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Mathematical simulation of radial heat transfer in packed beds by pseudohomogeneous modeling

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Particuology 2011年第2期9卷 107-113页

作者： Rodrigo Béttega Marcos flávio Pinto Moreira Ronaldo Guimaraes Corrêa José teixeira freire federal University of Uberlandia/School of Chemical Engineering-Av.Jo o Naves ávila 2121 Uberlandia-MGCEP 38400-902Brazil Western Paraná State University-Rua da faculdade 645 Jardim La SalleToledo-PRCEP 85903-000Brazil federal University of S o Carlos/Department of Chemical Engineering-Rod.Washington Luiz km 235 S o Carlos-SPCEP 13565-905P.O.Box 676Brazil

Uniform flow regime and constant effective thermal conductivity inside packed beds are commonly accepted in the evaluation of the fluid dynamics and heat transfer in such systems. However, several authors have confirmed the presence of an oscillatory velocity profile caused by the effective contribu~ tion of porosity profile in the fluid dynamic behavior of packed beds, which directly influences the heat transfer inside the beds. This paper describes the application of a pseudo-homogeneous mathematical model for describing heat transfer in packed beds with oscillatory profiles of velocity and porosity, using a radius-dependent model for effective thermal conductivity kr. Several temperature profiles were obtained in a packed bed system with thermal source located on the wall. The simulated temperature and effective thermal conductivity obtained from simulations were compared with experimental data and calculation from a model based on uniform kr fitting. The results indicate that the proposed mathematical modeling was capable of better reDresenting the heat transfer in the packed bed.

关键词： Packed bedHeat transferPseudohomogeneous modeling

Characterization of soil fauna under the influence of mercury atmospheric deposition in Atlantic forest, Rio de Janeiro, Brazil

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Journal of Environmental Sciences 2015年第6期27卷 217-227页

作者： Andressa Cristhy Buch Maria Elizabeth fernandes Correia Daniel Cabral teixeira Emmanoel Vieira Silva-filho Departamento de Geoquímica Universidade Federal Fluminense Embrapa Agrobiologia BR 465 km 7

The increasing levels of mercury（Hg） found in the atmosphere arising from anthropogenic sources, have been the object of great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the *** major input of Hg to ecosystems is through atmospheric deposition（wet and dry）, being transported in the atmosphere over large distances. The forest biomes are of strong importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transference to the soil through litter, playing an important role as sink of this element. Soil microarthropods are keys to understanding the soil ecosystem, and for such purpose were characterized by the soil fauna of two Units of forest Conservation of the state of the Rio de Janeiro, inwhich one of the areas suffer quite interference from petrochemicals and industrial anthropogenic activities and other area almost exempts of these perturbations. The results showed that soil and litter of the Atlantic forest in Brazil tend to stock high mercury concentrations, which could affect the abundance and richness of soil fauna, endangering its biodiversity and thereby the functioning of ecosystems.

关键词： Biodiversity Litter Microarthropods Soil Trace-element

Hazardous elements and amorphous nanoparticles in historical estuary coal mining area

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Geoscience frontiers 2019年第3期10卷 927-939页

作者： Ana L.Duarte Kátia DaBoit Marcos L.S.Oliveira Elba C.teixeira Ismael L.Schneider Luis f.O.Silva Department of Civil and Environmental Universidad de la Costa faculdade Meridional IMED fEPAM-funda■o Estadual de Prote■o Ambiental Henrique Luis Roessler

