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A machine learning driven 3D+1D model for efficient characterization of proton exchange membrane fuel cells

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Energy and AI

Energy and Ai 2024年第3期17卷 281-294页

作者： Yuwei Pan Haijun Ruan Billy Wu Yagya n.Regmi Huizhi Wang nigel P.Brandon Department of Earth Science and Engineering Imperial College LondonLondon SW72AZUK Dyson School of Design Engineering Imperial College LondonLondon SW72AZUK Centre for E-mobility and Clean Growth Coventry UniversityCoventry CV15FBUK manchester Fuel Cell innovation Centre Department of Natural SciencesManchester Metropolitan UniversityManchester M15GDUK Department of mechanical Engineering Imperial College LondonLondon SW72AZUK

The computational dem.nds of 3D continuum models for proton exchange membrane fuel cells remain substantial. One prevalent approach is the hierarchical model combining a 2D/3D flow field with a 1D sub-model for the catalyst layers and membrane. However, existing studies often simplify the 1D domain to a linearized 0D lumped model, potentially resulting in significant errors at high loads. in this study, we present a computationally efficient neural network driven 3D+1D model for proton exchange membrane fuel cells. The 3D sub-model captures transport in the gas channels and gas diffusion layers and is coupled with a 1D electrochemical sub-model for microporous layers, membrane, and catalyst layers. To reduce computational intensity of the full 1D description, a neural network surrogates the 1D electrochemical sub-model for coupling with the 3D domain. Trained by model-generated large synthetic datasets, the neural network achieves root mean square errors of less than 0.2%. The model is validated against experimental results under various relative humidities. it is then employed to investigate the nonlinear distribution of internal states under different operating conditions. With the neural network operating at 0.5% of the computing cost of the 1D sub-model, the hybrid model preserves a detailed and nonlinear representation of the internal fuel cell states while maintaining computational costs comparable to conventional 3D+0D models. The presented hybrid data-driven and physical modeling framework offers high accuracy and computing speed across a broad spectrum of operating conditions, potentially aiding the rapid optimization of both the membrane electrode assembly and the gas channel geometry.

关键词： Proton exchange membrane fuel cell Hierarchical model neural network Hybrid model

Effect of Zn Concentration on microstructural,Optical,and Hyperfine Properties of nanocrystalline a-Fe_(2)O_(3)

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Acta metallurgica Sinica(English Letters) 2014年第4期27卷 563-568页

作者： n.R.Panda D.Sahu B.S.Acharya P.nayak S.P.Pati D.Das School of Basic Science Indian Institute of Technology BhubaneswarBhubaneswar 751013OdishaIndia School of Physics Sambalpur UniversitySambalpur 768019OdishaIndia School of Chemistry Sambalpur UniversitySambalpur 768019OdishaIndia C.V.Raman College of Engineering Bhubaneswar 752054OdishaIndia Department of Electronic Engineering Tohoku UniversitySendai 980-8579Japan UGC-DAE CSR Sector IIILB-8Bidhan NagarKolkata 700098India

Efforts have been made to prepare nanocomposites of a-Fe2O3-ZnO by wet chemical route with varying concentrations of the *** microstructural properties of the samples are investigated by powder X-ray diffractometry（PXRD） and Transmission electron *** concentration of Zn ions（up to 20 at%） leads to the formation of nanocomposites of a-Fe2O3 and *** of ZnFe2O4 phase is detected by the substitution of higher concentration of Zn2？（30 at%） in the *** average size of the nanoparticles remains in the range of 22–27 nm as obtained from XRD *** results obtained from electron microscopic studies are also close to these *** measurem.nt shows the excitonic peak of ZnO around 390 nm which gets strengthened with Zn *** spectra show the metal–oxygen band below 700 *** temperature mssbauer studies of the samples show the transition of iron oxide form antiferromagnetic state to paramagnetic state with increasing concentration of Zn2？.Sharp quenching of hyperfine field with Zn concentration is observed as the Hintvalue reduced to zero from 51 T.

关键词： iron oxide ZnO Electron microscopy mssbauer study

Band gap tuning and p to n-type transition in mn-doped CuO nanostructured thin films

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Journal of Semiconductors 2022年第1期43卷 59-68页

作者： R.Rahaman m.Sharmin J.Podder Department of Physics Bangladesh University of Engineering and TechnologyDhaka 1000Bangladesh

Here we discuss the synthesis of copper(ii)oxide(CuO)and manganese(mn)-doped CuO thin films varying with 0 to 8 at%mn using the spray pyrolysis ***-deposited film surfaces comprised of agglomerated spherical nanoparticles and a semi-spongy porous structure for 4 at%mn *** dispersive analysis of X-rays confirmed the chemical composi-tion of the films.X-ray diffraction spectra showed a polycrystalline monoclinic structure with the predominance of the(11)*** band gap energy for direct and indirect transitions was estimated in the ranges from 2.67-2.90 eV and 0.11-1.73 eV,*** index and static dielectric constants were computed from the optical *** resistivity of CuO and mn-doped CuO(mn:CuO)thin films was found in the range from 10.5 to 28.6Ω·*** tiniest electron effective mass was calculated for 4 at%mn:CuO thin films.P to n-type transition was observed for 4 at%mn doping in CuO *** con-centration and mobility were found in the orders of 10^(17)cm^(-3)and 10^(-1)cm^(2)/(V·s),*** Hall coefficient was found to be between 9.9 and 29.8 cm^(3)/*** above results suggest the suitability of mn:CuO thin films in optoelectronic applications.

