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Accelerating phase-field-based microstructure evolution predictions via surrogate models trained by machine learning methods

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npj Computational Materials 2021年第1期7卷 9-19页

作者： David montes de oca Zapiain James A.Stewart Rémi Dingreville Center for Integrated Nanotechnologies Sandia National LaboratoriesAlbuquerqueNM 87185USA Energetic Materials Dynamic and Reactive Science Sandia National LaboratoriesAlbuquerqueNM 87185USA

The phase-field method is a powerful and versatile computational approach for modeling the evolution of microstructures and associated properties for a wide variety of physical,chemical,and biological ***,existing high-fidelity phase-field models are inherently computa fonally expensive,requiring high-performance computing resources and sophisticated numefical integration schemes to achieve a useful degree of *** this paper,we present a computationally inexpensive,accurate,data-driven surmogate model that directly learns the microstructural evolution of targeted systems by combining phase-field and history-dependent machine-learning *** integrate a statisti cally representative,low-dimensianal description of the micrastructure,obtained direcdy from phase-field simulations,with either a time-series multivariate adaptive regression splines autoregressive al garithm or a lang short-term memory neural *** neural-network-trained surrogate model shows the bestperformance and accurately predicts the nanlinear microstructure evolutian of a two-phase mixture during spinodal decomposition in seconds,without the need for"on-the-fly"solutions of the phase-field equations of *** also show that the predictions from our machine learned surrogate model can be fed directly as an input into a classical high-fideli ty phase-field model in order to accelerate the high-fidelity phase field simulations by leaping in *** machine-learned phase-field framework opens a promising path forward to use accelerated phase field simulations for discovering,understanding,and predicting processing-microstructure-performance relationships.

关键词： phase versatile statist

High Temperature Oxidation of a Work Roll grade High-Chromium White Cast Iron

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Journal of Iron and Steel Research International 2013年第10期20卷 122-129页

作者： J H Ramírez-Ramírez R Colás N F garza-montes-de-oca Faculty of Mechanical and Electrical Engineering Autonomous University of Nuevo Leon

High-chromium white cast iron is a common material for the manufacture of the work rolls used in the fin- ishing stands in hot strip mills. The high temperature oxidation behaviour of as-cast and heat-treated high-chromium white cast iron was studied by gravimetric means at 650 ℃ in atmospheres that included dry air and a mixture of dry air and water vapour. For both environmental and material conditions, the oxidation rate of the alloys was represen ted by parabolic trends and the oxidation phenomenon was more obvious when the samples were oxidised in water vapour. Water vapour also influenced the chemical composition of the oxides formed in the alloy and under this condi tion, the oxide scale formed on the alloy contained the oxides FeCr2O4 , （Fe,Cr）3O4 and （Fe,Cr）2 O3. In contrast, the alloys exposed to dry air conditions only experienced the formation of FeCr2O4 and （Fe,Cr）2O3. It was found that the presence of water vapour and the chromium content of the alloys increased the oxidation rate by a mechanism that involved chromium depletion of the oxide as a result of hydroxide formation. The differences observed in the oxi- dation behaviour of the alloy are discussed in terms of the composition of the oxidant atmosphere and the metallurgi cal condition of the specimens.

关键词： white cast iron oxidation water vapour work roll

Training data selection for accuracy and transferability of interatomic potentials

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npj Computational Materials 2022年第1期8卷 1795-1803页

作者： David montes de oca Zapiain Mitchell A.Wood Nicholas Lubbers Carlos ZP.ereyra Aidan P.Thompson Danny Perez Sandia National Laboratories AlbuquerqueNM87185USA Computer Computationaland Statistical Sciences DivisionLos Alamos National LaboratoryLos AlamosNM87545USA Mechanical and Aerospace Engineering University of California DavisDavisCA95616USA Theoretical Division Los Alamos National LaboratoryLos AlamosNM87545USA

Advances in machine learning(ML)have enabled the development of interatomic potentials that promise the accuracy of first principles methods and the low-cost,parallel efficiency of empirical ***,ML-based potentials struggle to achieve transferability,i.e.,provide consistent accuracy across configurations that differ from those used during *** order to realize the promise of ML-based potentials,systematic and scalable approaches to generate diverse training sets need to be *** work creates a diverse training set for tungsten in an automated manner using an entropy optimization ***,multiple polynomial and neural network potentials are trained on the entropy-optimized dataset.A corresponding set of potentials are trained on an expert-curated dataset for tungsten for *** models trained to the entropy-optimized data exhibited superior transferability compared to the expert-curated ***,the models trained to the expert-curated set exhibited a significant decrease in performance when evaluated on out-of-sample configurations.

