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Energy Geoscience 2021年第2期2卷 121-128页

作者： j.Ribeiro D.flores Department of Earth Sciences University of CoimbraRua Silvio Lima3030-790CoimbraPortugal Institute of Earth Sciences-Porto Pole Rua Do Campo Alegre 6874169-007PortoPortugal Environment and Spatial Planning Department of GeosciencesUniversity of PortoRua Do Campo Alegre 6874169-007PortoPortugal

The coal mining residues from past mining activities in the Douro Coalfield are emplaced in many dumps near the mining areas,causing substantial environmental *** study aims to contribute to the investigation of environmental impacts caused by the disposal of the residue in the Douro Coalfield through the determination of the geochemical composition of waste materials collected at 3 e 15 m depth,and of the water-leachable fraction produced by percolation in these materials inside the *** elements with higher concentration in the leachates are Ca,Cd,Co,Mg,Mn,Na,Ni,S,and Zn,indicating that they are the most easily leached and accessible elements for percolation and mobilization into the *** presence of these elements in the leachates is principally attributed to their occurrence as water-soluble ions in clays and sulphides affected by natural weathering conditions,which promotes their breakdown and occurrence as exchangeable *** leachates are classified as acid *** weathering and leaching in the Sao Pedro da Cova waste dump are the principal~paths for chemical elements to be percolated and mobilized to environment,posing risk to the soils,waters and ecosystems in the surrounding areas.

关键词： Coal mining Waste dump Water-soluble compound Hazardous element

Sensitivity-based Vulnerability Assessment of State Estimation

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journal of Modern Power Systems and Clean Energy 2021年第4期9卷 886-896页

作者： Gonzalo E.Constante-flores Antonio j.Conejo jiankang Wang Department of Electrical and Computer Engineering The Ohio State UniversityColumbusUSA Department of Integrated Systems Engineering and the Department of Electrical and Computer Engineering The Ohio State UniversityColumbusUSA

We propose a technique to assess the vulnerability of the power system state estimation. We aim at identifying the measurements that have a high potential of being the target of false data injection attacks. From the perspective of the adversary, such measurements have the following characteristics: ① being influential on the variable estimates;② corrupting their measured values is likely to be undetected. Additionally, such characteristics should not change significantly with the system operation condition. The proposed technique provides a systematic way of identifying the measurements with such characteristics. We illustrate our methodology on a 4-bus system, the New England 39-bus system, and the IEEE 118-bus test system, respectively.

关键词： False data injection attack state estimation sensitivity analysis singular value decomposition

Asphaltene Erosion Process in Air Plasma: Emission Spectroscopy and Surface Analysis for Air-Plasma Reactions

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Plasma Science and Technology 2012年第4期14卷 303-311页

作者： H.MARTINEZ O. flores j.C. POVEDA B. CAMPILLO Institute of Physical Sciences Autonomous National University of Mexico Chemistry Faculty Autonomous National University of Mexico

Optical emission spectroscopy （OES） was applied for plasma characterization during the erosion of asphaltene substrates. An amount of 100 mg of asphaltene was carefully applied to an electrode and exposed to air-plasma glow discharge at a pressure of 1.0 Torr. The plasma was generated in a stainless steel discharge chamber by an ac generator at a frequency of 60 Hz, output power of 50 W and a gas flow rate of 1.8 L/min. The electron temperature and ion density were estimated to be 2.15±0.11 eV and （1.24±0.05）× 10^16 m^-3, respectively, using a double Langmuir probe. OES was employed to observe the emission from the asphaltene exposed to air plasma. Both molecular band emission from N2, N2＋, OH, CH, NH, O2 as well as CN, and atomic light emission from V and Hγ were observed and used to monitor the evolution of asphaltene erosion. The asphaltene erosion was analyzed with the aid of a scanning electron microscope （SEM） equipped with an energy dispersive X-ray （EDX） detector. The EDX analysis showed that the time evolution of elements C, O, S and V were similar and the chemical composition of the exposed asphaltenes remained constant. Particle size evolution was measured, showing a maximum size of 2307 μm after 60 min. This behavior is most likely related to particle agglomeration as a function of time.

