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Fuel cell stack design and modelling with a double-stage boost converter coupled to a single-phase inverter

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CLeAn eneRGY 2024年第1期8卷 188-196页

作者： elnagi, Basem e. Ismaiel, Ahmed m. mansour, Hany S. e. Abd-Alwahab, m. n. Suez Canal Univ Fac Engn Elect Engn Dept Ismailia 41522 Egypt

A comprehensive proton-exchange membrane fuel cell stack model was developed and integrated with a two-stage DC/DC boost converter. It was directly coupled to a single-phase (two levels-four pulses) inverter without a transformer. The pulse-width modulation signal was used to independently regulate every converter phase. The converter was modelled using a mATLAB (R)/Simulink (R) environment and an appropriate voltage control method. The analysis features of the suggested circuit were created and, through established experiments, the simulation results were verified. A single-phase (two levels-four pulses) inverter control circuit was tested and it produced a pure sinusoidal waveform with voltage control. It matches the voltage of the network in terms of amplitude and frequency. A sinusoidal pulse-width modulation approach was performed using a single-phase (two levels-four pulses) pulse-width modulation inverter. The results demonstrated an enhancement in the standard of the output wave and tuned the dead time with a reduction of 63 mu s compared with 180 mu s in conventional techniques. A comprehensive model of a proton-exchange membrane fuel cell stack is integrated with a single-phase (two levels-four pulses) inverter without a transformer. Pulse-width modulation is used to independently regulate every converter phase. As a result, the dead time is reduced compared to conventional techniques. Graphical Abstract

关键词： Pem fuel cell pulse-width modulation single-phase inverter and double-stage DC/DC boost converter PeRFORmAnCe SYSTem

eDSUCh:A robust ensemble data summarization method for effective medical diagnosis

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Digital Communications and networks 2024年第1期10卷 182-189页

作者： mohiuddin Ahmed A.n.m.Bazlur Rashid School of Science Edith Cowan UniversityPerthAustralia

Identifying rare patterns for medical diagnosis is a challenging task due to heterogeneity and the volume of *** summarization can create a concise version of the original data that can be used for effective *** this paper,we propose an ensemble summarization method that combines clustering and sampling to create a summary of the original data to ensure the inclusion of rare *** the best of our knowledge,there has been no such technique available to augment the performance of anomaly detection techniques and simultaneously increase the efficiency of medical *** performance of popular anomaly detection algorithms increases significantly in terms of accuracy and computational complexity when the summaries are ***,the medical diagnosis becomes more effective,and our experimental results reflect that the combination of the proposed summarization scheme and all underlying algorithms used in this paper outperforms the most popular anomaly detection techniques.

关键词： Data summarization ensemble medical diagnosis Sampling

enhancement of coercivity,permeability,and dielectric properties of Co_(0.2)Zn_(0.3)ni_(0.5)eu_(x)Fe_(2-x)O_(4) ferrites for memory and high frequency devices

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Journal of Rare earths 2024年第6期42卷 1128-1135,I0005页

作者： I.Sardar m.D.Hossain m.S.Sikder m.n.I.Khan m.R.Rahman Physics Discipline Khulna UniversityKhulna9208Bangladesh Department of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh Department ofComputer Science and engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh material Science Division Atomic Energy CentreDhaka1000Bangladesh

Spinel cubic ferrites have huge applications in me mory and high frequency *** the improvement of these modern devices,the magnetic coercivity,permeability,and dielectric properties of a ferrite are the important *** article focuses on improving the magnetic coercivity,magnetic permeability,and dielectric properties of Co_(0.2)Zn_(0.3)ni_(0.5)eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FeSem),energy dispersive X-ray(eDX),vibrating sample magnetometer(VSm),and an impedance analyzer were used to characterize the structural,magnetic,and dielectric properties of the *** XRD patterns indicate the formation of spinel cubic structure of the samples with a secondary peak(euFeO_(3))for eu doped *** densities and porosities of the samples follow an inverse trend,where the doped samples’lattice parameters are increased with the increment of rare earth eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FeSem images,and it is increased from 121 to 198 *** analysis confirms that doping of the eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)ni_(0.5)eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the eu doped samples is greater than that of the mother alloy(x=0.00).The eDX study shows that there is no impurity contamination in the *** permeability and dielectric measurements show an improved quality factor of the eu-doped samples with low magnetic and dielectric *** dependent resistivity and impedance analysis also show the improved *** the observed properties of the samples,all the investigated ferrites might be strong candidates for potential applications in memory devices,magnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity Permeability eDX Resistivity

A FLeXIBLe OBJeCTIVe-COnSTRAInT APPROACH AnD A neW ALGORITHm FOR COnSTRUCTInG THe PAReTO FROnT OF mULTIOBJeCTIVe OPTImIZATIOn PROBLemS

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Acta mathematica Scientia 2024年第2期44卷 702-720页

