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Effect of the initial ECAP passes on crystal texture and residual stresses of 5083 aluminum alloy

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international Journal of Minerals,Metallurgy and Materials 2020年第6期27卷 801-808页

作者： L.Romero-Reséndiz A.Flores-Rivera i.A.Figueroa C.Braham C.Reyes-Ruiz i.alfonso G.González instituto de investigaciones en Materiales Universidad Nacional Autónoma de MéxicoCd.de México 04510México Procédés et ingénierie en Mécanique et Matériaux Arts et MétiersParis 75013France Departamento de Diseño y Manufactura Facultad de IngenieríaUniversidad Nacional Autónoma de MéxicoPIIT Apodaca 66629México instituto de investigaciones en Materiales Unidad MoreliaUniversidad Nacional Autónoma de MéxicoMorelia 58190México

To produce a highly refined microstructure,several metals or alloys have been processed via equal-channel angular pressing(ECAP).in this work,the mechanical and microstructural changes of the 5083 aluminum alloy in H11 condition after processed by two ECAP passes were *** ECAP H13 steel die with an inner angle(α)of 120°and outer curvature(β)of 20°was *** microstructural changes were associated with the loss of texture *** morphologies of the Mg2Si andα-Al(Mn,Fe)Si precipitates for the sample at the initial condition were similar to those subjected to two ECAP *** peak broadening measured by X-ray diffraction revealed an increment of both grain refinement and *** the second extrusion pass,the hardness increased by 62%compared with the initial ***,the heterogeneous hardness behavior was compatible with a highly localized dislocation *** two ECAP passes,shear parallel bands were observed to be at nearly 45°to the extrusion *** evaluation of first-order residual stress as a function of the depth of the analyzed sample displayed compressive or tensile values,depending on the measured *** the plastic deformation applied,the first and second-order residual stresses exhibited significant ***-Hall plots showed positive slopes,indicating an increment in the microstrain.

关键词： aluminum alloy equal-channel angular pressing texture microstructure residual stress

Effect of Sn on synthesis of nanocrystalline Ti-based alloy with fcc structure

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Transactions of Nonferrous Metals Society of China 2020年第8期30卷 2119-2131页

作者： C.AGUiLAR E.PiO A.MEDiNA C.PARRA R.MANGALARAJA P.MARTiN i.alfonso K.TELLO Departamento de ingeniería Metalúrgica y de Materiales Departamento de Física(+)Universidad Técnica Federico Santa MaríaValparaísoChile instituto de investigación en Metalurgia y Materiales Universidad Michoacana de San Nicolás de HidalgoMoreliaMéxico Laboratorio de Cerámicos Avanzados y Nanotecnologia Departamento de Ingeniería de MaterialesUniversidad de ConcepciónConcepciónChile instituto de investigaciones en Materiales Universidad Nacional Autónoma de MéxicoCampus Morelia UNAMMoreliaMéxico

The effect of the amount of Sn on the formation of fcc phase in Ti-13 Ta-x Sn(x=3,6,9 and 12,at.%)alloys was *** alloys were synthesized by mechanical alloying using a planetary mill,jar and balls of stabilized *** Rietveld refinement,it was found that the obtained fcc phase has crystallite size smaller than 10 nm and microstrain larger than *** conditions are required to form an fcc phase in Ti-based *** all samples,the microstructure of the fcc phase consists of equiaxial crystallites with sizes smaller than 10 *** largest presence of fcc phase in the studied Ti alloy was found with 6 at.%Sn,because this alloy exhibits the largest microstrain(1.5×10-2)and crystallite size of 6.5 *** data reveal that a solid solution and an amorphous phase were formed during *** necessary conditions to promote the formation of solid solution and amorphous phases were determined using thermodynamic *** the amount of Sn increases,the energy required to form an amorphous phase varies from approximately 10 to approximately-5 k J/mol for 3 and 12 at.%Sn,*** thermodynamic calculations are in agreement with XRD patterns analysis and HRTEM results.

