technical and Vocational training College Islamic Azad UniversityKermanshah BranchKermanshahIran

This paper presents a new control strategy for the rotor side converter of Doubly-Fed Induction Generator based Wind Turbine systems,under severe voltage *** main goal is to fulfill the Low Voltage Ride Through performance,required by modern grid *** this respect,the key point is to limit oscillations(particularly on rotor currents)triggered by line faults,so that the system keeps operating with graceful *** this aim,a suitable feedforward-feedback control solution is proposed for the DFIG rotor *** feedforward part exploits oscillation-free reference trajectories,analytically derived for the system internal *** feedback,designed accounting for control voltage limits,endows the system with robustness and further tame oscillations during ***,improved torque and stator reactive power tracking during faults is achieved,proposing an exact mapping between such quantities and rotor-side currents,which are conventionally used as controlled *** simulations are provided to validate the capability of the proposed approach to effectively cope with harsh faults.

关键词： Doubly-fed induction generator(DFIG) wind turbine(WT) feedforward-feedback control mapping solution low voltage ride through(LVRT)

Analysis of Tonal Noise Generating Mechanisms in Low-Speed Axial-Flow Fans

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Journal of Thermal Science 2016年第4期25卷 302-311页

作者： Edward Canepa andrea Cattanei Fabio Mazzocut Zecchin DIME-Universita di Genova via Montallegro 1 1-16145 Genoa Italy

The present paper reports a comparison of experimental SPL spectral data related to the tonal noise generated by axial-flow fans.A nine blade rotor has been operated at free discharge conditions and in four geometrical configurations in which different kinds of tonal noise generating mechanisms are present:large-scale inlet turbulent structures,tip-gap flow,turbulent wakes,and rotor-stator *** measurements have been taken in a hemi-anechoic chamber at constant rotational speed and,in order to vary the acoustic source strength,during low angular acceleration,linear speed *** order to avoid erroneous quantitative evaluations if the acoustic propagation effects are not considered,the acoustic response functions of the different test configurations have been computed by means of the spectral decomposition ***,the properties of the tonal noise generating mechanisms have been *** this aim,the constant-Strouhal number SPL,obtained by means of measurements taken during the speed ramps,have been compared with the propagation ***,the analysis of the phase of the acoustic pressure has allowed to distinguish between random and deterministic tonal noise generating mechanisms and to collect information about the presence of important propagation effects.

关键词： Axial-flow fans Tonal noise Acoustic response

Implications of butyrate and its derivatives for gut health and animal production

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Animal Nutrition 2018年第2期4卷 151-159页

作者： andrea Bedford Joshua Gong Guelph Research and Development Centre Agriculture and Agri-food Canada

Butyrate is produced by microbial fermentation in the large intestine of humans and *** serves as not only a primary nutrient that provides energy to colonocytes, but also a cellular mediator regulating multiple functions of gut cells and beyond, including gene expression, cell differentiation, gut tissue development, immune modulation, oxidative stress reduction, and diarrhea *** there are a large number of studies in human medicine using butyrate to treat intestinal disease, the importance of butyrate in maintaining gut health has also attracted significant research attention to its application for animal production, particularly as an alternative to in-feed *** to the difficulties of using butyrate in practice(i.e., offensive odor and absorption in the upper gut), different forms of butyrate,such as sodium butyrate and butyrate glycerides, have been developed and examined for their effects on gut health and growth performance across different *** and its derivatives generally demonstrate positive effects on animal production, including enhancement of gut development, control of enteric pathogens, reduction of inflammation, improvement of growth performance(including carcass composition), and modulation of gut *** benefits are more evident in young animals, and variations in the results have been *** present article has critically reviewed recent findings in animal research on butyrate and its derivatives in regard to their effects and mechanisms behind and discussed the implications of these findings for improving animal gut health and *** addition, significant findings of medical research in humans that are relevant to animal production have been cited.

关键词： Butyrate Butyrins Antibiotic alternatives Gut health Nutrition Animal production

Cuscuta, the Merchant of Proteins

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Molecular Plant 2020年第4期13卷 533-535页

作者： andrea Paterlini Yka Helariutta Sainsbury Laboratory University of CambridgeCambridgeUK Institute of Biotechnology HiLIFEUniversity of HelsinkiHelsinkiFinland

"If thou wilt lend this money,lend it not As to thy friends,[...]But lend it rather to thine enemy,Who,if he break,thou mayst with better face Exact the penalty"The merchant Antonio speaking to the moneylender Shylock... 详细信息

关键词： money chant Shy

Efficient object location determination and error analysis based on barycentric coordinates

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Visual Computing for Industry,Biomedicine,and Art 2020年第1期3卷 195-201页

作者： andrea Bodonyi Roland Kunkli Faculty of Informatics University of DebrecenDebrecen H-4028Hungary Doctoral School of Informatics University of DebrecenDebrecen H-4028Hungary

In this paper,we propose an efficient computational method for converting local coordinates to world coordinates using specially structured coordinate *** problem in question is the computation of world coordinates of an object throughout a motion,assuming that we only know the changing coordinates of some fixed surrounding reference points in the local coordinate system of the *** proposed method is based on barycentric coordinates;by taking the aforementioned static positions as the vertices of a polyhedron,we can specify the coordinates of the object in each step with the help of barycentric *** approach can significantly help us to achieve more accurate results than by using other possible *** the paper,we describe the problem and barycentric coordinate-based solution in *** then compare the barycentric method with a technique based on transformation matrices,which we also tested for solving our *** also present various diagrams that demonstrate the efficiency of our proposed approach in terms of precision and performance.

