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Ambient Air Particulate PM2.5 Concentrations and Identification of Source Categories at Chihuahua, Mexico

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Journal of Environmental Science and Engineering(A) 2013年第3期2卷 147-154页

作者： Ana Canseco-Lajas Ramon Gomez Vargas alfredo campos-Trujillo Department of Environment and Energy Advanced Materials Research Center Chihuahua 31109 Mexieo

Suspended particles in the air are pollutants formed by diverse materials and sizes. As determined in multiple studies, particulate matter equal to or less than 2.5 μrn also called breathable fraction is the one that penetrates the inferior respiratory system. The present study shows the results of a sampling campaign of particulate matter PM25 through 12 months at 3 sites： C33 （Clinic 33）, CIM （CIMAV） and A VA （Avalos） at Chihuahua, Mexico. The aim of this study was to determine the temporary concentrations of PM25, the concentration of metallic elements： Al, As, Co, Cu, Sb, Se, Fe, Mg, Mn, Ni, Pb and Zn, as well as their possible sources. The three sites had the same trend in the time, where in autumn and winter the higher concentrations were found. The yearly averages on sites C33, CIM, and AVA were 9.91, 12.74 and 21.67 μg·m^-3, respectively, finding that AVA site overpasses the standard of 15 μg·m^-3. The application of factor analysis to the data allowed to identify four source categories： crustal, related with Al-Co-Fe-Mg-Mn, vehicular, related with： As-Cu-Sb-Se; mixed, related with： As-Cu-Sb-Se-Pb-Zn and industrial related with Ni-Pb.

关键词： PM25 trace metallic elements factor analysis source categories.

Size Distribution of Particulate Matter of Metals in Urban Aerosols, Comarca Lagunera, Mexico

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Journal of Environmental Science and Engineering(A) 2012年第11期1卷 1260-1266页

作者： Roman Perez Sylvia Miranda alfredo campos Jorge Carrillo Elias Ramirez Gonzalo Garcia Herrera Renewable Energy and Environmental Protection Department Research Center on Advanced Materials C.S. (CIMAV)Chihuahua 31109 Mexico Faculty of Medicine Ju6rez University of Durango State Durango 35050 M~xico

This paper has demonstrated that there is great variation in the size range and chemical composition of metalliferous PM （particulate matter） present within Comarca Lagunera, M6xico due to the physiography of the terrain together the intense vehicular traffic, unpaved roads, cement and lime plants, marble quarries, brick plants, and the largest smelter of non-ferrous material in Latin America. Cascade impactor PM samples from six size ranges：〈 0.49 μm, 0.49-0.9 μm, 0.9-1.5μm, 1.5-3.0 p.m, 3.0-7.2 μm and 7.2-10 μm were collected from inside two stacks within G6mez Palacios and Torreon cities. ICP-AES （inductively coupled plasma-atomic emission spectrometry） analysis on collected Whatman fiberglass filters demonstrates that the PM are matrices mostly constituted of carbonates and silicates with abundant fine metalliferous particles. The metals with the most concentrations averaged over all size ranges were Cu, Fe, Mn, Ni, Pb and Ti. The size distributions of metals detected in this work have been plotted as normalized histogram concentration of each size fraction, the total concentration, and the aerodynamic particle diameter, which is a useful method for comparing the contributions of coarse and fine particles to pollutant concentrations.

关键词： Size distribution cascade impactor metals Comarca Lagunera Mexico ICP-AES.

Individual Aerosol Particles Emitted in the Ceramic-Tile Industry in Chihuahua, Mexico

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Journal of Environmental Science and Engineering(A) 2012年第11期1卷 1248-1259页

作者： Baiter Trujillo-Navarrete Francisco Paraguay-Delgado alfredo campos-Truj illo LuisaQuifiones-Montenegr Carmen Navarro Eduardo Herrera-Peraza Department of Environment and Energy Centro de Investigaciones de Materiales Avanzados S.C. Chihuahua 31109 M~xieo Department of Nanostructured Materials Centro de Investigaciones de Materiales Avanzados S.C. Chihuahua 31109 M~xico

The contribution of anthropogenic mineral aerosol dust has been of interest to understand the impact of dust aerosols on climate, and the health of workers occupational exposure. Several studies have been investigated the physical and chemical properties mainly in particulate matter. However, the characterizations have not extended diameters below to 1.0 μm. In this study, it described chemical composition and shape measurements of individual aerosol particles with 50% cut-off diameters less than 1.1 μm emitted at ceramic-tile manufacturing. Four emission sites of process were selected, and their samples were collected using a cascade-impactor, investigated using X-ray diffraction, energy dispersive X-ray spectroscopy, and digital image processing, where the data were analysed applying a combination of principal component and cluster analysis. Particles of tectosilicate （quartz, zeolite）, phyllosilicate （illite, montmorillonite）, and inosilicate （calcium silicate） were founded in all sampling sites; also, silicates mixed with transition metals oxides used as pigments （e.g., Fe, Ti, Co, Ni, Zn and Mo）. Silicates were granulated and flat crystals with a transparent, translucent appearance; otherwise, the mixture had flake shapes and opaque appearance. Analyses of multivariate data showed that the process stages emissions were related with specific composition and shape suggesting the use three measurements related （1） the internal axis, （2） roundness and （3） roughness to isolate particles shapes, and the presence of transition metals oxides as emissions tracer of the ceramic industry.