关键词： Ti-based alloy phase transformation fcc phase Rietveld analysis mechanical alloying

An innovative heterogeneous transfer learning framework to enhance the scalability of deep reinforcement learning controllers in buildings with integrated energy systems

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Building Simulation 2024年第5期17卷 739-770页

作者： Davide Coraci Silvio Brandi Tianzhen Hong alfonso Capozzoli Politecnico di Torino Department of EnergyTEBE research groupBAEDA Lab.Corso Duca degli Abruzzi 24Torino10129Italy Building Technology and Urban Systems Division Lawrence Berkeley National LaboratoryOne Cyclotron RoadBerkeleyCA 94720USA

Deep Reinforcement Learning(DRL)-based control shows enhanced performance in the management of integrated energy systems when compared with Rule-Based Controllers(RBCs),but it still lacks scalability and generalisation due to the necessity of using tailored models for the training *** Learning(TL)is a potential solution to address this ***,existing TL applications in building control have been mostly tested among buildings with similar features,not addressing the need to scale up advanced control in real-world scenarios with diverse energy *** paper assesses the performance of an online heterogeneous TL strategy,comparing it with RBC and offline and online DRL controllers in a simulation setup using EnergyPlus and *** study tests the transfer in both transductive and inductive settings of a DRL policy designed to manage a chiller coupled with a Thermal Energy Storage(TES).The control policy is pre-trained on a source building and transferred to various target buildings characterised by an integrated energy system including photovoltaic and battery energy storage systems,different building envelope features,occupancy schedule and boundary conditions(e.g.,weather and price signal).The TL approach incorporates model slicing,imitation learning and fine-tuning to handle diverse state spaces and reward functions between source and target *** show that the proposed methodology leads to a reduction of 10% in electricity cost and between 10% and 40% in the mean value of the daily average temperature violation rate compared to RBC and online DRL ***,online TL maximises self-sufficiency and self-consumption by 9% and 11% with respect to ***,online TL achieves worse performance compared to offline DRL in either transductive or inductive ***,offline Deep Reinforcement Learning(DRL)agents should be trained at least for 15 episodes to reach the same level of performance as the online

关键词： transfer learning reinforcement learning building control building energy management

Measuring impact of Lean Manufacturing Tools for Continuous improvement on Economic Sustainability

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Journal of Systems Science and Systems Engineering 2024年第4期33卷 452-474页

作者： Luis Javier Márquez Figueroa Jorge Luis García-Alcaraz Ahmed i.Osman alfonso Jesús Gil López Yashar Aryanfar Mika Sillanpää Mamdouh El Haj Assad Department of Electrical Engineering and Computer Science Universidad Autónoma de Ciudad JuárezCiudad JuárezChihuahuaMéxico Department of industrial Engineering and Manufacturing Universidad Autónoma de Ciudad JuárezCiudad JuárezChihuahuaMéxico School of Chemistry and Chemical Engineering Queens UniversityBelfastNorthern IrelandUK Department of Economic and Managerial Sciences University of La RiojaLa RiojaSpain Department of Chemical Engineering University of JohannesburgJohannesburgSouth Africa Department of Sustainable and Renewable Energy Engineering University of SharjahSharjahUAE

Using Lean Manufacturing(LM)tools in production processes is crucial for companies’economic,environmental,and social sustainability *** study shows a structural equation model(SEM)that shows the relationship between LM Tools like Kaizen(KAi),Gemba(GEM),Value Stream Mapping(VSM)and Key Performance indicator(KPi)with Economic Sustainability(ECS).Seven hypotheses were evaluated with data from 179 responses to a questionnaire about the Mexican maquiladora industry,showing that these variables are *** a 95%confidence level,the model was evaluated using the partial least squares *** findings indicate that the relationships between KAi and GEM and KAi and VSM have the strongest relationship,followed by VSM and ECS;however,VSM has the strongest effect on *** on these findings,it is recommended that managers adopt a continuous improvement(KAi)approach based on working directly on the shop floor(GEM and VSM)to support their decisions regarding economic growth(ECS).

关键词： Lean manufacturing economic sustainability structural equation model quality improvement

Autonomous Vehicle Platoons in Urban Road Networks:A Joint Distributed Reinforcement Learning and Model Predictive Control Approach

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iEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 141-156页