关键词： Barycentric coordinates Conversion Transformation Coordinate systems Location

Shear-induced particle segregation in binary mixtures:Verification of a percolation theory

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Particuology 2021年第4期19卷 214-222页

作者： Monica Tirapelle Silvia Volpato andrea C.Santomaso APTLab-Advanced Particle Technology Laboratory Department of Industrial EngineeringUniversity of PadovaVia Marzolo 935131 PadovaItaly

Granular materials composed of different-sized grains may experience undesired *** is detrimental for a lot of industries because it leads to an increase in production costs and *** these reasons,the segregation phenomena have been intensively studied in the last decades,and a lot of models have been provided by many ***,these models are mainly based on empirical relations rather than physical *** paper aims to confirm the main assumptions made by Volpato,Tirapelle,and Santomaso(2020)in their percolation theory by means of DEM *** simulated geometry is a tilting shear box filled with few tracer particles in a bed of coarser sized grains,and simulations are performed for a range of tilting frequencies and size *** results provide meaningful insight on the mathematical model parameters and allow us to say that the percolation theory relies on physically consistent assumptions.

关键词： Discrete element method Shear-induced percolation Segregation Parameter sensitivity analysis Percolation model

Topological optimization of ballistic protective structures through genetic algorithms in a vulnerability-driven environment

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Defence Technology（防务技术） 2024年第10期40卷 125-137页

作者： Salvatore Annunziata Luca Lomazzi Marco Giglio andrea Manes Politecnico di Milano Department of Mechanical EngineeringVia Giuseppe La Masa120156Italy

Reducing the vulnerability of a platform,i.e.,the risk of being affected by hostile objects,is of paramount importance in the design process of vehicles,especially aircraft.A simple and effective way to decrease vulnerability is to introduce protective structures to intercept and possibly stop ***,this type of solution can lead to a significant increase in weight,affecting the performance of the *** this reason,it is crucial to study possible solutions that allow reducing the vulnerability of the aircraft while containing the increase in structural *** possible strategy is to optimize the topology of protective solutions to find the optimal balance between vulnerability and the weight of the added *** the many optimization techniques available in the literature for this purpose,multiobjective genetic algorithms stand out as promising *** this context,this work proposes the use of a in-house software for vulnerability calculation to guide the process of topology optimization through multi-objective genetic algorithms,aiming to simultaneously minimize the weight of protective structures and *** addition to the use of the in-house software,which itself represents a novelty in the field of topology optimization of structures,the method incorporates a custom mutation function within the genetic algorithm,specifically developed using a graph-based approach to ensure the continuity of the generated *** tool developed for this work is capable of generating protections with optimized layouts considering two different types of impacting objects,namely bullets and fragments from detonating *** software outputs a set of non-dominated solutions describing different topologies that the user can choose from.

关键词： Topological optimization Protective structure Genetic algorithm Survivability Vulnerability

Controlling Properties of HSLA Line Pipe Steels for Oil and Gas Applications

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Journal of Iron and Steel Research International 2011年第S1期18卷 701-706页

作者： Mukhopadhyay Ananya Polo andrea Danieli Automation SpA via Stringher 433042 ButtrioUdineItaly

DANIELI has recently implemented its Coil Quality Estimator (DANIELI-CQETM) system to the Hot Strip Mill of United Metallurgical Company (OMK) at Vyksa,*** system is developed for the purpose of real time assessment and control of mechanical properties for hot rolled *** properties such as strength,toughness,ductility and hardness are predicted over the entire length of a strip while it is *** property estimation is based on the final microstructure as predicted from a group of interconnected physically based metallurgical models,supplemented by Artificial Neural *** CQE system is used for prediction and control of properties of HSLA line pipe grades steel and other *** system performance,is judged by accuracy and reliability of prediction,has been compared with the physical material testing data from the *** results are found to be *** is found useful for generation of test certificate of coil,quality assurance,process control,product development,and customer claim *** is used for resource optimization for production,and other operational improvements such as reduction of *** present paper shares the results of CQE performance for prediction of HSLA line pipe grade steels.

关键词： line pipe steels CQE mechanical property ANN process control

Numerical study on fatigue crack propagation behaviors in lubricated rolling contact

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Chinese Journal of Aeronautics 2021年第9期34卷 24-36页

作者： Haifeng HE Huaiju LIU Caichao ZHU andrea MURA State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China Department of Mechanical and Aerospace Engineering Politecnico di TorinoTorino 10129Italy

The surface-initiated Rolling Contact Fatigue(RCF)including pitting and micro-pitting is one of the key issues affecting the reliability of tribological components such as gears and bearings used in various *** this work,a surface-initiated crack Finite Element(FE)model which considers the effect of lubricant on crack faces was developed to investigate surface-initiated RCF using an automatic crack propagating Python *** lubricating states,initial crack parameters and loading conditions were simulated to analyze the evolution of crack propagation and the Stress Intensity Factors(SIFs).The RCF crack propagation path and life were predicted by employing the Maximum Tangential Stress(MTS)criterion coupled with the Paris’s law.A typical RCF failure is predicted in the numerical *** reveal that the lubricating pressurization dominates the surface-initiated *** addition,the initial crack angle has a significant effect on the RCF crack propagation path and the fatigue life.

关键词： Fatigue crack propagation Finite element Life prediction Lubricating states Rolling Contact Fatigue(RCF) Stress Intensity Factors(SIFs)