作者： n.HOSeInPOOR m.GHAZnAVI Faculty of mathematical Sciences Shahrood University of TechnologyShahroodIran

In this article, a novel scalarization technique, called the improved objective-constraint approach, is introduced to find efficient solutions of a given multiobjective programming problem. The presented scalarized problem extends the objective-constraint problem. It is demonstrated that how adding variables to the scalarized problem, can lead to find conditions for (weakly, properly) Pareto optimal solutions. Applying the obtained necessary and sufficient conditions, two algorithms for generating the Pareto front approximation of bi-objective and three-objective programming problems are designed. These algorithms are easy to implement and can achieve an even approximation of (weakly, properly) Pareto optimal solutions. These algorithms can be generalized for optimization problems with more than three criterion functions, too. The effectiveness and capability of the algorithms are demonstrated in test problems.

关键词： multiobjective optimization Pareto front scalarization objective-constraint approach proper efficient solution

experimental validation of double-fed induction generator in oscillating water column using circulatory system-based optimization

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CLeAn eneRGY 2024年第2期8卷 127-143页

作者： elnaghi, Basem e. Ismaiel, Ahmed m. Abdel-Kader, Fathy el Sayed mohammed, Reham H. Abelwhab, m. n. Suez Canal Univ Elect Power & Machine Dept Ismailia Egypt menoufia Univ Fac Engn Elect Machine & Power Dept Menoufia Egypt Suez Canal Univ Comp & Control Dept Ismailia Egypt

This paper validates the optimal operation for a grid-connected double-fed induction generator (DFIG) in an oscillating water column power plant (OWCPP). This study presents a novel optimization technique called the circulatory system-based optimization (CSBO) approach to develop six adaptive fuzzy logic controllers (AFLCs) with 30 parameters and compare them to chaotic-billiards optimization (C-BO) and genetic algorithm (GA). The proposed controller is also compared with a proportional-integral differential (PID) controller based on a self-adaptive global-best harmony search (SGHS). CSBO-based AFLCs are fully investigated under different scenarios and experimented with using a real-time interface DSP1104. The results of using CSBO-AFLCs revealed a fast time response, fast convergence, less overshoot and minimal error compared with those achieved with C-BO-AFLC, SGHS-PID and GA-AFLC during different case studies. The CSBO-based AFLCs ensure maximum power from the DFIG in an OWCPP and enhance dynamic response with very low errors. The results show that the CSBO shows better power tracking by 25% as compared with C-BO, by 45% when compared with the GA and by 56% when compared with PID. moreover, the integral absolute errors of six controllers are investigated to demonstrate the feasibility of CSBO-AFLC. The root mean square of the errors of six controllers using CSBO is improved by 68.27% when compared with GA, by 22.57% when compared with C-BO and by 38.42% when compared with PID. These indicators demonstrate the feasibility of CSBO when compared with other algorithms with the same OWCPP. This paper validates the optimal operation of a grid-connected double-fed induction generator in an oscillating water column using a novel optimization technique called the circulatory system-based optimization approach. experiments using a real-time simulator demonstrate the feasibility of the approach when compared with other algorithms. Graphical Abstract

关键词： circulatory system-based optimization approach adaptive fuzzy logic controller grid-tied oscillating water column power plant maximum power point tracking WAVe eneRGY-COnVeRSIOn DeSIGn OPTImIZATIOn ALGORITHm COnTROLLeR TURBIne

Direct microwave leaching conditions of rare earth elements in fluorescent wastes

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Journal of Rare earths 2024年第6期42卷 1165-1174,I0007页

作者： A.Bilen B.Birol m.n.Saridede S.S.Kaplan m.S.Sonmez Department of metallurgical and materials engineering Yildiz Technical UniversityIstanbulTurkey Department of Chemical engineering and materials Science Stevens Institute of TechnologyNew JereyUSA Department of metallurgical and materials engineering Istanbul Technical UniversityIstanbulTurkey

The luminescent phosphor powder in the fluorescent lamp constitutes 2%of the lamp’s *** can be mentioned that fluorescent wastes are a crucial raw material to produce rare earth *** the present study,microwave leaching process was conducted to dissolve rare earth elements yttrium(Y),europium(eu),and remaining rare earth elements(Rees)present in the phosphor powder of the fluorescent *** the yields were *** the microwave leaching process,the effects of the temperature(80-160℃),acid type(hydrochloric acid(HCl),nitric acid(HnO_(3)),sulphuric acid(H_(2)SO_(4))),acid concentration(0.5-6 mol/L),solid to liquid ratio(0.1:10-0.5:10)and reaction time(5-90 min)parameters on leaching efficiencies of varying rare earth elements and calcium were *** highest yield was obtained in the direct microwave leaching of fluorescent waste with the experimental conditions of 6 mol/L HCl,160℃,0.1:10 solid-to-liquid ratio(S:L),and 90 *** energy calculations were made,and kinetic models of the reactions were obtained,and it is observed that Y and eu dissolution is diffusion-controlled,on the other hand,lanthanum(La),cerium(Ce),and terbium(Tb)were examined to be chemical reaction ***,calcium(Ca)and gadolinium(Gd)seem coherent with the mixed ***,mathematical models of all experimental studies are created with the response surface Box-Behnken method and the correlation coefficients of all the models are over 90%.