关键词： entropy transfer configuration

Adsorption of cobalt by using inorganic components of sediment samples from water bodies

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International Journal of Sediment Research 2021年第4期36卷 524-531页

作者： Rocío montes de oca-Palma Marcos Solache-Ríos Melania Jiménez-Reyes José Juan garcía-Sánchez Perla Tatiana Almazán-Sánchez Instituto Nacional de Investigaciones Nucleares Departamento de Química Tecnológico de Estudios Superiores de Jocotitlán Cátedras CONACyT-Instituto Nacional de Investigaciones Nucleares

The adsorption of cobalt ions was evaluated using sediment samples from water bodies to investigate the adsorption properties of sediment and the behavior of these natural materials in the presence of nuclear and industrial waste. The two sediments(S1 and S2) were treated to eliminate humic and fulvic acids and then they were characterized by several techniques. The minerals found in both the sediments(X-ray diffraction) were quartz and albite; plus, goethite and muscovite in S1, and kaolinite and montmorillonite in S2. Point of zero charge(PZC) of S1 and S2 was 6.00 and 5.22, respectively. The specific area of S1(63.3 m2/g) is higher than S2(1.5 m2/g). Adsorption kinetics data for S1 and S2 were best fitted to the pseudo second-order model. The removal efficiency of S1 for cobalt was 96% with an adsorption capacity(qe) of 0.93 mg/g, and for S2 was 45% with a qeof 0.40 mg/g. The experimental data of the adsorption isotherms were adjusted to Langmuir and Freundlich models for S1 and S2, respectively. The thermodynamic parameters(enthalpy, entropy, and gibb’s free energy) indicated that the adsorption processes were endothermic, spontaneous, and chemisorption mechanism. The results show that the adsorption capacities of the sediments depend on their composition. These water sediments have important adsorption properties for cobalt, and they can be used in the treatment of nuclear and industrial aqueous wastes.

关键词： Water-body sediment Cobalt ions Adsorption

Microhabitat heterogeneity associated with Vanilla *** its influences on the microbial community of leaf litter and soil

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Soil Ecology Letters 2020年第3期2卷 195-208页

作者： gabriela montes de oca-Vasquez Frank Solano-Campos Bernal Azofeifa-Bolanos Amelia Paniagua-Vasquez Jose Vega-Baudrit Antonio Ruiz-Navarro Ruben Lopez-Mondejar Felipe Bastida National Nanotechnology Laboratory National Center for High Technology10109 PavasSan JoseCosta Rica School of Biological Sciences Universidad NacionalCampus Omar Dengo86-3000 HerediaCosta Rica Asociacion Nacional de Vainilleros Unidos San JoseCosta Rica Instituto de Investigacion y Servicios Forestales Universidad Nacional86-3000 HerediaCosta Rica Laboratory of Polymer Science and Technology School of ChemistryUniversidad NacionalCampus Omar Dengo86-3000 HerediaCosta Rica CEBAS-CSIC Department of Soil and Water ConservationCampus Universitario de Espinardo30100MurciaSpain Laboratory of Environmental Microbiology Institute of Microbiology of the CASVidenska 1083Praha 414220Czech Republic

The impact of forest microhabitats on physiochemical properties of the soil and that of microbial communities on tropical soils remain poorly *** elucidate the effect of tropical forest stand on leaf litter and soil microbial communities,we studied enzyme activities,microbial biomass,and diversity in three distinct microhabitats in terms of plant richness,diameter at breast height(DBH),and physiochemical properties of soil and litter,each associated with a different Vanilla *** the soil,positive correlations were found between electrical conductivity(EC)and total organic carbon(TOC)with phosphatase activity,and between nitrogen(N)and water-soluble carbon(WSC)content with urease activity(UA).In the litter,the water content was positively correlated with bacterial and fungal biomass,and N and WSC contents were positively correlated with fungal *** correlations were found between plant richness and UA in the soil,plant richness and fungal biomass in the soil and litter,and DBH and fungal biomass in the *** sequencing revealed differences between microhabitats in the relative abundance of some fungal and bacterial taxa and in the bacterial community composition of both litter and *** richness and diversity were different between microhabitats,and,in litter samples,they were negatively correlated with DBH and plant richness,*** contrast,none of the soil and litter physiochemical properties were significantly correlated with microbial *** results show that significant shifts in enzyme activity,microbial biomass,and diversity in the microhabitats were driven by key abiotic and biotic factors depending on the soil or litter sample type.

