Sistema de generación de electricidad mediante la conversión fotovoltaica de la energía solar : aplicación a una bomba de calor

OpenAIRE

Adeva Rivero, Álvaro

2015-01-01

La generación de electricidad mediante la conversión fotovoltaica de la energía solar para aplicaciones térmicas es un campo relativamente desconocido a día de hoy, sobre el cual existen pocas investigaciones. La diferencia fundamental con las aplicaciones típicas de los sistemas fotovoltaicos es la variabilidad de la demanda térmica del edificio, lo que se traduce en una demanda eléctrica variable a lo largo del día y de la temporada. Este aspecto es el que constituye el principal cuello de ...

Development of solar thermophotovoltaic systems = Desarrollo de sistemas termofotovoltaicos solares

OpenAIRE

Datas Medina, Alejandro

2011-01-01

Esta tesis aborda el análisis, tanto teórico como experimental, de los sitemas termofotovoltaicos solares. En estos sistemas, un material (emisor) se calienta hasta la incandescencia mediante radiaci ón solar. La radiación térmica emitida por dicho material se dirige hacia una célula fotovoltaica, que convierte dicha radiación en electricidad. En esta configuración, se pueden emplear elementos de control espectral para lograr que los fotones no útiles para el proceso de conversión fotovoltáic...

Possible sources for hydrogen production in Mexico; Posibles fuentes de produccion de hidrogeno en Mexico

Energy Technology Data Exchange (ETDEWEB)

Vazquez Esparza Mata, Esther; Perez Garcia, Edgar C. [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

2004-06-15

combustibles fosiles, a esta etapa podemos denominar periodo de transicion energetica cuando se termine este lapso de tiempo tendremos una eminente crisis energetica y sera necesario contar ya con nuevas alternativas energeticas, las cuales tengan un desarrollo sustentable y las cuales deberan de estar listas al termino de los proximos 20 anos. Una de las alternativas mas viables es la obtencion de energia a partir del hidrogeno, este es el elemento mas abundante en el universo, cerca del 75% esta constituido por el, pero no se encuentra en estado puro en la naturaleza. Para determinar cierto estado es necesario investigar acerca de los procesos para la obtencion de hidrogeno, la reformacion del gas natural, las reservas de gas natural, la distribucion de gas natural y la gasificacion integrada.

The Separation of Hydrogen Tritium and Tritium Hydride by Gas Chromatography; Separation de l'hydrogene, du tritium et de l'hydrure de tritium par chromatographic en phase gazeuse; Razdelenie vodoroda, tritiya i gidrida tritiya posredstvom gazovoj khromatografii; Separacion del hidrogeno, tritio e hidruro de tritio por cromatografia de gases

Energy Technology Data Exchange (ETDEWEB)

Smith, H A; Carter, Jr, E H [University of Tennessee, Knoxville, TN (United States)

1962-01-15

toute quantite de tritium ou d'hydrure de tritium sortant de la colonne. On a essaye de separer ces melanges avec des colonnes garnies de palladium sur silice, de silice, d'alumine et d'alumine recouverte d'oxyde de chrome ou d'oxyde ferrique. Aucune separation effective n'a ete realisee a l'aide de la colonne de palladium sur silice. On a obtenu une bonne separa- tion avec la colonne de silice, ou l'hydrogene servait d'entraineur; mais l'helium s'est revele inef- ficace pour l'elution des isotopes. L'alumine partiellement desactivee et gainee a donne des resultats satisfaisants lorsque l'entraineur etait de l'helium ou du neon; mais la meilleure separation etait assuree par une colonne d'alumine activee et non gainee. L'etalonnage a l'aide de melanges helium-tritium d'activite connue, additionnes de melanges equilibres hydrogene-tritium d'activite egalement connue, permet une evaluation quantitative du tritium et de l'hydrure de tritium. (author) [Spanish] Ahora que, gracias a la cromatografia en fase gaseosa, se ha logrado separar el hidrogeno, el deuterio y el deuteruro de hidrogeno, se estan realizando estudios analogos con mezclas de hidrogeno, tritio e hidruro de tritio. Puesto que se utiliza el tritio en cantidades apropiadas para la marcacion, no es posible emplear el catarometro usual para su deteccion. Los autores han salvado esta dificultad colocando, inmediatamente despues del catarometro, un electrometro de lengueeta vibratoria, provisto de un escape de alta resistencia que permite medir continuamente por medio de registradores sincronizados la actividad del tritio y del hidruro de tritio que puedan salir de la columna. Los autores han ensayado la separacion de estas mezclas mediante columnas rellenas con paladio precipitado sobre silice, con silice, con oxido de aluminio y con oxido de aluminio recubierto de oxido de cromo o de oxido ferrico. Con el relleno de paladio precipitado sobre silice no se logro obtener separacion neta. Al emplear hidrogeno como

Tratamiento superficial de materiales mediante luz solar concentrada: una opción mediante energías renovables

Directory of Open Access Journals (Sweden)

Martínez, D.

1998-04-01

Full Text Available The possible applications of solar furnaces to materials surface treatment are explained in an illustrative manner. A brief description of these systems is exposed, as well as an overview of the feasible industrial or testing applications for which their validity has been proven.

En este artículo se explica de manera ilustrativa la posible aplicación de los hornos solares al tratamiento superficial de materiales. Se realiza una breve descripción de estos sistemas y se da un repaso a las posibles aplicaciones industriales ó de ensayo para las que se ha demostrado su aptitud.

Hydrogen and energy recovery by gasification of petroleum coke from heavy crude refining; Recuperacion de hidrogeno y energia mediante gasificacion de coques de petroleo provenientes de refinacion de crudos pesados

Energy Technology Data Exchange (ETDEWEB)

Paniagua-Rodriguez, J.C [Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan (Mexico); Jimenez-Garcia, G. [Instituto Tecnologico del Valle de Morelia, Morelia, Michoacan (Mexico); Maya-Yescas, R. [Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan (Mexico)]. E-mail: rmayay@umich.mx

2013-03-15

Heavy oils exhibit high yields to bottom-of barrel products (low commercial value); depending on the metals content and on carbon residue the upgrading of bottoms could follow either hydroprocessing or carbon rejection. In particular the Mexican Maya, which is the most refined crude in Mexico, is upgraded by carbon rejection via delayed coking of vacuum residue. In order to obtain acceptable economic profit, it is necessary to transform that carbon (mainly petroleum coke) into useful higher added value products. Coke gasification could be used to obtain hydrogen and/or energy (preferable electrical), via the reaction of coke molecules with oxygen, carbon dioxide and water. Departing from the empiric formulas of five petroleum cokes, a kinetic scheme that consists of three linearly independent stoichiometric equations was recently developed; by including the enthalpy of each reaction and considering the gasification reactor as adiabatic, it is possible to predict product stream composition and high pressure steam that could be generated by the process. [Spanish] Los crudos pesados exhiben rendimientos altos a productos de-fondo-de-barril (de bajo valor comercial); dependiendo del contenido de metales y del residuo carbonoso, la mejora de fondos puede llevarse a cabo por hidrotratamiento o rechazo de carbon. En particular el crudo Maya, que es el mas refinado en Mexico, se mejora via rechazo de carbon por coquizacion retardada del residuo de vacio. A fin de obtener ganancias aceptables, es necesario transformar ese carbon (coque de petroleo, principalmente) en producto util de alto valor agregado. La gasificacion de coque puede usarse para obtener hidrogeno y/o energia (electrica de preferencia), via la reaccion de moleculas de coque con oxigeno, dioxido de carbono y agua. Recientemente se desarrollo un esquema cinetico que consiste de tres reacciones linealmente independientes, partiendo de las formulas empiricas de cinco coques de petroleo; incluyendo la entalpia

Mejora en la producción de recubrimientos de NiAl obtenidos por síntesis autopropagada a alta temperatura mediante energía solar concentrada

Directory of Open Access Journals (Sweden)

Sierra, C.

2005-12-01

Full Text Available The production of NiAl coatings on steel can be achieved in a quick, cheap and unpolluted way. All this advantages are possible using concentrated solar energy (CSE and selfpropagating high-temperature synthesis (SHS. SHS process allows the production of NiAl in short periods of using of the heat released in the reaction. Initial energy is provided by concentrated solar energy. The aim of this work is to improve the adherence between steel and coating. Two kinds of samples are examined: samples with Ni powder layer, and samples electroplated with nickel.

Se presenta un procedimiento para la obtención de recubrimientos de NiAl sobre acero, de forma rápida, barata y limpia desde el punto de vista medioambiental. Todas estas ventajas son posibles mediante el empleo combinado de la Energía Solar Concentrada (CSE y la Síntesis Autopropagada a Alta Temperatura (SHS aplicada a la producción de intermetálicos. Las reacciones SHS permiten la obtención de NiAl en procesos de corta duración, prácticamente instantáneos, aprovechando la elevada exotermicidad de la propia reacción. El aporte energético inicial se realiza concentrando radiación solar con una lente de Fresnel. El objetivo del trabajo presentado era mejorar la adherencia del recubrimiento de NiAl al acero base; se comparan los resultados de los ensayos entre probetas con una capa intermedia de polvo de níquel y probetas con níquel electrodepositado.

Analysis and adaptation of a mathematical model for the prediction of solar radiation; Analisis y adaptacion de un modelo matematico de prediccion de radiacion solar

Energy Technology Data Exchange (ETDEWEB)

Zambrano, Lorenzo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1987-12-31

There is an abundant, reliable, free, source of energy whose use can be planned and besides, practicably inexhaustible: the solar energy. In Mexico it constitutes an important resource, because of its geographical position; for this reason it is fundamental to know it well, either by means of measurements conducted for several years or by mathematical models. These last ones predict with meteorological variables, the values of the solar radiation with acceptable precision. At the Instituto de Investigaciones Electricas (IIE) a model is studied for the prediction of the solar radiation to be adapted to the local conditions of Mexico. It is used in simulation studies of the solar plants functioning and other solar systems. [Espanol] Existe una fuente de energia abundante, confiable, gratuita, cuyo uso puede planearse y, ademas, es practicamente inagotable: la solar. En Mexico constituye un recurso importante, por la posicion geografica del pais; por eso es fundamental conocerlo bien, ya mediante mediciones realizadas durante algunos anos, ya mediante modelos matematicos. Estos ultimos predicen, con datos de variables meteorologicas, los valores de la radiacion solar con precision aceptable. En el Instituto de Investigaciones Electricas (IIE) se estudia un modelo de prediccion de radiacion solar para adaptarlo a las condiciones locales de Mexico. Se usa en estudios de simulacion del funcionamiento de plantas helioelectricas y otros sistemas solares.

Analysis and adaptation of a mathematical model for the prediction of solar radiation; Analisis y adaptacion de un modelo matematico de prediccion de radiacion solar

Energy Technology Data Exchange (ETDEWEB)

Zambrano, Lorenzo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1986-12-31

There is an abundant, reliable, free, source of energy whose use can be planned and besides, practicably inexhaustible: the solar energy. In Mexico it constitutes an important resource, because of its geographical position; for this reason it is fundamental to know it well, either by means of measurements conducted for several years or by mathematical models. These last ones predict with meteorological variables, the values of the solar radiation with acceptable precision. At the Instituto de Investigaciones Electricas (IIE) a model is studied for the prediction of the solar radiation to be adapted to the local conditions of Mexico. It is used in simulation studies of the solar plants functioning and other solar systems. [Espanol] Existe una fuente de energia abundante, confiable, gratuita, cuyo uso puede planearse y, ademas, es practicamente inagotable: la solar. En Mexico constituye un recurso importante, por la posicion geografica del pais; por eso es fundamental conocerlo bien, ya mediante mediciones realizadas durante algunos anos, ya mediante modelos matematicos. Estos ultimos predicen, con datos de variables meteorologicas, los valores de la radiacion solar con precision aceptable. En el Instituto de Investigaciones Electricas (IIE) se estudia un modelo de prediccion de radiacion solar para adaptarlo a las condiciones locales de Mexico. Se usa en estudios de simulacion del funcionamiento de plantas helioelectricas y otros sistemas solares.

Ahorro energético mediante estrategias de iluminación natural optimizadas

Directory of Open Access Journals (Sweden)

Puigdomènech Franquesa, Joan

1986-04-01

Full Text Available Electrical charges in buildings and specially in those of commercial use, can be diminished by means of natural lighting strategies. Taking the climate features of our country into consideration, it is necessary to prevent the inconveniences caused by an en erg y excess in summer, so solar Controls are needed. The only practical way to achieve the suitable balance between thermal and light needs, so as to get a monthly or annual energetic balance optimization, is to operate with the computer. A programme with such characteristics is described here. Its application gives important sarings in non renouvable energy savings.Mediante estrategias de iluminación natural es posible disminuir las cargas eléctricas de los edificios y en especial los de uso comercial. Dadas las características climáticas de nuestro país es necesario prever los inconvenientes de un exceso de energía en verano, para lo cual es preciso disponer de controles solares. Encontrar el correcto equilibrio entre las necesidades térmicas y lumínicas en base a la optimización del balance energético mensual o anual es únicamente factible mediante el uso del ordenador. Un programa que responde a estas características es descrito en el presente trabajo, obteniéndose con su aplicación importantes ahorros en el consumo de energías no renovables.

Material for the storage of Mg-Ni-Based hydrogen produced by mechanical alloying; Materiales para almacenamiento de hidrogeno base Mg-Ni producidas por aleado mecanico

Energy Technology Data Exchange (ETDEWEB)

Zaldivar-Cadena, A. A. [Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Leon Santiago, M.; Suarez Alcantara, K.; Morales-Hernandez, J.; Cabanas Moreno, J. G. [Instituto Politecnico Nacional, UPALM, Mexico, D.F. (Mexico)]. E-mail: gcabanas@esfm.ipn.mx

2009-09-15

Combinations of Mg-5%Ni and Mg-20%Ni were prepared with mechanical alloying and evaluated for application as materials to store hydrogen. The effect of the dispersion of nickel in magnesium was studied using grinding times of 15 and 30 hours. Hydration experiments, including batch hydration tests, were performed at 200, 250 and 300 degrees Celsius at 2 Mpa during 30 minutes. Characterization techniques such as SEM-EDX and XRD were used to characterize the microstructure and composition of the powders. The hydrogen absorption-desorption characteristics of the alloys were evaluated using thermal analysis techniques such as DTA-TGA. Batch type preliminary experiments resulted in a variation in the quantities of MgH{sub 2} in the hydrate powders, depending on the hydrate composition and conditions. Gravimetry experiments with Mg-5%Ni powder combinations indicated hydrogen contents of approximately 5.59% - 6.12% in weight, showing rapid hydration kinetics at temperatures under 250 degrees Celsius; although the dehydration process occurred reasonably quickly only at temperatures between 250 and 300 degrees Celsius. The hydration/dehydration behavior is influenced by the tendency of forming Mg{sub 2}Ni in mechanically alloyed powders. This tendency is promoted by high Ni contents, long grinding times and high hydration temperatures. The best results are apparently obtained with an optimal balance of the dispersion of Ni, which depends on the Ni contents and grinding time. [Spanish] Mezclas de Mg-5%Ni y Mg-20%Ni fueron preparadas por aleado mecanico y evaluadas para su aplicacion como materiales para almacenamiento de hidrogeno. El efecto de la dispersion del niquel en el magnesio fue estudiado utilizando tiempos de molienda de 15 y 30 hrs. Experimentos de hidruracion incluyendo pruebas de hidruracion del tipo Batch fueron realizadas a 200, 250 y 300 grados centigrados a 2 Mpa durante 30 minutos. Tecnicas de caracterizacion como MEB-EDX y DRX fueron empleados en la

Sistema fotovoltaico de iluminación solar

OpenAIRE

Víctor Hugo Benítez Baltazar; Guadalupe Araceli Torres Valverde; Luis Armando Gámez Valdéz; Jesús Horacio Pacheco Ramírez

2013-01-01

El artículo es el resultado de un trabajo de investigación enfocado al uso de sistemas fotovoltaicos para la iluminación por medio de diodos emisores de luz tipo LED. Se busca reducir el consumo energético mediante la implementación de un sistema de iluminación basado en LED hasta en un 80%, donde la fuente primaria de energía es el Sol. Se demuestra la viabilidad de los sistemas solares de iluminación LED mediante la construcción de un prototipo. Los sistemas de iluminación fotovoltaicos son...

Production of hydrogen using the combination of water-gas shift and carbonatation reaction of a CO{sub 2} absorbent; Produccion de hidrogeno mediante la combinacion de las reacciones de desplazamiento de agua y carbonatacion de un absorbente de CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Escobedo-Bretado, M. A.; Ponce-Pena, P. [Facultad de Ciencias Quimicas, UJED, Durango, Durango (Mexico)]. E-mail: miguel.escobedo@ujed.mx; Delgado-Vigil, M. D.; Salinas-Gutierrez, J. M.; Lopez Ortiz, A.; Collins-Martinez, V.H. [Centro de Investigacion en Materiales Avanzados, S.C., Chihuahua, Chihuahua (Mexico)

2009-09-15

The production of hydrogen by the water-gas shift (WGS) normally requires multiple catalytic reactions followed by the separation of CO{sub 2} to obtain highly pure H{sub 2}. Nevertheless, using the combination of the WGS reaction and the solid-gas reaction between CO{sub 2} and an absorbent, the production of H{sub 2} and the separation of CO{sub 2} can be accomplished in a single step AEWGS (Absorption Enhanced Water Gas Shift). This combination of reactions was studied at the laboratory scale using a quartz fixed-bed reactor. The absorbents tested were calcined dolomite (CaO*MgO) and sodium zirconate (Na{sub 2}ZrO{sub 3}) in catalyst/absorbent mixtures (cat/abs) with weight ratios of 1/1, 1/2 and 2/1, using a high-temperature catalyst from the WGS reaction, synthesized in the laboratory (Fe-Cr). All the tests used 3cm{sup 3} of cat/abs, composed of 5% CO, 15% H{sub 2}O, 10.5% He and 69.5% N{sub 2}, with a spatial velocity (SV) of 1500h-1, 600 degrees Celsius and atmospheric pressure. The catalyst presented 100% conversion of CO to CO{sub 2}, maintaining its surface area after the reaction (12 m{sup 2}/g). The results with a dry base using the cat/abs mixture of 1/2 and CaO*MgO generated 95% H{sub 2} with 5% CO-free CO{sub 2}, while with Na{sub 2}ZrO{sub 3}, the maximum concentration of H{sub 2} was 70%, with 29% CO{sub 2} and 1% of CO without reacting. The results using only CaO*MgO (as a bifunctional material) presented a maximum H{sub 2} concentration of 96% and a minimum of 4% CO{sub 2}, as well as 7% CO without reaction, which was attributed to kinetic effects. [Spanish] La produccion de hidrogeno mediante la reaccion de desplazamiento de agua WGS (Water Gas Shift), normalmente requiere de multiples reacciones cataliticas seguidas por la separacion de CO{sub 2} para obtener H{sub 2} de alta pureza. Sin embargo mediante la combinacion de la reaccion WGS con la reaccion solido-gas entre el CO{sub 2} y un absorbente provee la oportunidad de producir H2 y

Hydro Solar 21- A building energetic demand providing system based on renewable energies and hydrogen; Hydro Solar 21- Energias renovables e hidrogeno para el abastecimiento energetico de un edificio

Energy Technology Data Exchange (ETDEWEB)

Renilla Collado, R.; Ortega Izquierdo, M.

2008-07-01

Hydro Solar 21 is an energy innovation Project carried out in Burgos City to develop an energy production system based on renewable energies to satisfy light and air condition requirements of a restored building. Nocturnal light demand is satisfied with hydrogen consumption in fuel cells. This hydrogen is produced with an energy renewable system made up of two wind turbine generators and a photovoltaic system. The air conditioning demand is satisfied with an adsorption solar system which produces cold water using thermal solar energy. (Author) 8 refs.

Hydrogen absorption in Mg1.95Ti0.05Ni0.95Cu0.05 alloy prepared with mechanical alloying and thermal treatment; Absorcion de hidrogeno en la aleacion Mg1.95Ti0.05Ni0.95Cu0.05 preparada por aleado mecanico y tratamiento termico

Energy Technology Data Exchange (ETDEWEB)

Martinez, Juan Bonifacio; Urena Nunez, Fernando [Instituto Nacional de Investigaciones Nucleares, Ocoyoacac, Estado de Mexico (Mexico)]. E-mail: juan.bonifacio@inin.gob.mx

2009-09-15

This work presents hydrogen absorption in quaternary alloy Mg1.95Ti0.05Ni0.95Cu0.05 obtained by the mechanical alloying method, followed by thermal treatment in ultra-high pure argon atmosphere. The composition of the phases, microstructure and morphology of ground powders and with thermal treatment were characterized by DRX, SEM/EDS and TEM. After 20 hours of mechanical grinding and recooked at 300 degrees Celsius/1h in argon atmosphere, the quaternary alloy has a Mg{sub 2}Ni crystalline hexagonal structure with a crystallite size under 10 nm. The absorption measurements were performed under a pressure of 0.2 to 1.2 MPa at a temperature of 200 degrees Celsius in a micro-reactor. The quantification of absorption-desorption of hydrogen in the intermetallic was conducted in a TGA-DSC simultaneous calorimeter. Metallic hydride-dehydride powder was characterized with SEM and XRD. [Spanish] En este trabajo se presenta la absorcion de hidrogeno en la aleacion cuaternaria Mg1.95Ti0.05Ni0.95Cu0.05 obtenida por el metodo de aleado mecanico, seguida de tratamiento termico en atmosfera de argon de ultra alta pureza. La composicion de las fases, microestructura y morfologia de los polvos molidos y con tratamiento termico fue caracterizada por DRX, SEM/EDS y TEM. Despues de 20 h de molienda mecanica con recocido a 300 grados Celsios/1h en atmosfera de argon, la aleacion cuaternaria tiene una estructura cristalina hexagonal Mg{sub 2}Ni con tamano de cristalito menor a 10 nm. Las mediciones de absorcion fueron realizadas bajo una presion de 0.2 a 1.2 MPa a una temperatura de 200 grados Celsios en un micro-reactor. La cuantificacion de absorcion-desorcion de hidrogeno en el intermetalico se realizo en un calorimetro simultaneo TGA-DSC. Se determino que la cantidad maxima absorbida de hidrogeno en la aleacion cuaternaria fue de 3.24% en peso cuando la presion fue de 0.8 MPa a dicha temperatura. Polvos metalicos hidrurados-deshidrurados se caracterizaron por SEM y XRD.

Evaluation of chemical pretreatments for enzymatic hydrolysis of lignocellulosic residues cassava (Manihot esculenta Crantz)

OpenAIRE

Niño López, Lilibeth; Acosta Cárdenas, Alejandro; Gelves Zambrano, Ricardo

2013-01-01

El efecto de diferentes pretratamientos químicos con ácido sulfúrico (H2SO4), hidróxido de sodio (NaOH) y peróxido de hidrogeno (H2O2), fueron evaluados mediante la cuantificación de azucares reductores totales producidos durante la etapa de hidrólisis enzimática de los residuos lignocelulósicos de yuca (Manihot esculenta Crantz) y el porcentaje (%) de remoción de lignina después del pretratamiento. La cantidad de residuos utilizados (1 y 5%) (w/v) a diferentes tamaños de partícula (1,18 y 0,...

Fragilización por hidrógeno en tuberías de acero

OpenAIRE

Gutiérrez-Solana Salcedo, Federico

2011-01-01

Se pretende analizar el comportamiento en presencia de hidrogeno de las tuberías de acero de sistemas de transporte de combustibles gaseosos en uso para ello: 1.- Se estudia la sensibilidad a la fragilización por hidrogeno del acero de estas tuberías por dos métodos diferentes: polarización catódica y ambiente de hidrogeno gaseoso diseñando y construyendo una cámara para ensayos mecánicos en hidrogeno a presión primera de su genero en España. 2.- Se determina la tenacidad a fractura kic de es...

Aprovechamiento solar en los terrenos agrarios de la Masía Can Gili, término municipal de Barberá del Vallés

OpenAIRE

Seven Porte, Xavier

2012-01-01

El objeto del presente proyecto define los conceptos y desarrolla cálculos necesarios para llevar a cabo el aprovechamiento energético mediante el uso de energías renovables, en nuestro caso la energía solar. La naturaleza de la energía solar proviene de esa gigantesca esfera formada de gases a alta temperatura. La temperatura en su interior se estima que es de 107 K, en su superficie oscila entre los 5762 y los 6300 K. El Sol genera energía mediante reacciones nucleares de ...

Plastic solar collector: feature and applications; Colector solar de plastico: Caracteristicas y aplicaciones

Energy Technology Data Exchange (ETDEWEB)

Bistoni, Silvia; Iriarte, Adolfo [Universidad Nacional de Catamarca, Catamarca (Argentina); Saravia, Luis [Universidad Nacional de Salta, Salta (Argentina)

2000-07-01

The Argentinean northwest (NOA) is an exceptional zone to use solar energy, because of its climate and its solar radiation levels. The aim of this paper is to analyze the use of low temperature solar heating system by mean of a plastic collector. The system proposed includes: a) Solar collectors built with plastic bags, welded in such a way that water, introduced at the top, falls by gravity through a zigzag long path. Each collector is fed by drip feed irrigations. b) Hot water storage and c) Water pump, hydraulic circuit and electronic controls. Two ways of use are proposed: as a water solar heating and as a system to heat greenhouses. In this second case, if during the day the air temperature inside the greenhouse is higher than the water storage temperature, the water will be heated in the bags. During the night the bags work as heat exchanger. When the temperature inside the greenhouse needs to be maintained at a constant value, the heating system is combined with a gas water heating. The equipment is described, performances are compared for both uses and the global heat exchange coefficient is calculated. The system's behavior inside a greenhouse is analyzed in two different situations. The utilization of plastic solar collectors has demonstrate to be a valid alternative for low temperature solar energy uses, specially in heating agricultural spaces. [Spanish] La region del Noreste Argentino (NOA), por su clima y muy en particular por los niveles de radiacion solar que posee, es una zona excepcional para el aprovechamiento de la energia solar. El objetivo de este trabajo es analizar el uso de la energia solar a baja temperatura mediante un colector de plastico. El sistema propuesto incluye: a) Colector solar construido con una bolsa de plastico soldada en forma tal, que el agua que se introduce por la parte superior cae por la gravedad siguiendo un camino en zigzag. Cada colector se alimenta mediante goteros de riego autocompensados. b) Almacenamiento

Applications of the use of the renewable energies, solar power and wind power, for the securing of hydrogen, as power supply of the fuel cells; Obtencion de hidrogeno, a partir de la electrolisis del agua mediante energias renovables almacenamiento y aplicaciones

Energy Technology Data Exchange (ETDEWEB)

San Martin, J. J.; Martin, I.; Aperribay, V.; San Martin, J. I.; Arrieta, J. M.; Zuazua, J.; Romero, E.

2004-07-01

The object of the presented communication is to show the applications of the use of the renewable energies, particularly the solar power and the wind power, for the securing of hydrogen, as power supply of the fuel cells. The electrical energy produced in the solar badges and in the windpowers is, principally, injected into the electrical networks, for his transport, distribution and consumption, if the network the demand. The novel aspect is, that if the network does not demand potency, this one is transformed into hydrogen at the same photovoltaic station or into the base of the tower of the windpower and, later, stored to feed the fuel cells, not producing to him any type of element pollutant, since the residual element is the water. (Author)

Solar heaters, should they be seen or not?; Calentadores solares, mostrarlos u ocultarlos?

Energy Technology Data Exchange (ETDEWEB)

Garcia Martinez, Octavio [Modulo Solar, S.A. de C.V., Cuernavaca, Morelos (Mexico)

2000-07-01

Talking about Solar Heaters, architects have two opposite points of view about aesthetics. Some architects are convinced that the collector field should be integrated into the original design or in buildings already built, these fields should be adapted and fully shown. On the other hand, there are those who prefer collectors not to be seen. This work, based on our experience since 1975, will show with photographOut experience since 1975 will be show with solutions that have satisfy each part. With worldwide expectations of massive use of solar energy in the first decade of the millennium, we think that is important to discuss whether: SOLAR HEATERS, should they be seen or not?. [Spanish] Con respecto a los aspectos esteticos de los equipos solares, en el medio arquitectonico existen dos corrientes plenamente contrapuestas: 1.- Aquellos que estan convencidos que hay que integrar los campos de colectores al diseno original o que hay que resolver en las edificaciones existentes la adaptacion de los mismos mostrandolos plenamente y 2.- Aquellos que prefieren ocultarlos. En este trabajo, basado en experiencias desde 1975, mostrara, mediante imagenes, ejemplos de soluciones que hay satisfecho a cada corriente. Con las expectativas mundiales del uso masivo de la energia solar en la primera decada del milenio, seria importante, de una buena vez, encauzar la polemica: EQUIPOS SOLARES SE DEBEN VER O NO?.

Sistema de gestión del agua en una planta de energía solar

OpenAIRE

Serra Lleonart, Alfons

2007-01-01

Premi al millor Projecte de Fi de Carrera presentat durant el curs 2006-2007 en l'àmbit d'Optimització de Recursos que atorga DOW CHEMICAL En un pueblo de la provincia de Sevilla, en Andalucía, se está proyectando la construcción de una central solar con tecnología de torre. Está central se abastece de la radiación solar para producir energía eléctrica mediante 600 espejos que reflejan la luz solar hacia una torre equipada en su parte superior con un receptor solar capaz de transf...

Análisis de la Ventilación Natural Mediante un Módulo Experimental de Fachada Ventilada Opaca

DEFF Research Database (Denmark)

Peci López, Fernando; Ruiz de Adana, Santiago; Jensen, Rasmus Lund

2011-01-01

Una fachada ventilada opaca (FVO) utiliza la energía solar para proporcionar ventilación natural y calefacción durante las estaciones frías, y evita el sobrecalentamiento en las cálidas. La estructura de una FVO es muy simple y utiliza un sencillo sistema de control de apertura y cierre de...... compuertas. En este trabajo se estudió un módulo experimental de FVO. El modulo consistía en una capa externa de acero galvanizado, una cámara de aire y la fachada de un edificio real como capa interior. Se obtuvieron medidas de caudal de aire, así como diferencias de temperatura entre el interior y el...... exterior de la FVO. Simultáneamente se midieron variables meteorológicas como la radiación solar, velocidad del viento o la temperatura exterior. Se relacionó la radiación solar y la velocidad del viento con la energía transmitida al aire de ventilación mediante el proceso de calentamiento del aire en la...

Fabricación de películas delgadas de CU2 S mediante una reacción de sustitución iónica

Directory of Open Access Journals (Sweden)

Gerardo Gordillo Guzmán

1990-01-01

Full Text Available Se formaron películas delgadas de sulfuro cuproso (CU2S topotaxialmente sobre películas delgadas de sulfuro de cadmio (CdS mediante una reacción de intercambio de iones de Cu (I provenientes de una solución de CuCI con Iones de Cd (lI de la red de sulfuro de cadmio. Dos tipos diferentes de soluciones de CuCI fueron investigados y los resultados experimentales se evaluaron por medio de medidas de la característica corriente- voltaje (I-V de las celdas solares de CU2 S/CdS obtenidas. Eficiencias de conversión de 4.5% se lograron con dichas celdas solares.

Electrochemical behavior of synthesized Al{sub x}Sn{sub y} with mechanical grinding in hydrogen evolution reaction (HER); Comportamiento electroquimico del Al{sub x}Sn{sub y} sintetizado por molienda mecanica en la REH (Reaccion de Evolucion de Hidrogeno)

Energy Technology Data Exchange (ETDEWEB)

Olvera Vazquez, S. L.; Arce Estrada, E. M. [Instituto Politecnico Nacional, Mexico, D.F. (Mexico )]. E-mail: seydyliz@hotmail.com

2009-09-15

Currently, the best catalyst for HER is Pt, nevertheless because of its high costs, many studies have been performed with a variety of materials, including AI, which is a promising source of hydrogen. Therefore, this work studied the effect of tin on Al{sub x}Sn{sub y} alloys obtained by mechanical grinding. The materials obtained were characterized with electron sweep microscopy, x-ray diffraction and electrochemical techniques. It was determined that the synthesized materials have a micrometer size and present at least two phases. The electrochemical characterization for use as electrocatalysts for the hydrogen evolution reaction (HER) was performed in an NaCl 2 M solution using potentiodynamic polarization and chronoamperometry techniques, showing that the materials with low tin contents have better electrocatalytic activity for HER. [Spanish] Actualmente el mejor catalizador para la REH es el Pt, sin embargo debido a sus altos costos se han realizado numerosos estudios con diversos materiales entre los cuales se encuentra el Al, que es una promisoria fuente de hidrogeno. Por tal motivo en este trabajo se realizaron estudios del efecto que presenta el contenido de estano en aleaciones Al{sub x}Sn{sub y} obtenidas por molienda mecanica. Los materiales obtenidos se caracterizaron por microscopia electronica de barrido, difraccion de rayos X y tecnicas electroquimicas. Se determino que los materiales sintetizados son de tamano micrometrico y que al menos presentan dos fases. La caracterizacion electroquimica para su uso como electrocatalizadores para la reaccion de evolucion de hidrogeno, REH, se llevo a cabo en una solucion de NaCl 2 M, empleando las tecnicas de polarizacion potenciodinamica y cronoamperometria, observandose que los materiales con contenidos bajos de estano presentan una mejor actividad electrocatalitica para la REH.

Oxygen reduction using platinum electrocatalysts prepared by liquid phase photo-deposition; Reduccion de oxigeno mediante electrocatalizadores de platino preparados por foto-deposicion en fase liquida

Energy Technology Data Exchange (ETDEWEB)

Ruiz-Camacho, B.; Perez-Galindo, J. A.; Valenzuela, M. A.; Gonzalez-Huerta, R. G. [Instituto Politecnico Nacional, ESIQIE, Mexico D.F. (Mexico)]. E-mail: rosgonzalez_h@yahoo.com.mx

2009-09-15

This work presents the synthesis and characterization of nanometric-sized Pt/C electrochemical catalysts using impregnation and liquid phase photo-deposition methods. Two platinum precursors were used, C{sub 10}H{sub 14}O{sub 4}Pt (Pt acetylacetonate, Pt(acac){sub 2}) and H{sub 2}PtCl{sub 6} (hexachloroplatinic acid) to study the effect on the particle size and the electrocatalytic behavior in the oxygen reduction reaction. The characterization of the catalysts was done using x-ray diffraction, hydrogen chemisorption and transmission electron microscopy. The electrochemical study was conducted with cyclic voltamperometry and rotary disc electrode (RDE) techniques. Pt (E-tek) was used as a reference catalyst. The peaks of the platinum were identified based on the x-ray diffraction results, and correspond to crystalline phases (111) and (200), whose intensity was greater when using H{sub 2}PtCl{sub 6} versus Pt(acac){sub 2}. The hydrogen chemisorption and transmission electron microscopy tests found that the larger-sized particle (1-5 nm) and greater metallic dispersion was obtained using Pt(acac){sub 2} as a platinum precursor and liquid phase photo-deposition. It was also found that this material presented the best electrochemical response, showing a open-circuit potential of 0.96 V and over-potential of 0.05 V with respect to H{sub 2}PtCl{sub 6} and of 0.22 V with respect to the catalyst obtained using impregnation. [Spanish] En este trabajo se presenta la sintesis y caracterizacion electroquimica de catalizadores de tamano nanometrico de Pt/C empleando los metodos de impregnacion y foto-deposicion en fase liquida. Se utilizaron dos precursores del platino C{sub 10}H{sub 14}O{sub 4}Pt (acetil-acetonato de Pt, Pt(acac){sub 2}) y H2PtCl6 (acido hexacloroplatinico), para estudiar el efecto que tienen sobre el tamano de particula y el comportamiento electrocatalitico en la reaccion de reduccion de oxigeno. La caracterizacion de los catalizadores se realizo mediante

Ahorros en los consumos para enfriamiento de espacios interiores mediante la evaluación de sistemas de protección solar en edificios residenciales en altura. El caso de la "ciudad-oasis" de Mendoza, Argentina

Directory of Open Access Journals (Sweden)

Julieta Balter

2016-06-01

Full Text Available El presente trabajo estudia el comportamiento térmico y energético de edificios residenciales en altura, en el contexto particular de una “ciudad-oasis”. Se plantea como objetivo la definición de sistemas de control solar adecuados en la envolvente para cada tipología material de edificio -másica y liviana- y para cada estrato en altura de las viviendas: debajo y sobre de la copa de los árboles. El monitoreo de viviendas en uso permite validar modelos geométricos (software Energy Plus y simular propuestas de aplicación de elementos de protección solar. Se analizan los ahorros en los consumos para enfriamiento en departamentos en niveles bajos, medios y altos. Los resultados muestran que en el edificio másico, en las viviendas ubicadas debajo de la copa de los árboles, es posible anular las cargas energéticas para enfriamiento mediante el uso de elementos exteriores de protección solar. Mientras que en las viviendas sobre la copa de los árboles, los ahorros energéticos se encuentran entre el 32% y 42%. En el edificio liviano, la aplicación de sistemas de control en departamentos bajo la copa de los árboles alcanza ahorros del orden del 53% y en las viviendas sobre la copa, las reducciones energéticas se encuentran entre el 46% y 54%. Las dimensiones adecuadas de tales elementos pueden generar propuestas posibles de ser transferidas a las normativas locales de edificación. 

Modelling the production of hydrogen (H{sub 2}) using natural gas in Venezuela. An approach involving the sustainability of productive processes; Modelizacion de la produccion de hidrogeno (H{sub 2}) usando gas natural en Venezuela. Una aproximacion a la sostenibilidad del proceso productivo

Energy Technology Data Exchange (ETDEWEB)

Rojas Zerpa, Juan [Centro Politecnico Superior, Universidad de Zaragoza (Espana)] email: juancarlosrojas4@yahoo.com

2009-09-15

The purpose of the present work is to formulate and evaluate a mathematical model inherent to the process to produce H{sub 2} in Venezuela through reforming natural gas and removing carbon dioxide (CO{sub 2}). The aim of this work is to identify opportunities to recover gas released through the air and from burning natural gas which, in turn, makes it possible to mitigate the effects of global warming. The development of the mathematical model is linear, and includes the production of H{sub 2} the efficiency of the energy conversion process, the cost of the main inputs and resources (natural gas, water and electricity), the cost of reforming and the CO{sub 2} capture system, transport and storage. Three scenarios were considered for the sustainable production of H{sub 2} conventional hydrogen production, H{sub 2} production with direct CO{sub 2} removal, and the production of H{sub 2} with CO{sub 2} removal and increased natural gas from depleted wells (EGR). The results indicate that in Venezuela, more than 1 million tons of hydrogen per year can be produced at a low cost of 1 $/K, with a CO{sub 2} removal effectiveness over 61% and an EGR factor of roughly 8%. In addition, a significant reduction in gas released into the atmosphere would prevent the yearly injection of more than 23 million tons of CO{sub 2} (11,7% of total national CO{sub 2}). The total production cost obtained is significantly lower than that mentioned in the literature, including the target cost by 2017 expected by the U.S. Department of Energy (DOE). [Spanish] El proposito del presente trabajo consiste en la formulacion y evaluacion de un modelo matematico inherente al proceso de produccion de H{sub 2} en Venezuela, mediante el reformado del gas natural y la remocion del dioxido de carbono (CO{sub 2}); con la finalidad de identificar oportunidades para la recuperacion de gas arrojado (venteo y quemado de gas natural) que a su vez permitan mitigar los efectos de calentamiento global. La

Corte de placas solares con láser. Estudio de modificaciones microestructurales

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Ramírez Del Valle, A. J.

2003-06-01

Full Text Available In photovoltaic solar cells manufacturing process, system breaks are produced. Recycling improves the material profitability. In this sense, manufacturing of components with non-straight shapes is not feasible using traditional methods. The processing of these materials through Nd-YAG laser, allows manufacturing with any geometric shape. This work shows a study of solar cells cutting process with laser. First of all, it is necessary to carry out a parameter optimization in order to make an accurate material cutting. The microstructure of the cutting area and possible microcompositional changes were studied by scanning electronic miscroscopy (SEM and X-ray analysis (EDX.

En el proceso de fabricación de placas fotovoltaicas se producen roturas de las células solares, por tanto, el reciclaje es necesario para mejorar la rentabilidad de este proceso, además, la fabricación de piezas de formas curvas no es factible por los métodos tradicionales. El procesado de estos materiales mediante un láser de Nd-YAG, permitirá la fabricación en cualquier forma geométrica además del mejor aprovechamiento de las placas desechadas por estar rotas. El presente trabajo muestra un estudio del proceso de corte de placas solares con láser. En primer lugar se procede a la optimización de los parámetros necesarios para realizar el corte de este material. La microestructura de la zona de corte y los posibles cambios microcomposicionales que se hayan podido producir, se estudian mediante microscopía electrónica de barrido, con microanálisis de energías dispersivas de Rayos X.

Caracterización a impacto de caucho reciclado mediante elementos finitos

OpenAIRE

Escribano Castro, Ane

2015-01-01

Análisis de caucho reciclado de manera hiperelástica mediante métodos de ajuste de Mínimos Cuadrados con programa MATLAB y Curve fitting mediante ANSYS. Para la parte viscoelástica se usa Algoritmo de Optimicación con MATLAB. Comprobación de resultados y fiabilidad.

Control system for solar tracking based on artificial vision; Sistema de control para seguimiento solar basado en vision artificial

Energy Technology Data Exchange (ETDEWEB)

Pacheco Ramirez, Jesus Horacio; Anaya Perez, Maria Elena; Benitez Baltazar, Victor Hugo [Universidad de onora, Hermosillo, Sonora (Mexico)]. E-mail: jpacheco@industrial.uson.mx; meanaya@industrial.uson.mx; vbenitez@industrial.uson.mx

2010-11-15

This work shows how artificial vision feedback can be applied to control systems. The control is applied to a solar panel in order to track the sun position. The algorithms to calculate the position of the sun and the image processing are developed in LabView. The responses obtained from the control show that it is possible to use vision for a control scheme in closed loop. [Spanish] El presente trabajo muestra la manera en la cual un sistema de control puede ser retroalimentado mediante vision artificial. El control es aplicado en un panel solar para realizar el seguimiento del sol a lo largo del dia. Los algoritmos para calcular la posicion del sol y para el tratamiento de la imagen fueron desarrollados en LabView. Las respuestas obtenidas del control muestran que es posible utilizar vision para un esquema de control en lazo cerrado.