In Brazil, intense coal exploitation activities have led to environmental deterioration, including soil mortification, water contamination, loss of ecosystem, and atmospheric contamination. In addition,considerable quantities of sulfur-rich residues are left behind in the mining area; these residues pose grave environmental issues as they undergo sulfide oxidation reactions. When sulfur oxides come in contact with water, extreme acid leachate is produced with great proportions of sulfate, and hazardous elements(HEs), which are identified as coal drainage(CMD). CMD is an environmental pollution challenge, particularly in countries with historic or active coal mines. To prevent CMD formation or its migration, the source must be controlled; however, this may not be feasible at many locations. In such scenarios, the mine water should be collected, treated, and discharged. In this study, data from 2005 to2010 was gathered on the geochemistry of 11 CMD discharges from ten different mines. There are several concerns and questions on the formation of nanominerals in mine acid drainage and on their reactions and interfaces. The detailed mineralogical and geochemical data presented in this paper were derived from previous studies on the coal mine areas in Brazil. Oxyhydroxides, sulfates, and nanoparticles in these areas possibly go through structural transformations depending on their size and formation conditions. The geochemistry of fe-precipitates(such as jarosite, goethite, and hematite) existent in the CMD-generating coal areas and those that could be considered as a potential source of hazardous elements(HEs)(e.g., Cr) were also studied because these precipitates are relatively stable in extremely low pH conditions. To simplify and improve poorly ordered iron, strontium, and aluminum phase characterization, field emission scanning electron microscopy(fE-SEM), high-resolution transmission electron microscopy(HR-TEM), micro-Raman spectroscopy, and X-ray diffraction(XRD) a

关键词： Brazilian coal mining Environmental impacts Minerals

Influence of Concentration of Vanadium in Zinc Oxide on Structural and Optical Properties with Lower Concentration

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Chinese Physics Letters 2009年第7期26卷 308-311页

作者：王丽伟徐征孟立建 Vasco teixeira 宋世庚徐叙瑢 Institute of Optoelectronics Technology and Key Laboratory of Luminescence and Optical Information Beijing Jiaotong University Beijing 100044 Departamento de ffsica Instituto Superior de Engenharia do Porto Rua Dr. Antdnio Bernardino de Almeida 431 4200-072 Porto Portugal Centro de ffsica Universidade do Minho Campus de Azurem 4800-058 Guimaraes Portugal 4Thin Film Center University of Paisley Paisley PAl 2BE Scotland Thin film Oenter University of Paisley Paisley PAl 2BE Scotland

ZnO films doped with different vanadium concentrations are deposited onto glass substrates by dc reactive magnetron sputtering using a zinc target doped with vanadium. The vanadium concentrations are examined by energy dispersive spectroscopy （EDS） and the charge state of vanadium in ZnO thin films is characterized by x-ray photoelectron spectroscopy. The results of x-ray diffraction （XRD） show that all the films have a wurtzite structure and grow mainly in the c-axis orientation. The grain size and residual stress in the deposited films are estimated by fitting the XRD results. The optical properties of the films are studied by measuring the transmittance. The optical constants （refractive index and extinction coefficient） and the film thickness are obtained by fitting the transmittance. All the results are discussed in relation with the doping of the vanadium.

关键词： sea surface nonliear interaction numerical method

Reduced semen quality in patients with testicular cancer seminoma is associated with alterations in the expression of sperm proteins

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Asian Journal of Andrology 2020年第1期22卷 88-93页

作者： Tania R dias Ashok Agarwal Peter N Pushparaj Gulfam Ahmad Rakesh Sharma American Center for Reproductive Medicine Cleveland ClinicClevelandOH 44195USA Department of Health Sciences Faculty of Health SciencesUniversity of Beira InteriorCovilha 6201-001Portugal Department of Microscopy and Unit for Multidisciplinary Research in Biomedicine Institute of Biomedical Sciences Abel SalazarUniversity of PortoPorto 4050-313Portugal Center of Excellence in Genomic Medicine Research Faculty of Applied Medical SciencesJeddah 21589Saudi Arabia Division of Pathology School of Medical SciencesSydney UniversityLidcombe NSW 2141Australia

Testicular cancer seminoma is one of the most common types of cancer among men of reproductive *** with this condition usually present reduced semen quality,even before initiating cancer ***,the underlying mechanisms by which testicular cancer seminoma affects male fertility are largely *** aim of this study was to investigate alterations in the sperm proteome of men with seminoma undergoing sperm banking before starting cancer therapy,in comparison to healthy proven fertile men(control group).A routine semen analysis was conducted before cryopreservation of the samples(n=15 per group).Men with seminoma showed a decrease in sperm motility(P=0.019),total motile count(P=0.001),concentration(P=0.003),and total sperm count(P=0.001).Quantitative proteomic analysis identified 393 differentially expressed proteins between the study *** proteins involved in spermatogenesis,sperm function,binding of sperm to the oocyte,and fertilization were selected for validation by western *** confirmed the underexpression of heat shock-related 70 kDa protein 2(P=0.041),ubiquinol-cytochrome C reductase core protein 2(P=0.026),and testis-specific sodium/potassium-transporting ATPase subunit alpha-4(P=0.016),as well as the overexpression of angiotensin I converting enzyme(P=0.005)in the seminoma *** altered expression levels of these proteins are associated with spermatogenesis dysfunction,reduced sperm kinematics and motility,failure in capacitation and *** findings of this study may explain the decrease in the fertilizing ability of men with seminoma before starting cancer therapy.

