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XRD Characterization of Crystallinity of Human Tooth Enamel under Influence of Mechanical Grinding

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Materials Sciences and Applications 2015年第6期6卷 464-472页

作者： Jose Reyes-Gasga Olga Koudriavtseva Raul Herrera-Becerra Arturo Escobosa Instituto de Física UNAM Circuito de la Investigación s/n Ciudad Universitaria México D.F. México Dep. Ingeniería Eléctrica—SEES CINVESTAV—IPN México D.F. México

Crystallinity refers to the degree of structural order in a solid and has a big influence on hardness, density, transparency and diffusion. Even within materials that are crystalline completely, the degree of structural perfection can vary, reflecting size and elastic strain of many independent crystalline regions (grains or crystallites) of which these materials are composed. In this work it was attempted to reduce the crystallinity of human enamel using a technique of mechanical grinding (MG) with an ultra-compact FRITSCH Mini-Mill PULVERISETTE 23 machine. Variation in the crystallinity through the MG was monitored by X-ray diffraction (XRD) by broadening of the diffraction peak and examined using the Williamson-Hall plot method. Crystallites in human enamel are regularly arranged and oriented (in the [001] direction) perpendicularly to the interface of enameldentin junction. The results showed an anisotropic feature in crystallinity. Reduction of the crystallinity along the a-axis is due to the crystal strain rather than to the refinement of crystal, and vice versa along the c-axis. After 230 h of the MG, the length of crystallites decreased from 100 nm to 30 nm and width from 40 nm to 37 nm approximately.

关键词： Human Tooth Enamel Crystal Structure Mechanical Grinding X-Ray Diffraction Crystallites

Transient Behavior of a System Composed of Conductive Thin Wire Structures Excited by Harmonic and Lightning Type Signals

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Journal of Electromagnetic Analysis and Applications 2014年第11期6卷 342-357页

作者： Eduardo Faleiro Gabriel Asensio Daniel García Gregorio Denche Jorge Moreno Departamento de Física Aplicada ETSIDI Universidad Politécnica de Madrid Madrid Spain Departamento de Matemática Aplicada ETSIDI Universidad Politécnica de Madrid Madrid Spain Departamento de Ingeniería Eléctrica ETSIDI Universidad Politécnica de Madrid Madrid Spain

The transient response of a system of independent electrodes buried in a semi-infinite conducting medium is studied. Using a simple and versatile numerical scheme written by the authors and based on the Electric Field Integral Equation (EFIE), the effect caused by harmonic signals ranging on frequency from Hz to hundred of MHz, and also by lightning type driving signal striking at a remote point far from the conductors, is extensively studied. The value of the scalar potential appearing on the electrodes as a function of the frequency of the applied signal is one of the variables investigated. Other features such as the input impedance at the injection point of the signal and the Ground Potential Rise (GPR) over the electrode system are also discussed.

关键词： Transferred Potentials Thin Wire Structures Lightning Pulses Electric Field Integral Equation Method of Moments

The Swirling Jet Generation Method and Its Effect on the Velocity Distribution

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Journal of Mechanics Engineering and Automation 2020年第1期10卷 16-26页

作者： Fernández Roque Tiburcio Correa Arredondo JoséArturo Mejía Carmona Alejandro Sandoval Lezama Jorge Vázquez Flores JoséFélix Tiburcio Fernández Roque Instituto Politécnico Nacional Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad TicomanAv.Ticoman No.600Col.San JoséTicomanAlcaldía Gustavo A.MaderoC.P.07340 México DFMéxico 不详

The wing tip vortex has a great similarity with the swirling *** these are generated of a simpler and more economic form in a laboratory,it is relevant to determine which the best method is for the generation of the swirling *** this paper,the velocity distribution obtained experimentally with the method of generation here proposed,which consists of the employment of an axial fan without stators,is compared with the velocity distribution of swirling jets generated with three different *** is observed that the velocity distribution obtained with the proposed method is similar with one of the methods found in the references,which uses fixed blades guides at the entry of the *** proposed method is suitable for the generation of the swirling jet and it is considered that it is simpler and more economic to use blades fixed guides.