关键词： Tropical rainforest Enzyme activity Microbial community composition Microbial biomass Plant richness

Rare Top decay <i>t</i>→<i>cγ</i>in general THDM-III

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Journal of Quantum Information Science 2017年第2期7卷 57-66页

作者： R. gaitán-Lozano J. H. montes de oca R. Martinez departamento de Física FES-Cuautitlan UNAM Estado de México México departamento de Física Universidad Nacional de Colombia Bogotá D.C. Colombia

We study the decay t →cγ?with flavor-changing neutral interactions in scalar sector of the type III Two Higgs Doublet Model (THDM-III) with mixing between neutral scalar fields as a result of considering the most general scalar potential. The branching ratio of the decay Br (t?→cγ) is calculated as function of the mixing parameters and masses of the neutral scalar fields. We obtain a Br (t?→cγ) of the order of 10−8 for the considered regions of the mixing parameters. Finally, one upper bound for the possible events is estimated to be n=18 by assuming an expected luminosity of the order of 300 fb−1.

关键词： Two Higgs Doublet Models Rare Top decays

Improvement of transfection with reprogramming factors in urine-derived cells

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BIOCELL 2020年第3期44卷 401-409页

作者： OLIVIA A.ROBLES-RODRÍgUEZ MARÍA J.LOERA-ARIAS JOSÉJ.PÉREZ-TRUJILLO ARNULFO VILLANUEVA-OLIVO ERNESTO PICÓN-gALINDO LAURA VILLARREAL-MARTÍNEZ ADOLFO SOTO-DOMÍNgUEZ HUMBERTO RODRÍgUEZROCHA ARACELY gARCÍA-gARCÍA ODILA SAUCEDO-CÁRdeNAS ROBERTO montes de oca-LUNA Facultad de Medicina Departamento de HistologíaUniversidad Autónoma de Nuevo LeónMonterreyC.P.64460México Hospital Universitario“Dr.JoséEleuterio gonzález gonzález” Servicio de HematologíaUniversidad Autónoma de Nuevo LeónMonterreyC.P.64460México Centro de Investigación Biomédica del Noreste Departamento de Genética MolecularInstituto Mexicano del Seguro SocialMonterreyC.P.64720México

Human-induced pluripotent stem cells(iPSCs)are an accessible source of adult-derived,patient-specific pluripotent stem cells for use in basic research,drug discovery,disease modeling,and stem cell *** the accessibility of methods to obtain iPSCs regardless of the cell source can enhance their clinical ***,our purpose is to report a simple protocol to obtain iPS-like cells from urine-derived renal epithelial cells(RECs)using different extracellular matrices and transfection *** this study,we began by culturing urine-derived cells from healthy donors to establish a primary culture of renal epithelial cells,followed by their ***,we generated iPS-like cells by transfecting renal epithelial cells(RECs)with vectors expressing Oct4,Sox2,L-Myc,Lin-28,and Klf4,and we compared the efficacy of different extracellular matrices and transfection *** resultant iPS-like cells showed a human embryonic stem cell-like morphology and expressed the specific pluripotency markers Oct3/4,Nanog,Lin28,and *** concluded that Lipofectamine Stem Cell transfection reagent is more effective than FugENE in obtaining iPS-like cells under the conditions ***,the three matrices are similar in their efficiency of obtaining iPS-like *** report provides an experimental protocol for obtaining and generating iPS-like cells from urine samples for further cell therapy research on different human diseases.