关键词： Anthropogenic source tile-ceramic mineral aerosol dust individual aerosol particle shape measures.

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

Influence of physical-anatomical wood variables on charcoal physical-mechanical properties

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Journal of Forestry Research 2023年第2期34卷 531-538页

作者： Allan Motta Couto Thiago campos Monteiro Paulo Fernando Trugilho JoséTarcísio Lima JoséReinaldo Moreira da Silva alfredo Napoli Diego Pierre de Almeida Department of Forestry Science State University of Mato Grosso do Sul–UEMSAv.Graziela Maciel BarrosoKm 12 Zona RuralAquidauanaMS 79200000Brazil Department of Forestry Engineering and Technology Federal University of Paraná–UFPRA V.Pref.Lothário Meissner 632Jardim BotânicoCuritibaPR 80210170Brazil Department of Forestry Science Federal UniversityLavras–UFLALavrasMG 37200000Brazil Département de Performance Des Systèmes de Production Et de Transformation Tropicaux Centre de Coopération Internationale em Recherche Agronomique pour le Développement–CIRADMontpellierFrance

This research assessed the relationship between wood physical-anatomical variables and charcoal physical-mechanical *** trees were harvested and mechanically processed into standard pieces for laboratory *** following variables were determined:wood density,fiber length and width,fiber lumen diameter and wall thickness,fiber wall fraction,and vessel *** charcoal was produced in a laboratory and gravimetric yield,relative density,and mechanical properties ***’s correlation coefficients,multivariate statistical analysis of canonical correlation,and principal component analysis were used to evaluate the relationship between wood and charcoal *** width was not significantly correlated with charcoal *** bulk density,hardness,and strength were positively correlated with wood density,fiber length,wall thickness,and wall *** properties were negatively correlated with fiber lumen diameter and vessel *** results will help identify the best wood with adequate physical-mechanical properties for industrial charcoal proces sing.

关键词： Biomass Density Energy Fiber Vessel

Hubbard U through polaronic defect states

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npj Computational Materials 2022年第1期8卷 2504-2511页

作者： Stefano Falletta alfredo Pasquarello Chaire de Simulationàl’Echelle Atomique(CSEA) Ecole Polytechnique Fédérale de Lausanne(EPFL)CH-1015LausanneSwitzerland

Since the preliminary work of Anisimov and co-workers,the Hubbard corrected DFT+U functional has been used for predicting properties of correlated materials by applying on-site effective Coulomb interactions to specific ***,the determination of the Hubbard U parameter has remained under intense discussion despite the multitude of approaches ***,we define a selection criterion based on the use of polaronic defect states for the enforcement of the piecewise linearity of the total energy upon electron occupation.A good agreement with results from piecewise linear hybrid functionals is found for the electronic and structural properties of polarons,including the formation *** values of U determined in this way are found to give a robust description of the polaron energetics upon variation of the considered *** particular,we also address a polaron hopping pathway,finding that the determined value of U leads to accurate energetics without requiring a configurational-dependent *** is emphasized that the selection of U should be based on physical properties directly associated with the orbitals to which U is applied,rather than on more global properties such as band gaps and band *** comparison,we also determine U through a well-established linear-response scheme finding noticeably different values of U and consequently different formation *** origins of these discrepancies are *** case studies,we consider the self-trapped electron in BiVO_(4),the self-trapped hole in MgO,the Li-trapped hole in MgO,and the Al-trapped hole inα-SiO_(2).