关键词： Swirling jet velocity distribution swirl intensity wingtip vortex tangential velocity

URBAN PHOTOVOLTAIC POTENTIAL OF INCLINED ROOFING FOR BUILDINGS IN HERITAGE CENTERS IN EQUATORIAL AREAS

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Journal of Green Building 2018年第3期13卷 45-69页

作者： Esteban Zalamea-León Juan Mena-Campos Antonio Barragán-Escandón Diego Parra-González Pablo Méndez-Santos Facultad de Arquitectura y Urbanismo Universidad de Cuenca(School of Architecture and UrbanismUniversity of Cuenca) Departamento de Ingeniería Gráfica Diseño and ProyectosUniversidad de Jaén(Department of Graphic EngineeringDesign and ProjectsUniversity of Jaén)JaénSpain.Department of Electrical EngineeringUniversidad Politécnica SalesianaCuencaEcuador Facultad de Ingeniería Universidad de Cuenca(Faculty of EngineeringUniversity of Cuenca) Departamento de Ingeniería Eléctrica Universidad Politécnica Salesiana(Department of Electrical EngineeringSalesiana Polytechnic University)

In situ renewable energy production is a favourable alternative for reducing pollu-tion and combating climate *** research area,Cuenca,Ecuador,is located in the Andes near the equator with optimal conditions for energy self-supply due to its low energy demands and low levels of irradiation *** this study,tem-porary fluctuations in consumption based on 2016 electricity consumption data are *** GIS,available roofing polygons are obtained,and the amount of usable solar radiation is estimated based on these *** available surface,orientation,and inclination information,electricity generation based on photovoltaic performance is estimated and compared for monocrystalline silica panels and pho-tovoltaic solar roof tiles,which are architectural alternatives.A potential net supply of 148%is found for monocrystalline silica photovoltaic panels in a typical format,whereas that of photovoltaic tiles is only 61%.In addition,production-demand imbalances are predicted in extreme months and average months and on extreme days due to variations in irradiation and demands.

关键词： solar energy photovoltaic on buildings photovoltaic architectural integration heritage centres energy efficiency

Agro-Industrial Waste as a Source of Raw Material:Eggshell and Ash of Agave salmiana Useful for the Synthesis of Hydroxyapatite

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Journal of Renewable Materials 2022年第12期10卷 3559-3572页

作者： Nora Elizondo-Villarreal Luz HVerástegui-Dominguez Jose JQuijano-Briones Francisco JVázquez-Rodríguez Eden Rodríguez-Castellanos Enrique López-Cuellar Ernesto Torres-Lopez Victor MCastaño-Meneses Universidad Autónoma de Nuevo León Facultad de Ciencias Fisico MatemáticasCiudad UniversitariaSan Nicolás de los GarzaNuevo LeónMéxico Universidad Autónoma de Nuevo León Facultad de ArquitecturaCiudad UniversiariaSan Nicolás de los GarzaNuevo LeónMéxico Universidad Autónoma de Nuevo León Facultad de Ingeniería Mecainicay EléctricaCiudad UniversitariaSan Nicolás de los GarzaNuevo LeónMéxico Centro de Física Aplicada y Tecnología Avanzada Universidad Nacional Autonoma de MéxicoQuerétaroMéxico

Agave salmiana ash and poultry eggshell powder as CaO sources were used for obtaining nanostructured hydro-xyapatite(HAP).The synthesis was carried out by the Green Chemistry Hydrothermal Biosynthesis at 180℃ with a pH of 5,by reacting CaO from Agave Salmiana ash and Eggshell powder,with dibasic caldium phosphate(CaH-PO_(4)+2H_(2)O)in an aqueous solution,with Aloe barbadensis *** product was characterized by X-ray dif-fraction,Fourier transform infrared spectroscopy(FT-IR),Scanning Electron Microscopy(SEM),and Transmission Electron Microscopy(TEM).The size and shape of the hydroxyapatite particles changed dramati-cally in the presence of Aloe *** crystals of Hydroxyapatite were observed when Eggshell powder and Agave salmiana ash were used as raw materials in the presence of the Aloe barbadensis *** with shapes of ribbons and plates from 1 micrometers to 8 micrometers were observed when using the eggshell powder in the presence of Aloe bar badensis and,in the case of Agave salmiana ash in the presence of Aloe bar-badensis,crystals with shapes of quadra ngular prisms and hexagonal(polyhedra)with sizes from 2 micrometers to 20 micrometers were *** was therefore successfully biosynthesized by a green and sus-tainable method that reduces the environmental impact.