Energy saving: optimal use of air conditioning equipment by means of the solar control; Ahorro de energia: uso optimo de los acondicionadores de aire mediante el control solar

Energy Technology Data Exchange (ETDEWEB)

Mejia D, David; Morillon G, David; Rodriguez V, Luis [Universidad Nacional Autonoma de Mexico (Mexico)

2001-09-01

In this article the evaluation of the solar heat gains through the transparent parts of a building (houses of social interest) is presented; with the purpose of determining the heat gains through windows during summer time and under the following conditions: without solar protection, with the use of eaves, solar breakers and, finally, with the use of both elements. With the determined percentage of the diminution of heat gains, the considered potential of energy saving in air conditioning was obtained that would be available if the houses were constructed with solar control. [Spanish] En este articulo se presenta la evaluacion de las ganancias de calor solar a traves de las partes transparentes de un edificio (viviendas de interes social); con el objeto de determinar las ganancias de calor a traves de ventanas para la epoca de verano y bajo las siguientes condiciones: sin proteccion solar, con el empleo de aleros, con quiebrasoles y, finalmente, con el empleo de ambos elementos. Con el porcentaje determinado de la disminucion de ganancias de calor, se obtuvo el potencial estimado de ahorro de energia en aire acondicionado que se tendria si las viviendas se construyen con control solar.

ANÁLISIS TERMODINÁMICO DE UN SISTEMA DE REFRIGERACIÓN SOLAR POR ABSORCIÓN USANDO SOLUCIONES DE MONOMETILAMINA - AGUA PARA LA CONSERVACIÓN DE ALIMENTOS ANÁLISE TERMODINÁMICA DUM SISTEMA DE REFRIGERAÇÃO SOLAR POR ABSORÇÃO USANDO COMO PARELHA MONOMETILAMINA - AGUA PARA A CONSERVA DE ALIMENTOS THERMODYNAMIC ANALYSIS OF A SOLAR ABSORPTION REFRIGERARON SYSTEM USING MONOMETHYLAMINE - WATER SOLUTIONS FOR FOOD STORAGE

Directory of Open Access Journals (Sweden)

CESAR A. ISAZA

2010-06-01

Full Text Available Este trabajo presenta la viabilidad de los sistemas de refrigeración solar por absorción usando soluciones de monometilamina - agua (MMA-A para aplicaciones en conservación de alimentos en las regiones rurales de Colombia, sin acceso a la red de energía eléctrica. Para suplirlos requerimientos de energía térmica se propone un sistema de calentamiento de agua con energía solar usando colectores de placa y un sistema de respaldo convencional. En este trabajo se determinó el coeficiente de operación (COP del sistema de refrigeración solar por absorción de una sola etapa en función de la temperatura en los diferentes componentes del ciclo. Los resultados indican que el sistema podría mejorarse mediante un mejor diseño en el intercambiador de calor de solución, el evaporador y el rectificador. Los resultados teóricos demuestran que el uso de la solución de MMA-A puede ser usada en sistemas de refrigeración por absorción operados con energía térmica de baja calidad, tales como la energía solar.Este trabalho apresenta a viabilidade e aplicabilidade dos sistemas de refrigeração solar por absorção usando como parelha a monometilamina - agua (MMA-W para fins de conservação de alimentos ñas regiões rurais da Colômbia, onde não há energía disponível. Propõese um sistema de calefação solar mediante coletores solares de placa plana com um sistema convencional de aquecimento auxiliar para suprir as necessidades energéticas do refrigerador por absorção. Determinou-se o coeficiente de desempenho (COP do sistema de refrigeração solar por absorção só de uma etapa em funçã da temperatura nos diferentes componentes do ciclo. Os resultados indicam que o sistema poderia se melhorar mediante um desenho melhorno intercambiador de calor de solução, o evaporador e o retificador os resultados teóricos demonstram que o uso da solução de MMA-W pode ser usada em sistemas de refrigeração como parelha absortiva operado

Low cost, efficient hybrid solar cells

OpenAIRE

Malinkiewicz, Olga

2017-01-01

Actualmente, existen diversas estrategias para producir energía limpia mediante fuentes renovables, pero es la explotación directa de la energía del Sol la que se presenta como una solución ideal, siendo la mayor fuente de energía verde en la Tierra. La potencia de la energía solar que llega a la Tierra cada año es del orden de 86000 TW (Terawatt, 1012 Watt). Esto representa 4800 veces la demanda energética anual del mundo, estimada en 18 TW. Además, todos los depósitos de energía fósil recon...

Action of Mercaptan and Disulfide in Hydrogen Atom Exchange Reactions; Action des Thioalcools et des Disulfures dans les Reactions d'Echange d'Atomes d'Hydrogene; Vozdejstvie merkaptanov i disul'fidov v reaktsiyakh obmena atoma vodoroda; Accion de los Mercaptanos y Disulfuros en las Reacciones de Intercambio del Hidrogeno Atomico

Energy Technology Data Exchange (ETDEWEB)

Cohen, S. G. [Brandeis University Waltham, MA (United States)

1965-10-15

'alcool optiquement actif et dans l'echange de deuterium, pendant l'inhibition. On constate une inhibition analogue lorsqu'un seul radical intermediaire se forme comme dans les systemes benzophenone-benzhydrol et acetophenone-alcool {alpha}-methylbenzyliquee. On constate une inhibition due aux composes soufres, par le meme mecanisme, dans la transformation de la benzophenone en benzopinacole, induite par les rayons gamma de {sup 60}Co; le naphtalene n'a aucun effet de protection sur la benzophenone dans ce systeme, alors qu'il arrete brusquement la reaction photochimique. La protection de solutes contre les effets des rayonnements au moyen de composes soufres resulte donc de reactions de transfert d'atomes d'hydrogene. La photoreduction de la benzophenone dans un ether est aussi inhibee par des reactions de transfert d'atomes d'hydrogene. Dans ce systeme (et non dans les systemes cetone-alcool), il existe un mecanisme par lequel les composes soufres peuvent etre consommes d'une maniere irreversible, ce qui entraftie une periode d'induction et non de retardement permanent, les effets d'environ 15 quanta etant annules par chaque molecule de compose soufre. (author) [Spanish] Es posible catalizar inhibir las reacciones inducidas por radicales libres, por accion fotoquimica y por radiaciones de alta energia aprovechando los rapidos intercambios de atomos de hidrogeno en mercaptanos y disulfuros. Los mercaptanos catalizan la descarbonilacion de aldehidos inducida por radicales, iniciada por la luz y sensibilizada por la benzofenona. La reaccion en cadena de transferencia de atomos de hidrogeno, R' + RCH = O -> RH + RC = O , se acelera mediante una secuencia similar de transferencias de atomos de hidrogeno donde interviene el compuesto sulfurado: R' + C{sub 6}H{sub 5}CH{sub 2}SH -> RH + C{sub 6}H{sub 5}CH{sub 2}S'; C{sub 6}H{sub 5}CH{sub 2}S + RCH = 0 -> C{sub 6}H{sub 5}CH{sub 2}SH + RC = 0. La fotorreduccion de la benzofenona a 2-propanol conduce al benzopinacol en virtud de una reaccion

AUMENTO DEL ÍNDICE SOLAR ULTRAVIOLETA CON LA ALTURA SOLAR ULTRAVIOLET INDEX INCREASE WITH ALTITUDE

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Miguel Rivas A

2008-09-01

Full Text Available En este trabajo se presentan los resultados obtenidos al realizar comparaciones entre mediciones experimentales de Índice solar ultravioleta (IUV obtenido a partir de datos experimentales y también de resultados teóricos proveniente del cálculo del IUV mediante el modelo TUV (modelo ultravioleta troposféricol. En especial se destacan los aumentos de la irradianza solar ultravioleta B (UVB 280-320 nm que se reciben a nivel del suelo debido a los aumentos de la altitud del lugar sobre el nivel del mar (efecto altitudinal. Los cálculos mediante el modelo TUV se realizaron en un período comprendido entre los años 1996-2003, introduciendo los parámetros de los lugares geográficos en que se hicieron las mediciones experimentales. Dado que una de las variables importantes de la que depende el IUV es la altitud sobre el nivel del mar y considerando que la zona norte de Chile es un lugar con características especiales para realizar este tipo de estudios, es que se han realizado experimentos para medir la irradianza solar UVB entre 0-3.200 m de altura, y a partir de estos datos se ha obtenido el IUV. La importancia de estos resultados radica en el hecho que a partir de ellos se pueden cuantificar el incremento de la irradianza UVB por cada 1.000 m de altitud sobre el nivel del mar. Un número creciente de personas se desplazan continuamente entre el nivel del mar y altitudes cercanas a los 5.000 m, debido a trabajos relacionados con: minería, turismo, transporte. En todos estos casos estas personas reciben importantes incrementos de irradianza solar UV, que pueden afectar gravemente su salud si no se informan de los riesgos para que puedan tomar precauciones.In this work we present results from ultraviolet solar index (IUV comparisons between values obtained from experimental measurements, with theoretical results obtained from tropospherical ultraviolet model (TUV. It is important to emphasise the observed increase in solar ultraviolet B (UVB

Photochemical degradation of emerging contaminants by solar processes: analytical assessment; Degradacion fotoquimica de contaminantes emergentes mediante procesos solares. Evaluacion analitica

Energy Technology Data Exchange (ETDEWEB)

Perez Estrada, L. A.; Aguera Lopez, A.; Malato Rodriguez, S.

2009-07-01

In recent years, the presence of pharmaceuticals in the aquatic environment has reached a growing interest. These new contaminants are important because many of them are not degraded under the typical biological treatments applied in the wastewater treatment plants and represent a continuous input into the environment. Thus compounds such as diclofenac, dipyrone and malachite green are present in surface waters in all Europe and crucial need for more enhanced technologies that can reduce its presence in the environment has become evident. In this sense, solar advanced oxidation processes represent a good choice for the treatment of hazardous non-biodegradable pollutants. This work deals with the solar photodegradation of these contaminants in aqueous solutions by TiO{sub 2} photo catalysis and photo-Fenton reaction. A pilot-scale facility using a compound parabolic collector (CPC) reactor was used for this study. Results obtained show rapid and complete oxidation of parent compounds and partial mineralization of dissolved organic carbon. The two treatment are compared on the basis of their kinetics (parent compound and TOC), formation of degradation products (as determined by ionic chromatography, GC/MS and LC/TOF-MS), and toxicity (as evaluated by Vibrio fischeri bacteria). (Author)

Procesamiento químico de interfases semiconductoras tipo CuInS2 / Buffer para células solares de lámina delgada

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Herrero, J.

2004-04-01

Full Text Available Some results are presented about the preparation of CuInS2 / buffer interfaces by chemical bath deposition. This type of interface has an interest for solar energy conversion by thin- film solar cells. It is shown that the deposition of buffer films with ZnSe composition onto CuInS2 is due to a combined electroless and chemical reaction process. Characterization of the CuInS2 / ZnSe structure is carried out with X-ray diffraction and microscope techniques (AFM, SEM. Solar cells of CuInS2 / ZnSe / ZnO type are characterized as a function of buffer layer deposition process.Se presentan resultados sobre la preparación mediante depósito químico de interfases CuInS2 / buffer. Estas interfases son de interés en la fabricación de células solares de lámina delgada. Se lleva a cabo el crecimiento de películas buffer de ZnSe en un baño químico, mediante a partir de reaccionesón electroless y química. La interfase CuInS2 / ZnSe resultante se caracteriza por medio de técnicas microscópicas (AFM, SEM. Se presentan resultados de células solares del tipo CuInS2 / ZnSe / ZnO, en función del tipo de depósito de la lámina buffer.

Evaluación del desempeño de un secador solar directo sobre semillas de cacao (Theobroma cacao L.

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Enrique Romero Frasca

2016-01-01

Full Text Available Se desarrolló un secador solar directo con un diseño basado en dispositivos deshidratadores rudimentarios de uso regular, en granjas cacaoteras de Tabasco; con el objetivo de evaluar su desempeño en la obtención de cacao seco con- forme a la NMX-F-352-S-1980, mediante una exposición a luz solar durante cuatro días. Re- sultados: disminución paulatina del contenido de humedad hasta en un 7.50%, en promedio, en un producto con valor comercial a insertarse en el mercado.

COMPORTAMIENTO DE LA TEMPERATURA DEL FLUJO DE AIRE EN UN ABSORBEDOR SOLAR BEHAVIOR OF THE TEMPERATURE OF THE FLOW OF AIR IN A SOLAR ABSORBER

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GERARDO C CIFUENTES

2009-12-01

Full Text Available El presente trabajo evalúa el comportamiento de la temperatura del flujo de aire en un colector solar de lecho de rocas, mediante un modelo matemático que simula las temperaturas del flujo de aire a la entrada y salida del colector. El modelo relaciona la geometría, la radiación incidente en el colector y las constantes propias del colector determinadas experimentalmente. Para el análisis se realizaron tres pruebas en las que se midieron las temperaturas del ambiente, de entrada y salida en el colector y la radiación solar incidente.The present work evaluates the behavior of the temperature of the flow of air in a solar collector of channel of rocks, by means of a mathematical model that simulates the temperatures from the flow of air to the entrance and exit of the collector. The pattern relates the geometry, the incident radiation in the collector and the constants own collector determined experimentally. For the analysis they were carried out three tests in those that the temperatures of the atmosphere were measured, of entrance and exit in the collector and the solar incident radiation.

Hierarchic control of the production of energy by means of plants of distributed solar collectors; Control jerarquico de la produccion de energia mediante plantas de colectores solares distribuidos

Energy Technology Data Exchange (ETDEWEB)

Martinez Cirre, C. R.

2008-07-01

This work presents several different approaches to hierarchical control algorithms designed for a parabolic-trough solar collector field to demonstrate the possibility of maximizing hypothetical profit possible from this type of plant by improving and increasing plant automation. This study was developed in the current world power supply scenario, posing the possibility of using renewable energies (among which is solar thermal power), which the author is interested in contributing to advancing through research on improved plant operation control. The design was made for the ACUREX distributed solar collector field at the Plataforma Solar de Almeria. The control structures implemented to improve production in the solar collector field are based on a simple two-layered hierarchical control. One regulation layer (Layer 1) in which two proposals have been implemented: a control scheme developed using the feedback linearization technique and another proposal consisting on parallel deed forward control with an I-PD (Integral-Proportional Derivative) control. three proposals were implemented in the top layer (Layer 2) for generating the setpoint, the first one based on a physical model, the second one based on a fuzzy model, and the last uses the physical model and an optimization function for finding the optimum setpoint. (Author)

Procedimiento de estabilizacion de mercurio liquido mediante cemento polimerico de azufre,via sulfuro de mercurio

OpenAIRE

López Gómez, Félix Antonio; López-Delgado, Aurora; Alguacil, Francisco José; Alonso Gámez, Manuel

2009-01-01

Procedimiento para la estabilización de mercurio líquido mediante la obtención de cementos poliméricos de azufre que comprende: (a) transformación del mercurio líquido en sulfuro de mercurio (metacinabrio) mediante reacción química, en condiciones estequiométricas, entre el mercurio y el azufre elemental; y (b) obtención de cemento polimérico de azufre mediante la incorporación el sulfuro de mercurio obtenido en la etapa anterior, en una mezcla estable constituida por áridos, azufre elemental...

ESTUDIO TEÓRICO DE LA MOLÉCULA DE HIDROGENO CALCULO AB-INITIO

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N. Quitián

2010-09-01

Full Text Available Utilizando la técnica LCGO-SCF-MO (Combinación Lineal de los Orbitales Moleculares en Orbitales Gausianos, en el método del Campo Auto-Coherente, se determinaron las energías de orbital, la energía electrónica total, la energía de repulsión nuclear y la energía de Hartree-Fock de la molécula de hidrógeno en su estado fundamental, mediante un cálculo ab initio y utilizando una base de funciones gausianas. Los orbitales moleculares fueron desarrollados en términos de una función Is contraída por átomo de hidrógeno, obtenida por la minimización de los coeficientes y de los exponentes de los orbitales gausianos para el átomo aislado. Los resultados obtenidos nos permiten afirmar que la base molecular mejora sensiblemente los resultados, acercándose más al límite de Hartree-Fock.

APLICACIÓN DE FOTOCATÁLISIS SOLAR A PH NEUTRO PARA LA ELIMINACIÓN DE CONTAMINANTES QUÍMICOS Y BIOLÓGICOS

OpenAIRE

Bernabeu García, Antonio

2012-01-01

Los estudios realizados en esta Tesis Doctoral se han centrado en la aplicación de los Procesos de Oxidación Avanzada (AOPs) en condiciones próximas a la neutralidad para la eliminación de contaminantes químicos (contaminantes emergentes) y biológicos (larvas de mejillón cebra) en aguas naturales, mediante aplicación de procesos de fotocatálisis solar heterogénea con TiO2 y foto-Fenton solar a pH neutro. Los tratamientos de oxidación aplicados a los contaminantes emergentes se han realizad...

Método de eliminación de trihalometanos y/o contaminantes emergentes mediante plasma

OpenAIRE

Erra Serrabasa, Pilar; Jover Comas, Eric; Molina Mansilla, Ricardo; Bertrán Serra, Enric; Bayona Termens, Josep María; Reyes Contreras, Carolina

2009-01-01

Método de eliminación de trihalometanos y/o contaminantes emergentes mediante plasma. Se describe un método de eliminación de trihalometanos y contaminantes refractarios en medios acuosos mediante la aplicación directa de plasma para conseguir la degradación de los compuestos contaminantes presentes en el agua.

Infrastructure of the hydrogen use and materials for fuel cells: key for its soon use; Infraestructura de uso de hidrogeno y materiales para celdas de combustible: clave para su pronto uso

Energy Technology Data Exchange (ETDEWEB)

Cano Castillo, Ulises; Rejon Garcia, Leonardo; Ojeda Hernandez, Mirna [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2000-07-01

de celdas de combustiononble (PEM) (celdas de membrana de intercambio prototipo o de electrolito de membrana polimerica), de la membrana intercambiadora de protones, difusor de gas, placas colectoras de corriente con campos de flujo de gases y electrocatalizadores. Se muestra una tabla de las aplicaciones de celdas de combustion de acuerdo al tipo de celda desde una potencia menor a 1 KW hasta mayores de 1 MW. Tambien se encuentra una tabla de los metodos de produccion de hidrogeno y tablas donde se representa el recorrido de hidrogeno en una celda PEM y los componentes basicos de una celda de combustion tipo PEM. En el articulo se da una tabla donde se muestra la comparacion de algunas propiedades de placas colectoras de corriente, asi como se muestra una grafica de los espectros de impedancia electroquimicas.

Modelado de un amortiguador magneto-reológico mediante EcosimPro

OpenAIRE

Rodríguez Cadenas, Rubén

2012-01-01

El objetivo de este proyecto es la creación de una librería en la herramienta de modelado y simulación EcosimPro enfocada a amortiguadores magneto‐reológicos. El modelado y simulación mediante cualquier herramienta informática permite la obtención de datos y el desarrollo de componentes con un coste inferior al que habría que invertir mediante una experimentación real. Además, permite llevar el componente hasta el límite sin el riesgo de romperlo o dejarlo inutilizable. Por tanto, se puede de...

Sensado de variables mediante terminal Android

OpenAIRE

Altaba Rosas, Mar

2017-01-01

El presente documento describe los procesos de diseño y desarrollo de un sistema que, a través de una aplicación móvil, sirve como dispositivo para el registro de la actividad cardíaca del paciente, mediante la obtención del electrocardiograma (ECG), y que permite detectar irregularidades para posteriormente, en caso que fuera necesario, poder enviar los datos adquiridos al profesional sanitario pertinente para que éste los analice. El sistema tiene dos componentes diferenciados, por un lado,...

Photo-catalysis Plants from basic research to commercial reality; Plantas de tratamiento mediante fotocatalisis solar: de la investigacion basica a una realidad comercial

Energy Technology Data Exchange (ETDEWEB)

Blanco, J.; Malato, S.

2007-07-01

The degradation process of nonbiodegradable organic substances by means of photo catalysis techniques allows the effective elimination of pollutants presents in water and air. The development during the last years of the solar photo catalysis technology, commonly called solar detoxification, has allowed that the first commercial plants based on solar collectors for the treatment of waste water containing persistent organic compounds become a reality. CIEMAT has played an essential roll on this process. This technology is based on the application of two different techniques (photo-Fenton and UV/TiO{sub 2} processes) implemented in static solar collectors CPC type (parabolic-compound). (Author)

Estimated saving potential and efficient use of energy in air conditioning by means of the solar protection; Potencial estimado de ahorro y uso eficiente de energia en aires acondicionados mediante la proteccion solar

Energy Technology Data Exchange (ETDEWEB)

Mejia D, David; Morillon G, David; Rodriguez V, Luis [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

2001-07-01

In here it is presented the analysis of the impact of the solar gains through the transparent parts of a prototype house of social interest, located in a dry warm climate. This analysis was made to determine the gains through windows for the summer time and under the following conditions: without outside solar protections, with the use of eaves, solar breakers and finally with the use of both systems of solar protection. The results were compared to obtain the considered potential of energy saving in cooling equipment, that could be obtained in future houses to build. [Spanish] Se presenta el analisis del impacto de las ganancias solares a traves de las partes transparentes de un prototipo de vivienda de interes social, ubicado en un clima calido seco. Dicho analisis se realizo para determinar las ganancias a traves de ventanas para la epoca de verano y bajo las siguientes condiciones: sin protecciones solares exteriores, con el empleo de aleros, con quiebrasoles y finalmente con el empleo de ambos sistemas de proteccion solar. Se compararon los resultados para obtener el potencial estimado de ahorro de energia en equipo de enfriamiento, que se tendria en las futuras viviendas por construir.

Reconciliando modularidad y eficiencia mediante atajos

OpenAIRE

Marco Gómez, Jordi; Franch Gutiérrez, Javier

1997-01-01

Se presenta en este artículo una propuesta para el desarrollo de programas eficientes en el marco de la programación con tipos abstractos de datos (TAD), con el objetivo de respetar la estructura modular de los programas propia de este ámbito. La propuesta se centra en el concepto de atajo como camino eficiente de acceso a los datos, alternativo al acceso mediante las operaciones propias del TAD, y se desarrolla sobre un TAD concreto, el almacén de elementos. La definición de los atajos es al...

Prototype of a control board solar tracking mechanism on a shaft; Prototipo de una tarjeta de control del mecanismo de seguimiento solar en un eje

Energy Technology Data Exchange (ETDEWEB)

Ramos Berumen, Carlos; Ramirez Benitez, Juan Rafael; Lopez Perez, Manuel de Jesus; Beltran Adan, Jose; Lagunas Mendoza, Javier [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2010-11-15

A solar concentrator prototype of Parabolic Trough (PT) for solar process heat generation has been designed, manufactured and put into operation by the Instituto de Investigaciones Electricas. By means of a sun tracking mechanism controlled by an automatic device, the PT is moving from East to West during the day then this way the solar energy is focused continually over the lineal receiver. Such movement is reached thanks to the electronic module fitted with special software. In this paper, the design of an electronic module based on calculation algorithm of the sun position along the day and over the year which controls the PT sun tracking is presented. The main purpose of the development is to integrate a control system which is using the algorithm of low cost (it was tested in a commercial system with success). [Spanish] El Instituto de Investigaciones Electricas (IIE) ha disenado, fabricado y puesto en operacion un prototipo de concentrador solar de canal parabolico para la generacion de calor de proceso. La tecnologia termosolar a concentracion de canal parabolica mantiene el concentrador moviendose de este a oeste durante el dia, enfocando continuamente el sol en el receptor lineal, mediante un mecanismo y un control automatico que permite el seguimiento aparente del sol. Se ha desarrollado el software para el control del mecanismo de seguimiento solar. En este articulo se presenta el diseno de un modulo electronico que controla el mecanismo de seguimiento solar de un canal parabolico, el cual tiene sus bases en un algoritmo que calcula la posicion del sol durante todo el dia y a lo largo del ano. El proposito principal es integrar un sistema de control de bajo costo, que utilice el algoritmo desarrollado por el IIE, el cual fue probado con exito en un sistema comercial para el seguimiento solar de un canal parabolico.

Modulación del crecimiento vertebral mediante electrocoagulación hemicircunferencial vertebral asistida

OpenAIRE

Caballero García, Alberto

2011-01-01

Nuestro trabajo está basado en la posibilidad de controlar el desarrollo asimétrico de los cartílagos de crecimiento vertebral, mediante la realización de una fisiodesis hemivertebral, con electrocoagulación, videoasistida por toracoscópica. Se realizará en cinco niveles torácicos, con un abordaje anterior mínimamente invasivo. Por lo tanto, planteamos como hipótesis de trabajo que La destrucción de las fisis de crecimiento vertebral mediante electrocoagulación, videoasistida por vía toracosc...

Programación por metas Energía alternativa mediante biomasa.

Directory of Open Access Journals (Sweden)

Guerrero Casas, Flor María

2003-01-01

Full Text Available En este trabajo se presenta un modelo multicriterio de localización de centrales de generación de energía eléctrica mediante biomasa. Los objetivos considerados son: (1 minimizar el coste total de la operación, (2 maximizar la producción de electricidad obtenida, (3 maximizar la distancia entre plantas, (4 maximizar la aceptación social y (5 establecer las plantas o ampliaciones en aquellos lugares donde exista una mayor predisposición por parte de las administraciones locales. Finalmente, se concluye con una aplicación práctica mediante programación por metas ponderadas para la región andaluza, considerando los residuos procedentes del olivar como fuente de energía.

Experiencia de fabricación de cocinas solares por una cooperativa de trabajo en Salta.

OpenAIRE

Belmonte, Silvina; Caso, Ricardo Alberto; Fernández, C.

2015-01-01

La transferencia tecnológica fue realizada con la cooperativa 26 de Agosto (Salta) e involucró la participación de múltiples actores institucionales a nivel nacional y local. El proyecto se desarrolló como una estrategia de negocios para brindar sustentabilidad a la cooperativa mediante la generación de fuentes estables de trabajo, y como una estrategia de difusión de tecnologías solares para la mejora de las condiciones de vida y del ambiente en la región. El proceso se llevó a cab...

Comparación del gasto energético en reposo determinado mediante calorimetría indirecta y estimado mediante fórmulas predictivas en mujeres con grados de obesidad I a III

OpenAIRE

Alicia Parra-Carriedo; Loren Cherem-Cherem; Daniela Galindo-De Noriega; Mary Carmen Díaz-Gutiérrez; Ana Bertha Pérez-Lizaur; César Hernández-Guerrero

2013-01-01

Introducción: La determinación del gasto energético en reposo (GER) se calcula cotidianamente a partir de fórmulas predictivas aunque el resultado varía dependiendo de la población. Objetivo: Comparar la determinación del GER mediante calorimetría indirecta y mediante las ecuaciones Harris-Benedict (HB), Mifflin (MF), Organización Mundial de la Salud (OMS), "Institute of Medicine" (IOM), Fórmula Rápida (FR) y Valencia (VA) en mujeres con grados de obesidad I a III. Métodos: Mujeres adultas me...

Comparative study on systems of residual water treatment in the process industry by evaporation, using fossils fuels or solar energy; Estudio comparativo sobre sistemas de tratamiento de aguas residuales de la industria de procesamiento por evaporacion, utilizando combustibles fosiles o energia solar

Energy Technology Data Exchange (ETDEWEB)

Landgrave Romero, Julio; Canseco Contreras, Jose [Facultad de Quimica, UNAM (Mexico)

1996-07-01

The residual water treatment of the process industry, nowadays is an imminent necessity in our country. In the present study two different forms are considered to concentrate residual waters: multiple effect evaporation and solar evaporation. The use of solar evaporation lagoons is a good possibility to conserving energy by means of the diminution of fossil fuel consumption. The design basis of the evaporation systems via multiple effect, as well as solar evaporation, the results of the respective sizing and the estimation of the corresponding costs are presented. A practical case is described on the cooking of cotton linters (flock) [Spanish] El tratamiento de aguas residuales de la industria de proceso, hoy en dia es una necesidad inminente en nuestro pais. En el presente trabajo se consideran dos formas distintas para concentrar las aguas residuales: evaporacion de multiple efecto y evaporacion solar. El empleo de lagunas de evaporacion solar es una buena posibilidad para conseguir el ahorro de energia mediante disminucion del consumo de combustibles fosiles. Se presentan las bases de diseno de los sistemas de evaporacion via multiple efecto, asi como solar, los resultados del dimensionamiento respectivo y la estimacion de los costos correspondientes. Se describe un caso practico sobre el cocido de linters de algodon (borra)

Ensayo no destructivo de soldaduras en pernos conectores mediante inspección acústica

OpenAIRE

Aznar, A.; Cervera, J.; Ortiz, J.; Hernando, J. I.

2012-01-01

Los pernos conectores aportan múltiples ventajas de uso, entre las que se encuentra el elevado margen de seguridad que ofrecen sus soldaduras ejecutadas mediante arco eléctrico. Estas soldaduras, aunque ampliamente fiables, son difícilmente comprobadas mediante ensayos no destructivos. Aparte de la inspección visual, que aporta gran información sobre la calidad de ejecución de la soldadura, el resto de ensayos no destructivos (líquidos penetrantes, partículas magnéticas, ultrasonidos, radiogr...

Algunos aspectos de la climatología solar del Uruguay Some aspects of the solar climatology of Uruguay

Directory of Open Access Journals (Sweden)

Hugo Grossi Gallegos

2010-12-01

Full Text Available La cobertura espacial de las redes de medición en tierra no puede satisfacer todas las necesidades de los usuarios debido a su baja densidad esto es más notable en el caso de la radiación solar. La escasez de datos de irradiación global es la razón para utilizar la heliofanía para su estimación mediante el empleo de diferentes correlaciones que han probado tener un buen ajuste con las mediciones. Para trazar cartas de heliofanía (y a partir de ellas, de irradiación solar global en un territorio tan extenso como América del Sur es necesario estudiar la relación error-distancia entre estaciones en zonas homogéneas. Para ello, lo habitual es analizar el comportamiento espacial de algunos estadísticos de campos aleatorios, como por ejemplo, la función estructura. En este trabajo, se han utilizado datos medios mensuales de heliofanía de Uruguay y se analizó su variación con la distancia entre estaciones. Se presentan gráficos obtenidos para diferentes épocas del año, analizándose las condiciones de extrapolación espacial de la información. Además, se muestran los resultados del análisis estadístico de series temporales de valores medios anuales de la heliofanía diaria mediante la aplicación del test de Mann-Kendall. Finalmente, se presentan 12 cartas con la distribución espacial de la media mensual de la heliofanía diaria.The spatial coverage of land measurement networks cannot fulfill all the user's needs because their density is low; and this fact becomes more important in the case of solar radiation. The scarcity of global irradiation data is the reason for using sunshine hours in order to estimate them through different correlations which have shown a good fit with the measurements data. In order to draw charts with the spatial distribution of the sunshine-hours monthly averages (and from them, global solar radiation charts also on such a vast territory as South America, it is necessary to study the error

Procedimiento para el diseño de un sistema de calentamiento solar-mixto de aire que utiliza agua como fluido de trabajo

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Luis Francisco Boada E.

1983-05-01

Full Text Available En este artículo se describe un sistema solar-mixto de calefacción de aire que incorpora colectores planos calentadores del agua, un tanque acumulador de calor y un dispositivo para el intercambio de calor agua-aire. Se presentan los ensayos que determinaron la disposición óptima del equipo para el intercambio de calor con flujo de agua por termosifón y el comportamiento térmico para diferentes flujos de aire, así como los ensayos para conocer el comportamiento del sistema de calentamiento solar de agua. Finalmente, el diseño se efectúa mediante un programa de computador adaptado para tal fin.

Technical-economic study of the development of a hydrogen-based energy system in Venezuela; Estudio tecnico-economico del desarrollo en Venezuela de un sistema energetico basado en el hidrogeno

Energy Technology Data Exchange (ETDEWEB)

Posso, F. [ULA-Tachira. San Cristobal (Venezuela)] email: fausto@ula.ve; Contreras, A. [ETSII-UNED (Venezuela)

2009-09-15

The feasibility of the development in Venezuela of a hydroelectric/hydrogen energy system (HHES) was studied. The application of this system is intended for rural sectors in the country with no available permanent and safe energy services. The study was conducted by developing and later simulating a mathematical model for each of the components of the energy system: transformation, storage, transport, distribution and final use. Structurally, the models are composed of an energy sub-model and a cost sub-model. The HHES model as a whole is obtained from the connection of the models and the components. The simulation is performed for operating conditions and parameter values that are most favorable for the proposed use, with the same temporal period in all cases. The results indicate that the annual production of H{sub 2} must increase in order to satisfy the growing energy needs of the rural study population. The total annual costs of the HHES decreased during the study period, primarily due to a decrease in the costs of the final use component, which indicates the behavior of total costs. A comparison of the results obtained with those from the literature demonstrate interest in the proposed system given the ideal economic and environmental conditions provided to the zone selected, primarily due to the availability of inexpensive hydroelectric energy in the country. The current feasibility of the development of the HHES is shown, as compared to the option of supplying electric energy to rural population centers via traditional electric installations. [Spanish] Se estudia la viabilidad del desarrollo en Venezuela del Sistema Energetico Hidroelectricidad/Hidrogeno, SEHH, con vista a su aplicacion en sectores rurales del pais que no disponen de servicios permanentes y seguros de energia. El estudio se realiza mediante la elaboracion y posterior simulacion de un modelo matematico para cada uno de los componentes del sistema energetico: transformacion, almacenamiento

Modelización numérica del proceso de transferencia de calor, del flujo convectivo inducido y de la potencia generada en una central eólico solar. Poster

OpenAIRE

Hurtado, Francisco J.; Sánchez Kaiser, Antonio; Zamora Parra, Blas; Lucas Miralles, Manuel; Viedma Robles, Antonio

2008-01-01

La chimenea eólico solar tiene por objeto producir energía eléctrica a partir de la energía del sol. La radiación solar incide sobre el colector que, a modo de invernadero, calienta el aire que hay en su interior. El aire caliente asciende por flotación a través de la chimenea, accionando y haciendo girar mediante este movimiento ascendente la turbina que se encuentra en la base de la chimenea. Esta turbina se conecta a un generador eléctrico que produce la corriente. El sistema está...

Understanding and improving the chemical vapor deposition process for solar grade silicon production

OpenAIRE

Ramos Cabal, Alba

2015-01-01

Esta Tesis Doctoral se centra en la investigación del proceso de producción de polisilicio para aplicaciones fotovoltaicas (FV) por la vía química; mediante procesos de depósito en fase vapor (CVD). El polisilicio para la industria FV recibe el nombre de silicio de grado solar (SoG Si). Por un lado, el proceso que domina hoy en día la producción de SoG Si está basado en la síntesis, destilación y descomposición de triclorosilano (TCS) en un reactor CVD -denominado reactor Siemens-. El materia...

Feasibility of implementation of an autonomous hybrid system for PEM fuel cells to electrify localities in rural Cuba; Factibilidad de implementacion de un sistema hibrido autonomo con celda de combustible PEM para electrificar localidades rurales en Cuba

Energy Technology Data Exchange (ETDEWEB)

Sanchez Torres, Yamir [Centro de Estudios de Tecnologias Energeticas Renovables (CETER), Ciudad de la Habana (Cuba)] e-mail: yamir@ceter.cujae.edu.cu

2009-09-15

a la electrificacion de zonas rurales alejadas de la red electrica nacional en Cuba. Se calculo la demanda electrica de la zona y el potencial energetico disponible, luego, mediante el uso de los programas informaticos de modelacion y simulacion, HOMER, PVSYST y Matlab 1,2,3, se determino la variabilidad del potencial eolico y fotovoltaico con las horas del dia y las estaciones climaticas a lo largo de un ano, asi como su efecto en la produccion de hidrogeno y electricidad. Se comprobo que incluso para los mas adversos escenarios se cumple con la demanda energetica necesaria. En el trabajo se ofrece detalladamente el comportamiento del sistema y se evidencia la no afectacion del entorno siendo posible la electrificacion y bienestar de los pobladores de la localidad.

Dimensionado mediante simulación de sistemas de energía solar fotovoltaica aplicados a la electrificación rural

Directory of Open Access Journals (Sweden)

Ciaddy Gina Rodríguez ‐ Borges

2011-01-01

Full Text Available El presente trabajo se basa en el método de dimensionamiento mediante simulación delcomportamiento energético de los sistemas fotovoltaicos, aplicados a la electrificación rural enregiones alejadas de la red eléctrica.Se establece la denominación de sistemas Sobre e Infradimensionados y se expone la solicitudrecibida para el análisis de un caso particular, donde se consideran dos opciones energéticas dediferentes niveles de calidades de servicio eléctrico y se solicita la valoración económica de cadaopción, con su correspondiente argumentación.El nivel de calidad se establece con el índice del % de fallos en el servicio de electricidad por falta deenergía en las baterías, además de la cantidad de los días de autonomía energética del sistema.Se concluye que para sistemas infradimensionados, y con un determinado nivel de calidad deservicio establecida, existen múltiples soluciones de dimensionado, y en determinadas condiciones,no siempre los sistemas de mayor nivel de calidad, son los de mayor costo, siendo posibledeterminar el mínimo costo en el dimensionado mediante el método de simulación.Palabras claves: sistemas fotovoltaicos autónomos, electrificación rural, calidad de sistemasenergéticos.___________________________________________________________________AbstractThe present work is based on the sizing method by means of simulation of the photovoltaic systemsenergy behavior, applied to rural electrification in regions far from the electric net.The denomination of infra/over sized systems is made and a requested analysis of one particularcase is exposed, where it is considered two energy options of different qualities of electric service andthe economic valuation of each option is requested, with its corresponding argument.The quality level is established with the fault index in the electricity service for energy lack in thebatteries, besides the quantity of energy autonomy days of the system.As conclusions, in infra

Gluteoplastia tridimensional mediante distribución volumétrica precisa

Directory of Open Access Journals (Sweden)

R. Alfonso Vallarta-Rodríguez

Full Text Available Introducción y objetivo. La gluteoplastia mediante lipoinyección debe ser una cirugía segura que partiendo de una planificación adecuada, permita un aumento moderado enfatizando contornos y mejorando la forma natural de la región glútea. Debe permitir obtener resultados predecibles, duraderos y reproducibles, además de ser aplicable en una amplia variedad de pacientes. Presentamos un método de gluteoplastia de aumento sistematizada con lipoinyección que además de ser reproducible, permite obtener resultados consistentes, naturales y permanentes, distribuyendo estratégicamente volúmenes en cuadrantes. Pacientes y Método. Con mínima manipulación del lipoaspirado, infiltramos cantidades controladas en 9 cuadrantes en cada nalga. El cuadrante central representa la zona de máxima proyección y recibe la mitad del volumen. Denominamos zonas primarias a los 4 cuadrantes en los ejes X-Y, zonas que reciben el 40% del volumen infiltrado. Las zonas secundarias o menores corresponden a los cuadrantes situados entre los cuadrantes principales, y reciben el 10% del volumen total. Resultados. Entre 2008 y 2013 intervenimos a 75 pacientes para aumento y remodelación de glúteos con la técnica descrita, todas mujeres de 24 a 52 años. Las pacientes presentaron una convalecencia favorable y una satisfacción del 93%. Nueve pacientes presentaron seromas que se resolvieron mediante aspiración en consultorio. No se presentaron complicaciones mayores. Conclusiones. Presentamos un método de remodelación glútea mediante lipoinyección que, además de ofrecer excelentes resultados, predecibles, consistentes, naturales y permanentes, es lógico y reproducible.

Planetary Nebulae with H2 Emission

OpenAIRE

Margarita Rosado; Lorena Arias

2003-01-01

Hacemos una revisión de la emisión en hidrogeno molecular (H2) de las nebulosas planetarias (NPs). Vemos como esta emisión se encuentra asociada a objetos de forma bipolar. Describimos los niveles de energía de la molécula de hidrogeno, los principales mecanismos para poblarlos (choques y fluorescencia) y las formas en que se puede discriminar que mecanismo opera. Proponemos que la cinemática del H2 también puede ser usada para discriminar el mecanismo de excitación de sus líneas de emisión. ...

Diseño de una central solar termoeléctrica de 50 Mw con 4 horas de almacenamiento con tecnología de canales parabólicos

OpenAIRE

Crespo Mencía, Diego

2010-01-01

En este proyecto, se detallan la metodología para el diseño de plantas termosolares y se calculan los principales parámetros para el diseño de la misma. El diseño tiene dos partes fundamentales. Por una parte la captación de la energía solar mediante un diseño optimizado del campo solar y por otra parte el diseño de ciclo de conversión de potencia con todos sus componentes auxiliares. La planta escogida tiene una potencia instalada de 50 MWe netos, que es el límite superior de potencia par...

Diseño mediante elementos finitos de componentes estructurales de un cuadricóptero para impresión 3D

OpenAIRE

PARDO APARISI, IVÁN

2016-01-01

El trabajo tiene como objetivo diseñar componentes estructurales, mediante el método de elementos finitos, que serán utilizados en un dron de cuatro rotores (cuadricóptero). Una característica particular de este proyecto es que los componentes estructurales a diseñar serán fabricados mediante impresión 3D. Pardo Aparisi, I. (2016). Diseño mediante elementos finitos de componentes estructurales de un cuadricóptero para impresión 3D. http://hdl.handle.net/10251/75994. TFGM

Manejo sostenible y sustentable de fincas productoras mediante procesos participativos en Sáchica, Boyacá

OpenAIRE

Ángel Eduardo Ramírez-Amaya; Germán Gonzalo Hurtado

2013-01-01

Objetivo. Elaborar un proyecto de desarrollo sostenible y sustentable de fincas productoras mediante procesos participativos en el municipio de Sáchica, Boyacá. Materiales y métodos. La investigación se realizó con familias campesinas de la vereda Arrayán Alto, del municipio de Sáchica, Boyacá, mediante la metodología Investigación Acción Participativa (IAP), que se centra en la participación de las comunidades para elaborar propuestas concertadas con ellas. El trabajo se desarrolló en varias...