关键词： mn:CuO spray pyrolysis FESem XRD band gap Hall effect

Complem.ntarity between quantum coherence and mixedness:a majorization approach

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Communications in Theoretical Physics 2023年第5期75卷 73-83页

作者： Yanet Alvarez marcelo Losada mariela Portesi Gustavo m Bosyk instituto de Física La Plata CONICET–UNLP1900 La PlataArgentina Facultad de Ciencias Exactas Universidad Nacional de La Plata1900 La PlataArgentina Facultad de matemática AstronomíaFísica y ComputaciónUniversidad Nacional de Córdoba5000 CórdobaArgentina

Quantum coherence is a relevant resource for various quantum information processing tasks,but it is fragile since it is generally affected by environmental *** is reflected in the loss of purity of the system,which in turn limits the amount of quantum coherence of *** a consequence,a complem.ntarity relation between coherence and mixedness *** works characterize this complem.ntarity through inequalities between theℓ1-norm of coherence and linear entropy,and between the relative entropy of coherence and von neumann ***,coherence-mixedness complem.ntarity is expected to be a general feature of quantum systems,regardless of the measures ***,an alternative approach to coherence-mixedness complem.ntarity,based on majorization theory,is *** quantifiers of coherence and mixedness,namely the coherence vector and the spectrum,respectively,are used,instead of scalar measures.A majorization relation for the tensor product of both vectorial quantifiers is obtained,capturing general aspects of the trade-off between coherence and *** optimal bound for qubit systems and numerical bounds for qutrit systems are ***,coherence-mixedness complem.ntarity relations are derived for a family of symmetric,concave and additive *** results provide a deeper insight into the relation between quantum coherence and mixedness.

关键词： coherence mixedness complem.ntarity majorization

Opal-Based Photonic Crystal Heterostructures

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Optics and Photonics Journal 2012年第3期2卷 206-210页

作者： A. Chiappini C. Armellini n. Bazzanella G. C. Righini m. Ferrari Centro Fermi Piazza del Viminale Roma Italy CnR-iFn CSMFO Lab. Via alla Cascata Povo Trento Italy Dip. di Fisica Università degli Studi di Trento Via Sommarive Povo Trento Italy

The fabrication of photonic crystal heterostructures is important for the applications in the fields of integrated photonic crystal chips and multi-frequency optical Bragg filters or mirrors;here we report on the fabrication and characterization of opal-based photonic crystal heterostructures. These heterostructures are created by using multilayer deposition of silica and polystyrene spheres. in the specific the fabricated structures involved both different lattice constant and dielectric function. Scanning electron microscopy (Sem) and ViS-niR transmittance and reflectance spectroscopy are used to characterize the systems. The Sem images show good ordering of the two-layer colloidal crystals constituting the heterostructures. The transmittance and reflectance spectra measured from the (111) plane of the heterostructure show that the composite colloidal photonic crystals have double photonic stop bands that matches the stop bands of the individual photonic crystals. This behaviour can be seen as a superposition of the properties of each individual layer.

关键词： Sol-Gel Colloidal Crystals Optical Properties Heterostructures

Phylogenetic analysis and protective effects of thymol and its chromatographic fractions from a novel wild mushroom in combating oxidative stress

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Food Science and Human Wellness 2021年第4期10卷 452-459页

作者： m.Subbulakshmi Sugapriya Dhanasekaran S.Abirami m.Kannan R.Palaniappan Divya Venugopal Department of microbiology K.R.College of Arts and ScienceKovilpattiTamil NaduIndia Department of medical Laboratory Sciences College of Applied Medical SciencesPrince Sattam Bin Abdulaziz UniversityWadi Al DawaserSaudi Arabia Department of microbiology Kamaraj CollegeThoothukudiTamil NaduIndia Research Department of Zoology V.H.N.Senthikumara Nadar College(Autonomus)VirudhunagarTamil NaduIndia Research Department of Computer Science V.H.N.Senthikumara Nadar College(Autonomus)VirudhunagarTamil NaduIndia