关键词： Hydroxyapatite raw materials Agave salmiana eggshell Aloe barbadensis surfactant

Assessment of Different WRF Configurations Performance for a Rain Event over Panama

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Atmospheric and Climate Sciences 2020年第3期10卷 280-297页

作者： Maibys Sierra-Lorenzo Arnoldo Bezanilla-Morlot Abel Dionisio Centella-Artola Anisbel León-Marcos Israel Borrajero-Montejo Adrián Luis Ferrer-Hernández Jesús Leonel Salazar-Gaitán Alcely Lau-Melo Freddy Picado-Traña Joel Pérez-Fernández Center for Atmospheric Physics Meteorology Institute La Habana Cuba Sección de Recursos Hídricos Autoridad del Canal de Panama Panama City Panama Dirección de Hidrometeorología Empresa de Transmisión Eléctrica S.A. Panama City Panama Water Center for the Humid Tropics of Latin America and the Caribbean Panama City Panama

A set of 15 combinations of microphysics and cumulus parameterizations for the WRF numerical model were tested in the forecast of a rain event on January 16 2018 over Panama. GPM satellite, upper air soundings and ground weather stations were used to evaluate the performance of each configuration. Different metrics were used to obtain the configurations that produced the best forecasts. The analysis showed a strong fluctuation of the diurnal precipitation cycle from one region to another. From the set of tests carried, BMJ with Morrison performed slightly above the other combinations in representing well the diurnal cycle for some domain areas, followed by Thom-Gr, WSM6-BMJ and WSM6-KF. While the experiments had a better performance forecasting over sea, they were not able to match the highest values of total precipitation. Regarding spatial rain distribution, all BMJ cumulus combinations showed the best skills mainly over the area comprising the Panama Canal while the others tended to overestimate the rain. Finally, most BMJ experiments showed the highest correlation factor and performed quite well representing the vertical profiles of relative humidity, temperature and wind.

关键词： Parameterization Microphysics WRF Rain

A High-Resolution Modeling Strategy to Assess Impacts of Climate Change for Mesoamerica and the Caribbean

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American Journal of Climate Change 2016年第2期5卷 202-228页

作者： Robert Oglesby Clinton Rowe Alfred Grunwaldt Ines Ferreira Franklyn Ruiz Jayaka Campbell Luis Alvarado Francisco Argenal Berta Olmedo Alejandro del Castillo Pilar Lopez Edwards Matos Yosef Nava Carlos Perez Joel Perez Department of Earth and Atmospheric Sciences University of Nebraska Lincoln NE USA Climate Change and Sustainability Division Inter-American Development Bank Washington DC USA Instituto de Hidrología Meteorología y Estudios Ambientales de Colombia Bogota Colombia University of the West Indies Kingston Jamaica Instituto Meteorológico Nacional Costa Rica San Jose Costa Rica Servicio Meteorológico Nacional de Honduras Dirección General de Aeronáutica Civil Tegucigalpa Honduras Empresa de Transmisión Eléctrica Paname?a Ciudad de Panamá Panamá Water Center for the Humid Tropics of Latin America and the Caribbean (CATHALAC) Ciudad de Panamá Panamá Unidad de Análisis Meteorológico Empresa de Transmisión Eléctrica Paname?a Ciudad de Panamá Panamá Instituto Nacional de Ecología y Cambio Climático Mexico City Mexico National Weather Service MARN San Salvador El Salvador

Mesoamerica and the Caribbean are low-latitude regions at risk for the effects of climate change. Global climate models provide large-scale assessment of climate drivers, but, at a horizontal resolution of 100 km, cannot resolve the effects of topography and land use as they impact the local temperature and precipitation that are keys to climate impacts. We developed a robust dynamical downscaling strategy that used the WRF regional climate model to downscale at 4 - 12 km resolution GCM results. Model verification demonstrates the need for such resolution of topography in order to properly simulate temperatures. Precipitation is more difficult to evaluate, being highly variable in time and space. Overall, a 36 km resolution is inadequate;12 km appears reasonable, especially in regions of low topography, but the 4 km resolution provides the best match with observations. This represents a tradeoff between model resolution and the computational effort needed to make simulations. A key goal is to provide climate change specialists in each country with the information they need to evaluate possible future climate change impacts.