Potencial de secado de yuca con aire natural y energía solar

Directory of Open Access Journals (Sweden)

Alfonso Parra Coronado

1990-01-01

Full Text Available En este trabajo se presentan los resultados de estudios del potencial de secado de productos agropecuarios con aire natural y energía solar de regiones tropicales, considerando el caso específico de la yuca. La evaluación del potencial de secado de una región se basa en el uso de un programa de computador  Simulación matemática, mediante el cual se obtienen los valores del caudal mínimo de aire requerido para secar el producto antes que éste alcance un nivel de deterioro preestablecido. Otros elementos metodológicos incluyen: manejo de la información meteorológica, mes crítico, patrón de agitación del producto, hora de iniciación del secado, patrón de operación del ventilador, uso de calor suplementario (energía solar e interpretación de los resultados con el fin de optimizar el sistema. Se presentan mapas para Colombia de líneas isocaudales e isoáreas de colector solar plano, con base en los cuales se puede obtener fácilmente la información requerida para el diseño de sistemas de secado de yuca a baja temperatura.

Tratamiento térmico de materiales en el Horno Solar de la PSA: líneas actuales de actividad

Directory of Open Access Journals (Sweden)

Cañadas, I.

2004-04-01

Full Text Available Concentrated solar energy gives controlled high flux density with a wide wavelength spectrum by means of solar furnaces, which design allows to attain very high heating rates and very high temperatures up to 3500 K. Solar furnaces are specially suitable for transformation or synthesis process, these installations are devoted to research in the fields of material characterization and treatment as well as chemical processes. During 2001, several test campaigns have been carried out in the Solar Furnace at the Plataforma Solar de Almería in collaboration with different European research institutes, under the umbrella of the European Commission`s Improving Human Potential Programme. Thus different lines of work have been launched demonstrating the feasibility and potential use of solar furnaces for such R&D field.

La energía solar concentrada permite proporcionar de forma controlada altas densidades de flujo energético con un amplio espectro de longitudes de onda mediante el uso de hornos solares, cuyo diseño permite alcanzar velocidades de calentamiento muy altas y temperaturas de hasta 3500ºC. Los hornos solares, por sus características, son especialmente adecuados para aplicaciones que conlleven la transformación o síntesis de materiales, siendo instalaciones dedicadas a la investigación en los campos de tratamiento y caracterización de materiales y procesos químicos. Durante el año 2001 en el Horno Solar de la Plataforma Solar de Almería se han realizado varias campañas de ensayos en colaboración con distintos centros de investigación europeos dentro del programa IHP de la Comisión Europea, abordándose diversas líneas de trabajo que han vuelto a demostrar la viabilidad y potencialidad del uso de los hornos solares para el tratamiento de materiales.

Reforming water to generate hydrogen using mechanical alloy; El reformado del agua para generar hidrogeno mediante aleado mecanico

Energy Technology Data Exchange (ETDEWEB)

Pena F, D. L.

2016-07-01

The objective of this research was to generate a hydrogen production system by means of mechanical milling, in which 0.1 g of magnesium were weighed using a volume of 300 μL for each water solvent (H{sub 2}O) and methanol (CH{sub 3}OH) in a container to start mechanical milling for 2, 4 and 6 h. Once the mechanical milling was finished, the hydrogen that was produced every two hours was measured to determine the appropriate milling time in the production, also in each period of time samples of the powders produced during the milling of Mg were taken, in this process we used characterization techniques such as: X-ray diffraction at an angle of 2θi 5 and 2θf 90 degrees and scanning electron microscopy, taking micrographs of 100, 500, 1000 and 5000 magnifications. According to the mechanical milling results hydrogen was obtained when using water, as well as with methanol. In the techniques of X-ray diffraction characterization different results were obtained before and after the milling, since by the diffractogram s is possible to observe how the magnesium to be put in the mechanical milling along with the water and methanol was diminishing to be transformed into hydroxide and magnesium oxide, as well as in the micrographs taken with scanning electron microscopy the change in the magnesium morphology to hydroxide and magnesium oxide is observed. (Author)

Construction of an electrolytic photocell fuel cell system used to energize a cellular telephone; Construccion de un sistema fotocelda-electrolizador-celda de combustible, utilizado para energizar un telefono celular

Energy Technology Data Exchange (ETDEWEB)

Fuentes Quezada, Eduardo; Rodriguez-Castellanos, A.; Solorza Feria, O. [CINVESTAV-IPN, Mexico, D.F. (Mexico)]. E-mail: edfq_1986@hotmail.com

2009-09-15

de carbono que es liberado a la atmosfera, ademas de contribuir en gran parte al calentamiento global del planeta. Una alternativa para la generacion de energia electrica es la utilizacion de celdas de combustible de membrana polimerica (PEMFC) las cuales promoveran la utilizacion de combustibles alternos como el hidrogeno. En este trabajo se presenta la puesta en operacion de un sistema constituido por una celda fotovoltaica un electrolizador y una PEMFC. La celda fotovoltaica trasforma la energia solar en electrica con la que se electroliza el agua proporcionando hidrogeno (combustible) y oxigeno (comburente). Se diseno y construyo un electrolizador el cual fue caracterizado mediante ensayos de polarizacion. Los gases obtenidos del electrolizador son alimentados a una celda de combustible disenada y construida en el laboratorio. Para darle aplicacion a este trabajo la energia producida en la celda de combustible es alimentada a un dispositivo de baja potencia como lo es la carga electrica de un telefono movil. La integracion de dispositivos electroquimicos revolucionaran por completo las fuentes de energia que hoy en dia estan basadas en los derivados del petroleo. Estos sistemas integrados son eficientes para la produccion de energia electrica sin emisiones de gases contaminantes.

Radiación solar y supervivencia en una plantación de Vara de Perlilla (Symphoricarpos microphyllus H.B.K.)

OpenAIRE

J. D. Hernández-García; D. A. Rodríguez-Trejo

2008-01-01

En el vivero de la División de Ciencias Forestales, Universidad Autónoma Chapingo, se estableció una plantación de arbustos de vara de perlilla (Symphoricarpos microphyllus H.B.K.), con el fin de estudiar su supervivencia y crecimiento a diferentes niveles de radiación solar. Para ello, los arbustos fueron plantados bajo una plantación de pino, en diferentes condiciones de cobertura de copas. Mediante una cámara digital con lente hemisférica y el uso del programa Hemiview© se midió: ...

A hybrid solar/diesel water heating system: in medicine area in a hospital in Mexico city; Sistema hibrido de energia solar y diesel para calentamiento de agua: caso en el area de medicina fisica en un hospital en la ciudad de Mexico

Energy Technology Data Exchange (ETDEWEB)

Nolasco Mejia, Miguel; Wolpert Kuri, Jorge [UNAM, Mexico, D.F. (Mexico)

2000-07-01

A hybrid solar/diesel water heating system for therapy in a hospital in Mexico is described in this paper. The use of solar energy in hospitals and clinics, represent an environmentally friendly alternative to the burning of fossil fuels. Analysis is made regarding the feasibility of integrating both solar energy and conventional energy (fuel oil) as back up, to satisfy the hot water demand for hydrotherapy in a hospital. Results from simulation show that solar energy is a cheap means to provide up to 60% of the hot water demand. The solar assisted system proposed uses flat plate solar collectors integrated with an existing hot water tank, where water is heated with vapor from a diesel ran boiler. This represents significant savings on the solar system cost. [Spanish] La utilizacion de la energia solar en hospitales y clinicas, representa una posibilidad para obtener ahorros importantes de energia para satisfacer la demanda de agua caliente. En el presente estudio se analiza la demanda de agua caliente para uso en medicina fisica (hidroterapia), en un hospital ubicado en la Cd. De Mexico y la factibilidad de usar la energia solar, empleando como apoyo el sistema tradicional de combustible fosil (diesel). Mediante un analisis termico se determina el calor necesario para satisfacer la demanda de agua caliente. El analisis economico muestra los costos del sistema solar, los ahorros que se tendran y el periodo de recuperacion de la inversion. Los resultados muestran que la utilizacion de la energia solar es factible debido a la disminucion tanto del consumo de combustible, como de las emisiones atmosfericas. Se propone la instalacion de un sistema solar con colectores planos y el aprovechamiento de uno de los dos tanques de agua caliente existentes, donde se efectua la trasferencia de calor al agua por medio de vapor, lo cual disminuye el costo del sistema solar. La aportacion solar puede ser mayor del 60%, el complemento sera aportado por el sistema tradicional con

Establecer las condiciones necesarias para procesar materiales termoestables mediante el rotomoldeo

OpenAIRE

Pérez O., Daniel

2009-01-01

En este trabajo se establecieron las condiciones necesarias para procesar materiales termoestables mediante la técnica de rotomoldeo, comenzando por el estudio de las condiciones de curado y viscosidad relativa, donde se evidenció una relación directa del porcentaje de catalizador en función del tiempo y la temperatura de polimerización.

Use of radioisotopes in studying the penetration of sulphur into iron during hydrogen cathode charging; Application des radioelements a l'etude de la penetration du soufre dans le fer lors du chargement en hydrogene cathodique; Ispol'zovanie radioehlementov dlya izucheniya proniknoveniya sery v zhelezo, kogda ona zaryazhaetsya katodnym vodorodom; Aplicacion de los radioelementos al estudio de la penetracion del azufre en el hierro durante la carga con hidrogeno catodico

Energy Technology Data Exchange (ETDEWEB)

Besnard, S; Talbot, J [Centre National de la Recherche Scientifique, Vitry (France)

1962-01-15

soufre aux joints des grains. Ce resultat, qui ne pouvait etre obtenu qu'avec l'aide des radiotraceurs, a des consequences importantes notamment dans l'industrie des petroles. Une etude analogue a ete faite en utilisant le radioisotope 32 du phosphore. (author) [Spanish] Determinados elementos, como por ejemplo el arsenico, se emplean corrientemente en el laboratorio para fomentar la penetracion del hidrogeno en el hierro. Por otra parte, se ha comprobado en la industria que la presencia de acido sulfhidrico intensifica la corrosion de los aceros por el hidrogeno. Cabia preguntarse si estas sustancias, que hasta ahora se consideraban como catalizadores, solo fomentan la absorcion del hidrogeno, o si ejercen una influencia directa sobre el metal. Los autores han estudiado este fenomeno en su laboratorio con ayuda de hierro electrolitico puro. Han efectuado la sobresaturacion con hidrogeno por carga catodica. Como sustancia de adicion emplearon sulfuro de sodio marcado con azufre-35. Lograron demostrar que en media hora a la temperatura de -15 Degree-Sign C, el azufre penetra en el hierro hasta una profundidad de unas 120 {mu}m. Han podido comprobar ademas que el azufre se localiza preferentemente en los limites intergranulares. Este resultado, que solo pudo obtenerse gracias a los indicadores radiactivos, tiene importantes consecuencias, en especial para la industria del petroleo. Los autores han realizado un estudio analogo utilizando el radioisotopo 32 del fosforo. (author) [Russian] Nekotorye ehlementy, kak naprimer mysh'yak, obychno ispol'zovalis' v laboratorii dlya oblegcheniya proniknoveniya vodoroda v zhelezo. V promyshlennosti bylo ustanovleno, chto korroziya stalej, vyzvannaya prisutstviem vodoroda, usilivaetsya pri nalichii sernistogo vodoroda. Voznikal vopros, dopuskali li ehti veshchestva, rassmatrivaemye do sikh por v kachestve katalizatorov, tol'ko samuyu bol'shuyu absorbtsiyu ili okazyvali neposredstvennoe vozdejstvie na metall. Izuchenie ehtogo yavleniya

Dimensionado de un sistema térmico solar mediante simulación y su validación energética; Sizing of a solar thermal system by means of simulation and their energy validation

Directory of Open Access Journals (Sweden)

Jesús M. Iglesias Ferrer

2015-04-01

Full Text Available El trabajo presenta las formulaciones para dimensionar y simular instalaciones térmicas solares.Se establecen los criterios para el análisis del sistema energético y la descripción del método de recuperación diferencial de la inversión. Se presentó un Proyecto Ejecutivo que fue ejecutado en elHotel “Puesta del Sol”. Posteriormente se realizó una evaluación en la instalación solar construida con el objetivo de validar los resultados obtenidos en la simulación. La comparación de los resultados se establece definiendo el % de aportación energética solar obtenido en las simulaciones y los resultados en los ensayos realizados con carga real. Se muestra el esquema de la instalación con el equipamiento que fuera utilizado en los ensayos establecidos. Estos resultados se recogieron en ficheros y gráficos en valores horarios, diarios y resultados mensuales. El estudio concluyó en un análisis integral anual donde se definió el comportamiento de la instalación solar en el período de explotación. This article presents the formulations to size and simulate a solar thermal installation. It is establish the criterions for the analysis of the energy system and description of the method of differential payback of the investment. With the results of the simulation, an ExecutiveProject was presented was executed in the Hotel "Puesta del Sol". Later on is decided to carry out an evaluation in the built installation with the objective of validating the results of thecontribution energy feigned lot, with the real results that it contributes the installation with real load. The level of comparison of the results settles down with the definition of the % of solar energy contribution is obtains in the previous simulations and the later results obtained in the test carried out in the installation built in the Hotel. The scheme of theinstallation is shown with the equipment was used in the established tests. These results are picked up in files

Ensayo no destructivo de soldaduras en pernos conectores mediante inspección acústica

Directory of Open Access Journals (Sweden)

Aznar, A.

2012-09-01

Full Text Available Headed studs are nowadays the standard steel-concrete connectors because of their competitive advantages. Firstly, they provide a high degree of safety thanks to semiautomatic electric arc welding. These welds are not suitable for typical non-destructive tests. The analytical study comprises several models. The first vibration modes have been obtained. The experimental research has developed first the measurement of the natural frequencies of 28 headed-studs in the sonic range. Then they have been tested by non-destructive and destructive tests. Finally theirs tests have been compared with their respective frequency measurements. A clear relationship between the measured frequencies and the lack of penetration of the welds has been established, that confirms the analytical prediction of this effect of the internal weld imperfections. Therefore, the feasibility of simple and absolutely non-destructive tests of welded studs by in site measurement of natural frequencies in the sonic range has been clearly established in this work.

Los pernos conectores aportan múltiples ventajas de uso, entre las que se encuentra el elevado margen de seguridad que ofrecen sus soldaduras ejecutadas mediante arco eléctrico. Estas soldaduras, aunque ampliamente fiables, son difícilmente comprobadas mediante ensayos no destructivos. El presente estudio plantea la inspección de soldaduras de pernos conectores mediante su espectro acústico. Analíticamente, la investigación se ha centrado en el cálculo de los primeros modos propios de vibración. Experimentalmente se han medido las frecuencias propias de resonancia de 28 pernos, en los que posteriormente se han llevado a cabo ensayos tanto no destructivos como destructivos. Se ha obtenido, tanto teórica como experimentalmente, una relación entre la frecuencia de vibración de los pernos conectores y la calidad de la soldadura. Por ello se verifica la posibilidad de inspección de estas

La prueba obtenida mediante coacción y su inadmisibilidad ante la Corte Interamericana de Derechos Humanos

OpenAIRE

Paúl Díaz, Álvaro

2016-01-01

La Corte Interamericana de Derechos Humanos efectúa un amplio análisis probatorio para determinar la ocurrencia de violaciones de derechos humanos. Ella tiende a ser muy flexible con la admisión de la prueba, sin perjuicio de ello estaría obligada a excluir confesiones obtenidas mediante coacción. En relación con esto, la Corte ha hecho afirmaciones que parecen propiciar la exclusión de toda prueba obtenida mediante coerción, y dar pie a la doctrina del fruto de árbol envenenado. Este artícul...

Ecology versus economy: is biohydrogen the fuel of the future?; Ecologia contra Economia: ¿es el biohidrogeno el combustible del futuro?

Energy Technology Data Exchange (ETDEWEB)

Patino, Rodrigo [Centro de Investigacion y de Estudios Avanzados, Unidad Merida, Merida, Yucatan (Mexico)] e-mail: rtarkus@mda.cinvestav.mx

2009-09-15

This work presents a literature review of scientific research on different methodologies developed to produce hydrogen. Current processes to obtain commercial hydrogen are completely unsustainable in terms of the use of natural resources and environmental degradation. Different bioprocesses have been proposed in recent years as environmentally clean alternatives to produce combustible gases, but balance has not yet been obtained between production costs and performance. Therefore, a comparative analysis is performed of the different methods to obtain hydrogen, their limitations and the future prospects for each one. An in-depth reflection is also provided about challenges and recommendations for scientific and technological research aimed at proposing hydrogen (or biohydrogen) as the substitute for fossil fuels over the course of the 21st century, including not only its production but also storage and energy transformation mechanisms. [Spanish] En este trabajo se presenta una revision bibliografica acerca de las distintas metodologias desarrolladas en investigacion cientifica para producir hidrogeno. Los procesos actuales por los que se obtiene hidrogeno comercial son completamente insostenibles en cuanto a la utilizacion de recursos naturales y deterioro del medio ambiente. En los ultimos anos se han propuesto distintos bioprocesos como alternativas medioambientalmente limpias para la produccion del combustible gaseoso, pero aun no se llega a obtener un balance entre los costos y los rendimientos de produccion. Se hace entonces un analisis comparativo de los distintos metodos de obtencion de hidrogeno, de las limitantes presentes y las perspectivas futuras para cada uno de ellos. Tambien se hace una profunda reflexion acerca del reto y la orientacion que deben tener las investigaciones cientificas y tecnologicas para proponer al hidrogeno (o al biohidrogeno) como el combustible que deba sustituir a los combustibles fosiles durante el transcurso del siglo XXI

Procedimiento de estabilización de mercurio líquido mediante cemento polimérico de azufre, vía sulfuro de mercurio.

OpenAIRE

López-Delgado, Aurora; López Gómez, Félix Antonio; Alguacil, Francisco José; Alonso Gámez, Manuel

2011-01-01

Procedimiento de estabilización de mercurio líquido mediante cemento polimérico de azufre, vía sulfuro de mercurio. Procedimiento para la estabilización de mercurio líquido mediante la obtención de cementos poliméricos de azufre que comprende: (a) transformación del mercurio líquido en sulfuro de mercurio (metacinabrio) mediante reacción química, en condiciones estequiométricas, entre el mercurio y el azufre elemental; y (b) obtención de cemento polimérico de azufre me...

Concentrating Solar Power Projects - Planta Solar 20 | Concentrating Solar

Science.gov (United States)

Power | NREL 20 This page provides information on Planta Solar 20, a concentrating solar power Solar's Planta Solar 20 (PS20) is a 20-megawatt power tower plant being constructed next to the PS10 tower and increasing incident solar radiation capture will increase net electrical power output by 10

Modelo de dinámica lateral de vehículo mediante bond graph

Directory of Open Access Journals (Sweden)

Juan Carlos Parra Márquez

2008-07-01

Full Text Available Este trabajo presenta los resultados de la investigación, cuyo objetivo es obtener un modelo matemático que permita determinar la dinámica lateral de un vehículo mediante el uso de Bond Graph. Este modelo es válido para robótica móvil. Los análisis de comportamiento del modelo han sido probados con simulaciones típicas del movimiento lateral de un vehículo. Finalmente, este modelo ha sido obtenido e implementado mediante el software 20-Sim. This paper presents the results of a research whose objective was to find a mathematical model in order to determine the lateral dynamic of Vehicle by means of the use of Bond Graph. This model is valid also for mobile robotics. The analyses of behavior of the model were realized across typical simulations of a vehicle in lateral movement. Finally, this mathematical model was obtained and implemented across the software 20-Sim.

Diseño e implementación de un sistema de adquisición de datos para medir potencia solar local

Directory of Open Access Journals (Sweden)

Joe Alexander Jiménez Herrera

2006-05-01

Full Text Available El presente trabajo versa sobre la medición de las componentes directa, difusa y global de la radiación solar, a través de piranómetros, con el debido acondicionamiento de las señales y digitalización de las mismas en el microprocesador HCS12. El almacenamiento de los datos se efectúa mediante memorias I2C, logrando una capacidad de captura de 13 días aproximadamente, almacenando tres datos por minuto durante el "día Solar". Además de contar, con una interfaz de visualización y comunicación serial constituida por un PC, un LCD y un teclado, con el cual permite modificar los parámetros del sistema. / The present work deals with the measurement of the direct, global and diffuse components of the solar radiation, through pyranometers, with the signs adaptation right and the digitalization of them in the microprocessor HCS12. The data storage is effected through memories I2C, achieving a capture capacity of 13 days approximately, storing 3 data by minute during the "solar day". Besides, it counts with a visualization and serial communication interface constituted by a PC, a LCD and a keyboard with which it allows modifying the system parameters.

Procedimiento para la obtención de levaduras vínicas superproductoras de manoproteínas mediante tecnologías no recombinantes

OpenAIRE

Barcenilla Moraleda, José María; González Ramos, Daniel; Tabera, Laura; González García, Ramón

2008-01-01

Procedimiento para la obtención de levaduras vínicas superproductoras de manoproteínas mediante tecnologías no recombinantes. Procedimiento para obtener cepas de levaduras superproductoras de manoproteínas mediante la selección de mutantes resistentes a la toxina K9, cepas obtenibles por dicho procedimiento y usos.

The Scattering of Slow Neutrons from Hydrogen and Ethylene; Diffusion des neutrons lents par l'hydrogene et par l'ethylene; O rasseyanii medlennykh nejtronov vodorodom i ehtilenom; Dispersion de neutrones lentos por hidrogeno y etileno

Energy Technology Data Exchange (ETDEWEB)

Bally, D; Tarina, V; Todireanu, S [Institute of Atomic Physics, Bucharest (Romania)

1963-01-15

The angular distribution of 1.61 A wavelength neutrons scattered from hydrogen and ethylene has been measured. For ethylene the pressure was varied from 15 to 60 atm and for hydrogen from 60 to 110 atm. The investigated angular range was between 5''o and 90{sup o}. The experimental results obtained have been compared with the differential cross-section calculated using the Krieger-Nelkin formulae. (author) [French] Les auteurs ont mesure la distribution angulaire des neutrons ayant une longueur d'onde de 1,61 A diffuses par de l'hydrogene et par l'ethylene. Ils ont fait varier la pression de l'ethylene de 15 a 60 atm et celle de l'hydrogene de 60 a 110 atm. Le domaine angulaire etudie etait compris entre 5{sup o} et 90{sup o}. Les resultats des experiences ont ete compares aux sections efficaces differentielles calculees au moyen des formules de Krieger-Nelkin. (author) [Spanish] Los autores han medido la distribucion angular de neutrones de longitud de onda igual a 1,61 A, despersados por hidrogeno y etileno. En el caso del etileno, la presion vario de 15 a 60 atm y en el del higrogeno, de 60 a 110 atm. Los autores han explorado angulos comprendidos entre 5{sup o} y 90{sup o}. comparan los resultados experimentales obtenidos con el valor de la seccion eficaz diferencial calculado con ayuda de las formulas de Kriger-Nelkin. (author)

Modelado del proceso de esterilización del hospital clínico universitario de Valladolid mediante diagramas IDEF

OpenAIRE

Viñas del Hoyo, Víctor

2015-01-01

El principal objetivo de este trabajo de fin de grado es elaborar mediante diagramas IDEF, más concretamente el IDEFO, cuál sería el funcionamiento de la central de esterilización de nueva construcción del Hospital Clínico Universitario de Valladolid, mediante la gestión por procesos. Otros objetivos secundarios pero no menos importantes de este proyecto son:comprender el modelo de gestión por procesos e identificar los pasos que hay que seguir para implantarla correctamente. Ver y aprender ...

HIDRODENITROGENACION DE CARBAZOL SOBRE CATALIZADORES NiMo/Al2O3-SiO2(x

Directory of Open Access Journals (Sweden)

Felipe Sánchez-Minero

2012-01-01

Full Text Available En este trabajo se estudió la velocidad de reacción del carbazol sobre catalizadores NiMo soportados sobre Al2O3 modificada superficialmente con SiO2 (0 y 10 % en peso de SiO2 en el soporte. Los catalizadores fueron evaluados en un reactor intermitente a cuatro temperaturas (287, 300, 312 y 325oC, presión de 4.0 MPa y relación molar hidrogeno/carbazol de 2400. A partir de los resultados experimentales se realizó un estudio cinético utilizando ecuaciones del tipo Langmuir-Hinshelwood (L-H. Luego, los parámetros cinéticos fueron estimados mediante la minimización de Powell (programa Scientist de MicroMath. Los resultados muestran que el catalizador con sílice (NiMo-SAC 10 alcanza una mayor actividad para la HDN de carbazol debido a que presenta un mayor número de sitios activos (valor de A, así como una menor fuerza de adsorción entre el reactante y la superficie catalítica (valor de KN, lo cual posiblemente favorece una mejor regeneración de sitios activos.

Extracción de ADN de Trypanosoma cruzi mediante tratamiento con bromuro de hexadecil-trimetil-amonio

Directory of Open Access Journals (Sweden)

Marcela Escalante

1997-06-01

Full Text Available En el presente trabajo se describe un método rápido, sencillo y eficaz para la obtención de ADN genómico de Trypanosoma cruzi, libre de impurezas y fácil de manipular. Dicho procedimiento se basa en la lisis del parásito con SDS y remoción de proteínas mediante la digestión con proteinasa K, seguida de la precipitación selectiva de carbohidratos y proteínas residuales con bromuro de hexadecil-trimetil-amonio (CTAB. Finalmente, el ADN se extrae con cloroformo: alcohol isoamílico y se recupera de la fase acuosa mediante precipitación con isopropanol.

Hybrids of Solar Sail, Solar Electric, and Solar Thermal Propulsion for Solar-System Exploration

Science.gov (United States)

Wilcox, Brian H.

2012-01-01

Solar sails have long been known to be an attractive method of propulsion in the inner solar system if the areal density of the overall spacecraft (S/C) could be reduced to approx.10 g/sq m. It has also long been recognized that the figure (precise shape) of useful solar sails needs to be reasonably good, so that the reflected light goes mostly in the desired direction. If one could make large reflective surfaces with reasonable figure at an areal density of approx.10 g/sq m, then several other attractive options emerge. One is to use such sails as solar concentrators for solar-electric propulsion. Current flight solar arrays have a specific output of approx. 100W/kg at 1 Astronomical Unit (AU) from the sun, and near-term advances promise to significantly increase this figure. A S/C with an areal density of 10 g/sq m could accelerate up to 29 km/s per year as a solar sail at 1 AU. Using the same sail as a concentrator at 30 AU, the same spacecraft could have up to approx. 45 W of electric power per kg of total S/C mass available for electric propulsion (EP). With an EP system that is 50% power-efficient, exhausting 10% of the initial S/C mass per year as propellant, the exhaust velocity is approx. 119 km/s and the acceleration is approx. 12 km/s per year. This hybrid thus opens attractive options for missions to the outer solar system, including sample-return missions. If solar-thermal propulsion were perfected, it would offer an attractive intermediate between solar sailing in the inner solar system and solar electric propulsion for the outer solar system. In the example above, both the solar sail and solar electric systems don't have a specific impulse that is near-optimal for the mission. Solar thermal propulsion, with an exhaust velocity of the order of 10 km/s, is better matched to many solar system exploration missions. This paper derives the basic relationships between these three propulsion options and gives examples of missions that might be enabled by

Concentrating Solar Power Projects - Khi Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL Khi Solar One This page provides information on Khi Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: February 8, 2016 Project Overview Project Name: Khi Solar One Country: South Africa Location

Concentrating Solar Power Projects - Nevada Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL Nevada Solar One This page provides information on Nevada Solar One, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. Acciona Energy's Nevada Solar One is the third largest CSP plant in the world and the first plant

Non-linear absorption for concentrated solar energy transport

Energy Technology Data Exchange (ETDEWEB)

Jaramillo, O. A; Del Rio, J.A; Huelsz, G [Centro de Investigacion de Energia, UNAM, Temixco, Morelos (Mexico)

2000-07-01

In order to determine the maximum solar energy that can be transported using SiO{sub 2} optical fibers, analysis of non-linear absorption is required. In this work, we model the interaction between solar radiation and the SiO{sub 2} optical fiber core to determine the dependence of the absorption of the radioactive intensity. Using Maxwell's equations we obtain the relation between the refractive index and the electric susceptibility up to second order in terms of the electric field intensity. This is not enough to obtain an explicit expression for the non-linear absorption. Thus, to obtain the non-linear optical response, we develop a microscopic model of an harmonic driven oscillators with damp ing, based on the Drude-Lorentz theory. We solve this model using experimental information for the SiO{sub 2} optical fiber, and we determine the frequency-dependence of the non-linear absorption and the non-linear extinction of SiO{sub 2} optical fibers. Our results estimate that the average value over the solar spectrum for the non-linear extinction coefficient for SiO{sub 2} is k{sub 2}=10{sup -}29m{sup 2}V{sup -}2. With this result we conclude that the non-linear part of the absorption coefficient of SiO{sub 2} optical fibers during the transport of concentrated solar energy achieved by a circular concentrator is negligible, and therefore the use of optical fibers for solar applications is an actual option. [Spanish] Con el objeto de determinar la maxima energia solar que puede transportarse usando fibras opticas de SiO{sub 2} se requiere el analisis de absorcion no linear. En este trabajo modelamos la interaccion entre la radiacion solar y el nucleo de la fibra optica de SiO{sub 2} para determinar la dependencia de la absorcion de la intensidad radioactiva. Mediante el uso de las ecuaciones de Maxwell obtenemos la relacion entre el indice de refraccion y la susceptibilidad electrica hasta el segundo orden en terminos de intensidad del campo electrico. Esto no es

Diseño y prototipaje del álabe para un miniaerogenerador mediante impresión 3D

OpenAIRE

Roy Mota, Andrea

2017-01-01

El objetivo de este proyecto consiste en el diseño de una maqueta de álabe para un mini aerogenerador y su posterior fabricación con PLA mediante la tecnología de impresión 3D no industrial. Para conseguirlo se creó una hoja de cálculo que torna la superficie del ala; se analizó la impresora 3D y se diseñó la estructura interna del aspa para dotarlo de resistencia según sus límites de impresión de la impresora mediante el programa Siemens Unigraphics NX10; se simularon los esfuerzos y a parti...

Mapas de Entornos Mediante Navegacion Difusa y Sistema de Teleoperacion de una Plataforma Pioneer P3-DX

Directory of Open Access Journals (Sweden)

Daniel Granda

2013-11-01

Full Text Available El presente proyecto describe el diseno e implementacion de aplicaciones de Teleoperacion, Adquisicion de Datos, Control Difuso de Velocidad y Mapeo de Entornos en 2D, para la plataforma movil Pioneer P3-DX mediante el uso de sonares, odometrıa y software libre GNU/Linux. El proyecto brinda una guıa para utilizar los conceptos de programacion en Python, que permite crear aplicaciones de manera versatil mediante el uso de librerıas como: GTK para el desarrollo del entorno grafico, PYFUZZY para el desarrollo del controlador difuso de velocidad y OPENCV para mostrar los mapas del entorno.

Simulation with Trnsys of thermal Solar System for desalination by means of inverse osmosis; Simulacion con Trnsys de sistemas solares termicos para desalinizacion mediante osmosis inversa

Energy Technology Data Exchange (ETDEWEB)

Lopez-Villada, J.; Bruno, J. C.; Coronas, A.

2008-07-01

The use of power cycles driven by solar energy to provide the required mechanical energy to drive the high-pressure pump of Reverse Osmosis systems for desalination is an interesting alternative to the conventional electric systems. In this paper it is presented a model developed in Trnsys/Trnopt for the optimisation of the operating temperature in these systems to maximise the desalted water production. The results obtained show that adjusting the plant operation to this optimal temperature following the ambient conditions at each moment, a very important increase in the desalted water production could be achieved. (Author)

Diseño óptimo de un disipador de calor para luminaria LED mediante moderación modelación computacional

Directory of Open Access Journals (Sweden)

Daniel Cahue Díaz

2014-01-01

Full Text Available En el presente trabajo se desarrolla una selección de materiales y simulación térmica en el diseño de disipadores de calor para sistemas de iluminación de estado sólido (SSL mejor conocidos como luminarias LEDs. Se desarrolló un modelo matemático con la capacidad de predecir el comportamiento térmico de la luminaria cuando se encuentra en operación. El modelo matemático fue resuelto mediante un software de distribución libre el cual permite resolver ecuaciones diferenciales mediante el método de elemento finito. Los resultados obtenidos en el modelo matemático planteado fueron validados con los resultados obtenidos mediante experimentación usando imágenes termográficas.

Microorganisms inactivation in wastewater by solar photo-Fenton at neutral pH; Inactivacion de microorganismos presentes en aguas mediante foto-Feton solar a pH neutro

Energy Technology Data Exchange (ETDEWEB)

Ortega Gomez, E.

2015-07-01

The global fresh water shortage, caused mainly by the drought and the pollution of sources, is one of the main environmental problems currently affecting the human race. Over the last few decades, water quality requirements for use in different activities has obliged us to find alternative solutions which requires a concerted effort at a scientific as well as political, economic and social level. In particular, treated wastewater recycling has come up recently as a source provision for sectors where high water quantities are consumed. In this regard, the main sector to benefit is agriculture, which produces the 60% of global food, according to Food and Agriculture Organization (FAO). As such, treatments that are able to guarantee water microbiological quality, as stated by governing law, are necessary and resolve disadvantages or problems with current treatment, Amongst new technologies available for wastewater regeneration, a noteworthy point is the high level of efficiency in Advanced Oxidation Processes (AOPs). Furthermore, those that are capable of using sunlight as a radiation source are of special interest, particularly the homogeneous photocatalytic process, solar photo-Fenton. Generally speaking, in Fenton reactions, an oxidant agent (H2O2) reacts with a catalyst (Fe2+) generating hydroxyl radicals, which are high oxidant and non-selective species causing the inactivation of several microorganisms. The presence of UV-A photons in sunlight leads to catalyst regeneration and the production of more hydroxyl radicals. One of the main goals of this research work has been to improve the knowledge about the microorganism inactivation process through solar photo-Fenton at neutral pH, which has been scarcely studied, for application as a tertiary treatment in a wastewater treatment plant (WWTP). With this aim in mind, the bacteria Enterococus faecalis (Gram-positive microorganism) has been used as a fecal pollution indicator since it has not been studied in great

Diferencias en la calciuria, estimada mediante el índice Ca/Cr en función del tipo de lactancia

OpenAIRE

Trigo López, Javier

2015-01-01

Se ha realizado un estudio descriptivo transversal sobre el comportamiento de la calciuria, estimada mediante el índice calcio/creatinina (ICC), en lactantes menores de 6 meses, analizando su posible relación con el tipo de alimentación (leche de fórmula o leche materna). Los resultados se obtuvieron a partir de muestras de orina de 44 lactantes sanos en los que se recoge el tipo de lactancia. El grupo alimentado mediante leche de fórmula presentó un ICC medio expresado en mg/mg de 0,59, mien...

A novel solar hot plate for cooking

Energy Technology Data Exchange (ETDEWEB)

Rincon Mejia, Eduardo A; Osorio Jaramillo, Fidel A [Facultad de Ingenieria, UAEMex, Toluca, Edo. (Mexico)

2000-07-01

tambien hot cakes, tocino, huevos, bistecs y papas fritas. La estufa solar de placa caliente llamada Tolocatzin consiste de una placa metalica horizontal que se calienta tanto por la parte superior como por la parte inferior por rayos de sol concentrados mediante un concentrador multiple compuesto basado en opticas sin imagen y construido con nueve vidrios plateados planos y espejos de aluminio curvados, de tal manera que pueden ser fabricados facilmente en una pequena fabrica o casa para un angulo de incidencia de 15 grados Celsius que permite la concentracion de la luz del sol sin seguir su trayectoria durante alrededor de una hora pueden alcanzarse temperaturas de hasta 240 grados Celsius en poco minutos. Esta temperatura es lo suficientemente alta para cocinar casi todas las comidas fritas o asadas. El diseno ha sido optimizado usando procedimientos para seguir la trayectoria de los rayos solares. La experiencia operacional con prototipos anteriores ha demostrado que la placa caliente solar Tolocatzin hace un excelente trabajo de cocimiento y podria ser usada en forma masiva en paises soleados.

Seguimiento de trayectorias tridimensionales de un quadrotor mediante control PVA

Directory of Open Access Journals (Sweden)

Silvia Estellés Martínez

2014-01-01

Full Text Available Resumen: Este trabajo presenta el modelado de un quadrotor como un sistema multicuerpo llevado a cabo mediante el software Vehicle- Sim, en el que los diferentes componentes del sistema son descritos mediante una estructura paterno-filial señalando las restricciones físicas entre ellos. Los modelos estructural y aerodinámico han sido desarrollados mediante este software, ampliamente utilizado en la simulación del comportamiento dinámico de vehículos.Sobre el modelo resultante se he desarrollado un algoritmo de control basado en la metodologia PVA con la finalidad de obtener un seguimiento de trayectoria mediante acciones de control suaves. Empleando la metodología convencional de control PVA no es posible estabilizar el vehículo en todos los rangos de posicionamiento lateral (y y longitudinal (x. En este artículo los autores muestran como esta limitación en el diseño de una estrategia de control PVA convencional es solventada con una modificación consistente en sustituir los parámetros constantes del PVA clásico por funciones dependientes del desplazamiento.El sistema de control es implementado para adecuarse a los requerimientos de las actuaciones y se diseña sobre la plataforma de simulación multidominio Simulink. Con la finalidad de obtener una importante mejora en la respuesta de posicionamiento, se im- plementa un generador de trayectorias continuas.Una vez que el modelo es desarrollado y el sistema de control implementado, los autores presentan el modelo matemático y los resultados de las simulaciones realizadas. Éstas validan el empleo tanto de la metodología de control PVA aplicada, como de la alimentación de trayectorias predefinidas, no sólo para la posición, sino también para la velocidad y aceleración. Abstract: In this work the authors present the modelling of a quadrotor as a multibody system carried out with the software VehicleSim, in which the different

Solar neutrinos and nonradial solar oscillations

International Nuclear Information System (INIS)

Zatsepin, G.T.; Gavryuseva, E.A.; Kopysov, Yu.S.

1980-01-01

The problem of origin of surface solar oscillations is considered. It is assumed that generation of oscillations is performed by the solar nucleus. The necessary excitation condition for gravitational oscillations of the solar nucleus is a sharp decrease of the oscillation amplitude outside the nucleus, where the nuclear reaction rates are small and only radiation losses are considerable. It is shown that the specific singularities of gravitational wave propagation in solar entrails permit to attain a significant reduction of the oscillation amplitude. The solar entrails can serve as an effective trap for gravitational waves, if the substance of the solar nucleus is close to the state of convectional equilibrium. In order that the g 1 quadrupole mode of the solar nucleus has a period of 2h 40 min and sharply decreases in the solar mantle, it is enough that only the external part of the solar nucleus is close to the state of convectional equilibrium. Closeness of the solar nucleus to the state of convectional equilibrium is an argument in favour of its periodic mixing. Periodic mixing of the solar nucleus can serve as a cause of a low counting rate of solar neutrinos in R.Davis chlorous detector

Concentrating Solar Power Projects - KaXu Solar One | Concentrating Solar

Science.gov (United States)

Power | NREL KaXu Solar One This page provides information on KaXu Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: April 14, 2015 Project Overview Project Name: KaXu Solar One Country: South Africa Location

SÍNTESIS DE ÓXIDOS TIPO PEROVSKITA MEDIANTE POLIMERIZACIÓN CON ÁCIDO CÍTRICO Y PROPIÓNICO

Directory of Open Access Journals (Sweden)

Jairo Gómez Cuaspud

2010-03-01

Full Text Available En este trabajo se describe la preparación de la perovskita La0,75Sr0,25Co0,5Fe0,5O3 (LaSrCoFeO, empleando una ruta de química húmeda, mediante la polimerización con ácido cítrico y propiónico, con el propósito de obtener materiales para potenciales aplicaciones como membranas de purificación de oxígeno y como materiales electródicos en celdas de combustible de óxido sólido (SOFC. Para ello, los sólidos se caracterizaron mediante difracción de rayos X (DRX y microscopia electrónica de barrido (SEM, con lo que se obtuvo información sobre la formación y pureza de fases, la morfología, la estructura y las propiedades superficiales de cada sistema, indicando que es posible obtener sólidos con una distribución de grano homogéneo, textura y relieve característicos, en cuyo contexto el método que involucra la polimerización con ácido cítrico mostró los mejores resultados. La composición global se determinó mediante microanálisis de rayos X de energía dispersiva (EDX, y se señaló una buena concordancia entre las composiciones propuestas y obtenidas. La caracterización realizada sugiere la presencia de pequeñas cantidades de carbono y algunos óxidos de lantano, estroncio y cobalto como principales contaminantes, específicamente en la muestra obtenida mediante la polimerización con ácido propiónico.

Solar India - 82: national solar energy convention

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

This document is the proceedings of the Solar India - 82 conference, which was held 17-19 December 1982. The papers are organized into functional groupings which include: (1) solar radiation, (2) flat plate solar collectors and solar water heaters, (3) solar concentrators, (4) solar air heaters and dryers, (5) solar ponds and energy storage, (6) solar cookers, (7) solar stills, (8) selective coatings, (9) photovoltaics, (10) space heating and cooling, (11) bio-energy, and (12) miscellaneous papers. The vast majority of the papers describe work carried out in India, the vast majority of the papers also contain relatively readable abstracts.