关键词： male fertility proteomics seminoma sperm proteins sperm quality testicular cancer

Simultaneously targeting extracellular vesicle trafficking and TGf-β receptor kinase activity blocks signaling hyperactivation and metastasis

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Signal Transduction and Targeted Therapy 2024年第1期9卷 308-325页

作者： Adilson fonseca teixeira Yanhong Wang Josephine Iaria Peter ten Dijke Hong-Jian Zhu Department of Surgery(The Royal Melbourne Hospital) The University of MelbourneParkvilleVICAustralia Huagene Institute Kecheng Science and Technology ParkPukou DistrictNanjingJiangsuChina Department of Cell and Chemical Biology Oncode InstituteLeiden University Medical CenterLeidenThe Netherlands

Metastasis is the leading cause of cancer-related *** growth factor beta(TGf-β)signaling drives metastasis and is strongly enhanced during cancer ***,the use of on-target TGf-βsignaling inhibitors in the treatment of cancer patients remains unsuccessful,highlighting a gap in the understanding of TGf-βbiology that limits the establishment of efficient anti-metastatic ***,we show that TGf-βsignaling hyperactivation in breast cancer cells is required for metastasis and relies on increased small extracellular vesicle(sEV)*** sEV’s unique role,TGf-βsignaling levels induced by sEVs exceed the activity of matching concentrations of soluble ligand TGf-β.further,genetic disruption of sEV secretion in highlymetastatic breast cancer cells impairs cancer cell aggressiveness by reducing TGf-βsignaling to nearly-normal ***,TGf-βsignaling activity in non-invasive breast cancer cells is inherently low,but can be amplified by sEVs,enabling invasion and metastasis of poorly-metastatic breast cancer *** the translational potential of inhibiting sEV trafficking in advanced breast cancers,treatment with dimethyl amiloride(DMA)decreases sEV secretion,TGf-βsignaling activity,and breast cancer progression in *** both the sEV trafficking and TGf-βsignaling by combining DMA and SB431542 at suboptimal doses potentiated this effect,normalizing the TGf-βsignaling in primary tumors to potently reduce circulating tumor cells,metastasis,and tumor ***,this study establishes sEVs as critical elements in TGf-βbiology,demonstrating the feasibility of inhibiting sEV trafficking as a new therapeutic approach to impair metastasis by normalizing TGf-βsignaling levels in breast cancer cells.

关键词： metastasis doses invasion

Epigenetic Regulation of a Powdery Mildew Resistance Gene in Medicago truncatula

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Molecular Plant 2013年第6期6卷 2000-2003页

作者： Shengming Yang fang Tang Eveline teixeira Caixeta Hongyan Zhu Department of Plant and Soil Sciences University of KentuckyLexingtonKY 40546USA Instituto de Biotecnologia Aplicada a Agropecuária Universidade Federal de VicosaVicosaMGBrazil

Dear Editor, Medicago truncatula is a model legume that is conge- neric with alfalfa （Medicago sativa）, a forage crop of global importance. Over the last decade, tremendous genetic and genomic tools have been developed for this model system, which has greatly facilitated the study of various aspects of legume genomics and biology. from an applied perspective, genomic information gained from M. truncatula is particu- larly useful for genetic improvement of cultivated alfalfa, a crop that is not amenable to genetic analysis because of its allogamous and autotetraploid nature （Yang et al., 2008）. for instance, M. truncatula can be used to clone the orthologs of many economically important genes in alfalfa,