关键词： asphaltene erosion surface analysis optical emission spectroscopy pulsedplasma glow discharge

A Numerical Study Comparing the Effect on Residual Stresses of Two Different Types of Projectiles During Shot Peening

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Computers, Materials & Continua 2016年第3期51卷 203-215页

作者： j.Solórzano-López F.A.García-Pastor Angélica flores-Luna UNAM Facultad de QuímicaCiudad de MéxicoMéxico Cinvestav Unidad Saltillo CoahuilaMéxico TecNM Instituto Tecnológico de Tláhuac IIICiudad de MéxicoMéxico

Shot peening is a widely used technique to improve fatigue life in metallic *** processing technique introduces a subsurface compressive residual stress field through a plastic deformation of the surface caused by the impact of a large number of high-speed *** are a number of parameters that affect the residual stress field depth and *** effects of the impact angle,shot speed and shot geometry are currently being *** particular,substituting spherical cast shots by cylindrical cut wire shots is an attractive option,especially in terms of *** effect of shot geometry on residual stresses,however,needs to be further *** industrial-scale experimentation is costly and cumbersome,mathematical modeling offers a convenient alternative to carry out this type of *** present work shows a comparison between the residual stresses generated by the impact of spherical and cylindrical projectiles on a steel *** threedimensional model was developed using ABAQUS finite element commercial software(Release 6.12,Dassault Systémes,France).The results show that cylindrical shots generate residual stress fields t hat a re higher in magnitude than t hose generated by a spherical ***,the residual stress field of cylindrical shots impacting the surface at an oblique angle shows an important degree of *** effect is not found when spherical shots impact the surface at the same oblique angle.

关键词： Shot Peening Finite element method Residual Stresses

Mechanical and natural ventilation systems in a greenhouse designed using computational fluid dynamics

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International journal of Agricultural and Biological Engineering 2014年第1期7卷 1-16页

作者： jorge flores-Velazquez juan I.Montero Esteban j.Baeza juan C.Lopez Mexican Institute of Water Technology.Paseo Cuauhnáhuac 8532 Col.ProgresoC.P.62550JiutepecMor.Mexico Institut de Recerca i Tecnologia Agroalimentàries 08348Cabrils(Barcelona)Spain IFAPA Centro La Mojonera(junta de Andalucía) Camino San Nicolás 104745 La MojoneraAlmeríaSpain Fundación Cajamar.Estación Experimental“Las Palmerillas”Autovía del Mediterráneo Km 416 704710El EjidoAlmeríaSpain

The aim of this study was to analyse air exchange and temperature distribution in a greenhouse with combined mechanical and natural ventilation and to design more efficient mechanical ventilation *** this purpose,a computational fluid dynamics(CFD)model of the greenhouse was *** configurations were considered:Configuration 1(mechanical ventilation and closed roof ventilators),Configurations 2 and 3(mechanical ventilation and roof ventilators open 30%and 100%,respectively).After validation,the CFD model was used to improve the design of the greenhouse mechanical ventilation system in each of the three configurations *** greenhouse lengths,28 m,50 m,75 m and 100 m,were used in the *** to fan ventilation only,roof ventilation improved the climate of fan-ventilated greenhouses in terms of the air exchange rate(22%)and climate uniformity because the internal air was mixed better than with mechanical ventilation *** the greenhouse length increased,more advantages were achieved with natural ventilation compared to mechanical *** most configurations,there was a strong linear correlation between temperature gradient and greenhouse *** greenhouse whose regression line had the steepest slope was the one with closed roof *** the fan capacity produced a general reduction in temperature,but the effect was less intense for the greenhouses with open roof *** to box inlet ventilators,an enlarged continuous inlet in the wall opposite the fans increased overall system performance because it eliminated backflow recirculation zones,which are prone to produce high temperatures.

关键词： greenhouse cooling fan ventilation roof ventilators combined ventilation

Ligand effects on the structure and vibrational properties of the thiolated Au18 cluster

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Progress in Natural Science:Materials International 2016年第5期26卷 510-515页

作者： Alfredo Tlahuice-flores CICFIM-Facultad de Ciencias Físico-Matemáticas Universidad Autónoma de Nuevo León

Most of the studies devoted to thiolated gold clusters suppose that their core and Au-S framework do not suffer from distortion independently of the protecting ligands（-SR） and it is assumed as correct to simplify the ligand as SCH3. In this work is delivered a systematic study of the structure and vibrational properties（IR and Raman）of the Au18（SR）14cluster. The pursued goal is to understand the dependency of the displayed vibrational properties of the thiolated Au18cluster with the ligands type. A set of six ligands was considered during calculations of the vibrational properties based on density functional theory（DFT） and in its dispersioncorrected approach（DFT-D）.