Desarrollo de la tecnología de MOVPE para el crecimiento de semiconductores III-V : fabricación de células solares para concentraciones luminosas elevadas

OpenAIRE

Galiana Blanco, Beatriz

2011-01-01

El trabajo de estas tesis trata sobre el desarrollo en el IES-UPM de la tecnología de crecimiento epitaxial de fase vapor mediante precursores metalorgánicos (MOVPE) para el crecimiento de células solares de semiconductores III-V para concentraciones luminosas elevadas. En la primera parte de la memoria se presentan los principios de la MOVPE y el estudio de los materiales semiconductores utilizados a lo largo de la tesis: GaAs, AlGaAs, GaInP y AlInP. Para ello, se ha analizado cómo influ...

Caracterización fisicoquímica de arenas en el distrito de San Juan Bautista y su potencial uso en la fabricación de celdas solares

OpenAIRE

V. R., Trigoso; Universidad Nacional de la Amazonía Peruana; J. M., Rojas A.; Universidad Nacional de la Amazonía Peruana; M. I., Silveira B.; Universidad Nacional de la Amazonía Peruana; T. L., Gómez; Universidad Nacional de la Amazonía Peruana; M. W., Ruiz; Universidad Nacional de la Amazonía Peruana; M. B., Lozano; Universidad Nacional de la Amazonía Peruana; H. J., Arce; Universidad Nacional de la Amazonía Peruana; R. J., Ríos; Universidad Nacional de la Amazonía Peruana

2016-01-01

Esta investigación se desarrolló en la ciudad de Iquitos entre los años 2010 y 2011, por la necesidad imperativa de aprovechar los recursos naturales existentes en la comunidad de San Juan Bautista, mediante la caracterización fisicoquímica de arenas observadas en cinco canteras de esta comunidad. Los análisis realizados fueron con vistas a un potencial uso como materia prima en la fabricación de celdas solares. La caracterización fisicoquímica mostró que las arenas analizadas tienen elevada ...

Procedimiento para la discriminación y mapeo de los rodales de nerdo en cultivos de girasol mediante teledetección

OpenAIRE

López Granados, Francisca; García Torres, Luis; Peña Barragán, José Manuel; Jurado-Expósito, Montserrat

2006-01-01

Procedimiento para la discriminación y mapeo de los rodales de nerdo en cultivos de girasol mediante teledetección. Procedimiento para mapear zonas infestadas de la mala hierba conocida como nerdo (Ridolfia segetum Moris) en plantaciones de girasol mediante teledetección. Tiene aplicación en Agricultura, y más concretamente en Empresas de Asistencia Técnica Agraria o Medioambiental, o en Auditorias Agroambientales Públicas o Privadas. Principalmente consiste en el anál...

Principios básicos y aplicación del aprendizaje mediante tareas

Directory of Open Access Journals (Sweden)

Estaire, Sheila

2011-04-01

Full Text Available En los últimos años el aprendizaje mediante tareas ha ido consolidándose como una nueva forma de enseñar y aprender lenguas extranjeras. Sin embargo existen una serie de aspectos prácticos relacionados con su aplicación en los que aún se puede profundizar. En este artículo, después de una introducción breve de algunos principios básicos, se discuten posibles procedimientos para determinar las tareas que constituyen el eje de un programa, así como para organizar el proceso de enseñanza / aprendizaje. A continuación se presentan diferentes modalidades de trabajo sobre los aspectos formales de la lengua, aspectos que es esencial tratar de forma rigurosa, minuciosa y sistemática. Este punto crucial se discute junto con una propuesta de estructura de curso que consta de dos componentes diferenciados. Por otra parte, los elementos innovadores del aprendizaje mediante tareas hacen imprescindible una gestión del aprendizaje también innovadora, aspecto que se trata en el último apartado a través de pautas metodológicas que potencian la eficacia de las tareas como instrumento de aprendizaje.

Pronósticos de inflación mediante técnicas bayesianas

Directory of Open Access Journals (Sweden)

Juan Diego Chavarría

2015-11-01

Full Text Available La efectividad de la política monetaria bajo un esquema de metas de inflación como el propuesto por el Banco Central de Costa Rica se basa en buena medida en el correcto y oportuno pronóstico de la inflación a corto y mediano plazo con el fin de diseñar de mejor forma las acciones de política monetaria. Así, el propósito de este trabajo es desarrollar una herramienta complementaria para elaborar pronósticos de inflación mediante un enfoque bayesiano. Para lo anterior se propone la utilización de la metodología Bayesian Model Averaging y de Weighted Average Least Squares. Los modelos de proyección especificados permitirían ampliar y complementar el análisis que se realiza actualmente con el Modelo Macroeconómico de Proyección Trimestral (MMPT del Banco Central de Costa Rica. Como resultado esta investigación muestra que, para datos de periodicidad mensual y a horizontes de pronóstico de 1 a 12 meses, es posible encontrar proyecciones mediante un proceso bayesiano que poseen una mayor capacidad predictiva en relación con aquellas producidas por un modelo autorregresivo.

Solar constant values for estimating solar radiation

International Nuclear Information System (INIS)

Li, Huashan; Lian, Yongwang; Wang, Xianlong; Ma, Weibin; Zhao, Liang

2011-01-01

There are many solar constant values given and adopted by researchers, leading to confusion in estimating solar radiation. In this study, some solar constant values collected from literature for estimating solar radiation with the Angstroem-Prescott correlation are tested in China using the measured data between 1971 and 2000. According to the ranking method based on the t-statistic, a strategy to select the best solar constant value for estimating the monthly average daily global solar radiation with the Angstroem-Prescott correlation is proposed. -- Research highlights: → The effect of the solar constant on estimating solar radiation is investigated. → The investigation covers a diverse range of climate and geography in China. → A strategy to select the best solar constant for estimating radiation is proposed.

Estudio comparativo del comportamiento de losas de concreto reforzado mediante los análisis elástico y límite

Directory of Open Access Journals (Sweden)

Julio Vergara García

1989-01-01

Full Text Available Presenta un resumen de la tesis de grado "Estudio comparativo de losas de concreto reforzado mediante los análisis elástico y límite". Este trabajo proporciona fórmulas, tablas y gráficas prácticas para determinar los momentos flectores y el volumen de refuerzo de los tipos de losas estudiados, sometidas a diferentes tipos de carga y analizados mediante la Teoría de la Elasticidad y el Análisis Límite.

Solar Energy Innovation Network | Solar Research | NREL

Science.gov (United States)

Energy Innovation Network Solar Energy Innovation Network The Solar Energy Innovation Network grid. Text version The Solar Energy Innovation Network is a collaborative research effort administered (DOE) Solar Energy Technologies Office to develop and demonstrate new ways for solar energy to improve

Monitorización de Signos Vitales Mediante una Red de Dispositivos Móviles

Directory of Open Access Journals (Sweden)

Daniel Cilio

2013-11-01

Full Text Available El desarrollo e implementación de diferentes proyectos tecnológicos, apoyados en el correspondiente conocimiento médico, pueden contribuir a resolver varios problemas del sector de la salud. Si bien en los últimos años se han realizado enormes esfuerzos para desarrollar tecnologías aplicables en ambientes clínicos, el desarrollo de tecnologías para atención médica domiciliar podría reducir la presión que agobia a los hospitales actualmente. En el presente proyecto se realiza el diseño e implementación de un sistema para monitorización de signos vitales, el cual mide la frecuencia cardiaca, la oxigenación sanguínea y la temperatura corporal de una persona. La información obtenida de cada signo vital es muestreada y procesada por una plataforma digital para posteriormente ser enviada mediante un módulo Bluetooth hacia un dispositivo móvil para su análisis y visualización. El prototipo fue evaluado mediante una batería de pruebas para medición de signos vitales en diferentes pacientes.

Ana?lisis cinemático de la marcha en pacientes con pie zambo tratados mediante el me?todo de Ponseti frente a la te?cnica quiru?rgica de liberacio?n posterior

OpenAIRE

Ferrando, A.; Salom Taverner, M.; Page, A.

2018-01-01

El objetivo principal de este proyecto consiste en valorar la evolución de la marcha en niños en edad preadolescente tratados mediante el método de Ponseti frente a los tratados mediante liberación posterior a partir de técnicas de valoración de la marcha mediante análisis biomecánico. Material y Métodos Estudio retrospectivo de casos y controles aprobado por el comité de ética. Grupo 1: 28 niños (39 pies) tratados mediante liberación posterior. Grupo 2: 18 pacientes (31 pies) tratados median...

The adsorption of hydrogen on a molecular sieve at -196{sup o}C and the observation of an isotope effect; Adsorption d'hydrogene sur un tamis moleculaire a -196{sup o}C et observation d'un effet isotopique; Absorbtsiya vodoroda na molekulyarnom fil'tre pri -196{sup o} i nablyudenie rezul'tatov dejstviya izotopov; Adsorcion de hidrogeno en un tamiz molecular a -196{sup o}C y observacion de un efecto isotopico

Energy Technology Data Exchange (ETDEWEB)

Duncombe, W G [Wellcome Research Laboratories, Beckenham, Kent (United Kingdom)

1962-03-15

tamis est utilise pour manipuler de petites quantites d'isotopes de l'hydrogene, etant donne qu'on procedera generalement a une desorption complete par chauffage. (author) [Spanish] El autor ha estudiado la posibilidad de utilizar un tamiz molecular Linde 4A como medio para manejar pequenos volumenes de isotopos del hidrogeno en un sistema de vacio, en sustitucion del lento metodo de la bomba de Toepler. Midio la presion de equilibrio (P) para varios volumenes (V) de hidrogeno adsorbido por un gramo de tamiz a -196{sup o} C. Los experimentos realizados con carbono activado demuestran la superioridad de tamiz como adsorbente de hidrogeno. En un sistema de 500 ml de volumen un gramo de tamiz adsorbe alrededor del 97 % de una muestra de hidrogeno de 1 ml. A -78{sup o} C la adsorcion es despreciable y a temperatura ambiente la desorcion es cuantitativa y rapida. El autor investigo la posibilidad de que se produzca un efecto isotopico adsorbiendo volumenes medidos de tritio (5 {mu}c/mol) a una presion de equilibrio de unos 5 mm, evacuando el sistema durante periodos de hasta 15 minutos, y midiendo el volumen de hidrogeno residual. Este ultimo se convirtio cuantitativamente en agua y despues en butano, cuya actividad se determino por recuento. La actividad especifica fue siempre superior a la del tritio que habia sufrido diez ciclos de adsorcion y desorcion sin bombeo intermedio, de forma que no hubiera perdida neta de gas. Este ultimo poseia la misma actividad especifica que el tritio no tratado procedente de la ampolla de almacenamiento. Se comprobo que el log (volumen residual/volumen inicial) era proporcional a 1/log (actividad especifica residual/actividad especifica inicial) en todo el intervalo estudiado (se extrajo por bombeo de 0 a 90 % de gas inicial). Despues de eliminar el 90 por ciento del gas, la razon de actividades especificas era del orden de 3. Es posible que se produzca un fraccionamiento isotopico durante la adsorcion, pero en estos experimentos se

Solar radiation in the Brazilian northeast

Energy Technology Data Exchange (ETDEWEB)

Tiba, Chigueru [Federal University of Pernambuco, Pernambuco (Brazil)

2000-07-01

actualmente y ciertamente comprende casi toda la informacion sobre recursos solares existentes (datos sobre radiacion solar y horas de sol) en Brasil. Se obtuvieron registros simultaneos de radiacion solar (medido por piranografos o piranometros) y horas de sol con heliografos en 35 diferentes lugares de la region noreste utilizando esta base de datos. Se colocaron los coeficientes a y b en los planos topograficos, cuyo alcance es la region noreste. Mediante el uso del metodo de interpolacion geoestadistico conocido como kriging, los valores de a y b fueron puestos en mapas de contorno, cubriendo la region noreste. Tambien se obtuvieron los mapas de error estimado del kriging. El objetivo general de este articulo es el de mejorar la cantidad de informacion actual existente sobre la radiacion solar en el noreste de Brasil. Con relacion a esto, los mapas de contorno de los coeficientes a y b han hecho posible estimar la radiacion solar en 82 localidades adicionales, en donde solo se disponia de los datos de las horas de sol.

Estudio de la reaccion de sulfurizacion de precursores Cu/In para la formacion de capas delgadas policristalinas de CuInS2 para celulas solares

OpenAIRE

Barcones Campo, Beatriz; Álvarez García, Jacobo; Calvo-Barrio, L.; Pérez Rodríguez, Alejandro; Romano Rodríguez, Alberto; Morante i Lleonart, Joan Ramon; Scheer, R.; Klenk, R.; Pietzker, Ch.

2004-01-01

En este trabajo se presenta un estudio detallado de los procesos implicados en la sulfurización de capas metálicas de Cu-In para la fabricación de células solares de CuInS2. Con este objeto, se ha desarrollado un experimento de sulfurización parcial de las capas, que han sido sometidas posteriormente a un tratamiento de selenización. El estudio de estas estructuras mediante Espectroscopía Raman y Espectroscopía de Electrones Auger (AES) ha permitido conocer algunos de los detalles de la reacc...

Caracterización espacial de PM10 en la ciudad de Medellín mediante modelos geoestadísticos

Directory of Open Access Journals (Sweden)

Libardo Antonio Londoño Ciro

2015-12-01

Full Text Available En este artículo se presenta un modelo geoestadístico para caracterizar espacialmente el comportamiento del contaminante PM10 en la ciudad de Medellín Colombia. Los datos se han tomado de nueve sitios de monitoreo en valor promedio mensual (µg/m3 durante el periodo enero 2003 a diciembre 2007. Se evaluaron diferentes modelos mediante pruebas de validación cruzada. El mejor modelo es el j-bessel. Se calculan los parámetros del modelo mediante pruebas ANOVA para agrupaciones trimestrales. Con Kriging ordinario y sistemas de información geográfica, se obtienen mapas de caracterización espacial del contaminante.

Protocolo de comunicación trabajador-robot mediante imágenes

OpenAIRE

Castilla Berduque, José Angel

2015-01-01

La idea del proyecto viene del concepto de “fábricas del futuro”, donde las barreras entre robots y humanos se rompen para que la colaboración entre ambos sea como en un equipo. Para la realización de este proyecto se ha utilizado el brazo robótico IRB120 de la marca ABB de 6 Grados de libertad, Matlab y el software Robot Studio. El Objetivo principal de este proyecto es establecer el protocolo de comunicación trabajador-robot mediante imágenes. El trabajador debería poder ...

Monitorización de un lecho fluidizado mediante acelerometría

OpenAIRE

Velasco Fernández, Mario

2013-01-01

El presente proyecto estudiará la posibilidad de monitorizar un reactor químico mediante sensores de vibración. Actualmente, no se realiza este tipo de monitorización sobre reactores químicos, y los estudios realizados al respecto son escasos. Se tratarán de establecer las posibles equivalencias entre las medidas realizadas con sensores de presión y de vibración. Para ello se realizará la monitorización de un modelo de reactor a escala, del laboratorio de la Universidad, utilizand...

Estabilización de Suelos mediante el empleo de Sales Cuaternarias

OpenAIRE

Juan M. Junco del Pino

2010-01-01

El Mundo se dirige hacia el aprovechamiento de los Suelos mediante el desarrollo de nuevas técnicas y adaptarse a las condiciones del entorno resulta importante para la Ingeniería. El mejoramiento de los suelos abre nuevas posibilidades de ahorro que pueden llegar de 20 a 45 % respecto a los costos de construcción convencional. La Estabilización Química de Suelos consiste en el empleo de sustancias químicas con el objetivo de modificar las propiedades del suelo para hacerlo más denso o increm...

Tratamiento de un efluente textil mediante electrooxidación-Salix babylonica

OpenAIRE

Sánchez Sánchez, Hilda Alejandra

2016-01-01

A nivel mundial, la industria textil es considerada una de las principales fuentes de descarga que afectan la calidad del agua debido al gran volumen que emplea en sus procesos y al uso de una amplia gama de colorantes sintéticos. En esta investigación se evaluó el tratamiento de un agua residual textil mediante un sistema acoplado de electrooxidación-Salix babylonica usando electrodos DDB. En el estudio, se construyó una celda electroquímica en batch, utilizando 5 electrodos paralelos vertic...

Lqr Robusto Mediante Incertidumbre Acotada En Los Datos

Directory of Open Access Journals (Sweden)

C. Ramos

2007-07-01

Full Text Available Resumen: En este trabajo se presenta el sintonizado del Regulador Lineal Cuadrático (LQR mediante la técnica de incertidumbre acotada en los datos o Bounded Data Uncertainties (BDU con el fin de mejorar la robustez del sistema, planteándose como un Min-Max donde se busca la mejor solución en el peor escenario posible. Así se ofrece un nuevo método guiado de ajuste del LQR, considerando los límites de la incertidumbre. La aplicación a sistemas multidimensionales no es trivial, pues presenta la forma de un Two-Point Boundary Value Problem (TPBVP, el cual se resuelve iterativamente. : Técnicas Minimax, Regularización, Método de Control LQR, Robustez, Incertidumbre, Ecuaciones Matriciales de Riccati, Problema de Valor Límite, Sistemas Multidimensionales

PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

Directory of Open Access Journals (Sweden)

M. Norhafana

2015-11-01

Full Text Available Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of a solar water heating system as well as to evaluate the performance of the solar collector in terms of useful heat of the multilayered absorber using the multidirectional ability of a solar simulator at several values of solar radiation. It is operated at three variables of solar radiation of 400 W/m2, 550 W/m2 and 700 W/m2 and using three different positions of angles at 0º, 45º and 90º. The results show that the multilayer absorber in the solar collector is only able to best adapt at 45° of solar simulator with different values of radiation intensity. At this angle the maximum values of useful heat and temperature difference are achieved. KEYWORDS: solar water heating system; solar collector; multilayered absorber; solar simulator; solar radiation 

Coupled solar still, solar heater

Energy Technology Data Exchange (ETDEWEB)

Davison, R R; Harris, W B; Moor, D H; Delyannis, A; Delyannis, E [eds.

1976-01-01

Computer simulation of combinations of solar stills and solar heaters indicates the probable economic advantage of such an arrangement in many locations if the size of the heater is optimized relative to that of the still. Experience with various low cost solar heaters is discussed.

The solarPACES strategy for the solar thermal breakthrough

International Nuclear Information System (INIS)

Burch, G.D.; Grasse, W.

1997-01-01

IEA(International Energy Agency)/SolarPACES(Solar Power and Chemical Energy systems)represents a world wide coalition for information sharing and collaboration on applications of concentrated solar energy. The current SolarPACES community has built up solar thermal system know-how over 15 years, is operating the three main solar test centres in the world. Its main activities are in the following four fields: solar thermal electric power systems, solar chemistry, solar technology and advanced applications and non-technical activities. The article presents the talk on the strategy of solarPACES given at the International Workshop on applied solar energy held in Tashkent(Uzbekistan) in June 1997. (A.A.D.)

Solar Market Research and Analysis | Solar Research | NREL

Science.gov (United States)

Analysis Solar Market Research and Analysis Through rigorous data collection, analysis, and stakeholder engagement, NREL's Solar Market Research and Analysis efforts further solar technologies' role in solar panels. Key areas for NREL's solar market research and analysis portfolio include the following

PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

OpenAIRE

M. Norhafana; Ahmad Faris Ismail; Z. A. A. Majid

2015-01-01

Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of...

Solar building

OpenAIRE

Zhang, Luxin

2014-01-01

In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

Concentrated solar power generation using solar receivers

Science.gov (United States)

Anderson, Bruce N.; Treece, William Dean; Brown, Dan; Bennhold, Florian; Hilgert, Christoph

2017-08-08

Inventive concentrated solar power systems using solar receivers, and related devices and methods, are generally described. Low pressure solar receivers are provided that function to convert solar radiation energy to thermal energy of a working fluid, e.g., a working fluid of a power generation or thermal storage system. In some embodiments, low pressure solar receivers are provided herein that are useful in conjunction with gas turbine based power generation systems.

KINETIC BEHAVIOR IN THE HYDROGENATION OF FURFURAL OVER Ir CATALYSTS SUPPORTED ON TiO2

Directory of Open Access Journals (Sweden)

HUGO ROJAS

2010-01-01

Full Text Available La cinética de la hidrogenación en fase líquida de furfural a alcohol furfurilico sobre catalizadores de Ir/TiO2 se estudio en el rango de temperaturas de 323 a 373 K, también se estudio el efecto de la concentración de furfural, presión de hidrogeno y del solvente empleado. Se obtuvo una alta selectividad hacía el alcohol furfurilico. Con las velocidades iníciales de reacción se determino el orden de reacción global. Los datos experimentales pueden también explicarse usando un modelo LangmuirHinshelwood considerando un solo tipo de sitio activo con adsorción disociativa de hidrogeno, siendo la reacción superficial la etapa limitante de la reacción, este modelo se ajusta a los datos experimentales.

A solar neutrino loophole: standard solar models

Energy Technology Data Exchange (ETDEWEB)

Rouse, C A [General Atomic Co., San Diego, Calif. (USA)

1975-11-01

The salient aspects of the existence theorem for a unique solution to a system of linear of nonlinear first-order, ordinary differential equations are given and applied to the equilibrium stellar structure equations. It is shown that values of pressure, temperature, mass and luminosity are needed at one point - and for the sun, the logical point is the solar radius. It is concluded that since standard solar model calculations use split boundary conditions, a solar neutrino loophole still remains: solar model calculations that seek to satisfy the necessary condition for a unique solution to the solar structure equations suggest a solar interior quite different from that deduced in standard models. This, in turn, suggests a theory of formation and solar evolution significantly different from the standard theory.

Estimating Monthly Solar Radiation in South-Central Chile Estimación de Radiación Solar Mensual en la Zona Centro Sur de Chile

Directory of Open Access Journals (Sweden)

José Álvarez

2011-12-01

mensual para la región centro sur de Chile mediante el uso del modelo r.sun y se validó con observaciones de estaciones meteorológicas automáticas. Se analizó el desempeño de los resultados de la irradiación global con los modelos Hargreaves-Samani (HS y Bristol-Campbell (BC. Las estimaciones del modelo calibrado r.sun explican un 89% de la varianza (r² = 0.89 en valores medios mensuales observados. El modelo se comportó muy bien para una amplia zona de las condiciones de Chile, comparados con los modelos HS y BC. Nuestras estimaciones de la radiación global utilizando el modelo r.sun podrían ser mejoradas aún más con una posterior calibración a partir de observaciones y una mejor estimación de la nubosidad en la medida que estén disponibles. Con procedimientos adicionales, el modelo r.sun podría ser utilizado para proporcionar estimaciones espaciales de la radiación solar diaria, semanal, mensual, y anual.

Evaluación de pretratamientos químicos para la hidrólisis enzimática de residuos lignocelulósicos de yuca (Manihot esculenta Crantz

Directory of Open Access Journals (Sweden)

Lilibeth Niño López

2013-01-01

Full Text Available El efecto de diferentes pretratamientos químicos con ácido sulfúrico (H2SO4, hidróxido de sodio (NaOH y peróxido de hidrogeno (H2O2, fueron evaluados mediante la cuantificación de azucares reductores totales producidos durante la etapa de hidrólisis enzimática de los residuos lignocelulósicos de yuca (Manihot esculenta Crantz y el porcentaje (% de remoción de lignina después del pretratamiento. La cantidad de residuos utilizados (1 y 5% (w/v a diferentes tamaños de partícula (1,18 y 0,6mm fueron pretratados por separado (hojas y tallos con H2SO4, NaOH y H2O2 a diferentes concentraciones (1 y 5% (w/v. Los residuos vegetales fueron hidrolizados con la enzima accellerase 1500 a 50°C, pH 5 y 140 rpm. El pretratamiento con NaOH permite la mayor liberación de azucares reductores totales durante la hidrólisis enzimática (3,7g/L en hojas seguido del pretratamiento con H2SO4 (2,11g/L y H2O2 (1,54g/L. En tallos las concentraciones de azúcares son menores.

Solar Systems

Science.gov (United States)

1979-01-01

The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

Biohydrogen production from diary processing wastewater by anaerobic biofilm reactors

Energy Technology Data Exchange (ETDEWEB)

Rios-Gonzalez, L.J.; Moreno-Davila, I.M.; Rodriguez-Martinez, J.; Garza-Garcia, Y. [Universidad Autonoma de Coahuila, Saltillo, Coahuila (Mexico)]. E-mail: leopoldo.rios@mail.uadec.mx

2009-09-15

to be employed for hydrogen production. [Spanish] Este articulo describe la produccion biologica de hidrogeno a partir de agua residual diaria via fermentacion anaerobica utilizando choque termico pretratado (100 grados centigrados, 30 min.) y procedimientos de tratamiento acido para enriquecer selectivamente el hidrogeno produciendo consorcios mezclados antes de la inoculacion de reactores por lote. El biorreactor empleado para el consorcio de inmovilizacion se opero a temperatura mesofilica (ambiente) (20{+-}3 grados centigrados), bajo condiciones acidofilicas (pH 4.0-4.5), HRT (2h), y un soporte natural para generar hidrogeno produciendo biopelicula de consorcios mezclados: Opuntia imbricata. El reactor se opero inicialmente con sorbitol (5g/L) durante 60 dias de operacion. Las pruebas de lote se llevaron a cabo empleando 20{+-}0.02g de soporte natural con biopelicula. Los experimentos de lote se realizaron para investigar el efecto de la DQO ((2.9-21.1 g-DQO/L), a pH inicial de 7.0, 32{+-}1 grados centigrados. La produccion maxima de hidrogeno se obtuvo a 21.1 g-COD/L. Se efectuaron experimentos del efecto del pH empleando una concentracion de sustrato optima (21.2 g-COD/L), a pH de 4 a 7 y 11.32 (pH de agua residual diaria) y 32{+-}1 grados centigrados. Los resultados de los experimentos indican que el cultivo inicial optimo fue de pH 4.0, pero podemos considerar tambien una produccion estable de hidrogeno a pH 11.32 (pH de agua residual diaria), por lo que se pudo evitar ajustar el pH, y usar agua residual diaria como queda en el proceso de produccion de queso. El pH operacional de 4.0 esta 1.5 unidades por debajo del reportado antes correspondiente al hidrogeno que producen los organismos. La influencia del efecto de la temperatura se realizo usando la concentracion de sustrato optima (21.2 g-COD/L), dos niveles de pH: 4.0 y 11.32, y cuatro diferentes temperaturas: 16{+-}3 grados centigrados (temperatura ambiente), 32{+-}1 grados centigrados, 45{+-}1 grados

Solar electricity and solar fuels

Science.gov (United States)

Spiers, David J.

1989-04-01

The nature of solar radiation and its variation with location is described. The distribution of energy in the solar spectrum places immediate limits on the theoretical efficiency of conversion processes, since practical absorbers cannot convert all wavelengths received to useful energy. The principles of solar energy conversion methods are described. Absorption of solar energy can give rise to direct electrical generation, heating, or chemical change. Electrical generation from sunlight can be achieved by photovoltaic systems directly or by thermal systems which use solar heat to drive a heat engine and generator. The technology used and under research for promising ways of producing electricity or fuel from solar energy is described. Photovoltaic technology is established today for remote area, small power applications, and photovoltaic module sales alone are over 100 million dollars per year at present. The photovoltaic market has grown steadily since the mid-1970's, as prices have fallen continuously. Future energy options are briefly described. The merits of a sustainable energy economy, based on renewable energy resources, including solar energy, are emphasized, as this seems to provide the only hope of eliminating the problems caused by the build-up of atmospheric carbon dioxide, acid rain pollution and nuclear waste disposal. There is no doubt that clean fuels which were derived from solar energy and either did not involve carbon dioxide and used atmospheric carbon dioxide as the source dioxide as the source of carbon would be a worthy ideal. Methods described could one day achieve this.

Solar irridiance variations and solar activity

International Nuclear Information System (INIS)

Willson, R.C.

1982-01-01

A mean value for the 1 AU total solar irradiance of 1368.2 W/m 2 and a downward trend of 0.05% per year were derived from measurements by the Active Cavity Radiometer Irradiance Monitor (ACRIM) experiment on the Solar Maximum Mission during 1980. Distinct temporary solar irradiance decreases associated with solar activity maxima were observed with a series of nine dips from April to October recurring at fairly regular intervals averaging 24 days. The decreases correlate inversely with sunspot area, 2800-MHz flux, and Zurich sunspot number. Dominant periods common to the irradiance and sunspot area power spectra link the irradiance decreases to sunspot flux deficit in solar active regions. Evidence of significant total irradiance modulation by facular flux excess is cited. A persistent radiative cycle of active regions consistent with the ACRIM irradiance results and the morphology of solar active regions was found. The pattern of regularly recurrent active region maxima between April and October suggests an asymmetry in solar activity generation during this period

Solar Training Network and Solar Ready Vets

Energy Technology Data Exchange (ETDEWEB)

Dalstrom, Tenley Ann

2016-09-14

In 2016, the White House announced the Solar Ready Vets program, funded under DOE's SunShot initiative would be administered by The Solar Foundation to connect transitioning military personnel to solar training and employment as they separate from service. This presentation is geared to informing and recruiting employer partners for the Solar Ready Vets program, and the Solar Training Network. It describes the programs, and the benefits to employers that choose to connect to the programs.

Solar Indices - Solar Flares

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

Solar Indices - Solar Ultraviolet

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

Solar Indices - Solar Corona

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

Solar Indices - Solar Irradiance

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

Design and energetical feasibility study of a refrigerated trailer with photovoltaic solar energy; Diseno y estudio de viabilidad energetica de un trailer refrigerado mediante energia solar fotovoltaica

Energy Technology Data Exchange (ETDEWEB)

Callen, S.; Ibanez, M.; Cabeza, L. F.

2004-07-01

In this study we have tried to show the energetic viability and the design of a refrigerated trailer, in which it has changed the traditional oil generator from the refrigeration system to a photovoltaic generator. Due to restrictions of design limited by trailer dimensions and the horizontal positions of modules, as one of the first conclusion has been necessary to reduce the refrigeration charge, to obtain the necessary energy savings to have technical viability of the project. The propositions to get the energy savings are to improve the thermal insulation of the trailer and to limit the kind and amount of products to transport. Finally, to apply the technology of solar refrigeration in the cooling unit of the trailer to optimise its performance. (Author)

Solar air conditioning. Dresden colloquium; Solare Klimatisierung. Dresdner Kolloquium

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

Subjects: R + D activities in solar air conditioning; dessicative and evaporative cooling (DEC) - systems and components; Chances of solar air conditioning in Europe; Practical experience with solar-assisted air conditioning; Performance of a solar system at Lissabon; DEC system in the Alsenblock building, Berlin; Does solar air conditioning require specially designed buildings; Performance of solar heated adsorption refrigerators; Low-capacity absacity absorption systems for solar air conditioning. [German] Die Kolloquiumsschrift beinhaltet Unterlagen ueber die abgehandelten Themen. Sie lauten: F and E-Aktivitaeten im Bereich Solare Klimatisierung; SGK(DEC-Technik) - ausgefuehrte Anlagen und deren Komponenten; Chancen der solaren Klimatisierung in Europa; Erfahrungen mit der solarunterstuetzten Klimatisierung; Energieverbrauch und Regelung von SGK-Anlagen; Betriebserfahrungen einer Solaranlage in Lissabon; Realisierung der SGK im Alsenblock Berlin; Erfordert die solare Klimatisierung besondere Gebaeude?; Betriebserfahrungen mit solar beheizten Adsorptionskaeltemaschinen; Absorptionsanlagen kleiner Leistung fuer solare Klimatisierung. (orig.)

Solar charge controller in solar street light

OpenAIRE

Dong, Haibo

2014-01-01

Recently, with the rapid development of scientific technology, the conventional energy cannot meet the requirement of human beings. People are looking for the utilization of renew energy. Solar en-ergy as a new clean energy has attract the eyes of people. The applications of solar energy are popular to human society. Solar street light is a good example. This thesis will focus on a deeper research of the popular and ubiquitous solar street light in China. However, solar charge controll...

The 3-D solar radioastronomy and the structure of the corona and the solar wind. [solar probes of solar activity

Science.gov (United States)

Steinberg, J. L.; Caroubalos, C.

1976-01-01

The mechanism causing solar radio bursts (1 and 111) is examined. It is proposed that a nonthermal energy source is responsible for the bursts; nonthermal energy is converted into electromagnetic energy. The advantages are examined for an out-of-the-ecliptic solar probe mission, which is proposed as a means of stereoscopically viewing solar radio bursts, solar magnetic fields, coronal structure, and the solar wind.

Encapsulación de moléculas pequeñas mediante la precipitación salina de poliuretanos catioméricos

OpenAIRE

Fernández d’Arlas, Borja; Corcuera, María Ángeles; Eceiza, Arantxa

2015-01-01

En este trabajo se estudia un copolímero de poliuretano catiomérico (PU) con alta proporción de uretano como agente encapsulante de fármacos modelos (FM) mediante la encapsulación inducida por precipitación salina del PU y FM a pH < pI del PU. Mediante espectroscopia UV-Vis se ha estimado el porcentaje de encapsulación de varios FMs proponiéndose un modelo semi-empírico para determinar la distribución observada en las eficiencias de encapsulación, E, en función de su volumen molar...

Collecting Solar Energy. Solar Energy Education Project.

Science.gov (United States)

O'Brien, Alexander

This solar energy learning module for use with junior high school students offers a list of activities, a pre-post test, job titles, basic solar energy vocabulary, and diagrams of solar energy collectors and installations. The purpose is to familiarize students with applications of solar energy and titles of jobs where this knowledge could be…

Solar energy

International Nuclear Information System (INIS)

Anon.

1992-01-01

This chapter discusses the role solar energy may have in the energy future of the US. The topics discussed in the chapter include the solar resource, solar architecture including passive solar design and solar collectors, solar-thermal concentrating systems including parabolic troughs and dishes and central receivers, photovoltaic cells including photovoltaic systems for home use, and environmental, health and safety issues

Utilización de Imágenes GOES en el Cálculo de Radiación Solar en la Región Sur del Ecuador

OpenAIRE

Álvarez Hernández, Orlando Hilarión

2014-01-01

Se presenta una aproximación a la radiación solar posible a obtener en las provincias de El Oro, Loja y Zamora Chinchipe, Región Sur de Ecuador (RSE) utilizando imágenes del Satélite Geoestacionario GOES-Este, y los datos de radiación global obtenidos en una red de cinco estaciones automáticas ubicada en la RSE a partir de las cuales se obtuvo un modelo teórico, mediante análisis de regresión múltiple entre las bandas RGB (Red, Green, Blue) de las imágenes Visible e Infrarroja del GOES y los ...

Solar Innovation Infographic | Solar Research | NREL

Science.gov (United States)

Innovation Infographic Solar Innovation Infographic Scientists have been working to harness power from the sun for about 200 years. Over the past 40 years, solar energy technologies have made research developments and industry milestones that helped shape our U.S. solar industry. Infographic Embed

Geometry of solar corona expansion and solar wind parameters

International Nuclear Information System (INIS)

Krajnev, M.B.

1980-01-01

The character of the parameter chanqe of solar wind plasma in the region of the Earth orbit is studied. The main regularities in the parametep behaviour of solar wind (plasma velocity and density) are qualitatively explained in the framework of a model according to which solar corona expansion stronqly differs from radial expansion, that is: the solar wind current lines are focused towards helioequator during the period of low solar activity with gradual transfer to radial expansion during the years of high solar activity. It is shown that the geometry of the solar wind current tubes and its change with the solar activity cycle can not serve an explanation of the observed change of the solar wind parameters

Control de la mano robot Inmoov-SR mediante casco NeuroSky Mindset

OpenAIRE

Hernández Martínez, Antonio

2017-01-01

En este trabajo el objetivo es conseguir controlar los movimientos de apertura y cierre de la mano robot InMoov-SR conectada al brazo IRB120 de ABB mediante señales EEG, recogidas por medio del casco NeuroSky Mindset. Las señales son recogidas cuando el sujeto está en estado basal y cuando realiza movimiento con su mano y son procesadas con la ayuda de Matlab para de esta manera conseguir establecer las señales de control necesarias para activar la apertura o el cierre de la mano. Final...

Parameterization models for solar radiation and solar technology applications

Energy Technology Data Exchange (ETDEWEB)

Khalil, Samy A. [National Research Institute of Astronomy and Geophysics, Solar and Space Department, Marsed Street, Helwan, 11421 Cairo (Egypt)

2008-08-15

Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined. (author)

Parameterization models for solar radiation and solar technology applications

International Nuclear Information System (INIS)

Khalil, Samy A.

2008-01-01

Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined

Variation of the solar wind velocity following solar flares

International Nuclear Information System (INIS)

Huang, Y.; Lee, Y.

1975-01-01

By use of the superposed epoch method, changes in the solar wind velocity following solar flares have been investigated by using the solar wind velocity data obtained by Pioneer 6 and 7 and Vela 3, 4, and 5 satellites. A significant increase of the solar wind velocity has been found on the second day following importance 3 solar flares and on the third day following importance 2 solar flares. No significant increase of the solar wind velocity has been found for limb flares. (auth)

Solar Market Research and Analysis Projects | Solar Research | NREL

Science.gov (United States)

Market Research and Analysis Projects Solar Market Research and Analysis Projects Solar market research and analysis efforts at NREL seek to further solar technologies' role in supporting a more . Midscale Commercial Market Solar Analysis NREL experts are providing analysis to expand the midscale solar

Solar energy

Science.gov (United States)

Rapp, D.

1981-01-01

The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

Solar Combisystems

DEFF Research Database (Denmark)

Thür, Alexander

2006-01-01

This note first introduces what is a solar combisystem, the structure how a solar combisystem is build up and what are criteria’s to evaluate a solar combisystem concept. Further on the main components of a solar combisystem, the main characteristics and possible advantages and disadvantages...... compared to each other are described. It is not the goal of this note to explain the technical details how to design all components of a solar combisystem. This is done during other lectures of the solar course and in other basic courses as well. This note tries to explain how a solar combisystem...

Solar energy

International Nuclear Information System (INIS)

Kruisheer, N.

1992-01-01

In five brief articles product information is given on solar energy applications with special attention to the Netherlands. After an introduction on solar energy availability in the Netherlands the developments in solar boiler techniques are dealt with. Solar water heaters have advantages for the environment, and government subsidies stimulate different uses of such water heaters. Also the developments of solar cells show good prospects, not only for developing countries, but also for the industrialized countries. In brief the developments in solar energy storage and the connection of solar equipment to the grid are discussed. Finally attention is paid to the applications of passive solar energy in the housing construction, the use of transparent thermal insulation and the developments of translucent materials. 18 figs., 18 ills

Hydrogen production through nuclear energy, a sustainable scenario in Mexico; Produccion de hidrogeno mediante energia nuclear, un escenario sostenible en Mexico

Energy Technology Data Exchange (ETDEWEB)

Ortega V, E.; Francois L, J.L. [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Laboratorio de Analisis en Ingenieria de Reactores Nucleares, Paseo Cuauhnahuac 8532, Jiutepec, Morelos (Mexico)]. e-mail: iqoren@gmail.com

2007-07-01

The energy is a key point in the social and economic development of a country, for such motive to assure the energy supply in Mexico it is of vital importance. The hydrogen it is without a doubt some one of the alternating promising fuels before the visible one necessity to decentralize the energy production based on hydrocarbons. The versatility of their applications, it high heating power and having with the more clean fuel cycle of the energy basket with which count at the moment, they are only some examples of their development potential. However the more abundant element of the universe it is not in their elementary form in our planet, it forms molecules like in the hydrocarbons or water and it stops their use it should be extracted. At the present time different methods are known for the extraction of hydrogen, there is thermal, electric, chemical, photovoltaic among others. The election of the extraction method and the primary energy source to carry out it are decisive to judge the sustainability of the hydrogen production. The sustainable development is defined as development that covers the present necessities without committing the necessity to cover the necessities of the future generations, and in the mark of this definition four indicators of the sustainable development of the different cycles of fuel were evaluated in the hydrogen production in Mexico. These indicators take in consideration the emissions of carbon dioxide in the atmosphere (environment), the readiness of the energy resources (technology), the impacts in the floor use (social) and the production costs of the cycles (economy). In this work the processes were studied at the moment available for the generation of hydrogen, those that use coal, natural gas, hydraulic, eolic energy, biomass and nuclear, as primary energy sources. These processes were evaluated with energy references of Mexico to obtain the best alternative for hydrogen production. (Author)

Golden Rays - July 2017 | Solar Research | Solar Research | NREL

Science.gov (United States)

, subscribe to the Solar Newsletter. SUBSCRIBE Hot Topics Two solar installers secure solar panels on the roof that has the potential to improve the efficiency of solar panels while leveraging existing

La participación de los trabajadores en el capital social mediante operaciones de asistencia financiera. Especial referencia al art. 81.2 LSA

OpenAIRE

Nieto Rojas, Patricia

2007-01-01

La integración de los trabajadores en el capital social puede ser instrumentada mediante diferentes vías: distribución gratuita de acciones, entrega de opciones sobre acciones o mediante la asistencia financiera para la adquisición de acciones; el objetivo del presente artículo es analizar las implicaciones laborales de este último mecanismo previsto en el artículo 81.2 LSA que exceptúa de la prohibición general de asistencia financiera a los negocios dirigidos a facilitar la adquisición de a...

Películas orgánicas delgadas preparadas mediante diversos métodos: propiedades ópticas, morfológicas y eléctricas

OpenAIRE

Pérez-Morales, M.

2005-01-01

En la presente Memoria se estudia la organización molecular de compuestos orgánicos, tales como derivados de porfirinas y C60, en películas de Langmuir formadas en la interfase aire-agua. Asimismo, se han depositado películas de derivados de porfirina sobre electrodos ITO mediante métodos electroquímicos. Por último, se han estudiado las propiedades fluorescentes de películas de porfirina preparadas mediante diversos métodos, para su posterior aplicación a la preparación de dispositivos elect...