mushrooms are good sources of phytochemicals that have antioxidant and anti-proliferative *** study identifi ed a unique isoform of 18S rRnA gene(864 bp)from a novel wild mushroom(SmK-1)(GenBank accession number:SUB3267363).Thin layer chromatographic(TLC)profiling of the methanolic extract of the dried mushroom fruiting bodies of SmK-1 revealed the presence of phenolic and fl avonoid fractions with retention factor(Rf)values of 0.955 and 0.927 *** GC/mS chromatograms of the SmK-1 methanolic extract identifi ed the main bioactive compound was phenol,5-methyl-2-(1-methylethyl)(74.00%)(thymol).The radical scavenging activity for the fl avonoid fraction was greater than the phenolic fractions(Rf–phenolics fractions>Rf–fl avonoid fractions)with the antioxidant activity more than that of standard ascorbic ***,the phenolic and flavonoid fractions of SmK-1 expressed cytotoxic effects in HeLa cells with iC50 values ranging from 5μg/mL to 80μg/mL in a dose-dependent *** present research highlights the presence of high thymol concentration in a novel wild mushroom that has antioxidant and anti-poliferative potential with therapeutic benefi *** application of thymol natural products from novel mushroom SmK-1 as nutrition supplem.nts could inhibit oxidative stress triggered by numerous pathologies that may pave the way to develop a new therapeutic natural drug.

关键词： Antioxidant Anti-proliferation Dietary mushrooms HeLa cells novel mushrooms Thymol

Revisiting novel symmetries in coupled n=2 supersymmetric quantum systems:examples and supervariable approach

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Communications in Theoretical Physics 2020年第10期72卷 103-112页

作者： aditi Pradeep Anjali S Binu m nair Saurabh Gupta Department of Physics and Astronomy University of British ColumbiaVancouver Campus325-6224 Agricultural RoadVancouverBC V6T 1Z1Canada Department of Physics National Institute of Technology Calicut

We revisit the novel symmetries in n=2 supersymmetric quantum mechanical models by considering specific examples of coupled ***,we extend our analysis to a general case and list out all the novel *** each case,we show the existence of two sets of discrete symmetries that correspond to the Hodge duality operator of differential ***,we are able to provide a proof of the conjecture which points out the existence of more than one set of discrete symmetry transformations corresponding to the Hodge duality ***,we derive on-shell nilpotent symmetries for a generalized superpotential within the framework of supervariable approach.

关键词： n=2 SUSY quantum mechanical system continuous and discrete symmetries de Rham cohomological operators (anti-)chiral supervariable approach SUSY invariant restrictions

Agro-Ecological adaptation and Participatory Evaluation of multipurpose Tree and Shrub Legumes in mid Altitudes of Sud-Kivu, D. R. Congo

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american Journal of Plant Sciences 2014年第13期5卷 2031-2039页

作者： m. m. D. Katunga B. J. B. muhigwa K. J. C. Kashala m. Kambuyi n. nyongombe B. L. maass m. Peters international Center for Tropical Agriculture (CiAT) Bukavu Democratic Republic of the Congo Institut National pour l’Etude et la Recherche agronomiques (INERA)-Mulungu Bukavu Democratic Republic of the Congo international Center for Tropical Agriculture (CiAT) Cali Colombia international Center for Tropical Agriculture (CiAT) Nairobi Kenya Université de Lubumbashi Faculté de Médecine Vétérinaire Lubumbashi Democratic Republic of the Congo Université Officielle de Bukavu Faculté des Sciences Bukavu Democratic Republic of the Congo Université Pédagogique nationale de Kinshasa Faculté de Médecine Vétérinaire Kinshasa Democratic Republic of the Congo

Livestock is traditionally managed in mixed crop-livestock production systems in Sud-Kivu, D. R. Congo. Currently, livestock production is facing numerous constraints due to wars and insecurity in the country, with looting of animals, demographic pressure on natural resources, and lack of extension services. multipurpose trees and shrubs with adequate forage quality could help overcome dry-season feed shortage. The objective of this research was to assess the agro-ecological adaptability of selected forage tree and shrub legumes combined with farmer participatory evaluation. The study was carried out at two distinct mid-altitude sites in Sud-Kivu. Trees and shrubs were planted randomly in eleven lines, with each species/accession consisting of nine plants split into three replications. Following a standardization cut after one year of growth, regular biomass harvests were performed every eight weeks during one year;Desmodium and Flem.ngia were cut at 0.5 m above soil surface, while Leucaena and Calliandra at 1 m. Before every harvest, plant height was measured and number of stems counted. Fresh leaf and stem biomass were weighted, sub samples dried and leaves analyzed for nutritive value. Results from agronomic evaluation show that Leucaena diversifolia iLRi 15551 and Leucaena leucocephala had the highest yield in the rainy season on fertile soil;during dry season, Leucaena diversifolia iLRi 15551 was superior. On poor soil, Flem.ngia macrophylla CiAT 17403 performed best in both seasons, however, its forage quality was relatively low. Forage tree and shrub legumes chosen by farmers were, in general, the same as those superior ones in agronomic evaluation.

关键词： multipurpose Trees and Shrubs Forage Legumes adaptation Participatory Evaluation Biomass Production

The effects of mastitis on chemical quality of set yoghourt

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The effects of mastitis on chemical quality of set yoghourt