关键词： Hubbard polaron piecewise

Implications of receptor for advanced glycation end products for progression from obesity to diabetes and from diabetes to cancer

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World Journal of Diabetes 2023年第7期14卷 977-994页

作者： Andrea Garza-campos José Roberto Prieto-Correa José alfredo Domínguez-Rosales Zamira Helena Hernández-Nazará Programa de Doctorado en Ciencias en Biología Molecular en Medicina Universidad de GuadalajaraGuadalajara 44340JaliscoMexico Departamento de Biología Molecular y Genómica Instituto de Investigación en Enfermedades Crónico-DegenerativasUniversidad de GuadalajaraGuadalajara 44340JaliscoMexico

Obesity and type 2 diabetes mellitus(T2DM)are chronic pathologies with a high incidence *** share some pathological mechanisms,including hyperinsulinemia,the production and release of hormones,and *** above,over time,affects other systems of the human body by causing tissue hypoxia,low-grade inflammation,and oxidative stress,which lay the pathophysiological groundwork for *** leading causes of death globally are T2DM and *** main alterations of this pathological triad include the accumulation of advanced glycation end products and the release of endogenous alarmins due to cell death(i.e.,damage-associated molecular patterns)such as the intracellular proteins high-mobility group box protein 1 and protein S100 that bind to the receptor for advanced glycation products(RAGE)-a multiligand receptor involved in inflammatory and metabolic and neoplastic *** review analyzes the latest advanced reports on the role of RAGE in the development of obesity,T2DM,and cancer,with an aim to understand the intracellular signaling mechanisms linked with cancer *** review also explores inflammation,oxidative stress,hypoxia,cellular senescence,RAGE ligands,tumor microenvironment changes,and the“cancer hallmarks”of the leading tumors associated with *** assimilation of this information could aid in the development of diagnostic and therapeutic approaches to lower the morbidity and mortality associated with these diseases.

关键词： Type 2 diabetes Cancer Obesity Advanced glycation end product receptor Receptor for advanced glycation end products Glycation end products,advanced

Planar matrices and arrays of Feynman diagrams:poles for higher k

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Communications in Theoretical Physics 2024年第4期76卷 1-13页

作者： alfredo Guevara Yong Zhang Perimeter Institute for Theoretical Physics WaterlooON N2L 2Y5Canada Department of Physics&Astronomy University of WaterlooWaterlooON N2L 3G1Canada Society of Fellows Harvard UniversityCambridgeMA 02138United States of America CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesNo.19A Yuquan RoadBejing 100049China

Planar arrays of tree diagrams were introduced as a generalization of Feynman diagrams that enable the computation of biadjoint amplitudes m_(n)(^(k))for k>*** this follow-up work,we investigate the poles of m_(n)(^(k))from the perspective of such *** general k,we characterize the underlying polytope as a Flag Complex and propose a computation of the amplitude-based solely on the knowledge of the poles,whose number is drastically less than the number of the full *** an example,we first provide all the poles for the cases(k,n)=(3,7),(3,8),(3,9),(3,10),(4,8)and(4,9)in terms of their planar arrays of degenerate Feynman *** then implement simple compatibility criteria together with an addition operation between arrays and recover the full collections/arrays for such *** the way,we implement hard and soft kinematical limits,which provide a map between the poles in kinematic space and their combinatoric *** use the operation to give a proof of a previously conjectured combinatorial duality for arrays in(k,n)and(n-k,n).We also outline the relation to boundary maps of the hypersimplex Δ_(k,n) and rays in the tropical Grassmannian Tr(k,n).

关键词： Feynman diagrams biadjoint amplitudes poles

Non invasive fibrosis biomarkers reduce but not substitute the need for liver biopsy

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World Journal of Gastroenterology 2006年第23期12卷 3682-3694页

作者： Giada Sebastiani alfredo Alberti Department of Clinical and Experimental Medicine University of PadovaPadovaItaly

Chronic liver diseases are very common worldwide, particularly those linked to viral hepatitis and to alcoholic and non-alcoholic fatty liver. Their natural history is variable and long-term evolution differs in individual patients. Optimised clinical management of compensated chronic liver diseases requires precise definition of the stage of liver fibrosis, the main determinant of prognosis and of most therapeutic decisions. Liver biopsy is the gold standard for assessment of hepatic fibrosis. However, it is invasive with possible complications, costly and prone to sampling errors. Many non-invasive markers of liver fibrosis have been recently proposed and assessed in the clinical setting as surrogates of liver biopsy. Direct markers are based on biochemical parameters directly linked to fibrogenesis while indirect markers use simple or more sophisticated parameters that correlate with liver fibrosis stages. Non-invasive markers of liver fibrosis have been tested in different forms of chronic liver disease and showed variable diagnostic performance, but accuracy rarely was above 75%-80%. Better results were obtained when markers were combined. On this line, we have recently proposed a set of algorithms that combine sequentially indirect non-invasive markers of liver fibrosis, reaching 90%-95% diagnostic accuracy with significant reduction in the need for liver biopsy. Based on available evidence, it can be anticipated that non-invasive markers of liver fibrosis and their combined use will soon become a most useful tool in the clinical management of many forms of chronic liver disease. However, their implementation is expected to reduce, but not to completely eliminate, the need for liver biopsy.

关键词： Chronic liver diseases Hepatic fibrosis Liverbiopsy Non invasive fibrosis markers