Estudio de la recuperación de cromo hexavalente mediante un reactor electroquímico de compartimentos separados por separadores cerámicos

OpenAIRE

REYES PINEDA, HENRY

2011-01-01

La Tesis Doctoral "Estudio de la recuperación de cromo hexavalente mediante un reactor electroquímico de compartimentos separados por separadores cerámicos" se centra en la posibilidad de recuperación del cromo hexavalente procedente de las disoluciones de mordentado de las industrias de metalizado de plásticos mediante la utilización de un reactor electroquímico de compartimentos separados por separadores cerámicos fabricados a diferente presión y diferente composición de almidón. Con la rec...

Valoración nutricional mediante curvas de crecimiento de la OMS y las clasificaciones de Gómez / Waterlow. Estudio de prevalencia. Cuenca-2015

OpenAIRE

Chacón Abril, Karla Lorena; Segarra Ortega, José Xavier; Lasso Lazo, Rubén Santiago; Huiracocha Tutivén, María de Lourdes

2016-01-01

OBJETIVO:Determinar la prevalencia de malnutrición mediante las curvas de crecimiento (OMS) y de desnutrición según la clasificación Gómez/Waterlow; establecer ventajas y desventajas del empleo de ambos sistemas de clasificación.MÉTODOS:Estudio de prevalencia realizado en el Subcentro de Salud Sinincay, con una población de 737 niños/as registrados en la matriz de vigilancia alimentaria y nutricional (SIVAN) durante Enero-Junio 2015, que identificó la malnutrición infantil mediante el uso de ...

Superficie específica de una bentonita mediante la adsorción de azul de metileno

OpenAIRE

Pinzón Bello, Jorge Alejo

2010-01-01

Se estudió la determinación de la superficie específica de una bentonita colombiana, procedente del Valle del Cauca, mediante la adsorción de azul de metileno, a 298 K. Este método se comparó con el de la adsorción de nitrógeno a 77 K.

Solar Special

International Nuclear Information System (INIS)

Van Roekel, A.; Osborne, J.; Schroeter, S.; De Jong, R.; De Saint Jacob, Y.

2009-01-01

Solar power is growing much faster than most policymakers and analysts realise. As costs come down and feed-in tariffs go up across Europe, a number of countries have started in pursuit of market leader Germany. But in Germany criticism is growing of the multi-billion-euro support schemes that keep the solar industry booming. In this section of the magazine several articles are dedicated to developments in solar energy in Europe. The first article is an overview story on the strong growing global market for solar cells, mainly thanks to subsidy schemes. The second article is on the position of foreign companies in the solar market in Italy. Article number three is dedicated to the conditions for solar technology companies to establish themselves in the German state of Saxony. Also the fifth article deals with the development of solar cells in Saxony: scientists, plant manufacturers and module producers in Saxony are working on new technologies that can be used to produce solar electricity cost-effectively. The goal is to bring the price down to match that of conventionally generated electricity within the next few years. The sixth article deals with the the solar power market in Belgium, which may be overheated or 'oversubsidized'. Article seven is on France, which used to be a pioneer in solar technology, but now produces only a fraction of the solar output of market leader Germany. However, new attractive feed-in-tariffs are changing the solar landscape drastically

Solar Indices - Solar Radio Flux

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

Control mediante modos deslizantes en tiempo discreto para el seguimiento de trayectorias de un robot móvil1

Directory of Open Access Journals (Sweden)

P.A. Niño-Suárez

2007-10-01

Full Text Available Resumen: En este trabajo se presenta una estrategia de control en tiempo discreto para el seguimiento de trayectorias de un robot móvil tipo (2,0 controlado remotamente. La estrategia de control se desarrolló mediante un enfoque de modos deslizantes, considerando el modelo discreto exacto del vehículo en el cual se incluyen los efectos del retardo de transporte causado por la propagación de las señales sobre una red de comunicación. El esquema de control garantiza el seguimiento de trayectorias predeterminadas obteniéndose convergencia asintótica de los errores de seguimiento. La estrategia propuesta es evaluada mediante una serie de resultados por simulación. Palabras clave: Robot móvil, retardos de transporte, control en tiempo discreto, modos deslizantes

Variations in Solar Parameters and Cosmic Rays with Solar Magnetic Polarity

Energy Technology Data Exchange (ETDEWEB)

Oh, S. [Department of Earth Science Education, Chonnam National University, Gwangju, 61186 (Korea, Republic of); Yi, Y., E-mail: suyeonoh@jnu.ac.kr [Department of Astronomy, Space Science and Geology, Chungnam National University, Daejeon, 34134 (Korea, Republic of)

2017-05-01

The sunspot number varies with the 11-year Schwabe cycle, and the solar magnetic polarity reverses every 11 years approximately at the solar maximum. Because of polarity reversal, the difference between odd and even solar cycles is seen in solar activity. In this study, we create the mean solar cycle expressed by phase using the monthly sunspot number for all solar cycles 1–23. We also generate the mean solar cycle for sunspot area, solar radio flux, and cosmic ray flux within the allowance of observational range. The mean solar cycle has one large peak at solar maximum for odd solar cycles and two small peaks for most even solar cycles. The odd and even solar cycles have the statistical difference in value and shape at a confidence level of at least 98%. For solar cycles 19–23, the second peak in the even solar cycle is larger than the first peak. This result is consistent with the frequent solar events during the declining phase after the solar maximum. The difference between odd and even solar cycles can be explained by a combined model of polarity reversal and solar rotation. In the positive/negative polarity, the polar magnetic field introduces angular momentum in the same/opposite direction as/to the solar rotation. Thus the addition/subtraction of angular momentum can increase/decrease the motion of plasma to support the formation of sunspots. Since the polarity reverses at the solar maximum, the opposite phenomenon occurs in the declining phase.

Manejo sostenible y sustentable de fincas productoras mediante procesos participativos en Sáchica, Boyacá

Directory of Open Access Journals (Sweden)

Ángel Eduardo Ramírez-Amaya

2013-07-01

Full Text Available Objetivo. Elaborar un proyecto de desarrollo sostenible y sustentable de fincas productoras mediante procesos participativos en el municipio de Sáchica, Boyacá. Materiales y métodos. La investigación se realizó con familias campesinas de la vereda Arrayán Alto, del municipio de Sáchica, Boyacá, mediante la metodología Investigación Acción Participativa (IAP, que se centra en la participación de las comunidades para elaborar propuestas concertadas con ellas. El trabajo se desarrolló en varias fases, que incluyeron un diagnóstico socioeconómico de las familias, capacitaciones y concientización en temas relacionados con la agricultura ecológica y de granjas integrales. Resultados. Se elaboró un plan de trabajo que permitió la construcción de un documento final que ha servido para el apoyo logístico o económico de las entidades gubernamentales locales para la instalación y plantación técnica del cultivo de gulupa con familias de la vereda Arrayán Alto.

Solar Proton Events in Six Solar Cycles

Science.gov (United States)

Vitaly, Ishkov

Based on materials the catalogs of solar proton events (SPE) in 1955 ‒ 2010 and list SPE for the current 24 solar cycle (SC) are examined confirmed SPE with E> 10 MeV proton flux in excess of 1 proton cm-2 s ster-1 (pfu) from Švestka and Simon’s (1955 - 1969) and 5 volumes Logachev’s (1970 - 2006) Catalogs of SPE. Historically thus it was formed, that the measurements of the proton fluxes began in the epoch “increased” solar activity (SC 18 ‒ 22), and includes transition period of the solar magnetic fields reconstruction from epoch “increased” to the epoch “lowered” solar activity (22 ‒ 23 SC). In current 24 SC ‒ first SC of the incipient epoch of “lowered” SA ‒ SPE realize under the new conditions, to that of previously not observed. As showed a study of five solar cycles with the reliable measurements of E> 10 MeV proton flux in excess of 1 pfu (1964 - 2013): ‒ a quantity of SPEs remained approximately identical in SC 20, 21, somewhat decreased in the initial solar cycle of the solar magnetic fields reconstruction period (22), but it returned to the same quantity in, the base for the period of reconstruction, SC 23. ‒ Into the first 5 years of the each solar cycle development the rate of the proton generation events noticeably increased in 22 cycles of solar activity and returned to the average in cycles 23 and 24. ‒ Extreme solar flare events are achieved, as a rule, in the solar magnetic fields reconstruction period (August - September 1859; June 1991; October ‒ November 2003.), it is confirmed also for SPE: the extreme fluxes of solar protons (S4) except one (August 1972) were occurred in period of perestroika (SC 22 and 23). This can speak, that inside the epochs SA, when the generation of magnetic field in the convective zone works in the steady-state regime, extreme SPE are improbable. ‒ The largest in the fluxes of protons (S3, S4) occur in the complexes of the active regions flare events, where magnetic field more

EL APRENDIZAJE DE LOS CONCEPTOS DE FUERZAS INTERMOLECULARES E INTRAMOLECULARES MEDIANTE LA MODELIZACIÓN DIDÁCTICA

Directory of Open Access Journals (Sweden)

CHRISTIAN FERNNEY GIRALDO MACÍAS

2013-07-01

Full Text Available La modelización está siendo usada para la enseñanza y el aprendizaje en las Ciencias Naturales en diferentes contextos y para atender a diferentes problemáticas. En este caso será utilizada para explorar y analizar la relevancia que puede tener su uso en el aprendizaje de los conceptos Fuerzas Intramoleculares e Intermolecualres, partiendo de la aplicación de una serie de actividades basadas en el Ciclo Didáctico (Jorba y Sanmartí, 1996. Los datos se discuten mediante tres aspectos principales: las ideas previas de los estudiantes, el trabajo con nuevo material (nuevos conceptos, experimentos sencillos y uso de herramientas informáticas y los argumentos finales, mediante el uso de situaciones problemas. Los resultados muestran, como los estudiantes (14 y 16 años de edad evidencian un progreso conceptual al argumentar con mayor claridad las situaciones problema abordadas en el transcurso del trabajo y en la construcción de modelos más cercanos al campo científico.

Anuncian primera produccion controlada de anti-atomos frios

CERN Document Server

2002-01-01

"Un equipo internacional que trabaja con el desacelerador de antiprotones del CERN, en Ginebra, ha conseguido la primera produccion controlada de miles de atomos de hidrogeno de baja energia, lo que facilitara en el futuro los analisis de precision en varias disciplinas cientificas" (1 page).

Early solar physics

CERN Document Server

Meadows, A J

1970-01-01

Early Solar Physics reviews developments in solar physics, particularly the advent of solar spectroscopy and the discovery of relationships between the various layers of the solar atmosphere and between the different forms of solar activity. Topics covered include solar observations during 1843; chemical analysis of the solar atmosphere; the spectrum of a solar prominence; and the solar eclipse of December 12, 1871. Spectroscopic observations of the sun are also presented. This book is comprised of 30 chapters and begins with an overview of ideas about the sun in the mid-nineteenth century, fo

Aplicación de técnicas de electrodeposición mediante pulsos de corriente para la obtención de recubrimientos metálicos

OpenAIRE

Imaz Molina, Naroa

2013-01-01

En la presente tesis doctoral se han aplicado herramientas quimiométricas en el estudio y optimización de los parámetros implicados en la electrodeposición de metales y aleaciones mediante pulsos de corriente, centrando el trabajo en dos procesos determinados: • Cromo duro: con objeto de mejorar la funcionalidad y durabilidad de estos recubrimientos tan extendidos industrialmente, se ha investigado el efecto de la electrodeposición mediante pulsos de corriente...

Atenuación de la asimetría y de la curtosis de las puntuaciones observadas mediante transformaciones de variables: Incidencia sobre la estructura factorial

OpenAIRE

Miguel Ángel Ruiz Díaz; María Noel Rodríguez Ayán

2008-01-01

En este trabajo se evalúa la incidencia de la atenuación, mediante transformaciones de variables, del sesgo y de la curtosis de las puntuaciones observadas, sobre la estructura factorial, estimada mediante análisis factorial exploratorio y confirmatorio. Los datos proceden de una escala de opinión estudiantil para la evaluación de profesores universitarios, de 16 ítems medidos en escala Likert. Las distribuciones observadas no se aproximan a la normalidad, por lo que ...

SolarChill - a solar PV refrigerator without battery

Energy Technology Data Exchange (ETDEWEB)

Pedersen, P.H.; Poulsen, S.; Katic, I. [Danish Technological Inst., Taastrup (Denmark)

2004-07-01

A solar powered refrigerator (SolarChill) has been developed in an international project involving Greenpeace International, GTZ, UNICEF, UNEP, WHO, industrial partners and Danish Technological Institute. The refrigerator is able to operate directly on solar PV panels, without battery or additional electronics, and is therefore suitable for locations where little maintenance and reliable operation is mandatory. The main objective of the SolarChill Project is to help deliver vaccines and refrigeration to the rural poor. To achieve this objective, the SolarChill Project developed - and plans to make freely available a versatile refrigeration technology that is environmentally sound, technologically reliable, and affordable. SolarChill does not use any fluorocarbons in its cooling system or in the insulation. For domestic and small business applications, another type of solar refrigerator is under development. This is an upright type, suitable for cool storage of food and beverages in areas where grid power is non-existent or unstable. The market potential for this type is thus present in industrialised countries as well as in countries under development. The unique feature of SolarChill is that energy is stored in ice instead of in batteries. An ice compartment keeps the cabinet at desired temperatures during the night. The paper describes the product development, possible SolarChill applications and experience with the two types of solar refrigerators, as well as results from the laboratory and field test. (orig.)

SOLAR-ISS: A new reference spectrum based on SOLAR/SOLSPEC observations

Science.gov (United States)

Meftah, M.; Damé, L.; Bolsée, D.; Hauchecorne, A.; Pereira, N.; Sluse, D.; Cessateur, G.; Irbah, A.; Bureau, J.; Weber, M.; Bramstedt, K.; Hilbig, T.; Thiéblemont, R.; Marchand, M.; Lefèvre, F.; Sarkissian, A.; Bekki, S.

2018-03-01

Context. Since April 5, 2008 and up to February 15, 2017, the SOLar SPECtrometer (SOLSPEC) instrument of the SOLAR payload on board the International Space Station (ISS) has performed accurate measurements of solar spectral irradiance (SSI) from the middle ultraviolet to the infrared (165 to 3088 nm). These measurements are of primary importance for a better understanding of solar physics and the impact of solar variability on climate. In particular, a new reference solar spectrum (SOLAR-ISS) is established in April 2008 during the solar minima of cycles 23-24 thanks to revised engineering corrections, improved calibrations, and advanced procedures to account for thermal and aging corrections of the SOLAR/SOLSPEC instrument. Aims: The main objective of this article is to present a new high-resolution solar spectrum with a mean absolute uncertainty of 1.26% at 1σ from 165 to 3000 nm. This solar spectrum is based on solar observations of the SOLAR/SOLSPEC space-based instrument. Methods: The SOLAR/SOLSPEC instrument consists of three separate double monochromators that use concave holographic gratings to cover the middle ultraviolet (UV), visible (VIS), and infrared (IR) domains. Our best ultraviolet, visible, and infrared spectra are merged into a single absolute solar spectrum covering the 165-3000 nm domain. The resulting solar spectrum has a spectral resolution varying between 0.6 and 9.5 nm in the 165-3000 nm wavelength range. We build a new solar reference spectrum (SOLAR-ISS) by constraining existing high-resolution spectra to SOLAR/SOLSPEC observed spectrum. For that purpose, we account for the difference of resolution between the two spectra using the SOLAR/SOLSPEC instrumental slit functions. Results: Using SOLAR/SOLSPEC data, a new solar spectrum covering the 165-3000 nm wavelength range is built and is representative of the 2008 solar minimum. It has a resolution better than 0.1 nm below 1000 nm and 1 nm in the 1000-3000 nm wavelength range. The new

Solar Thermal Energy; Energia Solar Termica

Energy Technology Data Exchange (ETDEWEB)

Perez-Martinez, M; Cuesta-Santianes, M J; Cabrera Jimenez, J A

2008-07-01

Approximately, 50 % of worldwide primary energy consumption is done in the form of heat in applications with a temperature lower than 250 degree centigree (low-medium temperature heat). These data clearly demonstrate the great potential of solar thermal energy to substitute conventional fossil fuels, which are becoming more expensive and are responsible for global warming. Low-medium temperature solar thermal energy is mainly used to obtain domestic hot water and provide space heating. Active solar thermal systems are those related to the use of solar thermal collectors. This study is dealing with low temperature solar thermal applications, mainly focusing on active solar thermal systems. This kind of systems has been extensively growing worldwide during the last years. At the end of 2006, the collector capacity in operation worldwide equalled 127.8 GWth. The technology is considered to be already developed and actions should be aimed at favouring a greater market penetration: diffusion, financial support, regulations establishment, etc. China and USA are the leading countries with a technology based on evacuated tube collectors and unglazed collectors, respectively. The rest of the world markets are dominated by the flat glazed collectors technology. (Author) 15 refs.

Solar cycle distribution of strong solar proton events and the related solar-terrestrial phenomena

Science.gov (United States)

Le, Guiming; Yang, Xingxing; Ding, Liuguang; Liu, Yonghua; Lu, Yangping; Chen, Minhao

2014-08-01

We investigated the solar cycle distribution of strong solar proton events (SPEs, peak flux ≥1000 pfu) and the solar-terrestrial phenomena associated with the strong SPEs during solar cycles 21-23. The results show that 37 strong SPEs were registered over this period of time, where 20 strong SPEs were originated from the super active regions (SARs) and 28 strong SPEs were accompanied by the X-class flares. Most strong SPEs were not associated with the ground level enhancement (GLE) event. Most strong SPEs occurred in the descending phases of the solar cycles. The weaker the solar cycle, the higher the proportion of strong SPES occurred in the descending phase of the cycle. The number of the strong SPEs that occurred within a solar cycle is poorly associated with the solar cycle size. The intensity of the SPEs is highly dependent of the location of their source regions, with the super SPEs (≥20000 pfu) distributed around solar disk center. A super SPE was always accompanied by a fast shock driven by the associated coronal mass ejection and a great geomagnetic storm. The source location of strongest GLE event is distributed in the well-connected region. The SPEs associated with super GLE events (peak increase rate ≥100%) which have their peak flux much lower than 10000 pfu were not accompanied by an intense geomagnetic storm.

SOLAR SOURCES OF 3He-RICH SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 24

International Nuclear Information System (INIS)

Nitta, Nariaki V.; Mason, Glenn M.; Wang, Linghua; Cohen, Christina M. S.; Wiedenbeck, Mark E.

2015-01-01

Using high-cadence EUV images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 3 He-rich solar energetic particle events at ≲1 MeV nucleon −1 that were well-observed by the Advanced Composition Explorer during solar cycle 24. Identification of the solar sources is based on the association of 3 He-rich events with type III radio bursts and electron events as observed by Wind. The source locations are further verified in EUV images from the Solar and Terrestrial Relations Observatory, which provides information on solar activities in the regions not visible from the Earth. Based on AIA observations, 3 He-rich events are not only associated with coronal jets as emphasized in solar cycle 23 studies, but also with more spatially extended eruptions. The properties of the 3 He-rich events do not appear to be strongly correlated with those of the source regions. As in the previous studies, the magnetic connection between the source region and the observer is not always reproduced adequately by the simple potential field source surface model combined with the Parker spiral. Instead, we find a broad longitudinal distribution of the source regions extending well beyond the west limb, with the longitude deviating significantly from that expected from the observed solar wind speed

Superficie específica de una bentonita mediante la adsorción de azul de metileno

Directory of Open Access Journals (Sweden)

Jorge Alejo Pinzón Bello

2010-07-01

Full Text Available Se estudió la determinación de la superficie específica de una bentonita colombiana, procedente del Valle del Cauca, mediante la adsorción de azul de metileno, a 298 K. Este método se comparó con el de la adsorción de nitrógeno a 77 K.

A High Rated Solar Water Distillation Unit for Solar Homes

Directory of Open Access Journals (Sweden)

Abhishek Saxena

2016-01-01

Full Text Available India is presently focusing on complete utilization of solar energy and saving fossil fuels, which are limited. Various solar energy systems like solar cookers, solar water heaters, solar lanterns, solar PV lights, and solar lamps are continuously availing by the people of India at a low cost and on good subsidies. Apart from this, India is a solar energy promising country with a good number of solar homes (carrying solar energy systems in its various locations. The present paper focuses on a unique combination of solar dish cooker (SDC and solar water heater (SWH to produce distilled water with a high distillate and a high daily productivity. The procedure has been discussed on the basis of experimental testing to produce distilled water by combining an evacuated type SWH and a SDC. Experimentation has been carried out in MIT, Moradabad (longitude, 28.83°N, and latitude, 78.78°E by developing the same experimental setup on behalf of solar homes. The daily productivity of distilled water was found around 3.66 litres per day in full sunshine hours for an approximated pH value of 7.7 and a ppm value of 21. The payback period (PBP has been estimated around 1.16 years of the present system.

Midscale Commercial Solar Market | Solar Research | NREL

Science.gov (United States)

States To help prospective solar customers understand and use the policies of their state for midsized Customers, which equips prospective solar customers with the tools necessary to understand and use the solar corporate customers (Alabama Power's Renewable Procurement Program), and a company with approval to sell

The Solar Energy Trifecta: Solar + Storage + Net Metering | State, Local,

Science.gov (United States)

and Tribal Governments | NREL The Solar Energy Trifecta: Solar + Storage + Net Metering The Solar Energy Trifecta: Solar + Storage + Net Metering February 12, 2018 by Benjamin Mow Massachusetts (DPU) seeking an advisory ruling on the eligibility of pairing solar-plus-storage systems with current

DIY Solar Market Analysis Webinar Series: Solar Resource and Technical

Science.gov (United States)

Series: Solar Resource and Technical Potential DIY Solar Market Analysis Webinar Series: Solar Resource and Technical Potential Wednesday, June 11, 2014 As part of a Do-It-Yourself Solar Market Analysis Potential | State, Local, and Tribal Governments | NREL DIY Solar Market Analysis Webinar

Solar Sailing

Science.gov (United States)

Johnson, Les

2009-01-01

Solar sailing is a topic of growing technical and popular interest. Solar sail propulsion will make space exploration more affordable and offer access to destinations within (and beyond) the solar system that are currently beyond our technical reach. The lecture will describe solar sails, how they work, and what they will be used for in the exploration of space. It will include a discussion of current plans for solar sails and how advanced technology, such as nanotechnology, might enhance their performance. Much has been accomplished recently to make solar sail technology very close to becoming an engineering reality and it will soon be used by the world s space agencies in the exploration of the solar system and beyond. The first part of the lecture will summarize state-of-the-art space propulsion systems and technologies. Though these other technologies are the key to any deep space exploration by humans, robots, or both, solar-sail propulsion will make space exploration more affordable and offer access to distant and difficult destinations. The second part of the lecture will describe the fundamentals of space solar sail propulsion and will describe the near-, mid- and far-term missions that might use solar sails as a propulsion system. The third part of the lecture will describe solar sail technology and the construction of current and future sailcraft, including the work of both government and private space organizations.

Preliminary design package for solar collector and solar pump

Science.gov (United States)

1978-01-01

A solar-operated pump using an existing solar collector, for use on solar heating and cooling and hot water systems is described. Preliminary design criteria of the collector and solar-powered pump is given including: design drawings, verification plans, and hazard analysis.

La creación de nuevas reglas técnicas en el IGBM mediante la Programación Genética

Directory of Open Access Journals (Sweden)

Fernando Fernández Rodríguez

2002-01-01

Full Text Available En este trabajo analizamos la capacidad de generar beneficios de reglas técnicas creadas mediante la programación genética en el Índice General de la Bolsa de Madrid . Esta nueva técnica, que no es mas que una expansión de los algoritmos genéticos, permite generar nuevas reglas de contratación en bolsa mediante procedimientos de optimización basados en la selección natural darwiniana. Se comparará los rendimientos obtenidos con la sencilla estrategia de comprar y mantener así como con las reglas basadas en medias móviles más comúnmente usadas en los mercados.

Recubrimientos metálicos sobre alúmina mediante procesos de reducción autocatalítica

Directory of Open Access Journals (Sweden)

Gómez de Salazar, J. M.

2000-10-01

Full Text Available In this work, a method for obtaining copper coating on alumina is described. One of the main applications for this coating is in the electronic industry, although it can be used as well as interlayer for dissimilar bonding between metals and alumina, both by solid state joining and by active brazing. The optimal activation conditions for the alumina using Ni salts and the influence of the surface preparation on the copper coating characteristic are described. The coating application is based on an autocatalithic reduction method. The influence of the deposition rate on the adherence of the copper coating has been studied as well. A kinetic study was carried out applying gravimetric and electrochemical methods. To obtaining coating with high adherence, it was necessary to apply heat treatments after the metallization process. The main objective of them was to achieve a chemical bond between the alumina substrate and the copper coating by formation of Al-Cu spinels, instead of the single mechanical bond.

En el presente trabajo se describe un método de obtención de recubrimientos de cobre sobre un cerámico tenaz como es la alúmina. Una de sus principales aplicaciones se encuentra en la industria electrónica, aunque también puede ser empleado como intermediario en la fabricación de uniones disimilares entre un metal y un cerámico mediante técnicas de unión en estado sólido o en soldadura fuerte reactiva. Se describen las condiciones óptimas de activación de la alúmina mediante sales de Ni, y la influencia que posee la preparación superficial de este substrato (Al2O3 sobre las capas de Cu obtenidas. Este proceso se realiza mediante reducción autocatalítica, habiéndose estudiado como influye la velocidad de deposición sobre la adherencia de la capa de cobre. También se realizaron estudios cinéticos del proceso de recubrimiento mediante ensayos gravimétricos y electroquímicos. Con el fin de obtener recubrimientos que

Solar shading how to integrate solar shading in sustainable buildings

CERN Document Server

Dolmans, Dick; Dutoo, Gonzague; Hall, Anders; Seppänen, Olli

2010-01-01

Solar Shading Guidebook gives a solid background on the physics of solar radiation and its behaviour in window with solar shading systems. Major focus of the Guidebook is on the effect of solar shading in the use of energy for cooling, heating and lighting. The book gives also practical guidance for selection, installation and operation of solar shading as well as future trends in integration of HVAC-systems with solar control.

Performances of solar water pumping station with solar tracker

International Nuclear Information System (INIS)

Buniatyan, V.V.; Vardanyan, A.A.

2011-01-01

For the solar water pumping stations ? solar tracking system with phototransistor is developed. On the basis of the experimental investigations the utility and efficiency of the PV water pumping station with solar tracker under different conditions of varying solar radiation in Armenia is shown

Tratamiento del polvo de aluminio mediante disolución acuosa

Directory of Open Access Journals (Sweden)

López, F. A.

2004-10-01

Full Text Available Aluminium dust from aluminium remelting industry is a hazardous residue because of its high reactivity in the presence of water. In order to apply the new European Directive about landfill of waste, a study of its hydrolysis was carried out. The influence of temperature, time and pH on the hydrolysis of the aluminium dust was studied. The hydrolysed solids were characterized by XRD and AAS; in the aqueous solutions the pH and the ionic conductivity were determined. The evolved gases were analysed by mass spectrometry. The reactivity of the dust, before and after hydrolysis, was investigated by analysing the ammonia, hydrogen sulphide and metallic aluminium. By hydrolysis at 60 °C and 48 h a much lower reactive material was obtained which could be disposed with minimal environmental impact.

El polvo de aluminio es un residuo generado en la metalurgia secundaria del aluminio y considerado peligroso como consecuencia de su elevada reactividad en presencia de humedad. Con objetivo de buscar un procedimiento de pretratamiento de dicho residuo, de acuerdo con la Directiva Europea sobre vertederos, se ha realizado el estudio del comportamiento del polvo de aluminio en medio acuoso. Para ello, se han analizado la influencia de la temperatura, el tiempo y el pH de reacción en su hidrólisis. Los sólidos hidrolizados se caracterizaron mediante EAA y DRX, mientras que en las soluciones acuosas resultantes se determinaron el pH y la conductividad iónica. Los gases liberados durante el proceso de hidrólisis se analizaron mediante espectrometría de masas. Asimismo, se ha determinado la reactividad del residuo antes y después de la hidrólisis, analizando amoniaco, sulfuro de hidrógeno y aluminio metálico. La hidrólisis, a 60 °C y después de 48 h, permite obtener material de muy baja reactividad que podría ser almacenado en vertedero.

The effect of oxidation time on the parameters of ITO/Si solar cell prepared by spray pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Kandil, S. A; Afifi, H. H; El-hefnawi, S. H; Eliwa, A.Y [Electronic Research Institute, Dokki, Cairo (Egypt)

2000-07-01

The indium tin oxide (ITO/N-Si) solar cells have been fabricated by spray pyrolysis technique. The silicon wafers are heated at 500 Celsius degrees with different oxidation time (2-20 min). The best values obtained for ITO/Si solar cell output parameters; open circuit voltage V{sub o}c, short circuit current density J{sub s}c, fill factor FF and efficiency {eta} are 0.48 V, 15 mA/cm{sup 2}, 0.7 and 10.1% respectively. The preceding results were obtained under conditions of 5 minutes oxidation time and the surface area equal to 8 mm{sup 2} when the light intensity is 50 MW/ cm{sup 2}. The values of V{sub o}c, J{sub s}c, FF and {eta} are affected strongly by the varying the oxidation time. This paper is devoted to explain the effect of the interfacial layer SiO{sub 2} thickness on the ITO/Si solar cell parameters as deduced from the I-V and C-V measurements. [Spanish] Mediante tecnicas de pirolisis de dispersion se han fabricado celdas solares de oxido de Indio estanado ITO/N-Si. Las obleas de silicon se calientan a 500 con diferentes tiempos de oxidacion (2-20 min.) Los mejores valores obtenidos para los parametros de produccion de las celdas solares ITO-Si de voltaje en circuito abierto V{sub o}c densidad de corriente de corto circuito J{sub s}c factor de llenado FF y eficiencia {eta} son de 0.48 V, 15 mA/cm{sup 2}, 0.7% y 10.1% respectivamente los resultados precedentes se obtuvieron bajo condiciones de 5 minutos de tiempo de oxidacion y la superficie del area=8 mm{sup 2} cuando la intensidad de la luz es de 50mW/Cm{sup 2}. Los valores de V{sub o}c, J{sub s}c, FF y {eta} se afectan fuertemente por la variacion del tiempo de oxidacion. Este articulo esta dedicado a explicar el efecto del espesor de la capa interfacial de SiO{sub 2} en los parametros de la celda solar ITO-Si como se deduce de las mediciones I-V y C-V.

Solar Energy.

Science.gov (United States)

Eaton, William W.

Presented is the utilization of solar radiation as an energy resource principally for the production of electricity. Included are discussions of solar thermal conversion, photovoltic conversion, wind energy, and energy from ocean temperature differences. Future solar energy plans, the role of solar energy in plant and fossil fuel production, and…

Desarrollo de un escáner 3D mediante cámaras estereoscópicas e iluminación láser

OpenAIRE

Cristina, Federico; Dapoto, Sebastián H.; Vegas, Javier; Artola, Verónica; Russo, Claudia Cecilia; Abásolo Guerrero, María José

2007-01-01

Los dispositivos de escaneo tridimensional permiten obtener modelos de objetos utilizando distintas técnicas de captura. Esta tarea puede ser llevada a cabo por ejemplo mediante estereovisión, el cual es un método de reconstrucción 3D a partir de fotografías. Las técnicas de reconstrucción 3D mediante luz se basan en la proyección de un patrón de luz conocido sobre una escena y a partir del análisis de la proyección puede deducirse la forma de los objetos. De esta manera, basándose en la info...

Solar Energy Systems

Science.gov (United States)

1984-01-01

Calibrated in kilowatt hours per square meter, the solar counter produced by Dodge Products, Inc. provides a numerical count of the solar energy that has accumulated on a surface. Solar energy sensing, measuring and recording devices in corporate solar cell technology developed by Lewis Research Center. Customers for their various devices include architects, engineers and others engaged in construction and operation of solar energy facilities; manufacturers of solar systems or solar related products, such as glare reducing windows; and solar energy planners in federal and state government agencies.

Solar energy: photovoltaics

International Nuclear Information System (INIS)

Goetzberger, A.; Voss, B.; Knobloch, J.

1994-01-01

This textbooks covers the following topics: foundations of photovoltaics, solar energy, P-N junctions, physics of solar cells, high-efficiency solar cells, technology of Si solar cells, other solar cells, photovoltaic applications. (orig.)

Solar Adaptive Optics

Directory of Open Access Journals (Sweden)

Thomas R. Rimmele

2011-06-01

Full Text Available Adaptive optics (AO has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO and Ground-Layer AO (GLAO will be given.

Análisis de la biodiversidad de macroinvertebrados bentónicos del Río Cunas mediante indicadores ambientales, Junín - Perú

OpenAIRE

Custodio Villanueva, María

2013-01-01

El objetivo de la investigación fue analizar el estado de la biodiversidad de macroinvertebrados bentónicos del río Cunas mediante indicadores ambientales. Se utilizaron los métodos de observación, descripción y explicación; el tipo de investigación es básica y el diseño no experimental, de tipo longitudinal. Se definieron tres sectores de muestreo, San Blas, Huarisca y La Perla. La valoración de las presiones antrópicas se realizó mediante la determinación de DBO5 aportada por aguas residual...

Análisis de la biodiversidad de macroinvertebrados bentónicos del río Cunas mediante indicadores ambientales, Junín-Perú

OpenAIRE

María Custodio Villanueva; Fernán Cosme Chanamé Zapata

2016-01-01

El objetivo de la investigación fue analizar el estado de la biodiversidad de macroinvertebrados bentónicos del río Cunas mediante indicadores ambientales. Se definieron tres sectores de muestreo en dos épocas contrastantes. La valoración de las presiones antrópicas se realizó mediante la determinación de la carga de DBO5 aportada por aguas residuales. Se colectaron muestras de agua para la determinación de nitratos, fosfatos y coliformes termotolerantes. Los indicadores medidos in situ fuero...

Solar radiophysics

International Nuclear Information System (INIS)

McLean, D.J.; Labrum, N.R.

1985-01-01

This book treats all aspects of solar radioastronomy at metre wavelengths, particularly work carried out on the Australian radioheliograph at Culgoora, with which most of the authors have been associated in one way or another. After an introductory section on historical aspects, the solar atmosphere, solar flares, and coronal radio emission, the book deals with instrumentation, theory, and details of observations and interpretations of the various aspects of metrewave solar radioastronomy, including burst types, solar storms, and the quiet sun. (U.K.)

Fomento de la conciencia ambiental mediante el blog UNAECOLÓGICA

Directory of Open Access Journals (Sweden)

Nereidy Velásquez

2016-01-01

Full Text Available El propósito del artículo es presentar una propuesta para fomentar la conciencia ambiental mediante el uso del blog. En este trabajo se organizaron los referentes teóricos relacionados con la educación ambiental y con la web, la cual constituye un espacio que ofrece información consistente y veraz sobre cualquier temática. El blog UNAECOLÓGICA es una propuesta que se crea con el fin de generar espacios para la comunicación, la interacción, la construcción del conocimiento ambiental y estimular en la comunidad unista la participación, la empatía y la solidaridad hacia su entorno.  Entre algunas de las secciones que presenta UNAECOLÓGICA, se encuentran: Notiambiente, Literambiente, Ecorelatos. Ecofrases, entre otras.

Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion

Science.gov (United States)

Kang, Jinho; Marshall, I. A.; Torrico, M. N.; Taylor, C. R.; Ely, Jeffry; Henderson, Angel Z.; Kim, J.-W.; Sauti, G.; Gibbons, L. J.; Park, C.;

Control de costos mediante el análisis de valor ganado : caso aplicativo

OpenAIRE

Prado Ponce, Eduard Javier; Prado Ponce, Eduard Javier; Prado Ponce, Eduard Javier

2015-01-01

El control de costos y el control de plazos son muy importantes ya que pueden dar como resultados informes que permitan aplicar planes correctivos e incluso preventivos si se analizan con suficiente antelación. Existen empresas que se dedican a la construcción de obras civiles, que actualmente carece de un proceso para la planificación y control en la ejecución de obra, debido a ello surge la necesidad de desarrollar una metodología que permita a la empresa optimizar sus recursos mediante ...

Detección facial y reconocimiento anímico mediante las expresiones faciales

OpenAIRE

BARTUAL GONZÁLEZ, RAQUEL

2017-01-01

The project is based on the software development elaborated with the program LabView. The mentioned program aims to detect people's faces in a video, as well as their genre and mood state. El proyecto se basa en el desarrollo de un software elaborado con el programa LabView. Dicho programa pretende detectar la cara de las personas en un vídeo, así como su género y su estado de ánimo. Bartual González, R. (2017). Detección facial y reconocimiento anímico mediante las expresiones faciales...

Metalgoritmo de optimización combinatoria mediante la exploración de grafos.

OpenAIRE

Pastor, Rafael

1999-01-01

Actualmente, aunque existen procedimientos específicos para resolver de forma óptima algunos problemas concretos de optimización combinatoria, la mayoría se deben solucionar con técnicas generales de exploración del espacio de soluciones, y más concretamente mediante procedimientos de exploración enumerativos en árboles y grafos de búsqueda.Se analizan los procedimientos de este tipo expuestos en la literatura, tanto en el área de la investigación operativa como en el de la inteligencia artif...

Deciphering Solar Magnetic Activity: Spotting Solar Cycle 25

Energy Technology Data Exchange (ETDEWEB)

McIntosh, Scott W. [High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO (United States); Leamon, Robert J., E-mail: mscott@ucar.edu [Department of Astronomy, University of Maryland, College Park, MD (United States)

2017-06-26

We present observational signatures of solar cycle 25 onset. Those signatures are visibly following a migratory path from high to low latitudes. They had starting points that are asymmetrically offset in each hemisphere at times that are 21–22 years after the corresponding, same polarity, activity bands of solar cycle 23 started their migration. Those bands define the so-called “extended solar cycle.” The four magnetic bands currently present in the system are approaching a mutually cancelling configuration, and solar minimum conditions are imminent. Further, using a tuned analysis of the daily band latitude-time diagnostics, we are able to utilize the longitudinal wave number (m = 1) variation in the data to more clearly reveal the presence of the solar cycle 25 bands. This clarification illustrates that prevalently active longitudes (different in each hemisphere) exist at mid-latitudes presently, lasting many solar rotations, that can be used for detailed study over the next several years with instruments like the Spectrograph on IRIS, the Spectropolarimeter on Hinode, and, when they come online, similar instruments on the Daniel K. Inouye Solar Telescope (DKIST) as we watch those bands evolve following the cancellation of the solar cycle 24 activity bands at the equator late in 2019.

Photovoltaic solar concentrator

Science.gov (United States)

Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J.; Sanchez, Carlos Anthony; Clews, Peggy J.; Gupta, Vipin P.

2015-09-08

A process including forming a photovoltaic solar cell on a substrate, the photovoltaic solar cell comprising an anchor positioned between the photovoltaic solar cell and the substrate to suspend the photovoltaic solar cell from the substrate. A surface of the photovoltaic solar cell opposite the substrate is attached to a receiving substrate. The receiving substrate may be bonded to the photovoltaic solar cell using an adhesive force or a metal connecting member. The photovoltaic solar cell is then detached from the substrate by lifting the receiving substrate having the photovoltaic solar cell attached thereto and severing the anchor connecting the photovoltaic solar cell to the substrate. Depending upon the type of receiving substrate used, the photovoltaic solar cell may be removed from the receiving substrate or remain on the receiving substrate for use in the final product.

Modelación de un colector solar para calentamiento de aire; Modelling ofa solar collector for air heating

Directory of Open Access Journals (Sweden)

Amadou Koulibaly

2015-09-01

Full Text Available En este trabajo es desarrollada la modelación de un colector solar plano para calentamiento de aire operado con convección natural. El análisis del colector mediante balances de masa y energía no estacionarios aplicados a cada uno de los elementos componentes del colector permitió desarrollar un programa en Visual Basic que simula el comportamiento dinámico del colector ante variaciones de las condiciones de operación y variaciones de los parámetros de diseño (dimensiones del colector, tipo de material de cubierta y dimensiones, material de la placa absorbedora y sus dimensiones, eficiencia óptica y tipo y espesor de aislamiento. Los resultados muestran que el software puede ser empleado para el diseño de colectores para calentamiento de aire, además de poder ser empleado para obtener las temperaturas de cada componente del colector y el rendimiento térmico instantáneo. El software también ofrece los elementos para determinar la constante de tiempo que caracteriza la dinámica del colector.In this paper the modeling of a flat solar collector for air heating was developed. This collector works with natural convection. The analysis of the collector was made using unsteady mass and energy balances applied to each component of collector. The equations were solved usinga Visual Basic code with the target to simulate the dynamics performance of the collector when the operating conditions and the design parameters are modified. The dimensions of the collector, the material and dimensions of the covert, the material and dimensions of the absorber plate, the optic efficiency and the type and thin of the insulator are the fundamentals design parameters that can be varied. The results of the simulation show that the software can be used for the design of collectors for heating air. Additionally, the software permits to determine the temperature of each component, the instantaneous efficiency of the collector and offers the elements to obtain

Solarbundesliga (Solar League) and SolarLokal. Competition and campaign for communities

Energy Technology Data Exchange (ETDEWEB)

Vollmer, C. [Deutsche Umwelthilfe e.V., Radolfzell (Germany)

2006-07-01

Summary: Currently more solar power plants are built in Germany than ever before. Citizens, farmers, companies, initiatives and local authorities are participating. Solarbundesliga (Solar League), launched in April 2001, offers a forum for these solar minded actors. It ensures that the local commitment of these actors is known all over Germany and in doing so awakens the competitive drive in many people. The Solarbundesliga is organised by Deutsche Umwelthilfe and the specialist journal Solarthemen. It is a very good instrument to show the outcome of the solar energy supply at the local level in media friendly means. The image campaign SolarLokal of the Deutsche Umwelthilfe and SolarWorld, one of the biggest solar companies worldwide, is a very good approach for municipalities to inform their citizens about the benefits of solar energy. According to a recent opinion poll, SolarLokal contributes to an increase in solar current plants in the participating cities and towns. Additionally, it brings craftspeople having experience in installing solar power plants and interested citizens together. So, SolarLokal provides incentives to the local economy. The idea of SolarLokal is transferable to other countries. In January 2006 the partner campaign IsIaSolar was started in Teneriffa. (orig.)