作者： Luigi D’alfonso Francesco Giannini Giuseppe Franzè Giuseppe Fedele Francesco Pupo Giancarlo Fortino iEEE the Department of Computer Engineering ModelingElectronics and SystemsUniversitàdella CalabriaVia Pietro BucciCubo 42-CRende(CS)87036Italy the Department of Mechanical Engineering Energy Engineering and ManagementUniversitàdella CalabriaVia Pietro BucciCubo 42-CRende(CS)87036Italy

in this paper, platoons of autonomous vehicles operating in urban road networks are considered. From a methodological point of view, the problem of interest consists of formally characterizing vehicle state trajectory tubes by means of routing decisions complying with traffic congestion criteria. To this end, a novel distributed control architecture is conceived by taking advantage of two methodologies: deep reinforcement learning and model predictive control. On one hand, the routing decisions are obtained by using a distributed reinforcement learning algorithm that exploits available traffic data at each road junction. On the other hand, a bank of model predictive controllers is in charge of computing the more adequate control action for each involved vehicle. Such tasks are here combined into a single framework:the deep reinforcement learning output(action) is translated into a set-point to be tracked by the model predictive controller;conversely, the current vehicle position, resulting from the application of the control move, is exploited by the deep reinforcement learning unit for improving its reliability. The main novelty of the proposed solution lies in its hybrid nature: on one hand it fully exploits deep reinforcement learning capabilities for decisionmaking purposes;on the other hand, time-varying hard constraints are always satisfied during the dynamical platoon evolution imposed by the computed routing decisions. To efficiently evaluate the performance of the proposed control architecture, a co-design procedure, involving the SUMO and MATLAB platforms, is implemented so that complex operating environments can be used, and the information coming from road maps(links,junctions, obstacles, semaphores, etc.) and vehicle state trajectories can be shared and exchanged. Finally by considering as operating scenario a real entire city block and a platoon of eleven vehicles described by double-integrator models, several simulations have been performed with the a

关键词： Distributed model predictive control distributed reinforcement learning routing decisions urban road networks

Polyoxidovanadates a new therapeutic alternative for neurodegenerative and aging diseases

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Neural Regeneration Research 2024年第3期19卷 571-577页

作者： Sonia irais Gonzalez-Cano Gonzalo Flores Jorge Guevara Julio Cesar Morales-Medina Samuel Treviño alfonso Diaz Faculty of Chemical Sciences Benemerita Autonomous University of PueblaPueblaMexico institute of Physiology Benemerita Autonomous University of PueblaPueblaMexico Department of Biochemistry Faculty of MedicineNational Autonomous University of MexicoMexico CityMexico Animal Reproduction Research Center CINVESTAV-Autonomous University of TlaxcalaTlaxcalaMexico

Aging is a natural phenomenon characterized by a progressive decline in physiological integrity,leading to a deterioration of cognitive function and increasing the risk of suffering from chronic-degenerative diseases,including cardiovascular diseases,osteoporosis,cancer,diabetes,and *** is considered the major risk factor for Parkinson’s and Alzheimer’s disease ***,diabetes and insulin resistance constitute additional risk factors for developing neurodegenerative ***,no treatment can effectively reverse these neurodegenerative ***,some antidiabetic drugs have opened the possibility of being used against neurodegenerative *** the previous framework,Vanadium species have demonstrated a notable antidiabetic *** research group evaluated polyoxidovanadates such as decavanadate and metforminium-decavanadate with preventive and corrective activity on neurodegeneration in brain-specific areas from rats with metabolic *** results suggest that these polyoxidovanadates induce neuronal and cognitive restoration *** review aims to describe the therapeutic potential of polyoxidovanadates as insulin-enhancer agents in the brain,constituting a therapeutic alternative for aging and neurodegenerative diseases.

关键词： Alzheimer’s disease antidiabetic brain cognition diabetes insulin neurodegeneration neuroinflammation oxidative stress Vanadium species

Long-term trends in the abundance and breeding performance in Adélie penguins:the Argentine Ecosystem Monitoring Program

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Advances in Polar Science 2024年第1期35卷 132-140页

作者： Mariana A.JUÁRES AnahíM.SiLVESTRO Brenda C.alfonso M.Mercedes SANTOS Departamento Biología de Predadores Tope Instituto Antártico Argentino(IAA)Buenos Aires B1650CSPArgentina Consejo Nacional de investigaciones Científicas y Técnicas(CONiCET) Buenos Aires C1425FQBArgentina Laboratorios Anexos Facultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataLa Plata B1904AMAArgentina iNEDES(CONiCET-UNLu) Buenos Aires C1425FQBArgentina Facultad de Ciencias Naturales y Museo Universidad Nacional de La PlataLa Plata B1900FWAArgentina instituto Antártico Argentino(iAA) Buenos Aires B1650CSPArgentina

in this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys islands;Stranger Point/Cabo Funes,South Shetland islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/*** yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies ***,the magnitude of change was higher at Stranger Point than that in the remaining ***,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study ***,it displayed greater variability at Martin Point compared to the other two colonies under *** the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza ***,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.