关键词： Reprogramming factors iPSCs Renal epithelial cells Extracellular matrix Transfection reagent

Relationship between methylation and colonic inflammation in inflammatory bowel disease

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World Journal of gastroenterology 2014年第30期20卷 10591-10598页

作者： Triana Lobaton Daniel Azuara Francisco Rodriguez-Moranta Carolina Loayza Xavier Sanjuan Javier de oca Ana Fernandez-Robles Jordi guardiola gabriel Capella department of gastroenterology University Hospital of BellvitgeIDIBELLHospitalet de Llobregat08907 BarcelonaSpain Translational Research Laboratory Catalan Institute of OncologyIDIBELLHospitalet de Llobregat08907 BarcelonaSpain department of Pathology University Hospital of BellvitgeIDIBELLHospitalet de Llobregat08907 BarcelonaSpain department of Surgery Colorectal UnitUniversity Hospital of BellvitgeIDIBELLHospitalet de Llobregat08907 BarcelonaSpain

AIM:To investigate the relationship between the methylation status in the SLIT2 and TgFB2 promoters and colonic inflammation in inflammatory bowel disease ***:We evaluated the methylation status of 2genes(SLIT2 and TgFB2)in 226 biopsies taken from62 colonoscopies of 38 patients(29 ulcerative colitis and 9 Crohn’s colitis)using methylation-specific melting curve *** relationships between methylation status and clinical,biological,endoscopic and histological activities were ***-three of the 38patients had a second colonoscopy and were included in a longitudinal *** results were given as the means±SD of the sample and range,except when *** t analysis,U Mann Whitney and ANOVA factor were used to compare the *** results were based on theχ2 ***:SLIT2 methylation was more frequent in samples with endoscopic activity than with endoscopic remission(55%vs 18%,Pgher in samples with acute inflammation(56.5%)than in samples with chronic(24%)or absent inflammation(15%)(PgFB2methylation,the correlation was only significant with endoscopic *** was higher in the distal colon for both genes(PgFB2).In the multivariate analysis,only inflammation status(and not disease duration or extension)was independently associated with SLIT2 methylation[OR=6.6(95%CI:1.65-27.36),P=0.009].In the longitudinal analysis,the maintenance of endoscopic remission was protective for ***:Endoscopic and histological inflammation are predictive for SLIT2 methylation.

关键词： Colonic inflammation Inflammatory bowel disease Aberrant methylation Dysplasia Colitis associated colorectal cancer

Management of occult hepatitis B virus infection:An update for the clinician

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World Journal of gastroenterology 2011年第12期17卷 1563-1568页

作者： JoséLuis Lledó Conrado Fernández María Luisa gutiérrez Sara ocaa gastroenterology Unit Hospital Universitario Fundación AlcorcónAv Budapest-128922 AlcorcónMadridSpain Laboratory Unit Hospital Universitario Fundación AlcorcónAv Budapest-128922 AlcorcónMadridSpain

Occult hepatitis B virus(HBV) infection(OBI) is defined by the presence of HBV DNA in the liver tissue of individuals who test negative for hepatitis B surface antigen(HBsAg).Patients who have recovered from acute hepatitis B can carry HBV genomes for a long time and show histological patterns of mild necro-inflammation,even fibrosis,years after the resolution of acute hepatitis,without showing any clinical or biochemical evidence of liver *** least in conditions of immunocompetence,OBI is inoffensive itself,but when other relevant causes of liver damage are present it might make the course of the liver disease *** risk of HBV transmission through transfusion is related to blood donations negative for HBsAg that have been collected during the pre-seroconversion period or during chronic *** of HBV nucleic acid amplification testing and multivalent anti-HBs antibodies in the HBsAg assays is recommended for detection of true and false OBI,*** is not known if prior hepatitis B immunization with an optimal anti-HBs response in cases of HBV transmission through organ transplantation can effectively modulate or abort the *** of anti-viral agents as prophylaxis in patients with serological evidence of past HBV infection prevents reactivation of OBI after transplantation in most *** of OBI has been observed in other conditions that cause immunosuppression,in which antiviral therapy could be delayed until the HBV DNA or HBsAg becomes *** might contribute to the progression of liver fibrosis and hepatocellular carcinoma development in patients with chronic liver disease.

关键词： Occult hepatitis B Management Blood transfusion Organ transplantation Virus reactivation Chronic liver disease Hepatocellular carcinoma