关键词： Rare earth elements(Rees) Direct microwave leaching Fluorescent waste Kinetic models Response surface method

effect of cold-working on corrosion induced damage in lug joints

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Defence Technology（防务技术） 2024年第6期36卷 175-182页

作者： Ramanath m.n Chikmath L. murthy H. Department of Aerospace engineering Indian Institute of Technology-MadrasChennai 600036India Department of Aeronautical engineering KLS Gogte Institute of TechnologyBelagavi 590008India

Lug joints are preferred joineries for transferring heavy loads to parent components in aerospace *** experience corrosion due to environmental conditions,improper surface finishes and rubbing displacement between the pin and *** causes damage of different sizes and shapes near the *** degradation due to corrosion-induced damage is modelled as a through-pit at one of the identified critical locations through stress *** effect of this pit on fatigue crack initiation life is ***-hole is pre-stressed by cold-working and the benefits of inducing plastic wake on the intended performance of the lug joint during the damages due to corrosion are brought out and compared with non-cold-worked *** analysis is performed on this lug joint with *** results obtained highlight the benefits of cold-working and the methodology can be extended to damage growth and analyse the effect of surface treatments for better structural integrity of components of aerospace vehicles.

关键词： Lug joint Corrosion Crack initiation Cold-working Structural integrity

nanomotion of bacteria to determine metabolic profile

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nanotechnology and Precision engineering 2024年第1期7卷 1-9页

作者： S.n.Pleskova e.V.Lazarenko n.A.Bezrukov R.n.Kriukov A.V.Boryakov m.e.Dokukin S.I.Surodin Research Laboratory of Scanning Probe microscopy Lobachevsky State University of Nizhny NovgorodNizhny Novgorod 603950Russia Department of nanotechnology and Biotechnology Nizhny Novgorod State Technical University n.a.R.E.AlekseevNizhny Novgorod 603950Russia Sarov Physics and Technology Institute National Research Nuclear University MEPhISarov 607186Russia

In addition to their visible motion such as swimming(e.g.,with the help ofﬂagella),bacteria can also exhibit nanomotion that is detectable only with highly sensitive instruments,and this study shows that it is possible to detect bacterial nanomotion using an AFm detection *** results show that the nanomotion characteristics depend on the bacterial strain,and that nanomotion can be used to sense the metabolic activity of bacteria because the oscillations are sensitive to the food preferences of the bacteria and the type of surrounding medium.

关键词： nanomotion Bacteria Cantilever Oscillation Atomic force microscopy metabolism

Predicting effects of tunnel throttling of annular freeway vehicular flow by a continuum model

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Journal of Traffic and Transportation engineering(english edition) 2024年第4期11卷 733-746页

作者： Zhongmin Huang m.n.Smirnova n.n.Smirnov Zuojin Zhu Faculty of engineering Science University of Science and Technology of ChinaHefei 230026China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Faculty of mechanics and mathematics Lomonosov Moscow State UniversityMoscow 119992Russia

Fluid flow throttling is common in industrial and building services *** tunnel throttling of vehicular flow is caused by the abrupt number reduction of roadway lane,as the tunnel has a lower lane number than in the roadway normal *** predict the effects of tunnel throttling of annular freeway vehicular flow,a three-lane continuum model is ***Ⅲof the tunnel is completely blocked due to the need of tunnel rehabilitation,*** exists mandatory net lane-changing rate from laneⅢto laneⅡjust upstream of the tunnel entrance,which is described by a model of random number generated through a golden section *** net-changing rate between adjacent lanes is modeled using a lane-changing time expressed explicitly in algebraic *** paper assumes that the annular freeway has a total length of 100 km,a two-lane tunnel of length 2 km with a speed limit of 80 km/*** free flow speeds on lanesⅠ,ⅡandⅢare assumed to be 110,100 and 90 km/h *** on the three-lane continuum model,numerical simulations of vehicular flows on the annular freeway with such a tunnel are conducted with a reliable numerical method of 3rd-order *** results reveal that the vehicular flow has a smaller threshold of traffic jam formation in comparison with the case without tunnel *** fuel consumption can be estimated by interpolation with time averaged grid traffic speed and an assumed curve of vehicle *** vehicle fuel consumption is lane number dependent,distributes with initial density concavely,ranging from 5.56 to 8.00 *** throttling leads to an earlier traffic jam formation in comparison with the case without tunnel throttling.

关键词： effects of tunnel throttling Vehicle fuel consumption Travel time Threshold of traffic jam formation Continuum model