Solar Adaptive Optics.

Science.gov (United States)

Rimmele, Thomas R; Marino, Jose

Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given. Supplementary material is available for this article at 10.12942/lrsp-2011-2.

Análisis de la utilidad de la olfatogustometría mediante BAST-24 en la población diabética y su relación con la función renal

OpenAIRE

Gascón Rubio, María Cristina

2014-01-01

157 p. : il., graf. Realizamos un estudio descriptivo observacional del sentido del olfato mediante el test BAST-24 de la población diabética. Valoramos su función renal mediante determinaciones analíticas.

Aspectos por considerar para una efectiva integración universitaria mediante las nuevas tecnologías. Una perspectiva desde la sociología de las organizaciones

OpenAIRE

Cordero, Aleska

2008-01-01

En el presente artículo se desarrollan algunas ideas y consideraciones por tomar en cuenta, desde el enfoque organizacional, para fundamentar una efectiva integración iberoamericana entre las instituciones universitarias mediante el uso de las nuevas tecnologías. Se presentan ciertos conceptos provenientes de la teoría organizacional (cultura organizacional, cultura profesional, resistencia al cambio) mediante los cuales es posible abordar el análisis de los problemas que se plantean en las i...

PROPUESTA DE CONEXIÓN DE ENTORNOS IPv6 MEDIANTE UN BACKBONE MPLS/IPv4

Directory of Open Access Journals (Sweden)

Nancy Yaneth Gelvez García

2013-09-01

Full Text Available Las redes actuales MPLS/IPv4 presentan las ventajas de poder implementar ingeniería de tráfico, así como realizar diferenciación de flujos mediante clases de servicio (CoS frente a las redes con enrutamiento IP tradicional. En aras de aprovechar cualidades estratégicas durante la etapa de coexistencia entre IPv4 e IPv6 existen 4 métodos para proveer conectividad a islas IPv6 [1] remotas a través de una infraestructura de core MPLS con IPv4 nativo [2], sin embargo una de las formas que permite un rápida y fácil provisión de la misma dados los mínimos requisitos de configuración y de equipos es la de disponer túneles IPv6 en los enrutadores de acceso (CE de la red. No obstante, sus cuatro variantes (manual, GRE, 6to4 e IPv6 compatible IPv4 [3] resultan adecuadas o no según las características inherentes de la red a interconectar; por tanto este artículo presenta las ventajas y desventajas propias de la utilización de cada técnica de entunelamiento como resultado de la interconexión con los cuatro tipos de túneles de una red emulada mediante GNS3+Dynamips.

DIMENSIONAMIENTO DE UN SISTEMA DE ENERGÍA TERMOSOLAR MEDIANTE EL USO DE UN MODELO

Directory of Open Access Journals (Sweden)

Arturo Daniel Alarcón Rodríguez

2004-01-01

Full Text Available En el presente artículo se expone el método de dimensionamiento de sistemas termosolares mediante el uso de un modelo matemático. Este método es comúnmente usado debido que es simple, flexible pero a la vez muy potente. La simulación del sistema termosolar se realiza en base a un modelo matemático que describe los fenómenos térmicos que ocurren mediante un conjunto de ecuaciones diferenciales. Los parámetros que determinan el modelo son coeficientes de intercambio de calor entre los elementos del sistema, parámetros que representan las características de los componentes del sistema termosolar y parámetros que representan las condiciones en las que trabajará el sistema. Estos parámetros se determinan en base a recomendaciones de bibliografía, observaciones, mediciones de campo y correlaciones adecuadas. El uso de un modelo para el dimensionamiento de un sistema termosolar resulta una herramienta muy útil, ya que se adapta a distintas configuraciones de sistemas termosolares. Permite asimismo, tener una idea bastante aproximada del comportamiento del sistema termosolar en distintas condiciones de uso, la que sólo podría obtenerse a través de experimentos físicos complicados y por ende costosos.

Monitoring of the solar activity and solar energetic particles

International Nuclear Information System (INIS)

Akioka, Maki; Kubo, Yuki; Nagatsuma, Tsutomu; Ohtaka, Kazuhiro

2009-01-01

Solar activity is the source of various space weather phenomena in geospace and deep space. Solar X-ray radiation in flare, energetic particles, coronal mass ejection (CME) can cause various kind of disturbance near earth space. Therefore, detailed monitoring of the solar activity and its propagation in the interplanetary space is essential task for space weather. For example, solar energetic particle which sometimes affect spacecraft operation and manned space flight, is considered to be produced by solar flares and travelling shockwave caused by flares and CME. The research and development of monitoring technique and system for various solar activity has been an important topic of space weather forecast program in NICT. In this article, we will introduce the real time data acquisitions of STEREO and optical and radio observations of the Sun at Hiraiso Solar Observatory. (author)

Solar Newsletter | Solar Research | NREL

Science.gov (United States)

more about work by this consortium, which crosses national laboratories, on new materials and designs information on NREL's research and development of solar technologies. To receive new issues by email prize, focused on solar energy technologies, and will release the prize rules and open registration

Photovoltaic. Solar thermal. Solar thermal electricity

International Nuclear Information System (INIS)

2009-01-01

The year 2008 was excellent for solar energy in the European Union. The growth of the installed capacity for photovoltaic was +159% (it means +4747.018 MW) to reach 9689.952 MW and that for solar thermal was +51.5% (it means +3172.5 MW) to reach 19982.7 MW. Worldwide concentrated solar thermal capacity stood at 679 MW in 2009, while this figure may seem low, the sector has a promising future ahead of it. (A.C.)

Solar opacities constrained by solar neutrinos and solar oscillations

International Nuclear Information System (INIS)

Cox, A.N.

1989-01-01

This review discusses the current situation for opacities at the solar center, the solar surface, and for the few million kelvin temperatures that occur below the convection zone. The solar center conditions are important because they are crucial for the neutrino production, which continues to be predicted about 4 times that observed. The main extinction effects there are free-free photon absorption in the electric fields of the hydrogen, helium and the CNO atoms, free electron scattering of photons, and the bound-free and bound-bound absorption of photons by iron atoms with two electrons in the 1s bound level. An assumption that the iron is condensed-out below the convection zone, and the opacity in the central regions is thereby reduced, results in about a 25 percent reduction in the central opacity but only a 5 percent reduction at the base of the convection zone. Furthermore, the p-mode solar oscillations are changed with this assumption, and do not fit the observed ones as well as for standard models. A discussion of the large effective opacity reduction by weakly interacting massive particles also results in poor agreement with observed p-mode oscillation frequencies. The much larger opacities for the solar surface layers from the Los Alamos Astrophysical Opacity Library instead of the widely used Cox and Tabor values show small improvements in oscillation frequency predictions, but the largest effect is in the discussion of p-mode stability. Solar oscillation frequencies can serve as an opacity experiment for the temperatures and densities, respectively, of a few million kelvin and between 0.1 and 10 g/cm 3 . Current oscillation frequency calculations indicate that possibly the Opacity Library values need an increase of typically 15 percent just at the bottom of the convection zone at 3 x 10 6 K. 41 refs., 15 figs., 1 tab

3D Visualization of Solar Data: Preparing for Solar Orbiter and Parker Solar Probe

Science.gov (United States)

Mueller, D.; Nicula, B.; Felix, S.; Verstringe, F.; Bourgoignie, B.; Csillaghy, A.; Berghmans, D.; Jiggens, P.; Ireland, J.; Fleck, B.

2017-12-01

Solar Orbiter and Parker Solar Probe will focus on exploring the linkage between the Sun and the heliosphere. These new missions will collect unique data that will allow us to study, e.g., the coupling between macroscopic physical processes to those on kinetic scales, the generation of solar energetic particles and their propagation into the heliosphere and the origin and acceleration of solar wind plasma. Combined with the several petabytes of data from NASA's Solar Dynamics Observatory, the scientific community will soon have access to multi­dimensional remote-sensing and complex in-situ observations from different vantage points, complemented by petabytes of simulation data. Answering overarching science questions like "How do solar transients drive heliospheric variability and space weather?" will only be possible if the community has the necessary tools at hand. In this contribution, we will present recent progress in visualizing the Sun and its magnetic field in 3D using the open-source JHelioviewer framework, which is part of the ESA/NASA Helioviewer Project.

Effect of the empty fraction in a solar reactor of fluidized bed; Efecto de la fraccion vacia en un reactor solar de lecho fluidizado

Energy Technology Data Exchange (ETDEWEB)

Torres, Alejandro; Romero-Paredes, Hernando; Vazquez, Alejandro; Torijano, Eugenio; Ambriz, Juan J [Universidad Autonoma Metropilitana-Iztapalapa, Mexico, D.F. (Mexico)

2000-07-01

de lecho fluidizado que a la vez sirve como receptor solar de un sistema de almacenamiento termoquimico de la energia solar. Los complejos fenomenos que se tienen en estos reactores hacen dificil su dimensionamiento para su aplicacion solar. Por ello, modelar y simular su comportamiento sin y con reaccion quimica ayuda a paliar este inconveniente. Uno de los fenomenos presentes es el cambio de la fraccion vacia en la cual concentramos nuestra atencion. En este trabajo se propone una alternativa en el modelado de estos sistemas considerando las fluctuaciones locales de la fraccion vacia o porosidad {epsilon}(x, y) en el lecho. Para esto se propone una distribucion probabilistica uniforme para todos los nodos de la malla (x, y) del lecho donde se asocian valores de porosidad locales para cada nodo de la malla mediante un generador aleatorio donde {epsilon}(x, y){epsilon} [0.1]. La fraccion nueva juega un papel muy importante debido a que la penetracion de la radiacion solar en estos sistemas de cuerpos opacos depende directamente de la distribucion de espacios vacios en la trayectoria de la radiacion incidente que afecta su comportamiento termico y cinetico. De los resultados se puede comprobar la caracteristica de no isotermicidad del reactor lo que conlleva, una vez alcanzada la temperatura de reaccion, a un perfil de concentraciones disperso. La fraccion vacia es un parametro que influye grandemente en estos perfiles y que incrementando el numero de fluidizacion es como se logra disminuir ese tiempo. En conclusion, se resalta la importancia que juega la fraccion vacia en la evolucion tanto de los perfiles de temperatura como de concentracion. El comportamiento del lecho en la simulacion se hace mas precisa de acuerdo con los resultados experimentales previamente obtenidos.

Calculating the diffuse solar radiation in regions without solar radiation measurements

International Nuclear Information System (INIS)

Li, Huashan; Bu, Xianbiao; Long, Zhen; Zhao, Liang; Ma, Weibin

2012-01-01

Correlations for calculating diffuse solar radiation can be classified into models with global solar radiation (H-based method) and without it (Non-H method). The objective of the present study is to compare the performance of H-based and Non-H methods for calculating the diffuse solar radiation in regions without solar radiation measurements. The comparison is carried out at eight meteorological stations in China focusing on the monthly average daily diffuse solar radiation. Based on statistical error tests, the results show that the Non-H method that includes other readily available meteorological elements gives better estimates. Therefore, it can be concluded that the Non-H method is more appropriate than the H-based one for calculating the diffuse solar radiation in regions without solar radiation measurements. -- Highlights: ► Methods for calculating diffuse solar radiation in regions without solar radiation measurements are investigated. ► Diffuse solar radiation models can be classified into two groups according to global solar radiation. ► Two approaches are compared at the eight meteorological stations in China. ► The method without global solar radiation is recommended.

Solar homebuilders program: getting builders to build solar

Energy Technology Data Exchange (ETDEWEB)

Parkin, B.; Allen, D.

1981-01-01

The homebuilding industry can open the way to wide-scale residential use of solar energy. Under the Northwest Power Act, the Department of Energy's Bonneville Power Administration, Western Solar Utilization Network and the Solar Energy Research Institute are working together with the Home Builders Association of Metropolitan Portland and the Portland chapter of the American Institute of Architects on a program that will affect 7 cities in the Pacific Northwest. Modeled after the successful Denver Metro Homebuilders Program, the project is being implemented in 3 cities in 1981 and three additional cities in 1982. In each of the 7 cities builders and developers will be provided with design, performance monitoring and marketing assistance for constructing passive solar prototypes. The result is ten passive solar homes of superior design and of an affordable price in each city. The secondary result of this program is expected to be a total of 2700 solar homes produced outside the program by builders from 1981-1985. Builders influenced to build passive solar homes outside the program could result in as many as 500,000 homes produced by the year 2000.

Estimation of monthly solar radiation distribution for solar energy system analysis

International Nuclear Information System (INIS)

Coskun, C.; Oktay, Z.; Dincer, I.

2011-01-01

The concept of probability density frequency, which is successfully used for analyses of wind speed and outdoor temperature distributions, is now modified and proposed for estimating solar radiation distributions for design and analysis of solar energy systems. In this study, global solar radiation distribution is comprehensively analyzed for photovoltaic (PV) panel and thermal collector systems. In this regard, a case study is conducted with actual global solar irradiation data of the last 15 years recorded by the Turkish State Meteorological Service. It is found that intensity of global solar irradiance greatly affects energy and exergy efficiencies and hence the performance of collectors. -- Research highlights: → The first study to apply global solar radiation distribution in solar system analyzes. → The first study showing global solar radiation distribution as a parameter of the solar irradiance intensity. → Time probability intensity frequency and probability power distribution do not have similar distribution patterns for each month. → There is no relation between the distribution of annual time lapse and solar energy with the intensity of solar irradiance.

Principles of solar engineering

CERN Document Server

Goswami, D Yogi

2015-01-01

Introduction to Solar Energy ConversionGlobal Energy Needs and ResourcesSolar EnergyEnergy StorageEconomics of Solar SystemsSummary of RE ResourcesForecast of Future Energy MixReferencesFundamentals of Solar RadiationThe Physics of the Sun and Its Energy TransportThermal Radiation FundamentalsSun-Earth Geometric RelationshipSolar RadiationEstimation of Terrestrial Solar RadiationModels Based on Long-Term Measured Horizontal Solar RadiationMeasurement of Solar RadiationSolar Radiation Mapping Using Satellite DataReferencesSuggested ReadingsSolar Thermal CollectorsRadiative Properties and Characteristics of MaterialsFlat-Plate CollectorsTubular Solar Energy CollectorsExperimental Testing of CollectorsConcentrating Solar CollectorsParabolic Trough ConcentratorCompound-Curvature Solar ConcentratorsCentral Receiver CollectorFresnel Reflectors and LensesSolar Concentrator SummaryReferencesSuggested ReadingThermal Energy Storage and TransportThermal Energy StorageTypes of TESDesign of Storage SystemEnergy Transport ...

Solar Plus: A Holistic Approach to Distributed Solar PV

Energy Technology Data Exchange (ETDEWEB)

O' Shaughnessy, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ardani, Kristen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-05-25

Solar 'plus' refers to an emerging approach to distributed solar photovoltaic (PV) deployment that uses energy storage and controllable devices to optimize customer economics. The solar plus approach increases customer system value through technologies such as electric batteries, smart domestic water heaters, smart air-conditioner (AC) units, and electric vehicles We use an NREL optimization model to explore the customer-side economics of solar plus under various utility rate structures and net metering rates. We explore optimal solar plus applications in five case studies with different net metering rates and rate structures. The model deploys different configurations of PV, batteries, smart domestic water heaters, and smart AC units in response to different rate structures and customer load profiles. The results indicate that solar plus improves the customer economics of PV and may mitigate some of the negative impacts of evolving rate structures on PV economics. Solar plus may become an increasingly viable model for optimizing PV customer economics in an evolving rate environment.

Solar Plus: A Holistic Approach to Distributed Solar PV

Energy Technology Data Exchange (ETDEWEB)

OShaughnessy, Eric J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ardani, Kristen B. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cutler, Dylan S. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-06-08

Solar 'plus' refers to an emerging approach to distributed solar photovoltaic (PV) deployment that uses energy storage and controllable devices to optimize customer economics. The solar plus approach increases customer system value through technologies such as electric batteries, smart domestic water heaters, smart air-conditioner (AC) units, and electric vehicles We use an NREL optimization model to explore the customer-side economics of solar plus under various utility rate structures and net metering rates. We explore optimal solar plus applications in five case studies with different net metering rates and rate structures. The model deploys different configurations of PV, batteries, smart domestic water heaters, and smart AC units in response to different rate structures and customer load profiles. The results indicate that solar plus improves the customer economics of PV and may mitigate some of the negative impacts of evolving rate structures on PV economics. Solar plus may become an increasingly viable model for optimizing PV customer economics in an evolving rate environment.

Mathematical modeling of the hydrogen evolution reaction using HClO{sub 4} and H{sub 2}SO{sub 4} as electrolytes; Modelacion matematica de la reaccion de evolucion del hidrogeno utilizando HClO{sub 4} y H{sub 2}SO{sub 4} como electrolitos

Energy Technology Data Exchange (ETDEWEB)

Ortega Chavez, Laura; Herrera Peraza, Eduardo; Alonso Nunez, Gabriel [Centro de Investigacion en Materiales Avanzados, Chihuahua, Chihuahua (Mexico); Manzanarez Papayanopoulos, Luisa [PROFEPA, Mexico D.F. (Mexico); Verde Gomez, Ysmael [Instituto Tecnologico de Cancun, Cancun, Quintana Roo (Mexico); Keer Rendon, Arturo [Centro de Investigacion en Materiales Avanzados, Chihuahua, Chihuahua (Mexico)

2008-01-15

tecnologia, se ha visto limitada por factores tales como el elevado costo de los distintos componentes que conforman una celda de combustible. Por ejemplo, el platino empleado por excelencia como el mejor catalizador para llevar a cabo la reaccion quimica entre hidrogeno y oxigeno, responsable de la produccion de energia electrica. En la busqueda de la optimizacion o sustitucion del platino, es importante contar con una metodologia que permita realizar un diagnostico in situ del estado de dicho catalizador. Este diagnostico involucra aspectos tales como la determinacion de los sitios activos y la carga y la degradacion que el catalizador puede ir sufriendo durante el funcionamiento de la celda. El presente trabajo consiste en el desarrollo de un modelo matematico que alimentado con las constantes de velocidad y los fenomenos involucrados en la reaccion de la evolucion del hidrogeno, produce como datos de salida, las curvas de polarizacion (E vs I) y de espectroscopia de impedancia electroquimica para dicha reaccion. Se considero para la modelacion, al Pt monocristalino preferenciado en las direcciones (111) y (100) como catalizador y usando diversos acidos como electrolitos. Las curvas obtenidas con el algoritmo matematico muestran una correlacion de la influencia del tipo y concentracion de los acidos usados como electrolitos y la densidad de corriente electrica debido a la evolucion del H{sub 2}. Finalmente, este modelo deja abierta la posibilidad de explorar el efecto del cambio en los valores de las variables involucradas en las reacciones de una celda de combustible, lo que nos permitira evaluar in situ el estado y comportamiento del catalizador.

Diseño e implementación de un sistema de seguridad vehicular mediante reconocimiento facial a través de visión artificial

OpenAIRE

Cajas Idrovo, Marco Vinicio; Viri Ávila, Pablo Andrés

2017-01-01

El documento consiste en un sistema de seguridad antirrobo de vehículos basado en visión artificial mediante varias técnicas de reconocimiento facial, el cual permite el encendido y la conducción de personas autorizadas previamente establecida en una base de datos y niega el acceso a otras personas haciendo sonar alarmas, esto se logra mediante la activación del relé de la bomba de gasolina, el reconocimiento se lo hace cada cierto tiempo para a cada momento verificar la identidad de la perso...

Evaluación genotóxica, mediante la prueba de micronúcleos, de la exposición a drogas psicoactivas en individuos del suroccidente colombiano

Directory of Open Access Journals (Sweden)

LS. Hoyos

2001-07-01

genotóxico de estas drogas mediante la prueba de Micronúcleos (Mn, que identifica fragmentos cromosómicos o cromosomas enteros excluidos del núcleo celular y que es un biomarcador temprano de exposición e indicador de riesgo incrementado de cáncer. El objetivo de este estudio fue: evaluar el daño genético inducido por el consumo de drogas psicoactivas mediante cuantificación de micronúcleos en linfocitos binucleados de sangre periférica de individuos consumidores y no c onsumidores.

Frontier of solar observation. Solar activity observed by 'HINODE' mission

International Nuclear Information System (INIS)

Watanabe, Tetsuya

2008-01-01

After launched in September 2006, solar observation satellite 'HINODE' has been a solar observatory on orbit with the scientific instruments well operated and its continuous observation was conducted steadily on almost all solar atmospheres from photosphere to corona. 'HINODE' was equipped with the solar optical telescope, extreme-ultraviolet imaging spectrometer and x-ray telescope and aimed at clarifying the mystery of solar physics related with coronal heating and magnetic reconnection. Present state of 'HINODE' was described from observations made in initial observation results, which have made several discoveries, such as Alfven waves in the corona, unexpected dynamics in the chromosphere and photosphere, continuous outflowing plasma as a possible source of solar wind, and fine structures of magnetic field in sunspots and solar surface. (T. Tanaka)

Caracterización de polipropileno con fibra de vidrio y policarbonato/acrilonitrilo butadieno estireno microespumados mediante moldeo por inyección MuCell®

OpenAIRE

Rojas Jiménez, Ana

2016-01-01

El proyecto tiene como objetivo el análisis morfológico y de propiedades mecánicas de placas de polipropileno con fibra de vidrio (PP-GF30) y de policarbonato/acrilonitrilo butadieno estireno (PC/ABS), inyectadas mediante microespumación física (MuCell®). Este proyecto se enmarca dentro de un estudio más amplio que tiene como objetivo la comparación entre dos métodos de espumado físico mediante moldeo por inyección: el proceso MuCell® y un nuevo proceso del grupo Volkswagen...

"DETECCIÓN DE TRASTORNO DE DEFICIT DE ATENCIÓN MEDIANTE LA ESCALA DE CONNERS EN NIÑOS 6 A 9 AÑOS DE EDAD"

OpenAIRE

Cancino Estrada, Yurixhi

2012-01-01

Antecedentes: el TDAH es la enfermedad psiquiátrica crónica más frecuente en la edad pediátrica. Su prevalencia es del 3 al 5%. No existe una encuesta única para sospechar TDAH, una de ellas es la escala de Conners, al detectar oportunamente a estos niños e iniciar tratamiento, se disminuye fracaso escolar y rechazo social. Objetivo: detectar TDAH mediante la escala de Conners en niños de 6 a 9 años de edad. Material y métodos: estudio descriptivo mediante aplicación de l...

Trial products of solar cars; Solar car no shisaku

Energy Technology Data Exchange (ETDEWEB)

Shimizu, A; Hatakeyama, S; Sugiura, S; Shinoda, S; Daigo, Y; Fujihara, Y; Yano, K; Kasuga, M [Yamanashi University, Yamanashi (Japan). Faculty of Engineering

1997-11-25

A solar car was trially manufactured installing solar panels on a motor-wheelchair for the old (senior car). It is a car for one person with maximum speed of 6km/h, motor of 360w, two of storage battery of 12Vtimes29AH, and two of solar cell of 20Vtimes3A. The output of solar cell is about 100W, which may not be enough to drive a 360W motor. However, if action time per day is about 2 hours, the required power 700WH, and the sunshine duration 7 hours per day, solar cells of 100W can generate 700WH. This is stored in battery, and when it is short, it is supplemented by nighttime power. Product prices are 200,000-250,000 yen. A solar go-cart was trially manufactured remodeling the gasoline-run go-cart. It is a solar go-cart for one person with maximum speed of 30km/h, a motor of 600W, four of storage battery of 12Vtimes29AH, and four of solar cell of 20Vtimes3A. The output of solar battery at 200W is a third of the motor power, with battery charged three times the travel time. More than 1000 persons trially rode the go-cart. 2 figs.

Solar Design Workbook

Energy Technology Data Exchange (ETDEWEB)

Franta, G.; Baylin, F.; Crowther, R.; Dubin, F.; Grace, A., Griffith, J.W.; Holtz, M.; Kutscher, C.; Nordham, D.; Selkowitz, S.; Villecco, M.

1981-06-01

This Solar Design Workbook presents solar building design applications for commercial buildir^s. The book is divided into four sections. The first section describes the variety of solar applications in buildings including conservation aspects, solar fundamentals, passive systems, active systems, daylighting, and other solar options. Solar system design evaluation techniques including considerations for building energy requirements, passive systems, active systems, and economics are presented in Section II. The third section attempts to assist the designer in the building design process for energy conservation and solar applications including options and considerations for pre-design, design, and post-design phases. The information required for the solar design proee^ has not been fully developed at this time. Therefore, Section III is incomplete, but an overview of the considerations with some of the design proces elements is presented. Section IV illustrates ease studies that utilize solar applications in the building design.

Representación del Conocimiento en curriculo mediante esquemas preconceptuales

Directory of Open Access Journals (Sweden)

Carlos Mario Zapata

2011-09-01

Full Text Available El concepto de currículo se torna más y más complejo en tanto aparecen nuevos estudios que lo complementan. Como consecuencia, los modelos que, gráfica o formalmente, tratan de representar el conocimiento alrededor del currículo se ocupan cada vez más de aspectos locales, de este modo le restan generalidad de comprensión. Por ello, en este artículo de investigación se realiza una revisión acerca de los diferentes enfoques del currículo a lo largo del siglo XX y de los modelos que representan este concepto. Finalmente, se propone una representación integradora de las diferentes visiones de currículo mediante los denominados esquemas preconceptuales, que consisten en diagramas para la representación del conocimiento cercanos al lenguaje natural

Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

Science.gov (United States)

Longe, Karen M.; McClelland, Michael J.

Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

Solar energy in building construction practice. Solar architecture and solar engineering - fundamentals and uses. Sonnenenergie in der Baupraxis. Solar-Architektur und Solar-Technik - Grundlagen und Anwendungen

Energy Technology Data Exchange (ETDEWEB)

Weik, H.; Hahn, G.; Marschall, F.; Meister, H.; Peters, W.; Ranft, F.

1991-01-01

This anthology presents a number of overall suggestions for modern, trend-setting building construction. Details are given about active in addition to passive solar energy utilization, i.e. combinations of solar architecture and solar engineering. In an intelligible way accessible to non-physicist readers, part one discusses the related physicotechnical and town-planning fundamentals. Parts two and three are dedicated to building construction practice. They discuss the various problems of solar energy utilization from the point of view of architects, and refer to economic aspects and thermal insulation. Numerous pictures, diagrams and tables complete the book. (BWI) With 59 figs.

Proceedings of the Canadian Solar Industries Association Solar Forum 2005 : sunny days ahead : a forum on solar energy for government officials

International Nuclear Information System (INIS)

2006-01-01

Solar energy is the fastest growing energy source in the world. Government involvement is critical in the deployment of solar energy. This forum focused on the application of solar energy in government facilities. The forum was divided into 3 sessions: (1) solar technologies and markets; (2) government initiatives that support solar energy; and (3) the use of solar energy on government facilities in Canada. The current state of solar technologies and products in Canada was reviewed. Solar thermal markets were discussed with reference to passive solar energy and photovoltaic applications. On-site solar generation for federal facilities was discussed, and various federal initiatives were reviewed. Issues concerning Ontario's standard offer contract program were discussed. Government users and buyers of solar products spoke of their experiences in using solar energy and the challenges that were faced. The role that solar energy can play in reducing government costs was discussed, as well as the impact of solar energy on the environment. Opportunities and barriers to the use of solar energy in Canada were explored. The conference featured 14 presentations, of which 2 have been catalogued separately for inclusion in this database. refs., tabs., figs

Solar energy collector

Science.gov (United States)

Brin, Raymond L.; Pace, Thomas L.

1978-01-01

The invention relates to a solar energy collector comprising solar energy absorbing material within chamber having a transparent wall, solar energy being transmitted through the transparent wall, and efficiently absorbed by the absorbing material, for transfer to a heat transfer fluid. The solar energy absorbing material, of generally foraminous nature, absorbs and transmits the solar energy with improved efficiency.

Solar magnetohydrodynamics

International Nuclear Information System (INIS)

Priest, E.R.

1982-01-01

Solar MHD is an important tool for understanding many solar phenomena. It also plays a crucial role in explaining the behaviour of more general cosmical magnetic fields and plasmas, since the Sun provides a natural laboratory in which such behaviour may be studied. While terrestrial experiments are invaluable in demonstrating general plasma properties, conclusions from them cannot be applied uncritically to solar plasmas and have in the past given rise to misconceptions about solar magnetic field behaviour. Important differences between a laboratory plasma on Earth and the Sun include the nature of boundary conditions, the energy balance, the effect of gravity and the size of the magnetic Reynolds number (generally of order unity on the Earth and very much larger on the Sun). The overall structure of the book is as follows. It begins with two introductory chapters on solar observations and the MHD equations. Then the fundamentals of MHD are developed in chapters on magnetostatics, waves, shocks, and instabilities. Finally, the theory is applied to the solar phenomena of atmospheric heating, sunspots, dynamos, flares, prominences, and the solar wind. (Auth.)

Fabricación aditiva mediante sinterizado láser de polvos de acero inoxidable martensítico AISI 420

OpenAIRE

Vega Nava, Sergio

2014-01-01

Busqueda de los parámetros de fabricación adecuados y los tratamientos térmicos a realizar, con el fin de alcanzar durezas de 50 HRC y una adecuada porosidad, en el acero inoxidable AISI 420 obtenido mediante sinterizado láser.

SOLAR AIRCRAFT DESIGN

OpenAIRE

RAHMATI, Sadegh; GHASED, Amir

2015-01-01

Abstract. Generally domain Aircraft uses conventional fuel. These fuel having limited life, high cost and pollutant. Also nowadays price of petrol and other fuels are going to be higher, because of scarcity of those fuels. So there is great demand of use of non-exhaustible unlimited source of energy like solar energy. Solar aircraft is one of the ways to utilize solar energy. Solar aircraft uses solar panel to collect the solar radiation for immediate use but it also store the remaining part ...

Solar engine system

International Nuclear Information System (INIS)

Tan, K.K.; Bahrom Sanugi; Chen, L.C.; Chong, K.K.; Jasmy Yunus; Kannan, K.S.; Lim, B.H.; Noriah Bidin; Omar Aliman; Sahar Salehan; Sheikh Ab Rezan Sheikh A H; Tam, C.M.; Chen, Y.T.

2001-01-01

This paper reports the revolutionary solar engine system in Universiti Teknologi Malaysia (UTM). The solar engine is a single cylinder stirling engine driven by solar thermal energy. A first prototype solar engine has been built and demonstrated. A new-concept non-imaging focusing heliostat and a recently invented optical receiver are used in the demonstration. Second generation of prototype solar engine is described briefly. In this paper, the solar engine system development is reported. Measurement for the first prototype engine speed, temperature and specifications are presented. The benefits and potential applications for the future solar engine system, especially for the electricity generating aspect are discussed. (Author)

Clasificación automática mediante la CDU con el procedimiento en cadena

OpenAIRE

San Segundo Manuel, Rosa

2002-01-01

Actas de las I Jornadas de Tratamiento y Recuperación de Información (JOTRI), Valencia, España, 4-5 julio 2002 Se entiende por clasificación automática el proceso de agrupar según el contenido las referencias de los documentos o bien los propios documentos electróneos. Este proceso se realiza mediante programas capaces de comparar términos empleados utilizados en el documento. E incluso hay otras formas automáticas de clasificación que emplean procedimientos auto...

Solar engineering 1994

International Nuclear Information System (INIS)

Klett, D.E.; Hogan, R.E.; Tanaka, Tadayoshi

1994-01-01

This volume of 83 papers constitutes the Proceedings of the 1994 International Solar Energy Conference held March 27--30, 1994 in San Francisco, California. The Conference was jointly sponsored by the Solar Energy Division of the American Society of Mechanical Engineers, The Japan Society of Mechanical Engineers and the Japan Solar Energy Society. This is the fourth cooperation between ASME, JSME and JSES in cosponsoring the International Solar Energy Conference. The papers cover a wide range of solar technologies from low temperature solar ponds and desalinization to high temperature concentrators for space applications and central receivers for terrestrial power generation. Other topics covered include solar detoxification of hazardous waste, dish Stirling systems, solar cooling, photovoltaics, building energy analysis and conservation, simulation, and testing and measurement techniques. All papers were indexed separately for the data base

Solar array technology evaluation program for SEPS (Solar Electrical Propulsion Stage)

Science.gov (United States)

1974-01-01

An evaluation of the technology and the development of a preliminary design for a 25 kilowatt solar array system for solar electric propulsion are discussed. The solar array has a power to weight ratio of 65 watts per kilogram. The solar array system is composed of two wings. Each wing consists of a solar array blanket, a blanket launch storage container, an extension/retraction mast assembly, a blanket tensioning system, an array electrical harness, and hardware for supporting the system for launch and in the operating position. The technology evaluation was performed to assess the applicable solar array state-of-the-art and to define supporting research necessary to achieve technology readiness for meeting the solar electric propulsion system solar array design requirements.

Solar wind structure out of the ecliptic plane over solar cycles

Science.gov (United States)

Sokol, J. M.; Bzowski, M.; Tokumaru, M.

2017-12-01

Sun constantly emits a stream of plasma known as solar wind. Ground-based observations of the solar wind speed through the interplanetary scintillations (IPS) of radio flux from distant point sources and in-situ measurements by Ulysses mission revealed that the solar wind flow has different characteristics depending on the latitude. This latitudinal structure evolves with the cycle of solar activity. The knowledge on the evolution of solar wind structure is important for understanding the interaction between the interstellar medium surrounding the Sun and the solar wind, which is responsible for creation of the heliosphere. The solar wind structure must be taken into account in interpretation of most of the observations of heliospheric energetic neutral atoms, interstellar neutral atoms, pickup ions, and heliospheric backscatter glow. The information on the solar wind structure is not any longer available from direct measurements after the termination of Ulysses mission and the only source of the solar wind out of the ecliptic plane is the IPS observations. However, the solar wind structure obtained from this method contains inevitable gaps in the time- and heliolatitude coverage. Sokół et al 2015 used the solar wind speed data out of the ecliptic plane retrieved from the IPS observations performed by Institute for Space-Earth Environmental Research (Nagoya University, Japan) and developed a methodology to construct a model of evolution of solar wind speed and density from 1985 to 2013 that fills the data gaps. In this paper we will present a refined model of the solar wind speed and density structure as a function of heliographic latitude updated by the most recent data from IPS observations. And we will discuss methods of extrapolation of the solar wind structure out of the ecliptic plane for the past solar cycles, when the data were not available, as well as forecasting for few years upward.

Gasification of heavy fuels to produce electrical energy and hydrogen; Gasificacion de combustibles pesados para producir energia electrica e hidrogeno

Energy Technology Data Exchange (ETDEWEB)

Vera Garcia, Oscar Alberto [Universidad Nacional Autonoma de Mexico(UNAM), Mexico, D.F. (Mexico)

2006-11-15

integrado (CCGI). El segundo, examina la incorporacion de un reactor shift en el cual el gas de sintesis se transforma en CO{sub 2} y H{sub 2} el cual se usa para mover la turbina a gas, adaptada para hidrogeno puro. Finalmente se estudia la cantidad de otros subproductos que se pueden obtener de estos ciclos de cogeneracion tales como CO{sub 2} para ser usado en recuperacion secundaria de pozos petroleros, N{sub 2} para ser usado en la industria de fertilizantes o en la propia produccion petrolera y H{sub 2} para ser usado en la industria petroquimica o en la generacion con celdas de combustible. Todos los casos son estudiados en forma cuantitativa, realizando los balances de masa y energia de cada uno de ellos. Para darle mas sentido practico a los calculos, se han tomado como base los datos tecnicos de la Central Valladolid de Comision Federal de Electricidad (CFE). Este articulo proporciona una idea basica, pero muy practica, para estimar el consumo de combustible de los diferentes modos de arreglo de una central CCGI, asi como los volumenes de los diferentes gases que se pueden producir y las modificaciones al tamano de los equipos que se requieren.

Solar Heating Systems with Evacuated Tubular Solar Collector

DEFF Research Database (Denmark)

Qin, Lin; Furbo, Simon

1998-01-01

Recently different designed evacuated tubular solar collectors were introduced on the market by different Chinese companies. In the present study, investigations on the performance of four different Chinese evacuated tubular collectors and of solar heating systems using these collectors were...... carried out, employing both laboratory test and theoretical calculations. The collectors were tested in a small solar domestic hot water (SDHW) system in a laboratory test facility under realistic conditions. The yearly thermal performance of solar heating systems with these evacuated tubular collectors......, as well as with normal flat-plate collectors was calculated under Danish weather conditions. It is found that, for small SDHW systems with a combi tank design, an increase of 25% -55% net utilized solar energy can be achieved by using these evacuated tubular collectors instead of normal flat...

Producción de hidrogeno a partir de plasticos mediante pirólisis y reformado catalítico en línea

OpenAIRE

Urruchi Vadillo, Ane

2015-01-01

Los plásticos proporcionan claros beneficios a la sociedad, es un material de innegable utilidad presente en infinidad de productos de uso cotidiano . No obstante, p ese a no ser considerados resi duos peligrosos, los res i duos plásticos representan un problema ambiental global de creciente preocupación ya que la cultura del uso y desecho que prevalece hoy en día hac e que la generación de res i duos ocurra de manera mas...

Mejoramiento de propiedades mecánicas y tribológicas en herramientas industriales mediante aplicación de recubrimientos multicapa de TiN/ZrN

Directory of Open Access Journals (Sweden)

Maryory Astrid Gómez

2010-01-01

Full Text Available En el presente trabajo se depositaron recubrimientos multicapa de TiN/ZrN con 10 bicapas y recubrimientos monocapa de TiN y ZrN mediante pulverización catódica magnetrón r.f. Además, el recubrimiento multicapa se aplicó en fresadoras y se evaluó su desempeño en términos de vida útil de la herramienta. Los recubrimientos se caracterizaron a escala de laboratorio mediante difracción de rayos X, microscopía de fuerza atómica, microdureza Knoop, pruebas de desgaste mediante CaloTest y medidas de adhesión por la prueba de rayado. El recubrimiento multicapa superó a los recubrimientos monocapa en resistencia al desgaste, dureza superficial y carga crítica soportada. La adhesión mostrada por todos los recubrimientos fue muy buena como para ser considerados recubrimientos para aplicaciones industriales. Se incrementó la vida útil de fresas industriales en un 54,1 % con la aplicación del recubrimiento multicapa.

Crean 'antimateria' en gran cantidad

CERN Multimedia

Macedo, C

2002-01-01

"Como si se tratara de una historia de ciencia ficcion, un grupo de cientificos del Laboratorio Europeo de Fisica de Particulas (CERN), en Ginebra, anuncio que produjo por primera vez una gran cantidad de antimateria de hidrogeno, lo que representa un gran paso para entender la formacion del Universo" (1 page).

Deteccion de Chlamydia trachomatis en muestras uretrales mediante inmunofluorescencia directa Detecção de Chlamydia trachomatis em amostras uretrais mediante imunofluorescência direta Detection of Chlamydia trachomatis in urethral samples by means of direct immunofluorescence

Directory of Open Access Journals (Sweden)

Myra Wilson Schuster

1989-12-01

Full Text Available Se estudiaron 82 pacientes con uretritis para la búsqueda de Chlamydia trachomatis mediante inmunofluorescencia directa, Neisscria gonorrhoeae, Mycoplastna y Ureaplasma mediante métodos estándar. Se encontró un 19,5% de Chlamydia trachomatis y en 11 de ellos (68,8% se encontró asociada a otras bacterias y estos pacientes presentó una secreción escasa-gelatinosa.Em 82 doentes com uretrite foi pesquisada a presença de Chlamydia trachomatis, utilizando a prova da imunofluorescência direta, e de Neisseria gonorrhoeae, Mycoplasma e Ureaplasma, utilizando os métodos padrões. Ch. trachomatis foi encontrada em 19,5% dos casos, sendo que em 11 deles (68,8% observou-se associação entre Chlamydia e as outras bactérias pesquisadas. Nesses pacientes observou-se presença de secreção uretral escassa e de aspecto gelatinoso.The presence of Chlamydia trachomatis was studied by the direct immunofluorescence test, as also was that of Neisseria gonorrhoeae, Mycoplasma and Ureaplasma by the standard methods, in 82 patients with urethral discharge. Ch. trachomatis was found in 19.5% (16 of the cases and in 11 of them (68.8% there was association with the other bacteria investigated. This eleven patients presented a scanty gelatinous discharge.