关键词： Gold cluster Ligand effects Structure Vibration Au18(SR)14 Density functional theory

Cerium extraction by metallothermic reduction using cerium oxide powder injection

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journal of Rare Earths 2011年第1期29卷 74-76页

作者： j.S.Luna A A.flores V R.Muiz V A.F.Fuentes j.Torres N.Rodríguez R j.C.Ortiz P.Orozco CINVESTAV Unidad Saltillo Saltillo-Monterrey Highway Km.13.5P.O.Box 66325000SaltilloCoahuilaMéxico Faculty of Engineering Autonomous Univer-sity of CoahuilaCamporedondo UnitSaltilloCoahuilaMéxico Department of Metal Mechanics Technological Institute of SaltilloV.Carranza Blvd 2400SaltilloCoahuilaZC 25280México Academic Unit of Engineering Autonomous University of CoahuilaLopez Velarde Av.ZacatecasZac.ZC 98060

This work presented the feasibility of cerium recovery by Al-Mg alloy through the metallothermic reduction of CeO2 to obtain a master alloy Al-4%Ce. The master alloy obtained in this investigation was for the grain refinement and modification of Al-Si alloys. The reagent was incorporated into a molten alloy using the submerged powder injection technique, and metallic samples were obtained during injection. Chemical and microstructural analyses （by inductively coupled plasma （ICP） and scanning electron microscopy （SEM）, respectively） confirmed the possibility of Ce uptake in the bath （0 to 4 wt.%）, as CeO2 was reduced through metallothermic reactions in the molten alloys. Based on the characterization of reaction products, the sequence of the reaction was proposed.

关键词： cerium recovery metallothermic reduction reaction products rare earths

Near shore seismic movements induced by seaquakes using the boundary element method

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Earthquake Engineering and Engineering Vibration 2017年第3期16卷 571-585页

作者： Alejandro Rodríguez-Castellanos Manuel Carbajal-Romero Norberto flores-Guzmán j.Efraín Rodríguez-Sánchez Andriy Kryvko instituto mexicano del petróleo eje central lázaro cárdenas 152Gustavo A.MaderoDistrito FederalMéxico escuela superior de ingeniería mecánicay eléctrica instituto politécnico nacionalupalmEdif.5Av.Instituto Politécnico Nacional S/NCol.LindavistaGustavo A.MaderoDistrito FederalMéxico escuela superior de ingeniería mecánicay eléctrica instituto politécnico nacionalunidad profesional azcapotzalcoDistrito FederalMéxico centro de investigación en matemáticas jalisco s/nmineral de valencianaguanajuatoMéxico

This study quantifies seismic amplifications in near-shore arising from seaquakes. Within the Boundary Element Method, boundary elements are used to irradiate waves and force densities obtained for each element. Huygens′ Principle is implemented since the diffracted waves are constructed at the boundary from which they are radiated, which is equivalent to Somigliana′s theorem. Application of boundary conditions leads to a system of integral equations of the Fredholm type of second kind and zero order. Several numerical configurations are analyzed： The first is used to verify the present formulation with ideal sea floor configurations to estimate seismic amplifications. With the formulation verified, simple slope configurations are studied to estimate spectra of seismic motions. It is found that P-waves can produce seismic amplifications from 1.2 to 3.9 times the amplitude of the incident wave. SV-waves can generate seismic amplifications up to 4.5 times the incident wave. Another relevant finding is that the highest amplifications are at the shore compared to the ones at the sea floor.

关键词： seismic amplifications seaquake earthquake elastic waves boundary element method near shore cities

Subclinical cardiovascular disease in type 2 diabetes mellitus: To screen or not to screen

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World journal of Clinical Cases 2014年第9期2卷 415-421页

作者： juan j Chillarón juana A flores-Le Roux David Benaiges juan Pedro-Botet Department of Endocrinology and Nutrition Hospital del Mar Passeig Marítim 25-29 08003 Barcelona Spain Institut Municipal d'Investigacions Mèdiques Passeig Marítim 25-29 08003 Barcelona Spain Departament de Medicina Universitat Autònoma de Barcelona 08193 Cerdanyola (NOT Sarda?ola) del Vallés Barcelona Spain

The prevalence of type 2 diabetes mellitus(T2DM) has risen in recent decades, and cardiovascular disease remains the leading cause of death in this population. Several clinical trials have demonstrated the benefit of tight control of risk factors on the incidence and mortality of cardiovascular disease. However, in clinical practice, few patients achieve the therapeutic goals. The current diagnostic procedures for subclinical cardiovascular disease in T2 DM patients have not been shown to improve prognosis or mortality, probably because they do not categorize cardiovascular risk. Thus, clinical practice guidelines do not systematically recommend screening for subclinical atherosclerosis in these patients, although it is known that patients with extracoronary atherosclerosis, microangiopathy and poorlycontrolled cardiovascular risk factors are at high risk for cardiovascular disease. Improvements in the reliability of diagnostic tests, with fewer side effects and better cost efficiency, may better help to stratify cardiovascular risk in this group of patients, and further evaluation on this topic should be considered.

关键词： Cardiovascular disease Type 2 diabetes mellitus Cardiovascular risk