关键词： long-term monitoring Adélie penguin breeding pairs chicks crèched breeding success population trends

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Microstructures and mechanical properties of laser-directed energy deposited CrCoNi medium-entropy alloy

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Rare Metals 2024年第7期43卷 3286-3300页

作者： Wen-Jie Zhao Chang-Yu Liu Peng-Cheng Che Zhi-Liang Ning Hong-Bo Fan Jian-Fei Sun Yong-Jiang Huang alfonso H.W.Ngan National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China Space Environment Simulation Research infrastructure Harbin Institute of TechnologyHarbin 150001China Department of Mechanical Engineering The University of Hong KongHong Kong 999077China

The distinctive intrinsic heat treatment(iHT)originating from cyclic reheating in the laser-directed energy deposition(LDED) has attracted growing attention in recent *** this investigation,simulations and experimental characterizations were performed to examine the impact of iHT on the micros true ture and mechanical properties of LDED-fabricated CrCoNi medium-entropy alloy(MEA).The results show that the intensity of the iHT is proportional to the utilized laser energy density(LED).As the LED increased,significant dynamic recrystallization and grain refinement occurred within the alloy due to the enhanced intensity of ***,the high LED leads to severe hot cracking within the as-built MEA,resulting in inferior *** decreasing LED,the hot cracking was effectively ***,low LED weakened the intensity of iHT and consequently inhibited kinetic conditions of dynamic recrystallization,resulting in a heterogeneous grain structure characterized by multi-scale-sized *** structure provides significant hetero-deformation-induced hardening during plastic deformation,enabling the alloy to have a sustainable work-hardening *** expect that this work will have implications in taking full advantage of the unique iHT of the LDED process to fabricate ME As with excellent metallurgical quality and mechanical performance.

关键词： intrinsic heat treatment Laser-directed energy deposition CrCoNi MEA Dynamic recrystallization Heterogeneous grain structure

Electrifying Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) for focalized heating in oxygen transport membranes

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Journal of Energy Chemistry 2024年第4期91卷 99-110页

作者： Marwan Laqdiem Julio García-Fayos Laura Almar alfonso J.Carrillo Álvaro Represa JoséM.López Nieto Sonia Escolástico David Catalán-Martinez Jose M.Serra instituto de Tecnología Química(Universitat Politècnica de València–Consejo Superior de investigaciones Científicas) Av.Los Naranjos s/nE-46022 ValenciaSpain

industry decarbonization requires the development of highly efficient and flexible technologies relying on renewable energy resources,especially biomass and solar/wind *** the case of pure oxygen production,oxygen transport membranes(OTMs)appear as an alternative technology for the cryogenic distillation of air,the industrially-established process of producing ***,OTMs could provide oxygen from different sources(air,water,CO_(2),etc.),and they are more flexible in adapting to current processes,producing oxygen at 700^(-1)000℃.Furthermore,OTMs can be integrated into catalytic membrane reactors,providing new pathways for different *** first part of this study was focused on electrification on a traditional OTM material(Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)),imposing different electric currents/voltages along a capillary *** to the emerging Joule effect,the membrane-surface temperature and the associated O_(2) permeation flux could be ***,the OTM is electrically and locally heated and reaches 900℃on the surface,whereas the surrounding of the membrane was maintained at 650℃.The O_(2)permeation flux reached for the electrified membranes was~3.7 NmL min^(-1)cm^(-2),corresponding to the flux obtained with an OTM non-electrified at 900℃.The influence of depositing a porous Ce_(0.8)Tb_(0.2)O_(2-δ) catalytic/protective layer on the outer membrane surface revealed that lower surface temperatures(830℃)were detected at the same imposed electric ***,the electrification concept was demonstrated in a catalytic membrane reactor(CMR)where the oxidative dehydrogenation of ethane(ODHE)was carried *** reaction is very sensitive to temperature,and here,we demonstrate an improvement of the ethylene yield by reaching moderate temperatures in the reaction chamber while the O_(2) injection into the reaction can be easily fine-tuned.

关键词： Oxygen permeation Oxidative dehydrogenation of ethane Oxygen transport membranes Joule effect Mixed ionic-electronic conductors Catalytic membrane reactors