Solar air-conditioning. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

Within the 3rd International Conference on solar air-conditioning in Palermo (Italy) at 30th September to 2nd October, 2009 the following lectures were held: (1) Removal of non-technological barriers to solar cooling technology across Southern European islands (Stefano Rugginenti); (2) The added economic and environmental value of solar thermal systems in microgrids with combined heat and power (Chris Marney); (3) Australian solar cooling interest group (Paul Kohlenbach); (4) Designing of a technology roadmap for solar assisted air conditioning in Austria (Hilbert Focke); (5) Solar cooling in the new context of renewable policies at European level (Raffaele Piria); (6) Prototype of a solar driven steam jet ejector chiller (Clemens Pollerberg); (7) New integrated solar air conditioning system (Joan Carlos Bruno); (8) Primary energy optimised operation of solar driven desiccant evaporative cooling systems through innovative control strategies; (9) Green chiller association (Uli Jakob); (10) Climate Well {sup registered} (Olof Hallstrom); (11) Low capacity absorption chillers for solar cooling applications (Gregor Weidner); (12) Solar cooling in residential, small scale commercial and industrial applications with adsorption technology (Walter Mittelbach); (13) French solar heating and cooling development programme based on energy performance (Daniel Mugnier); (14) Mirrox fresnel process heat collectors for industrial applications and solar cooling (Christian Zahler); (15) Modelling and analyzing solar cooling systems in polysun (Seyen Hossein Rezaei); (16) Solar cooling application in Valle Susa Italy (Sufia Jung); (17) Virtual case study on small solar cooling systems within the SolarCombi+Project (Bjoern Nienborg); (18) Design of solar cooling plants under uncertainty (Fernando Dominguez-Munoz); (19) Fast pre-design of systems using solar thermally driven chillers (Hans-Martin Henning); (20) Design of a high fraction solar heating and cooling plant in southern

IMPLEMENTACIÓN DE UN SISTEMA DE CALEFACCIÓN SOLAR TÉRMICO: ANÁLISIS ENERGÉTICO Y ECONÓMICO

Directory of Open Access Journals (Sweden)

Juan Pablo Vargas Bautista

2016-07-01

Full Text Available El siguiente trabajo presenta la implementación de un sistema de calefacción solar térmico que usa tubos al vacío para el calentamiento de un fluido térmico, aprovechando la energía solar como fuente primaria de energía. La energía almacenada en el fluido es utilizada para climatizar un ambiente de una superficie de 45.5 m2. El sistema se desarrolló con el objetivo de determinar la factibilidad tanto técnica como económica para su implementación en regiones de clima frío en Bolivia. El sistema cuenta con un colector solar de tubos al vacío que se conecta mediante tuberías a un intercambiador de calor tipo radiador. Se usó una bomba para la circulación del fluido caliente del colector al radiador y un ventilador para acelerar la transferencia de calor en el ambiente a climatizar. El sistema de calefacción cuenta con un termostato para el control de la temperatura ambiente para optimizar la energía solar disponible y el consumo de energía eléctrica de la bomba de agua y ventilador de aire. Con la implementación del sistema de calefacción, se consiguió aumentar la temperatura del ambiente de prueba a la temperatura deseada en 3 horas de funcionamiento, en el tiempo restante, el colector solar térmico almacenó la energía solar disponible en el tanque de agua para usarlo al día siguiente. Se comparó el sistema de calefacción solar con un calefactor eléctrico (4 kW bajo las mismas condiciones de operación. Se estimó un ahorro en energía eléctrica mensual de 163.1 kWh/mes con el sistema de calefacción solar que se traduce a un ahorro económico estimado de 23.4 $US/mes. Al reducir el consumo de energía eléctrica también se reduce la emisión de gases de efecto invernadero (G.E.I. en 81.5 kg de CO2/mes. Para el presente caso de estudio, el tiempo en el que se puede recuperar la inversión del sistema de calefacción solar térmico respecto al calefactor eléctrico es de 5.3 años. Como un parámetro importante se

Solar Energy Evolution and Diffusion Studies Webinars | Solar Research |

Science.gov (United States)

NREL Studies Webinars Solar Energy Evolution and Diffusion Studies Webinars These webinars . Department of Energy's Solar Energy Evolution and Diffusion Studies (SEEDS) program. SEEDS 2017-2019 Study Residential Solar July 20, 2017 Presenters: Kiran Lakkaraju, Sandia National Laboratories Yevgeniy Vorobeychik

Solar '80s: A Teacher's Handbook for Solar Energy Education.

Science.gov (United States)

LaHart, David E.

This guide is intended to assist the teacher in exploring energy issues and the technology of solar energy conversion and associated technologies. Sections of the guide include: (1) Rationale; (2) Technology Overview; (3) Sun Day Suggestions for School; (4) Backyard Solar Water Heater; (5) Solar Tea; (6) Biogas; (7) Solar Cells; (8) Economics; (9)…

Solar heating systems for houses. A design handbook for solar combisystems

International Nuclear Information System (INIS)

Weiss, W.

2003-11-01

A handbook giving guidance on systems for providing combined solar space heating and solar water heating for houses has been produced by an international team. The guidance focuses on selection of the optimum combi-system for groups of single-family houses and multi-family houses. Standard classification and evaluation procedures are described. The book should be a valuable tool for building engineers, architects, solar manufacturers and installers of solar solar energy systems, and anyone interested in optimizing combined water and space heating solar systems

Predicción del color y contenido de humedad en café cerezo mediante redes neuronales y regresión de mínimos cuadrados parciales

Directory of Open Access Journals (Sweden)

Wilson Manuel Castro Silupu

2015-12-01

Full Text Available La presente investigación se enfocó en el desarrollo de modelos de predicción del color en coordenadas CIELab y el contenido de humedad de café cerezo mediante la tecnología de imágenes hiperespectrales; comparando el ajuste por un modelo de regresión lineal múltiple – PLSR (Partialleastsquareregression y un modelo no lineal (ANN – artiftial neural network. La muestra se conformó de 200 granos de café cerezo en diferentes estados de madurez, dividiéndola en 120 granos para calibración y 80 de validación.La  muestra fue caracterizada mediante colorimetría en el espacio CIELab y determinación de la humedad. Posteriormente se adquirieron imágenes hiperespectrales de cada granos y se almacenaron en formato *.bil. El procesamiento de las imágenes se realizó mediante un sistema desarrollado e implementado en el software matemático Matlab 2010a, mediante funciones *.m e interfaces de usuario (GUIs. Se desarrollaron modelos de ajuste para cada una de las coordenadas de color y el contenido de humedad, calculándose los coeficientes de correlación en calibración y validación. Los resultados mostraron que las redes neuronales tienen un mayor ajuste en calibración con coeficientes de correlación superiores a 0,90 mientras que el PLSR genero coeficientes entre 0,42 y 0,48.

Medida de la dureza de sólidos mediante nanoindentación

Directory of Open Access Journals (Sweden)

Alkorta, J.

2005-10-01

Full Text Available Hardness is not readily measurable by means of instrumented indentation since the value of the contact area depends on the pile-up or sink-in occurring near the contact surface of the sample. The most widespread method to estimate it by means of the loading/unloading curve of indentation, Oliver and Pharr’s method, deviates, in the extreme cases, up to a 25% from the real values since it only takes into account the elastic deflection. In this work, a new correction based on Oliver and Pharr’s method is proposed that agrees with the numerical calculations. Plastic hardening behaviour of the sample must be known to accurately estimate the contact area.

La medida de la dureza mediante indentación con registro de carga y desplazamiento no es evidente, dada la incertidumbre sobre el tamaño de huella debido al levantamiento (pile-up o hundimiento (sink-in plásticos de la superficie de la muestra alrededor del indentador. El método más utilizado para la medida de la dureza mediante la curva de carga/descarga de indentación, el de Oliver y Pharr, sólo tiene en cuenta hundimiento elástico, por lo que el error en la medida de la dureza y el módulo de Young puede llegar hasta un 25% en los casos más extremos. En el presente trabajo se discute una posible corrección al método de Oliver y Pharr para una obtención más ajustada del área de contacto de la huella. Esta corrección requiere de un conocimiento a priori o a posteriori del comportamiento plástico del material.

CERN... Solar Style

CERN Multimedia

2001-01-01

Inventor William van Sprolant presenting the Solar Club's latest invention, the solar fountain. The CERN Solar Club is giving new meaning to the phrase 'fun in the sun' with their most recently developed contraption, the Solar Fountain. The Fountain was presented to the public just outside of Restaurant 1 on Wednesday October, 17th and uses solar energy to run a water pump at its base to propel a golden plastic ball up into the air. As lovely as the fountain is, the funny thing about it is that the height of the water jet and the ball are an artistic method of measuring the amount of solar power being captured by the photovoltaique panel (no batteries included). The day it was presented started out cloudy, but as the afternoon wore on, the weather brightened and the fountain jumped to life. William van Sprolant, the Solar Fountain's inventor, had great fun with the fountain in front of a group of visiting children swiveling the solar panel in multiple directions. 'Everyone who installs solar panels worrie...

Solar workshops financial incentives

Energy Technology Data Exchange (ETDEWEB)

None

1979-01-01

Ten one-day workshops were held across the United States. Information in this workbook is compiled in conjunction with those workshops. The following discussions are included: solar as a fuel (history); why alternative fuels are being sought today; the need for conservation; advantages of solar energy; the potential of solar energy; why solar energy is not more widely used; a definition of solar; how solar can help meet energy demands; Federal policies and programs; what solar technologies exist today that can be effectively utilized (thermal applications, fuels from biomass, solar electric). Additional information is presented in three attachments: Energy-Conserving Methods; Domestic Policy Review of Solar Energy; and DOE Secretary's Annual Report to Congress-Solar Section. (MCW)

Development of a Greek solar map based on solar model estimations

Science.gov (United States)

Kambezidis, H. D.; Psiloglou, B. E.; Kavadias, K. A.; Paliatsos, A. G.; Bartzokas, A.

2016-05-01

The realization of Renewable Energy Sources (RES) for power generation as the only environmentally friendly solution, moved solar systems to the forefront of the energy market in the last decade. The capacity of the solar power doubles almost every two years in many European countries, including Greece. This rise has brought the need for reliable predictions of meteorological data that can easily be utilized for proper RES-site allocation. The absence of solar measurements has, therefore, raised the demand for deploying a suitable model in order to create a solar map. The generation of a solar map for Greece, could provide solid foundations on the prediction of the energy production of a solar power plant that is installed in the area, by providing an estimation of the solar energy acquired at each longitude and latitude of the map. In the present work, the well-known Meteorological Radiation Model (MRM), a broadband solar radiation model, is engaged. This model utilizes common meteorological data, such as air temperature, relative humidity, barometric pressure and sunshine duration, in order to calculate solar radiation through MRM for areas where such data are not available. Hourly values of the above meteorological parameters are acquired from 39 meteorological stations, evenly dispersed around Greece; hourly values of solar radiation are calculated from MRM. Then, by using an integrated spatial interpolation method, a Greek solar energy map is generated, providing annual solar energy values all over Greece.

The Effects of Solar Irradience and Ambient Temperature on Solar ...

African Journals Online (AJOL)

Solar energy is abundant. It is however low grade energy and cannot be easily used in the form it occurs for work. Converting solar energy directly to electricity, using solar photovoltaic (PV) modules is however a low efficiency process. Optimizing this conversion, especially in the face of the high cost of solar panels, is thus ...

Concentrating Solar Power Projects - ISCC Duba 1 | Concentrating Solar

Science.gov (United States)

Solar Break Ground: 2016 Start Production: 2017 Participants Developer(s): Saudi Electricity Co. Owner(s ) (%): Saudi Electricity Co. EPC Contractor: Initec Energia Generation Offtaker(s): Saudi Electricity Co. Plant Configuration Solar Field SCA Manufacturer (Model): Flabeg (Ultimate Trough) HCE Manufacturer: Archimede Solar

Photovoltaic solar cell

Science.gov (United States)

Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

2015-09-08

A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

Solar Power Sources

DEFF Research Database (Denmark)

Kim, Katherine A.; Mentesidi, Konstantina; Yang, Yongheng

2017-01-01

a significant change. Beyond this energy transition, the still declining cost of the solar technology has become an important driving force for more solar-powered systems. However, high penetration of solar-powered systems also brings technical challenges to the entire energy systems. In order to fully address......Solar power is highly abundant, relatively reliable, and not limited to a geographic region, making it one of the most important renewable energy sources. Catering for a clean and green energy system, solar energy will be an active player in the future mixed power grid that is also undergoing...... those issues, the technological properties of solar power should be investigated. Thus, the basics of solar power technology will be introduced and discussed in this chapter....

Photovoltaic solar concentrator

Science.gov (United States)

Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

2016-03-15

A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

Smart solar tanks for small solar domestic hot water systems

DEFF Research Database (Denmark)

Furbo, Simon; Andersen, Elsa; Knudsen, Søren

2005-01-01

Investigation of small SDHW systems based on smart solar tanks are presented. The domestic water in a smart solar tank can be heated both by solar collectors and by means of an auxiliary energy supply system. The auxiliary energy supply system – in this study electric heating elements – heats up...... systems, based on differently designed smart solar tanks and a traditional SDHW system were investigated by means of laboratory experiments and theoretical calculations. The investigations showed that the yearly thermal performance of SDHW systems with smart solar tanks is 5-35% higher than the thermal...... performance of traditional SDHW systems. Estimates indicate that the performance/cost ratio can be improved by up to 25% by using a smart solar tank instead of a traditional tank when the backup energy system is electric heating elements. Further, smart solar tanks are suitable for unknown, variable, large...

Radiación Solar UV-B y estrés en las plantas

Directory of Open Access Journals (Sweden)

Pedro José Almanza Merchán

2004-11-01

Full Text Available Las plantas son las encargadas de la realización de procesos metabólicos esenciales. Ellas tienen la posibilidad de generar oxígeno y compuestos alimenticios a través de la  fotosíntesis a partir del agua, el dióxido de carbono y la energía solar. Por lo tanto, son esenciales para el mantenimiento de la vida en el planeta. El lugar donde se desarrollan, se convierte en la fuente de información que determinará la cantidad y calidad de la cosecha. La luz es heterogénea y cambiante de ahí que las plantas se hallan expuestas a radiaciones adversas para la realización de sus procesos metabólicos. Es así, como han desarrollado una serie de adaptaciones estructurales y fisiológicas que les permiten soportar y aprovechar la radiación disponible. La energía solar ultravioleta es inhibidora, y puede ocasionar algunos desbalances biosintéticos, que a su vez, mediante las rutas del metabolismo  secundario, podrían generar propiedades especiales imprimiendo tipicidad en frutos producidos en climas fríos tropicales, con características regionales o de denominación de origen. La biosíntesis secundaria, suele hallarse restringida a fases específicas del desarrollo de la planta y a situaciones  de estrés; condiciones que inducen a la expresión de genes que codifican varias enzima de la ruta biosintética de compuestos fenilpropanoides

Indicadores de eficiencia relativa del proceso de gestión de crédito en un banco colombiano, mediante análisis envolvente de datos (DEA)

OpenAIRE

Sánchez-Gooding, Sandra Paola; Rodríguez-Lozano, Gloria Isabel

2016-01-01

El presente trabajo tiene como objetivo medir la eficiencia relativa de las unidades que participan en el proceso de gestión de crédito de un banco colombiano, mediante la utilización del análisis envolvente de datos (Data Envelopment Analysis, DEA). Mediante un doble proceso de optimización, esta metodología de programación lineal avanzada genera un único índice de eficiencia relativa para cada una de las unidades estudiadas, aunque es capaz de incluir múltiples recursos y múltiples salidas....

Evaluacion de competencias mediante prácticas dirigidas sobre proyectos de edificación

OpenAIRE

Castilla, Franciso; Castilla, Franciso; Sanz, David; González, Jesús; Pérez, Víctor

2011-01-01

La Búsqueda de herramientas eficaces para la evaluación de competencias transversales, comunes a diferentes asignaturas de un mismo plan de estudios, es uno de los pilares del nuevo Espacio Europeo de Educación Superior. El trabajo que aquí se presenta pretende mostrar las experiencias realizadas en primer curso del Grado en Ingeniería de Edificación en la Escuela Politécnica de Cuenca mediante prácticas dirigidas sobre edificios y proyectos de edificación. El objetivo principal es obtener...

Estudio mediante resonancia magnética de efectos pretransicionales en cristales líquidos

OpenAIRE

Vaca Chavez, Fabián

2002-01-01

Tesis (Doctor en Física)--Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física, 2002. Se presenta el estudio mediante la técnica de Resonancia Magnética Nuclear de los efectos pretransicionales en diferentes fases de cristales líquidos termotrópicos y liotrópicos. Estos compuestos son materia de innumerables trabajos tanto teóricos como experimentales, debido a que son materiales extremadamente interesantes por sus aplicaciones tecnológicas, ópticas y biológicas. Se...

The Measurement of Natural Tritium Levels in Geiger Counters; Determination quantitative du tritium naturel par compteurs Geiger; Izmerenie urovnej estestvennogo tritiya v schetchikakh Gejgera; Medicion de concentraciones naturales de tritio mediante contadores Geiger

Energy Technology Data Exchange (ETDEWEB)

O' Brien, B J [Institute of Nuclear Sciences, Gracefield (New Zealand)

1962-01-15

sont particulierement satisfaisantes. L'auteur decrit un dispositif de comptage qui comprend un compteur rempli d'hydrogene a la pression de 40 cm de mercure, la substance de coupage utilisee etant l'ethylamine. Le bruit de fond est de 3 cpm, et la pente du palier correspondant relativement faible. (author) [Spanish] El autor describe un metodo de analisis de tritio en un contador de 300 ml que funciona con arreglo al principio de la extincion interna por medio de gases. Originariamente se aplico un sistema basado en el empleo de una mezcla de etileno y argon como gas extintor, en combinacion con un anillo de anticoincidencias. Ahora bien, las caracteristicas del rellano de la curva de recuento al emplear un circuito de anticoincidencias no resultaban satisfactorias cuando el numero de impulsos era reducido, debido a una extincion deficiente, y por tal motivo se trato de encontrar una mezcla gaseosa mas eficaz. El autor estudia la causa de la pendiente del rellano de la curva del recuento de fondo y enumera las propiedades que debe reunir un gas extintor adecuado para el recuento del hidrogeno. Detalla los resultados de un estudio de las caracteristicas de recuento del hidrogeno usando como sustancias extintoras el benceno, el bromuro de etilo, el eter etilico, la isopropil amina, el hexano, la etilamina y el isopieno. Se comprobo que la etilamina y el eter etilico, en particular, presentan caracteristicas de extincion muy satisfactorias. El autor describe un sistema de recuento basado en el empleo de un contador que se rellena con hidrogeno a la presion de 40 cm de Hg y en el cual se usa etilamina para la extincion. La actividad de fondo asciende a 3 impulsos por minuto, siendo relativamente debil la pendiente del rellano de la curva correspondiente. (author) [Russian] Daetsya opisanie metoda podscheta tritiya v 300ml gazovom schetchike s ispol'zovaniem gazov dlya gasheniya. Pervonachal'no byla primenena sistema s kol'tsom nesovpadenij pri ispol'zovanii ehtilen

CONTROL ROBUSTO DE UN SISTEMA MECÁNICO SIMPLE MEDIANTE UNA HERRAMIENTA GRAFICA

Directory of Open Access Journals (Sweden)

LUINI HURTADO CORTÉS

2010-01-01

Full Text Available en este artículo se presenta el diseño de un controlador robusto para un sistema masaresorteamortiguador . Con el fin de realizar un diseño simple, se tomó en cuenta únicamente la incertidumbre en los parámetros de la planta. Los cálculos del problema se realizaron con una interfaz gráfica desarrollada para el diseño de controladores robustos, disponible para la Toolbox de Control Robusto de Matlab Ò . Se pretende que este ejercicio sirva como tutorial de introducción al análisis y diseño de sistemas de control robusto mediante el uso de la interfaz gráfica.

The solar kettle-thermos flask (SK-TF) and solar vacuum tube oven

Energy Technology Data Exchange (ETDEWEB)

Yak, Alex Kee Koo [AkayConsult Enterprise, Johor Bahru (Malaysia)

2008-07-01

The Solar Kettle-Thermos Flask (SK-TF) and Solar Vacuum Tube Oven (SaVeTao): A Cost Effective, Sustainable and Renewable Water Pasteurization and Food Processing System For The Developing World. Based on the perfect solar thermal energy harvesting paradigm of maximum solar radiation absorption and minimum loss of stored converted solar thermal energy, Solar Vacuum Glass Tubes (SVGT) indefinitely delivers solar pasteurized safe drinking water, powered solely by free solar energy. The SVGT is the heart of the SK-TF. Being vacuum insulated, the SK-TF doubles up as a vacuum flask, delivering stored solar heated water in the morning before the Sun is up. With a high stagnation temperature of more than 200 C, the SK-TF can also be used for other heating purposes e.g. an oven or autoclave. Powered solely by free solar energy, the SK-TF and SaVeTaO could very well be the answer in providing safe solar pasteurized drinking water and cooking to the global poor and needy in a sustainable and renewable way. (orig.)

Research and development of hydrogen and fuel cells technology at the IIE; Investigacion y desarrollo de tecnologia de hidrogeno y celdas de combustible en el IIE

Energy Technology Data Exchange (ETDEWEB)

Cano C, Ulises; Arriaga H, Gerardo; Romero C, T; Medrano V, M. Consolacion; Gonzalez, A. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2005-07-01

In April, 2001, a fuel cells project was initiated at the Instituto de Investigaciones Electricas (IIE) as a part of the interest of this institution for such a technology. Towards end of that same year, a group dedicated to research and development (R and D) activities was implemented and efforts were initiated for the assembly of a laboratory with specialized infrastructure that would support these activities. Thus, in the last two years, the hydrogen and fuel cells group has taken under its responsibility the task of renewing and conditioning a space to receive specialized instrumentation and to initiate its operation, as well as to develop its own knowledge on the technology of fuel cells. The R and D work related to fuel cells was initiated from basic electrochemical studies of platinum electrodes on vitreous coal in acid solutions, to determine kinetic parameters and structural properties. Since the main components of PEM cells to a great extent define the cost of the technology, other additional efforts related to basic studies for the development of components as bipolar plates, are described by the same author in 2001. Other work on basic research is bound to the response of fuel monocells under different operation conditions, and that also will be reviewed in this article. [Spanish] En abril del 2001, se inicio un proyecto de celdas de combustible en el IIE como parte del interes de esta institucion por tal tecnologia. Hacia finales de ese mismo ano, se conformo un grupo dedicado a actividades de investigacion y desarrollo (I y D) y se iniciaron esfuerzos para el montaje de un laboratorio con infraestructura especializada que apoyara estas actividades. Asi, en los ultimos dos anos, el grupo de hidrogeno y celdas de combustible se ha dado a la tarea de renovar y acondicionar un espacio para recibir instrumentacion especializada e iniciar su operacion, asi como a desarrollar su propio conocimiento de tecnologia de celdas de combustible. Los trabajos de I y

DETECCIÓN DEL DISCO ÓPTICO EN RETINOGRAFÍAS MEDIANTE UNA ESTRATEGIA EVOLUTIVA (µ+λ

Directory of Open Access Journals (Sweden)

Germán Sánchez Torres

Full Text Available En este artículo se presenta un procedimiento para la detección del disco óptico (DO en retinografías, mediante un algoritmo evolutivo. El procedimiento tiene dos etapas principales: la detección gruesa de la posición del DO y el refinamiento de los bordes del contorno. La detección gruesa ubica la posición del DO mediante un algoritmo evolutivo, cuyos individuos tienen como función objetivo la cantidad de píxeles brillantes y el número de bordes de la red de conductos sanguíneos, contenidos dentro de una circunferencia. La etapa de refinamiento aplica un procedimiento geométrico, para deformar el círculo inicial, ajustando el borde de éste con la posición del píxel de mayor variación en dirección al vector normal. El procedimiento fue evaluado empleando los repositorios públicos STARE y DIAREDB, procesando imágenes de pacientes sanos y con alteraciones de las retina, generadas por la presencia de retinopatía diabética. Los resultados experimentales muestran que el método propuesto puede identificar la posición del disco óptico en retinografías con una precisión cercana al 96 %.

Análisis de vulnerabilidad mediante modelamiento hidrodinámico del cauce del río seco del Cono Sur de la ciudad de Tacna

OpenAIRE

Frisancho Camero, Felix Ladislao

2015-01-01

La cuenca del río Seco tiene un área de 1 106,49 Km2 y una cuenca húmeda de 344,74 Km2, contando con el aporte de tres sub cuencas: Caplina , Palca y Vilavilani Yungane. Se analizó las variables del estudio, siendo la población que habita en la zona, infraestructura urbana y la hidrología y geología de la cuenca. Mediante el análisis de frecuencias se estimaron las precipitaciones, intensidades o caudales máximos, para diferentes períodos de retorno, mediante la aplicación de modelos probabil...

Promoción de salud y prevención de adicciones en adolescentes mediante la actividad física y el arte : Proyecto Faro

OpenAIRE

Tarducci, Gabriel Omar; Butler Tau, Gabriela; Gárgano, Sofía; Gandini, Agustina; Lencina, Gustavo; Biera, Rosa; Valle, Mara; Ciochini, Patricia; Olmedo, Teresa Inés; Villa, María Eugenia; Berdula, Lorena Irene; Díaz, Hernán; Sánchez Olguín, Gerardo

2015-01-01

El Proyecto Faro se lleva a cabo a mediante la Cátedra de Teoría de la práctica artística de la Facultad de Bellas Artes y la Cátedra Seminario de actividad física para la salud de la facultad de Humanidades y Ciencias de la Educación de la UNLP. Mediante este proyecto se desarrollaron guías de promoción de salud y prevención de adicciones destinadas a adolescentes para ser utilizadas a nivel escolar y extraescolar. Objetivo: Potenciar la salud con especial énfasis en la prevención de adiccio...

Solar Simulator

Science.gov (United States)

1981-01-01

Oriel Corporation's simulators have a high pressure xenon lamp whose reflected light is processed by an optical system to produce a uniform solar beam. Because of many different types of applications, the simulators must be adjustable to replicate many different areas of the solar radiation spectrum. Simulators are laboratory tools for such purposes as testing and calibrating solar cells, or other solar energy systems, testing dyes, paints and pigments, pharmaceuticals and cosmetic preparations, plant and animal studies, food and agriculture studies and oceanographic research.

Solar collector array

Science.gov (United States)

Hall, John Champlin; Martins, Guy Lawrence

2015-09-06

A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

Diagnóstico de fallas en el sistema de lubricación de un motor de combustión interna a gasolina Hyundai Accent DOHC 1.5L mediante análisis de vibraciones

OpenAIRE

Buestán Ramírez, Christian Santiago; Jarama Herrera, Carlos Teodoro

2016-01-01

En este documento se presenta el diagnóstico de fallas en el sistema de lubricación de un motor de combustión interna Hyundai Accent 1.5L mediante análisis de vibraciones, en el cual mediante el uso de un diseño experimental se adquirió las señales vibroacústicas, las que fueron procesadas mediante la Transformada de Fourier; para el posterior análisis de resultados por Comparación Espectral y Análisis de Componentes Principales (ACP). This research presents the fault diagnosis in the lubr...

Impacts of the Solar Investment Tax Credit On State-Level Solar Outcomes

OpenAIRE

Kolachalam, Sriman

2017-01-01

In this paper, I investigate the effects of the U.S. federally implemented Solar Investment Tax Credit (ITC) on states’ solar energy installation and utilization. In particular, I compare relative trends in solar installation and utilization between states with initially higher levels of solar and states with initially lower levels of solar, before and after the implementation of the Solar ITC. My findings demonstrate that states with initially higher level...

Detección Molecular de Toxinas Termoestable y Termolabil de Escherichia coli mediante Hibridación

Directory of Open Access Journals (Sweden)

Isabel Arias B

2002-10-01

Full Text Available Objetivos: Identificar mediante el método de hibridización por colony blot las toxinas de Escherichia coli enterotoxigénica y relacionar los resultados con los serotipos encontrados. Materiales y métodos: se evaluaron todas las cepas de E. Coli recolectadas en el Hospital de Emergencias Pediátricas de Lima durante los meses de diciembre de 1998 - abril 1999. Se usaron dos sendas de ADN que identificaban el gen de la toxina termolábil (LT y el de la toxina termoestable (ST Para la detección de los serotipos se usaron 22 antisueros de diferentes categorías de E. coli. Resultados: se encontraron 233 cepas de E. coli, 27,9% de E. coli poseían el gen LT, 3,0% el gen ST y 1,3% tenían ambos. Conclusiones: los serotipos y la presencia de los genes LT y ST no necesariamente tienen relación, demostrándose que la identificación serológica es importante en el estudio epidemiológico de diarreas causadas por E. coli debiéndose confirmar la identificación de las categorías patogénicas mediante la detección de factores de virulencia.

Valoración de las aguas residuales mediante procedimientos analíticos y biológicos

Directory of Open Access Journals (Sweden)

M. Carballo

2002-06-01

Full Text Available Ciertos procedimientos, basados en aproximaciones analíticas y biológicas, están demostrando ser útiles en la valoración del riesgo de las aguas residuales urbanas procedentes de las Plantas de Tratamiento. Estos efluentes, considerados “mezclas complejas”, compuestos por sustancias de muy diferente naturaleza, origen y características toxicológicas y medio ambientales, requieren una valoración realista. Con el fin de colaborar al conocimiento de una parte de la realidad de nuestro país, presentamos un estudio sobre once depuradoras urbanas en las que se ha realizado un perfil de compuestos orgánicos y una valoración toxicológica mediante tests de toxicidad agudos, crónicos, de estrogenicidad, mutagenicidad y teratogenia. Los resultados muestran que 7 efluentes presentan toxicidad aguda, 3 toxicidad crónica y 4 estrogenicidad. Destacamos el hecho de que los 4 efluentes que presentan estrogenicidad, poseen al menos 3 de las sustancias estrogénicas detectadas mediante el perfil cromatográfico. Este tipo de consideraciones nos hace reflexionar sobre la necesidad de incorporar este tipo de metodologías para disponer de un conocimiento más realista de estas situaciones.

Ciberacoso mediante teléfono móvil e Internet en las relaciones de noviazgo entre jóvenes

Directory of Open Access Journals (Sweden)

Roberto Martínez Pecino

2015-01-01

Full Text Available El ciberacoso es un fenómeno ampliamente analizado entre adolescentes, sin embargo en España ha sido poco estudiado entre jóvenes y particularmente en sus relaciones de noviazgo. Empleando una metodología cuantitativa este estudio analiza el ciberacoso mediante el teléfono móvil e Internet en las relaciones de noviazgo en una muestra compuesta por 336 estudiantes universitarios. El análisis de resultados indica que un 57,2% declara haber sido victimizado por su pareja mediante el teléfono móvil, y un 27,4% a través de Internet. El porcentaje de chicos victimizados fue mayor que el de las chicas. Un 47,6% declara haber acosado a su pareja a través del teléfono móvil, y un 14% a través de Internet. El porcentaje de chicos que lo ejerció fue superior al de las chicas. Los análisis de regresión muestran la relación entre haber sido victimizado por la pareja a través de uno de estos medios y el ejercicio del ciberacoso hacia la pareja mediante el mismo medio tecnológico. Los efectos de interacción ponen de manifiesto que los chicos victimizados a través del teléfono móvil o de Internet se implican, en mayor medida que las chicas victimizadas, como agresores en este fenómeno. Los resultados sugieren una modernización en los tipos de violencia que experimenta la juventud en sus relaciones de pareja.

Producción de materiales en lámina delgada mediante técnicas láser

Directory of Open Access Journals (Sweden)

Afonso, C. N.

1998-04-01

Full Text Available Pulsed laser deposition is a recently developed technique with a large potential in producing materials of technological interest that are not easily produced by more conventional techniques, such as complex oxides or hard ceramics. We will first review the special features of this technique to then show current results of our own research in producing optically doped waveguides either with rare-earth ions or metal nanoparticles.

Mediante la moderna técnica de depósito por láser pulsado (PLD se pueden obtener materiales de alto interés tecnológico, como son óxidos complejos o cerámicas duras que no son fáciles de obtener por otras técnicas más convencionales. En el presente trabajo, se revisan, en primer lugar, las características especiales de esta técnica. A continuación, se presentan los resultados obtenidos en las investigaciones actualmente en marcha en nuestro laboratorio sobre dopado óptico de materiales mediante especies activas, como los iones de tierras raras o partículas nanocristalinas en matrices aislantes.

Solar neutrinos and solar accretion of interstellar matter

International Nuclear Information System (INIS)

Newman, M.J.; Talbot, R.J. Jr.

1976-01-01

It is argued that if the Hoyle-Lyttleton mass accretion rate applies (Proc. Camb. Phil. Soc., Math. Phys. Sci. 35: 405 (1939)) the accretion of interstellar matter by the Sun is sufficient to enhance the surface heavy element abundances. This will also apply to other solar-type stars. The enhancement may be sufficient to allow the construction of consistent solar models with an interior heavy element abundance significantly lower than the observed surface abundance. This state of affairs lowers the predicted solar neutrino flux. It has been suggested that a similar enhancement of surface abundances might occur due to accretion of 'planetesimals' left over after formation of the solar system, and both processes may occur, thereby increasing the effect. The simple accretion model of Hoyle and Lyttleton is discussed mathematically. A crucial question to be answered by future research, however, is whether or not accretion on to the solar surface actually occurs. One of the most obvious obstacles is the outward flowing solar wind, and this is discussed. It appears that the outward flow can be reversed to an inward flow for certain interstellar cloud densities. (U.K.)

Solar action: solar hot water in The Netherlands

International Nuclear Information System (INIS)

Van de Water, Adrie

2001-01-01

This paper focuses on the use of solar hot water systems in the Netherlands, and reports on the Dutch Solar Domestic Hot Water System agreement signed in 1999 and set up to enhance the development of the market for solar domestic hot water (SDHW) systems and their application as a sustainable energy source. The Dutch Thermal Solar Energy Programme's objectives and goals, the subsidy schemes for thermal solar energy administered by Senter - an agency of the Ministry of Economic Affairs (MEA), and the project-based and individual approaches to boosting the sales of SDHW systems are examined. Large system sales, the targeting of consumers via a national campaign, and national publicity using the slogan 'Sustainable energy. Goes without saying' commissioned by the MEA are discussed along with the support shown by the Dutch power distribution companies for SDHW systems, marketing aspects, and the outlook for sales of SDHW systems

Introduction to solar cell production

International Nuclear Information System (INIS)

Kim, Gyeong Hae; Lee, Jun Sin

2009-08-01

This book introduces solar cell production. It is made up eight chapters, which are summary of solar cell with structure and prospect of the business, special variable of solar cell on light of the sun and factor causing variable of solar cell, production of solar cell with surface texturing, diffusion, metal printing dry and firing and edge isolation, process of solar cell on silicone wafer for solar cell, forming of electrodes, introduction of thin film solar cell on operating of solar cell, process of production and high efficiency of thin film solar cell, sorting of solar cell and production with background of silicone solar cell and thin film solar cell, structure and production of thin film solar cell and compound solar cell, introduction of solar cell module and the Industrial condition and prospect of solar cell.

Solar constraints

International Nuclear Information System (INIS)

Provost, J.

1984-01-01

Accurate tests of the theory of stellar structure and evolution are available from the Sun's observations. The solar constraints are reviewed, with a special attention to the recent progress in observing global solar oscillations. Each constraint is sensitive to a given region of the Sun. The present solar models (standard, low Z, mixed) are discussed with respect to neutrino flux, low and high degree five-minute oscillations and low degree internal gravity modes. It appears that actually there do not exist solar models able to fully account for all the observed quantities. (Auth.)

SOLAR WIND HEAVY IONS OVER SOLAR CYCLE 23: ACE/SWICS MEASUREMENTS

International Nuclear Information System (INIS)

Lepri, S. T.; Landi, E.; Zurbuchen, T. H.

2013-01-01

Solar wind plasma and compositional properties reflect the physical properties of the corona and its evolution over time. Studies comparing the previous solar minimum with the most recent, unusual solar minimum indicate that significant environmental changes are occurring globally on the Sun. For example, the magnetic field decreased 30% between the last two solar minima, and the ionic charge states of O have been reported to change toward lower values in the fast wind. In this work, we systematically and comprehensively analyze the compositional changes of the solar wind during cycle 23 from 2000 to 2010 while the Sun moved from solar maximum to solar minimum. We find a systematic change of C, O, Si, and Fe ionic charge states toward lower ionization distributions. We also discuss long-term changes in elemental abundances and show that there is a ∼50% decrease of heavy ion abundances (He, C, O, Si, and Fe) relative to H as the Sun went from solar maximum to solar minimum. During this time, the relative abundances in the slow wind remain organized by their first ionization potential. We discuss these results and their implications for models of the evolution of the solar atmosphere, and for the identification of the fast and slow wind themselves.

Cristalización de vidrios ricos en sílice preparados mediante sol-gel en el sistema alúmina-circona-sílice

Directory of Open Access Journals (Sweden)

Popa, M.

2004-02-01

Full Text Available The crystallization of ZrSiO4 and its evolution with temperature from chemically homogeneous alumina-silica-zirconia powders prepared by sol-gel method from alcoxide mixtures was studied in the silica-rich region. A glass with the same composition was obtained by quenching in water from the melt. The gel-glasses evolution and microstructure were studied by means of XRD, IR and SEM/EDX, in the range of temperatures up to 1650oC. The materials consisted mainly of amorphous phase up to 1200oC, at which partial crystallization of cristobalite was observed. IR spectroscopy analysis showed zircon bands after thermal treatment at 1200oC. The crystallization of zircon and zirconia particles at 1550oC was confirmed by SEM/EDX analysis. At 1650oC the only stable crystalline phase observed after 40 h of thermal treatment was zircon.

La cristalización de ZrSiO4 y su evolución con la temperatura se ha estudiado en la región rica en sílice, a partir de polvos amorfos y químicamente homogéneos de alumina-sílice-circona, preparados mediante método sol-gel usando mezclas de alcóxidos. Se obtuvo un vidrio con idéntica composición mediante enfriamiento rápido por inmersión en agua del material fundido. La evolución y la microestructura de los vidrios obtenidos se estudió mediante difracción de rayos X, infrarrojos, microscopía electrónica de barrido y análisis químico, en el rango de temperaturas hasta 1650oC. Los materiales están formados principalmente por fase amorfa hasta 1200oC, temperatura a la cual se observa la cristalización parcial de cristobalita. El análisis por espectroscopía de infrarrojos muestra bandas de circón en muestras tratadas térmicamente por encima de 1200oC. Las observaciones mediante microscopía electrónica confirman la cristalización de partículas de circón y circona a 1550oC. A 1650oC la cristobalita ha fundido y la única fase cristalina estable detectada mediante XRD tras 40 h a esta temperatura

Coordinated weather balloon solar radiation measurements during a solar eclipse.

Science.gov (United States)

Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

2016-09-28

Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. © 2016 The Authors.

Development of nonmetallic solar collector and solar-powered pump

Science.gov (United States)

Parker, J. C.

1979-01-01

Design and building of two unique components for solar heating (1. flatplate solar collector using no metal components, and 2. solar powered pump for heating and cooling systems are outlined in report. Report also discusses hardware, deliverable end items, problems encountered during fabrication and testing, and performance certification.

Solar thermal

International Nuclear Information System (INIS)

Jones, J.

2006-01-01

While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m 3 - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become increasingly important as

Solar thermal

Energy Technology Data Exchange (ETDEWEB)

Jones, J.

2006-07-15

While wind power is widely acknowledged as the most developed of the 'new' renewables, the number two technology, in terms of installed capacity functioning worldwide, is solar heating, or solar thermal. The author has investigated recent industry reports on how these markets are developing. The authors of an International Energy Agency (IEA) survey studied 41 countries in depth at the end of 2004, revealing that 141 million m{sup 3} - corresponding to an installed capacity of 98.4 GWth - were installed in the sample countries (these nations represent 3.74 billion people, about 57% of the world's population). The installed capacity within the areas studied represents approximately 85%-90% of the solar thermal market worldwide. The use of solar heating varies greatly between countries - even close neighbours - and between economic regions. Its uptake often has more to do with policy than solar resource. There is also different uptake of technology. In China, Europe and Japan, plants with flat-plate and evacuated tube collectors are used, mainly to heat water and for space heating. Unglazed plastic collectors, used mainly for swimming pool heating, meanwhile, dominate the North American markets. Though the majority of solar heating installations today are installed on domestic rooftops, the larger-scale installations should not be overlooked. One important part of the market is the hotel sector - in particular hotels in locations that serve the seasonal summer holiday market, where solar is extremely effective. Likewise hospitals and residential homes, multi-family apartment blocks and sports centres are all good examples of places where solar thermal can deliver results. There are also a growing number of industrial applications, where solar thermal can meet the hot water needs (and possibly more) of a range of industries, such as food processing and agriculture. The ability of solar to provide a heat source for cooling is expected to become

Availability of solar radiation and standards for solar access

Energy Technology Data Exchange (ETDEWEB)

Casabianca, G.A.; Evans, J.M. [Research Centre Habitat and Energy, Facultad de Arquitectura, Diseno y Urbanismo, Universidad de Buenos Aires, Capital Federal (Argentina)

1997-12-31

In southern Argentina, a region between latitudes 38 deg C and 55 deg C S, the heating demand in the residential sector is high while the availability of solar radiation is limited. A new proposal for solar access standards has been developed, taking into account the climatic conditions of each location, the effective availability of solar radiation and the direct sunlight requirements. This study analyses the climatic conditions for the Patagonia, relating heating demand and solar radiation availability in different sites, and presents the development of new sunlight standards that respond to these regional conditions. As a result of this study, the new Argentine standard TRAM 11.603 includes new conditions to protect solar access and provide design recommendations. (orig.) 4 refs.

Solar Energy Technician/Installer

Science.gov (United States)

Moore, Pam

2007-01-01

Solar power (also known as solar energy) is solar radiation emitted from the sun. Large panels that absorb the sun's energy as the sun beats down on them gather solar power. The energy in the rays can be used for heat (solar thermal energy) or converted to electricity (photovoltaic energy). Each solar energy project, from conception to…

Solar Energy and You.

Science.gov (United States)

Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

This booklet provides an introduction to solar energy by discussing: (1) how a home is heated; (2) how solar energy can help in the heating process; (3) the characteristics of passive solar houses; (4) the characteristics of active solar houses; (5) how solar heat is stored; and (6) other uses of solar energy. Also provided are 10 questions to…

Solar energy an introduction

CERN Document Server

Mackay, Michael E

2015-01-01

Solar Energy presents an introduction to all aspects of solar energy, from photovoltaic devices to active and passive solar thermal energy conversion, giving both a detailed and broad perspective of the field. It is aimed at the beginner involved in solar energy or a related field, or for someone wanting to gain a broader perspective of solar energy technologies. A chapter considering solar radiation, basic principles applied to solar energy, semiconductor physics, and light absorption brings the reader on equal footing with the technology of either solar generated electrical current or useful heat. Details of how a solar cell works and then production of current from a photovoltaic device is discussed. Characterization of a solar cell is examined, allowing one the ability to interpret the current-voltage relation, followed by discussion of parameter extraction from this relation. This information can be used to understand what limits the performance of a given solar cell with the potential to optimize its pe...

Solar energy guide

International Nuclear Information System (INIS)

Lentz, A.; Winter, R.