关键词： Anti powdery mildew gene Alfalfa Genetic regulation

Unusual ovarian hyperstimulation syndrome presentation:Pleural effusion without ascites.A case report

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World Journal of Clinical Cases 2025年第8期13卷 26-34页

作者： Íngrid Solsona Sara Peralta Yasmina Barral francisco fàbregues Pepita Giménez-Bonafé Department of Physiological Sciences Physiology UnitFaculty of Medicine and Health SciencesBellvitge CampusUniversitat de BarcelonaIDIBELLBarcelona 08907CataloniaSpain Institut Clinic of Gynecology Obstetrics and NeonatologyHospital ClínicInstitut d'Investigacions Biomèdiques August Pi i SunyerFaculty of MedicineUniversity of BarcelonaBarcelona 08036CataloniaSpain Department of Physiological Sciences Faculty of Medicine and Health SciencesBellvitge CampusUniversitat de BarcelonaIDIBELLL'Hospitalet de Llobregat 08907BarcelonaSpain

BACKGROUND Ovarian hyperstimulation syndrome(OHSS)is a life-threatening complication that can occur in the luteal phase or early pregnancy after controlled ovarian *** case report highlights a unique manifestation of OHSS involving pleural effusion(PE)in a patient without identifiable risk *** SUMMARY A 39-year-old woman who underwent controlled ovarian hyperstimulation for an in vitro fertilization(IVf)cycle experienced dyspnea on the eleventh day of post oocyte *** diagnosis was severe OHSS with a unique manifestation of PE without *** management involved fluid balance and treatment with albumin,furosemide,thromboembolic prophylaxis,and thoracentesis.A continued drainage of the pleural cavity was *** patient had a favo-rable outcome,and a dichorionic diamniotic gestation passed without *** OHSS and its potential complications can include respiratory distress and PE,as well as thromboembolic disorders.

关键词： Dyspnea Infertility In vitro fertilization Ovarian hyperstimulation syndrome Pleural effusion Thoracentesis Case report

Reliability assessment for serviceability limit states of stiffened deep cement mixing column-supported embankments

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2402-2422页

作者： Chana Phutthananon Pornkasem Jongpradist Kangwan Kandavorawong Daniel dias Xiangfeng Guo Pitthaya Jamsawang Construction Innovations and future Infrastructures Research Center Department of Civil EngineeringFaculty of EngineeringKing Mongkut’s University of Technology ThonburiBangkok10140Thailand Laboratory 3SR Grenoble INPCNRSGrenoble Alpes UniversityGrenoble38000France Department of Civil and Environmental Engineering National University of SingaporeSingapore119077Singapore Soil Engineering Research Center Department of Civil EngineeringKing Mongkut’s University of Technology North BangkokBangkok10800Thailand

The reliability and deterministic analyses of wood-cored stiffened deep cement mixing and deep cement mixing column-supported embankments(referred to as WSCSE and DCSE,respectively)considering serviceability limit state requirements are presented in this *** field theory was used to simulate the spatial variability of soilcement mixing(SCM)material in which the adaptive Kriging Monte Carlo simulation was adopted to estimate the failure probability of a columnsupported embankment(CSE)system.A new method for stochastically generating random values of unconfined compressive strength(qu)and the ratio(Ru)between the undrained elastic modulus and qu of SCM material based on statistical correlation data is *** performance of CSEs concerning changes in the mean(μ),coefficient of variation(CoV),and vertical spatial correlation length(θv)of qu and Ru are presented and *** obtained results indicate that WSCSE can provide a significantly higher reliability level and can tolerate more SCM material spatial variability than *** performance of DCSE and WSCSE,which can be considered satisfactory in a deterministic framework,cannot guarantee an acceptable reliability level from a probabilistic *** highlights the importance and necessity of employing reliability analyses for the design of ***,consideration of only μ and CoV of qu seems to be sufficient for reliability analysis of WSCSE while for DCSE,uncertainties regarding the Ru(*** μ and CoV)and θv of qu cannot be ignored.

关键词： Reliability analysis Column-supported embankment(CSE) Stiffened deep cement mixing column Serviceability Adaptive kriging Monte Carlo simulation