关键词： Regional Climate Models Dynamical Downscaling Strategy Mesoamerica and Caribbean Climate Change

Effect of Glucose Concentrations on the Growth and Metabolism of Brettanomyces bruxellensis under Aerobic Conditions

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Advances in Microbiology 2013年第3期3卷 227-232页

作者： Ortiz-Muniz Benigno Corro-Herrera Victor Gomez-Rodriguez Javier Domínguez-González JoséManuel Aguilar-Uscanga María Guadalupe Instituto Tecnológico Superior de Tierra Blanca Av.Veracruz s/n.Col.PEMEXVeracruzMéxico Instituto Tecnológico de Veracruz Unidad de Investigación y Desarrollo en Alimentos(UNIDA)Dpto Ing.Eléctrica y ElectrónicaCol.Formando HogarVeracruzMéxico Universidad de Vigo Departamento de Ingeniería QuímicaFacultad de CienciasCampus OurenceOurenseSpain

Acetic acid can be directly produced from glucose in one-step fermentation by using yeasts of the genus Brettanomyces bruxellensis, hence increasing the industrial application to manufacture products with simplified bioprocesses. Thereby, this work evaluates the influence of initial glucose concentration on the growth and acetic acid production by B. bruxellensis. The results obtained confirmed the presence of Crabtree effect on B. bruxellensis under low glucose concentrations. The maximum acetic acid concentration reached was 15.4 g·L-1 starting with 100 g·L-1 leading to a product yield of 0.154 g·g-1 and a specific acetic acid production rate of 0.05 g·g-1·h-1. The results also indicate that after reaching the acetic acid critic threshold of 4 g·L-1 the metabolism can induce the growth second phase even residual glucose was present on the culture media at high starting glucose concentrations. Additionally, it was observed a lineal relationship between cell viability and acetic acid production.

关键词： Glucose Brettanomyces bruxellensis Acetic Acid Inhibition Crabtree Effect

Synchronized bioluminescence behavior of a set of fireflies involving fractional operators of Liouville-Caputo type

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International Journal of Biomathematics 2018年第3期11卷 221-245页

作者： J. E. Escalante-Martínez J. F. Gómez-Aguilar C. Calderón-Ramón A. Aguilar-Meléndez P. Padilla-Longoria Facultad de Ingenierla Mecdnica y Eldctrica Universidad Veracruzana Av. Venustiano Carranza S/N Col. Revolución C.P. 93390 Poza Rica Veracruz Mdéxico CONACyT- Tecnoldgico Nacional de México/CENIDET Interior Internado Palmira S/N Col. Palmira C.P. 62490 Cuernavaca Morelos México Facultad de Ingeniería Mecdnica y Eléctrica Universidad Veracruzana Av. Venustiano Carranza S/N Col. Revolución C.P. 93390 Poza Rica Veracruz México Facultad de Ingeniera Civil Universidad Veracruzana Av. Venustiano Carranza S/N Col. Revolución C.P. 93390 Poza Rica Veracruz México Instituto de Investigaciones en Matemdticas Aplicadas y Sistemas (IIMAS) UNAM Circuito Escolar Cd. Universitaria Del. Coyoacan México D.F. C.P. 04510 México

In this paper, a system of fractional differential equations that model the synchronized bioluminescence behavior of a set of fireflies put on two spatial arrangements is presented; the alternative representation of these equations contains fractional operators of IAouvillc-Caputo type. The objective of the model is to qualitatively recover synchronization and show that it is persistent. It is shown that the effort made by each firefly glow changes with respect to the number of male competitors and the distance between them. The conditions on biological parameters are interpreted.

关键词： Fractional calculus Liouville Caputo fractional derivative synchronicity fireflies bioluminescence Adams Bashforth-Moulton method.