1993-07-01

Many aspects with regard to the practical use of solar energy are discussed. This guide is aimed at informing local and regional administrators, committee members of housing corporations and public utilities and public relations officers on the possibilities to use solar energy. In chapter one an overview is given of the use of solar energy in the housing sector, the recreational sector, agricultural sector, industry, trade and other sectors. In the chapters two, three and four attention is paid to passive solar energy, active thermal solar energy and photovoltaic energy respectively. In the chapters five and six aspects concerning the implementation of solar energy systems in practice are discussed. First an outline of the parties involved in implementing solar energy is given: the municipality, the energy utility, the province, local authorities, advisors, housing constructors and the occupants of the buildings. Then attention is paid to the consequences of implementing solar energy for the building inspection and regulations, the finances, energy savings and the environment. In chapter seven an overview is given of the subsidy regulations of the European Community, the Dutch national and local governments. Chapter contains addresses of solar thermal systems, photovoltaic systems and other institutes operating in the field of solar energy, as well as the titles of a number of brochures and courses. 51 figs., 7 tabs., 86 refs

Solar storms; Tormentas solares

Energy Technology Data Exchange (ETDEWEB)

Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

2016-08-01

Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

Characteristic studies on solar x-ray flares and solar radio bursts during descending phases of solar cycles 22 and 23

International Nuclear Information System (INIS)

Bhattacharya, J.; De, B.K.; Guha, A.

2014-01-01

In this paper, a comparative study between the solar X-ray flares and solar radio bursts in terms of their duration and energy has been done. This has been done by analyzing the data in a statistical way covering the descending phase of the 22nd and 23rd solar cycles. It has been observed that the most probable value of duration of both solar X-ray flares and solar radio bursts remain same for a particular cycle. There is a slight variation in the most probable value of duration in going from 22nd cycle to 23rd cycle in the case of both kinds of events. This small variation may be due to the variation of polar field. A low correlation has been observed between energy fluxes in solar X-ray flares and in solar radio bursts. This has been attributed to the non symmetric contribution of energy to the solar radio and X-ray band controlled by solar magnetic field

Solar energy modulator

Science.gov (United States)

Hale, R. R. (Inventor); Mcdougal, A. R.

1984-01-01

A module is described with a receiver having a solar energy acceptance opening and supported by a mounting ring along the optic axis of a parabolic mirror in coaxial alignment for receiving solar energy from the mirror, and a solar flux modulator plate for varying the quantity of solar energy flux received by the acceptance opening of the module. The modulator plate is characterized by an annular, plate-like body, the internal diameter of which is equal to or slightly greater than the diameter of the solar energy acceptance opening of the receiver. Slave cylinders are connected to the modulator plate for supporting the plate for axial displacement along the axis of the mirror, therby shading the opening with respect to solar energy flux reflected from the surface of the mirror to the solar energy acceptance opening.

A hybrid solar chemical looping combustion system with a high solar share

International Nuclear Information System (INIS)

Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

2014-01-01

Highlights: • A novel hybrid solar chemical looping combustion system is presented. • This hybrid CLC system integrates a CLC plant with a solar thermal energy plant. • The oxygen carrier particles are used for chemical and sensible thermal energy storage. • A solar cavity reactor is proposed for fuel reactor. • The calculations show a total solar share of around 60% can be achieved. - Abstract: A novel hybrid solar chemical looping combustion (Hy-Sol-CLC) is presented, in which the oxygen carrier particles in a CLC system are employed to provide thermal energy storage for concentrated solar thermal energy. This hybrid aims to take advantage of key features of a chemical looping combustion (CLC) system that are desirable for solar energy systems, notably their inherent chemical and sensible energy storage systems, the relatively low temperature of the “fuel” reactor (to which the concentrated solar thermal energy is added in a hybrid) relative to that of the final temperature of the product gas and the potential to operate the fuel reactor at a different pressure to the heated gas stream. By this approach, it is aimed to achieve high efficiency of the solar energy, infrastructure sharing, economic synergy, base load power generation and a high solar fraction of the total energy. In the proposed Hy-Sol-CLC system, a cavity solar receiver has been chosen for fuel reactor while for the storage of the oxygen carrier particles two reservoirs have been added to a conventional CLC. A heat exchanger is also proposed to provide independent control of the temperatures of the storage reservoirs from those of solar fuel and air reactors. The system is simulated using Aspen Plus software for the average diurnal profile of normal irradiance for Port Augusta, South Australia. The operating temperature of the fuel reactor, solar absorption efficiency, solar share, fraction of the solar thermal energy stored within the solar reactor, the fractions of sensible and

Solar and terrestrial physics. [effects of solar activities on earth environment

Science.gov (United States)

1975-01-01

The effects of solar radiation on the near space and biomental earth, the upper atmosphere, and the magnetosphere are discussed. Data obtained from the OSO satellites pertaining to the solar cycle variation of extreme ultraviolet (EUV) radiation are analyzed. The effects of solar cycle variation of the characteristics of the solar wind are examined. The fluid mechanics of shock waves and the specific relationship to the characteristics of solar shock waves are investigated. The solar and corpuscular heating of the upper atmosphere is reported based on the findings of the AEROS and NATE experiments. Seasonal variations of the upper atmosphere composition are plotted based on OGO-6 mass spectrometer data.

The SolarPACES strategy for the solar thermal breakthrough

Energy Technology Data Exchange (ETDEWEB)

Burch, G.D. [U.S. Department of Energy, Washington, DC (United States)

1997-12-31

Our national solar thermal research programs and our combined efforts conducted through IEA/SolarPACES have brought about many breakthroughs in the development of solar thermal technology. We have components and systems that are much more efficient, much more reliable, and can be built much more cost-efficiently than just a few years ago. As our technology development proceeds, we undoubtedly will continue to make significant progress, breakthroughs in fact, in all these areas - progress that will bring us even closer to economic parity with more conventional forms of energy. And while this progress is absolutely necessary, the question is whether it will be enough to allow solar thermal to break into the mainstream of global energy supply. Our new IEA/SolarPACES strategy, crafted and approved over the course of the past year, has recognized the changes we must face and given us license to begin to make those changes. We must begin addressing financial hurdles, work to create a more favorable regulatory and tax environment, support development of international partnerships, and expand the visibility and excitement of solar thermal technology to achieve the final breakthroughs we need to allow solar thermal energy to live up to its vast potential. (orig./AKF)

Solar energy conversion

Energy Technology Data Exchange (ETDEWEB)

Kistler, J.

1981-08-05

The photovoltaic generator is the central part of all solar systems. Flat solar cells embedded in glass are preferred which can also convert diffuse solar radiation. Hybrid modules generate electrical and thermal energy simultaneously. With decreasing generator cost, the cost of energy storage becomes critical. Development activities are mostly directed on the development of stationary lead accumulator batteries and the electronic charging and protective systems. The block diagram of the current converter is presented, and applications of solar systems in domestic heating engineering, transportation technology, communications, and hydrological engineering. Solar villages are recommended which, established in bilateral cooperation with Third World authorities, may demonstrate the advantages of solar energy in heat and electric power generation.

Solar cosmic rays in the system of solar terrestrial relations

Science.gov (United States)

Miroshnichenko, Leonty I.

2008-02-01

In this brief review, we discuss a number of geophysical effects of solar energetic particles (SEPs) or solar cosmic rays (SCR). We concentrate mainly on the observational evidence and proposed mechanisms of some expected effects and/or poor-studied phenomena discovered within the last three decades, in particular, depletion of the ozone layer, perturbations in the global electric current, effects on the winter storm vorticity, change of the atmospheric transparency and production of nitrates. Some "archaeological" data on SCR fluxes in the past and upper limit of total energy induced by SEPs are also discussed. Due attention is paid to the periodicities in the solar particle fluxes. Actually, many solar, heliospheric and terrestrial parameters changing generally in phase with the solar activity are subjected to a temporary depression close to the solar maximum ("Gnevyshev Gap"). A similar gap has been found recently in the yearly numbers of the >10 MeV proton events. All the above-mentioned findings are evidently of great importance in the studies of general proton emissivity of the Sun and long-term trends in the behaviour of solar magnetic fields. In addition, these data can be very helpful for elaborating the methods for prediction of the radiation conditions in space and for estimation of the SEPs' contribution to solar effects on the geosphere, their relative role in the formation of terrestrial weather and climate and in the problem of solar-terrestrial relations (STR) on the whole.

Deciphering solar magnetic activity: on grand minima in solar activity

Energy Technology Data Exchange (ETDEWEB)

McIntosh, Scott W. [High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO (United States); Leamon, Robert J., E-mail: mscott@ucar.edu [Department of Physics, Montana State University, Bozeman, MT (United States)

2015-07-08

The Sun provides the energy necessary to sustain our existence. While the Sun provides for us, it is also capable of taking away. The weather and climatic scales of solar evolution and the Sun-Earth connection are not well- understood. There has been tremendous progress in the century since the discovery of solar magnetism—magnetism that ultimately drives the electromagnetic, particulate, and eruptive forcing of our planetary system. There is contemporary evidence of a decrease in solar magnetism, perhaps even indicators of a significant downward trend, over recent decades. Are we entering a minimum in solar activity that is deeper and longer than a typical solar minimum, a “grand minimum”? How could we tell if we are? What is a grand minimum and how does the Sun recover? These are very pertinent questions for modern civilization. In this paper we present a hypothetical demonstration of entry and exit from grand minimum conditions based on a recent analysis of solar features over the past 20 years and their possible connection to the origins of the 11(&ish) year solar activity cycle.

Deciphering Solar Magnetic Activity: On Grand Minima in Solar Activity

Directory of Open Access Journals (Sweden)

Scott William Mcintosh

2015-07-01

Full Text Available The Sun provides the energy necessary to sustain our existence. While the Sun provides for us, it is also capable of taking away. The weather and climatic scales of solar evolution and the Sun-Earth connection are not well understood. There has been tremendous progress in the century since the discovery of solar magnetism - magnetism that ultimately drives the electromagnetic, particulate and eruptive forcing of our planetary system. There is contemporary evidence of a decrease in solar magnetism, perhaps even indicators of a significant downward trend, over recent decades. Are we entering a minimum in solar activity that is deeper and longer than a typical solar minimum, a grand minimum? How could we tell if we are? What is a grand minimum and how does the Sun recover? These are very pertinent questions for modern civilization. In this paper we present a hypothetical demonstration of entry and exit from grand minimum conditions based on a recent analysis of solar features over the past 20 years and their possible connection to the origins of the 11(-ish year solar activity cycle.

Deciphering Solar Magnetic Activity: On Grand Minima in Solar Activity

Science.gov (United States)

Mcintosh, Scott; Leamon, Robert

2015-07-01

The Sun provides the energy necessary to sustain our existence. While the Sun provides for us, it is also capable of taking away. The weather and climatic scales of solar evolution and the Sun-Earth connection are not well understood. There has been tremendous progress in the century since the discovery of solar magnetism - magnetism that ultimately drives the electromagnetic, particulate and eruptive forcing of our planetary system. There is contemporary evidence of a decrease in solar magnetism, perhaps even indicators of a significant downward trend, over recent decades. Are we entering a minimum in solar activity that is deeper and longer than a typical solar minimum, a "grand minimum"? How could we tell if we are? What is a grand minimum and how does the Sun recover? These are very pertinent questions for modern civilization. In this paper we present a hypothetical demonstration of entry and exit from grand minimum conditions based on a recent analysis of solar features over the past 20 years and their possible connection to the origins of the 11(-ish) year solar activity cycle.

Connectable solar air collectors

Energy Technology Data Exchange (ETDEWEB)

Oestergaard Jensen, S.; Bosanac, M.

2002-02-01

The project has proved that it is possible to manufacture solar air collector panels, which in an easy way can be connected into large collector arrays with integrated ducting without loss of efficiency. The developed connectable solar air collectors are based on the use of matrix absorbers in the form of perforated metal sheets. Three interconnected solar air collectors of the above type - each with an transparent area of approx. 3 m{sup 2} - was tested and compared with parallel tests on two single solar air collectors also with a transparent area of approx. 3 m{sup 2} One of the single solar air collectors has an identical absorber as the connectable solar air collectors while the absorber of the other single solar air collector was a fibre cloth. The efficiency of the three solar air collectors proved to be almost identical in the investigated range of mass flow rates and temperature differences. The solar air collectors further proved to be very efficient - as efficient as the second most efficient solar air collectors tested in the IEA task 19 project Solar Air Systems. Some problems remain although to be solved: the pressure drop across especially the connectable solar air collectors is too high - mainly across the inlets of the solar air collectors. It should, however, be possible to considerably reduce the pressure losses with a more aerodynamic design of the inlet and outlet of the solar air collectors; The connectable solar air collectors are easy connectable but the air tightness of the connections in the present form is not good enough. As leakage leads to lower efficiencies focus should be put on making the connections more air tight without loosing the easiness in connecting the solar air collectors. As a spin off of the project a simple and easy way to determine the efficiency of solar, air collectors for pre-heating of fresh air has been validated. The simple method of determining the efficiency has with success been compared with an advance method

Laying the Foundation for a Solar America: The Million Solar Roofs Initiative

Energy Technology Data Exchange (ETDEWEB)

Strahs, G.; Tombari, C.

2006-10-01

As the U.S. Department of Energy's Solar Energy Technology Program embarks on the next phase of its technology acceptance efforts under the Solar America Initiative, there is merit to examining the program's previous market transformation effort, the Million Solar Roofs Initiative. Its goal was to transform markets for distributed solar technologies by facilitating the installation of solar systems.

Experiencia inicial con el retiro de electrodos de estimulación cardiaca mediante una técnica de extracción percutánea mecánica

OpenAIRE

Mauricio Duque; Juan C. Díaz; Jorge E. Marín; Julián M. Aristizábal; Jorge E. Velásquez; Laura Duque; William Uribe

2015-01-01

Introducción: En Colombia el uso de técnicas de extracción de electrodos de estimulación cardiaca es infrecuente, en parte debido al alto costo de los materiales utilizados para la extracción percutánea y por otra parte por los riesgos percibidos asociados al procedimiento. Esto ha llevado a que muchos electrodos disfuncionantes o infectados sean abandonados o retirados mediante cirugía abierta. Con base en lo anterior se ha desarrollado un programa de extracción de electrodos mediante el uso...

Coupling of Luminescent Solar Concentrators to Plasmonic Solar Cells

Science.gov (United States)

Wang, Shu-Yi

To make inexpensive solar cells is a continuous goal for solar photovoltaic (PV) energy industry. Thin film solar cells of various materials have been developed and continue to emerge in order to replace bulk silicon solar cells. A thin film solar cell not only uses less material but also requires a less expensive refinery process. In addition, other advantages coming along with small thickness are higher open circuit voltage and higher conversion efficiency. However, thin film solar cells, especially those made of silicon, have significant optical losses. In order to address this problem, this thesis investigates the spectral coupling of thin films PV to luminescent solar concentrators (LSC). LSC are passive devices, consisting of plastic sheets embedded with fluorescent dyes which absorb part of the incoming radiation spectrum and emit at specific wavelength. The emitted light is concentrated by total internal reflection to the edge of the sheet, where the PVs are placed. Since the light emitted from the LSC edge is usually in a narrow spectral range, it is possible to employ diverse strategies to enhance PV absorption at the peak of the emission wavelength. Employing plasmonic nanostructures has been shown to enhance absorption of thin films via forward scattering, diffraction and localized surface plasmon. These two strategies are theoretically investigated here for improving the absorption and elevating the output power of a thin film solar cell. First, the idea of spectral coupling of luminescent solar concentrators to plasmonic solar cells is introduced to assess its potential for increasing the power output. This study is carried out employing P3HT/PC60BM organic solar cells and LSC with Lumogen Red dyes. A simplified spectral coupling analysis is employed to predict the power density, considering the output spectrum of the LSC equivalent to the emission spectrum of the dye and neglecting any angular dependence. Plasmonic tuning is conducted to enhance

Solar coronal non-thermal processes (Solar Maximum Mission). Final report

International Nuclear Information System (INIS)

Hudson, H.S.

1983-02-01

The Solar Maximum Mission was used to study solar coronal phenomena in hard X-radiation, since its instrument complement included the first solar hard X-ray telescope. Phenomena related to those discovered from OSO-5 and OSO-7 observations were emphasized

Optimising Solar Photocatalytic Mineralization of Pesticides at Solar Plant by Adding Inorganic Oxidising Species: Application to the Recycling of Pesticide Containers; Optimizacion de la Mineralizacion Fotocatalitica de Pesticidas en una Planta Solar mediante Adicion de Especies Inorganicas Oxidantes: Aplicacion al Reciclado de Envases de Pesticidas

Energy Technology Data Exchange (ETDEWEB)

Blanco, J.; Malato, S.; Fernandez, P.; Caceres, J.; Campos, A.; Carrion, A. [Ciemat. Plataforma Solar de Almeria. Almeria (Spain)

2000-07-01

This paper focuses on optimising the use of additional oxidants in the photocatalytic degradation of a complex mixture of ten commercial pesticides. The CPC solar pilot plant used for the tests has 8.9 m''2 of collector surface and a total volume of 247 L. Same TOC quantities of each pesticide were added to achieve the desired initial TOC concentration in all the experiments (from 5 tp 100 mg of TOC per litre). Experiments were performed with H{sub 2}O{sub 2} and S{sub 2}O{sub 8}''-2, but only peroxydisulphate was chosen for optimisation, because better results have been obtained with it. In addition to the consumption of the oxidant under different experiment conditions, the effect of peroxydisulphate and TOC concentrations was also evaluated. The mechanism of peroxydisulphate action is discussed with these results. The effect of reusing water and catalysts has also been studied. The results obtained from these experiments have been used to decide the dimensions and operating conditions of a solar photocatalytic plant, the final objective of which is the treatment of rinsates produced by washing pesticide containers. (Author) 37 refs.

Characteristics of Solar Wind Density Depletions During Solar Cycles 23 and 24

Directory of Open Access Journals (Sweden)

Keunchan Park

2017-06-01

Full Text Available Solar wind density depletions are phenomena that solar wind density is rapidly decreased and keep the state. They are generally believed to be caused by the interplanetary (IP shocks. However, there are other cases that are hardly associated with IP shocks. We set up a hypothesis for this phenomenon and analyze this study. We have collected the solar wind parameters such as density, speed and interplanetary magnetic field (IMF data related to the solar wind density depletion events during the period from 1996 to 2013 that are obtained with the advanced composition explorer (ACE and the Wind satellite. We also calculate two pressures (magnetic, dynamic and analyze the relation with density depletion. As a result, we found total 53 events and the most these phenomena’s sources caused by IP shock are interplanetary coronal mass ejection (ICME. We also found that solar wind density depletions are scarcely related with IP shock’s parameters. The solar wind density is correlated with solar wind dynamic pressure within density depletion. However, the solar wind density has an little anti-correlation with IMF strength during all events of solar wind density depletion, regardless of the presence of IP shocks. Additionally, In 47 events of IP shocks, we find 6 events that show a feature of blast wave. The quantities of IP shocks are weaker than blast wave from the Sun, they are declined in a short time after increasing rapidly. We thus argue that IMF strength or dynamic pressure are an important factor in understanding the nature of solar wind density depletion. Since IMF strength and solar wind speed varies with solar cycle, we will also investigate the characteristics of solar wind density depletion events in different phases of solar cycle as an additional clue to their physical nature.

Apparent Relations Between Solar Activity and Solar Tides Caused by the Planets

Science.gov (United States)

Hung, Ching-Cheh

2007-01-01

A solar storm is a storm of ions and electrons from the Sun. Large solar storms are usually preceded by solar flares, phenomena that can be characterized quantitatively from Earth. Twenty-five of the thirty-eight largest known solar flares were observed to start when one or more tide-producing planets (Mercury, Venus, Earth, and Jupiter) were either nearly above the event positions (less than 10 deg. longitude) or at the opposing side of the Sun. The probability for this to happen at random is 0.039 percent. This supports the hypothesis that the force or momentum balance (between the solar atmospheric pressure, the gravity field, and magnetic field) on plasma in the looping magnetic field lines in solar corona could be disturbed by tides, resulting in magnetic field reconnection, solar flares, and solar storms. Separately, from the daily position data of Venus, Earth, and Jupiter, an 11-year planet alignment cycle is observed to approximately match the sunspot cycle. This observation supports the hypothesis that the resonance and beat between the solar tide cycle and nontidal solar activity cycle influences the sunspot cycle and its varying magnitudes. The above relations between the unpredictable solar flares and the predictable solar tidal effects could be used and further developed to forecast the dangerous space weather and therefore reduce its destructive power against the humans in space and satellites controlling mobile phones and global positioning satellite (GPS) systems.

Solar energy utilization by solar cells and superblack absorbers

Energy Technology Data Exchange (ETDEWEB)

Bonnet, D; Selders, M

1975-10-31

A review is presented of the physical principles responsible for the characteristics of solar cells, with particular reference to Si homojunction and CdS--Cu/sub 2/S thin film devices. Electric power generation from solar cells still appears uncompetitive economically except in special circumstances, but heating from solar energy using selective absorbers with low reemission is more promising.

Solar electricity potentials and optimal angles for mounting solar ...

African Journals Online (AJOL)

The need for harnessing solar energy using solar panels mounted at optimal inclination angles in the six geopolitical zones of Nigeria is presented. The optimal angle for mounting solar panels as presented by Photovoltaic Geographic Information System (PVGIS) ranges from 11º to 14º in the Southern zone and 13º to 16º ...

Estimación del gasto energético en el paciente quemado mediante la utilización de ecuaciones predictivas: revisión bibliográfica

OpenAIRE

Teresa Núñez-Vinaveirán; Manuel Sánchez; Pablo Millán; José Ramón Martínez-Méndez; Carmen Iglesias; César Casado-Pérez; Abelardo García-de-Lorenzo

2014-01-01

Introducción: La valoración de las necesidades calóricas del paciente quemado se ha basado en la medición del gasto energético en reposo (GER) mediante calorimetría indirecta, no siempre disponible en las unidades de quemados, o en su estimación mediante el uso de ecuaciones predictivas. Objetivos: analizar la historia y estado del arte del uso de las ecuaciones predictivas de GER en el paciente quemado crítico, y determinar su validez. Métodos: revisión bibliográfica de estudios y revisiones...

Detecting photovoltaic solar panels using hyperspectral imagery and estimating solar power production

Science.gov (United States)

Czirjak, Daniel

2017-04-01

Remote sensing platforms have consistently demonstrated the ability to detect, and in some cases identify, specific targets of interest, and photovoltaic solar panels are shown to have a unique spectral signature that is consistent across multiple manufacturers and construction methods. Solar panels are proven to be detectable in hyperspectral imagery using common statistical target detection methods such as the adaptive cosine estimator, and false alarms can be mitigated through the use of a spectral verification process that eliminates pixels that do not have the key spectral features of photovoltaic solar panel reflectance spectrum. The normalized solar panel index is described and is a key component in the false-alarm mitigation process. After spectral verification, these solar panel arrays are confirmed on openly available literal imagery and can be measured using numerous open-source algorithms and tools. The measurements allow for the assessment of overall solar power generation capacity using an equation that accounts for solar insolation, the area of solar panels, and the efficiency of the solar panels conversion of solar energy to power. Using a known location with readily available information, the methods outlined in this paper estimate the power generation capabilities within 6% of the rated power.

EVALUACIÓN DEL COMPORTAMIENTO IN VITRO DE RECUBRIMIENTOS DE HIDROXIAPATITA DEPOSITADOS MEDIANTE PROYECCIÓN TÉRMICA POR COMBUSTIÓN OXIACETILÉNICA SOBRE UN SUSTRATO DE Ti6Al4V

Directory of Open Access Journals (Sweden)

HAMILTON COPETE

2013-01-01

Full Text Available Recubrimientos de Hidroxiapatita sintética producida por precipitación y calcinación a 850 °C fueron depositados sobre sustratos de Ti6Al4V mediante proyección térmica por combustión. Las fases presentes en el material sintetizado y en los recubrimientos elaborados fueron determinadas mediante Difracción de Rayos X. Los recubrimientos fueron evaluados en condiciones in vitro con fluido fisiológico a 37 °C que simula el plasma humano, por periodos de 3, 7, 15 y 30 días. La superficie de los recubrimientos fue caracterizada antes y después de los ensayos in vitro mediante Microscopía Electrónica de Barrido y por Barrido de Energía Dispersiva. La concentración de iones de fosfato y de calcio en el fluido fisiológico fue determinada mediante espectrofotometría. Los resultados de las pruebas in vitro sugieren la acción de dos mecanismos: disolución del recubrimiento en el fluido fisiológico y posterior precipitación de cristales de calcio y fósforo sobre la superficie de la capa de Hidroxiapatita.

Solar flares, CMEs and solar energetic particle events during solar cycle 24

Science.gov (United States)

Pande, Bimal; Pande, Seema; Chandra, Ramesh; Chandra Mathpal, Mahesh

2018-01-01

We present here a study of Solar Energetic Particle Events (SEPs) associated with solar flares during 2010-2014 in solar cycle 24. We have selected the flare events (≥GOES M-class), which produced SEPs. The SEPs are classified into three categories i.e. weak (proton intensity ≤ 1 pfu), minor (1 pfu pfu) and major (proton intensity ≥ 10 pfu). We used the GOES data for the SEP events which have intensity greater than one pfu and SOHO/ERNE data for the SEP event less than one pfu intensity. In addition to the flare and SEP properties, we have also discussed different properties of associated CMEs.

Solar atmosphere wave dynamics generated by solar global oscillating eigenmodes

Science.gov (United States)

Griffiths, M. K.; Fedun, V.; Erdélyi, R.; Zheng, R.

2018-01-01

The solar atmosphere exhibits a diverse range of wave phenomena, where one of the earliest discovered was the five-minute global acoustic oscillation, also referred to as the p-mode. The analysis of wave propagation in the solar atmosphere may be used as a diagnostic tool to estimate accurately the physical characteristics of the Sun's atmospheric layers. In this paper, we investigate the dynamics and upward propagation of waves which are generated by the solar global eigenmodes. We report on a series of hydrodynamic simulations of a realistically stratified model of the solar atmosphere representing its lower region from the photosphere to low corona. With the objective of modelling atmospheric perturbations, propagating from the photosphere into the chromosphere, transition region and low corona, generated by the photospheric global oscillations the simulations use photospheric drivers mimicking the solar p-modes. The drivers are spatially structured harmonics across the computational box parallel to the solar surface. The drivers perturb the atmosphere at 0.5 Mm above the bottom boundary of the model and are placed coincident with the location of the temperature minimum. A combination of the VALIIIC and McWhirter solar atmospheres are used as the background equilibrium model. We report how synthetic photospheric oscillations may manifest in a magnetic field free model of the quiet Sun. To carry out the simulations, we employed the magnetohydrodynamics code, SMAUG (Sheffield MHD Accelerated Using GPUs). Our results show that the amount of energy propagating into the solar atmosphere is consistent with a model of solar global oscillations described by Taroyan and Erdélyi (2008) using the Klein-Gordon equation. The computed results indicate a power law which is compared to observations reported by Ireland et al. (2015) using data from the Solar Dynamics Observatory/Atmospheric Imaging Assembly.

Recubrimientos de TiN depositados mediante ACPVD sobre aleaciones de magnesio AM60

Directory of Open Access Journals (Sweden)

Pichel, M.

2013-06-01

Full Text Available Magnesium alloys are reaching special interest due to their good specific properties, low cost and good manufacturing properties. However, their low hardness, wear and corrosion resistance limit their applications in certain sectors of industry. These drawbacks can be solved by applying hard ceramic coatings, such as nitrides or metal carbides. TiN is one of the most used coatings due to its high adhesion, hardness, low coefficient of friction and chemical stability. Physical vapor deposition by cathodic arc CAPVD, is a versatile technique, which uses low temperatures and high ionization energies, generating homogeneous coatings. To achieve coatings with high quality, a careful control of the manufacturing parameters is required, such as bias voltage, gas flow or intensity. This paper focuses on magnesium alloys, AM60, coated with TiN using physical vapor deposition cathodic arc technique (CAPVD at different intensity values (40A and 100A and surface preparation (grinding up to 4000 grit and polished to 3μm. It was included a final condition with an intermediate Al film. The samples were characterized by X-ray diffraction, roughness, optical microscopy and scanning electron.Las aleaciones de magnesio están alcanzando especial interés gracias a sus buenas propiedades específicas, bajo coste y buenas propiedades de moldeabilidad. No obstante su baja dureza, resistencia a desgaste y corrosión, limita sus aplicaciones en ciertos campos de la industria. Estos inconvenientes se pueden solucionar aplicando recubrimientos duros cerámicos, como nitruros o carburos metálicos. El TiN es uno de los más utilizados debido a su alta adherencia, dureza, bajo coeficiente de fricción y estabilidad química. La deposición física en fase vapor mediante arco catódico, ACPVD, es una técnica muy versátil, que emplea bajas temperaturas y altas energías de ionización, generando recubrimientos de bajo espesor, homogéneos y de calidad. Para alcanzar

Solar Schematic

Science.gov (United States)

1979-01-01

The home shown at right is specially designed to accommodate solar heating units; it has roof planes in four directions, allowing placement of solar collectors for best exposure to the sun. Plans (bottom) and complete working blueprints for the solar-heated house are being marketed by Home Building Plan Service, Portland, Oregon. The company also offers an inexpensive schematic (center) showing how a homeowner only moderately skilled in the use of tools can build his own solar energy system, applicable to new or existing structures. The schematic is based upon the design of a low-cost solar home heating system built and tested by NASA's Langley Research Center; used to supplement a warm-air heating system, it can save the homeowner about 40 percent of his annual heating bill for a modest investment in materials and components. Home Building Plan Service saved considerable research time by obtaining a NASA technical report which details the Langley work. The resulting schematic includes construction plans and simplified explanations of solar heat collection, collectors and other components, passive heat factors, domestic hot water supply and how to work with local heating engineers.

Programa Antiestrés de Sincronización Cerebral mediante estimulación visual

OpenAIRE

Riccardi Sabatier, Yanitza; Caraballo Pons, Isabel; Miyares Cao, Carlos Manuel; Lago Mendoza, Guillermo; Lauzán Álvarez, Efreín

2014-01-01

Se presenta un programa computarizado que permite la sincronización de las ondas cerebrales mediante una estimulación visual, a una frecuencia similar a la actividad eléctrica del cerebro en estado de sedación, lo cual favorece la disminución de los niveles de estrés en los pacientes que acuden al Centro de Histoterapia Placentaria para tratar las patologías de Vitiligo, Psoriasis y Alopecia Areata. La aplicación informática fue programada en lenguaje Delphi 7.0 y cuenta con dos módulos para ...

Solar panel thermal cycling testing by solar simulation and infrared radiation methods

Science.gov (United States)

Nuss, H. E.

1980-01-01

For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

Solar Mosaic Inc. Mosaic Home Solar Loan SunShot 9 Final Report

Energy Technology Data Exchange (ETDEWEB)

Walsh, Colin James [Solar Mosaic Inc., Oakland, CA (United States)

2017-02-09

The 6686 Mosaic SunShot award has helped Solar Mosaic Inc to progress from an early stage startup focused on commercial crowdfunding to a leading multi-state residential solar lender. The software platform is now used by the majority of the nation's top solar installers and offers a variety of simple home solar loans. Mosaic is has originated approximately $1Bil in solar loans to date to put solar on over 35k rooftops. The company now lends to homeowners with a wide range of credit scores across multiple states and mitigates boundaries preventing them from profiting from ownership of a home solar system. The project included milestones in 5 main categories: 1. Lending to homeowners outside of CA 2. Lending to homeowners with FICO scores under 700 3. Packaging O&M with the home solar loan 4. Allowing residential installers to process home solar loans via API 5. Lowering customer acquisition costs below $1500 This report includes a detailed review of the final results achieved and key findings.

Idaho | Midmarket Solar Policies in the United States | Solar Research |

Science.gov (United States)

% interest for solar PV projects. Low-interest financing Idaho Energy Resources Authority Solar PV project for financing through the Idaho Governor's Office and the Idaho Energy Resources Authority. Latest -owned community solar project for Idaho Power. Net Metering Idaho does not have statewide net metering

Solar magnetohydrodynamics

International Nuclear Information System (INIS)

Priest, E.R.

1982-01-01

The book serves several purposes. First set of chapters gives a concise general introduction to solar physics. In a second set the basic methods of magnetohydrodynamics are developed. A third set of chapters is an account of current theories for observed phenomena. The book is suitable for a course in solar physics and it also provides a comprehensive review of present magnetohydrodynamical models in solar physics. (SC)

Solar renovation demonstration projects

Energy Technology Data Exchange (ETDEWEB)

Bruun Joergensen, O [ed.

1998-10-01

In the framework of the IEA SHC Programme, a Task on building renovation was initiated, `Task 20, Solar Energy in Building Renovation`. In a part of the task, Subtask C `Design of Solar Renovation Projects`, different solar renovation demonstration projects were developed. The objective of Subtask C was to demonstrate the application of advanced solar renovation concepts on real buildings. This report documents 16 different solar renovation demonstration projects including the design processes of the projects. The projects include the renovation of houses, schools, laboratories, and factories. Several solar techniques were used: building integrated solar collectors, glazed balconies, ventilated solar walls, transparent insulation, second skin facades, daylight elements and photovoltaic systems. These techniques are used in several simple as well as more complex system designs. (au)

Solar neutrinos, helioseismology and the solar internal dynamics

Energy Technology Data Exchange (ETDEWEB)

Turck-Chieze, Sylvaine [Service d' Astrophysique/IRFU/DSM/CEA, 91191 Gif sur Yvette Cedex (France); Couvidat, Sebastien, E-mail: sylvaine.turck-chieze@cea.fr, E-mail: couvidat@stanford.edu [HEPL, Stanford University, Stanford, CA 94305 (United States)

2011-08-15

Neutrinos are fundamental particles ubiquitous in the Universe and whose properties remain elusive despite more than 50 years of intense research activity. This review illustrates the importance of solar neutrinos in astrophysics, nuclear physics and particle physics. After a description of the historical context, we remind the reader of the noticeable properties of these particles and of the stakes of the solar neutrino puzzle. The standard solar model triggered persistent efforts in fundamental physics to predict the solar neutrino fluxes, and its constantly evolving predictions have been regularly compared with the detected neutrino signals. Anticipating that this standard model could not reproduce the internal solar dynamics, a seismic solar model was developed which enriched theoretical neutrino flux predictions with in situ observation of acoustic and gravity waves propagating in the Sun. This seismic model contributed to the stabilization of the neutrino flux predictions. This review recalls the main historical steps, from the pioneering Homestake mine experiment and the GALLEX-SAGE experiments capturing the first proton-proton neutrinos. It emphasizes the importance of the SuperKamiokande and SNO detectors. Both experiments demonstrated that the solar-emitted electron neutrinos are partially transformed into other neutrino flavors before reaching the Earth. This sustained experimental effort opens the door to neutrino astronomy, with long-base lines and underground detectors. The success of BOREXINO in detecting the {sup 7}Be neutrino signal alone instills confidence in physicists' ability to detect each neutrino source separately. It justifies the building of a new generation of detectors to measure the entire solar neutrino spectrum in greater detail, as well as supernova neutrinos. A coherent picture has emerged from neutrino physics and helioseismology. Today, new paradigms take shape in these two fields: neutrinos are massive particles, but their

Updated determination of the solar neutrino fluxes from solar neutrino data

Energy Technology Data Exchange (ETDEWEB)

Bergström, Johannes [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Gonzalez-Garcia, M. C. [Departament d’Estructura i Constituents de la Matèria and Institut de Ciencies del Cosmos,Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA) (Spain); C.N. Yang Institute for Theoretical Physics,State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States); Maltoni, Michele [Instituto de Física Teórica UAM/CSIC,Calle de Nicolás Cabrera 13-15, Universidad Autónoma de Madrid,Cantoblanco, E-28049 Madrid (Spain); Peña-Garay, Carlos [Instituto de Física Corpuscular (IFIC), CSIC and Universitat de Valencia,Calle Catedrático José Beltrán, 2, E-46090 Paterna, Valencia (Spain); Serenelli, Aldo M. [Institut de Ciencies de l’Espai (ICE-CSIC/IEEC),Campus UAB, Carrer de Can Magrans s/n, 08193 Cerdanyola del Valls (Spain); Song, Ningqiang [C.N. Yang Institute for Theoretical Physics,State University of New York at Stony Brook, Stony Brook, NY 11794-3840 (United States)

2016-03-18

We present an update of the determination of the solar neutrino fluxes from a global analysis of the solar and terrestrial neutrino data in the framework of three-neutrino mixing. Using a Bayesian analysis we reconstruct the posterior probability distribution function for the eight normalization parameters of the solar neutrino fluxes plus the relevant masses and mixing, with and without imposing the luminosity constraint. We then use these results to compare the description provided by different Standard Solar Models. Our results show that, at present, both models with low and high metallicity can describe the data with equivalent statistical agreement. We also argue that even with the present experimental precision the solar neutrino data have the potential to improve the accuracy of the solar model predictions.

Solar variability observed through changes in solar figure and mean diameter

International Nuclear Information System (INIS)

Hill, H.A.

1984-01-01

The objective of the project is to detect and monitor climatically significant solar variability by accurate monitoring of the associated variability in solar shape and diameter. The observing program for this project was initiated in 1981. Solar diameter measurements have been taken and data reduction programs for these measurements have been developed. Theoretical analysis of the expected change in the intensity from the solar atmosphere to a given mechanial driving has progressed to the extent that changes in the solar diameter can be related to the associated change in the solar luminosity. An absolute calibration system for the telescope has been constructed and is currently being tested. A proposal is made for the continuation of the work in each of these areas

Solar distillers with mirrors; Destiladores solares con espejos

Energy Technology Data Exchange (ETDEWEB)

Fasulo, A.; Adaro, J.; Marchesi, J.; Follari, J.

2004-07-01

The possibilities to incorporate mirrors to solar distillers are analyzed numerically. We take into account two designs to build the glazing cover, and the two possibilities of orientation of one of these. We determine the quantity of solar radiation that receives each one, for we use it data of hourly radiation, of one year, obtained in the Solar Energy Laboratory. the data are representative of a typical solar year. We obtain a relationship of use of the solar radiation first according to the design of the cover and their orientation. To incorporate mirrors we find that the best strategy, to cover the two designs, they are two mirrors of 50 cm of high for 3m of long such that each one of these they can be guided in independent form. We compare the results with a previous proposal that uses a mirror of 1 m of height, applied one of the orientations. We find the differences and that they give until 74% of increment of the radiation on one of the devices. (Author)

Cálculo del poder de la lente intraocular mediante biometría ultrasónica

Directory of Open Access Journals (Sweden)

Yileika Elías García

Full Text Available Objetivo: caracterizar el comportamiento del cálculo de la lente intraocular mediante biometría ultrasónica. Métodos: se realizó un estudio descriptivo y prospectivo, con un grupo de pacientes atendidos por el Servicio de Catarata del Centro Oftalmológico «Enrique Cabrera», que recibieron tratamiento quirúrgico por catarata con implante de lente intraocular, mediante técnica de Blumenthal. La muestra se conformó con 160 ojos y se estudiaron las variables: sorpresa refractiva, edad, longitud axial y promedio queratométrico según resultado refractivo, poder dióptrico de la lente y componente esférico según edad. Resultados: como resultados más sobresalientes, se obtuvo que el 78,7 % no presentó error en el cálculo de la lente, la mayoría de los pacientes tenían 60 años y más, predominó el rango de longitud axial entre 22 y 24,4 (67,5 %, el promedio queratométrico de 43 a 44,99 (64,3 %, el poder dióptrico del lente de + 20 a + 23 dioptrías (48,2 % y el componente esférico entre 0,00 y +/-1,00 dioptrías (78,8%. Conclusiones: se considera que la biometría ultrasónica resulta adecuada para el cálculo correcto del lente.

Solar thermal power: the seamless solar link to the conventional power world

International Nuclear Information System (INIS)

Geyer, Michael; Quaschning, Volker

2000-01-01

This article focuses on solar thermal power generation and describes two solar thermal power concepts, namely, the parabolic trough or solar farm, and the solar central receiver or power tower. Details are given of grid-connected parabolic trough power plants in California and recent developments in collector design and absorber tubes, and the operation of power tower plants with different heat transfer media. Market issues are discussed, and solar thermal power projects under development, and application for support for solar thermal power projects under the Global Environment Facility's Operational Programme by Egypt, India, Iran, Mexico and Morocco are reported

Solar Irradiance & On Grid Solar Power Systems with Net Metering in Pakistan

Directory of Open Access Journals (Sweden)

Haleema Qamar

2016-06-01

Full Text Available This paper presents a case study of solar irradiance and scope of on-grid solar power systems with net-metering in Pakistan. Detailed analysis of solar irradiance in Pakistan is being carried out by developing the dedicated solar excel sheets. The need of on grid solar power systems for the present energy crisis in developing countries like Pakistan is also discussed. It also presents the inclination of many countries especially USA and Europe towards it. Identification of barriers for implementing on grid net metered solar power systems in Pakistan along with solutions of these barriers is carried out.

Solar energy in Uruguay. Increase the use of solar panels

International Nuclear Information System (INIS)

Matos, V.

2010-01-01

This article is about the future of the solar energy in Uruguay. The main aspects of this kind of energy are solar thermic which is used for cooking food and heating water through solar collectors as well as the photovoltaics which allows the generation of electricity

Bias-dependent high saturation solar LBIC scanning of solar cells

Energy Technology Data Exchange (ETDEWEB)

Vorster, F.J.; van Dyk, E.E. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

2007-06-15

A light beam-induced current measurement system that uses concentrated solar radiation as a beam probe to map spatially distributed defects on a solar cell has been developed and tested [F.J. Vorster, E.E. van Dyk, Rev. Sci. Instrum., submitted for review]. The induced current response from a flat plate EFG Si solar cell was mapped as a function of surface position and cell bias by using a solar light beam induced current (S-LBIC) mapping system while at the same time dynamically biasing the whole cell with an external voltage. This paper examines the issues relating to transient capacitive effects as well as the electrical behaviour of typical solar cell defect mechanisms under spot illumination. By examining the bias dependence of the S-LBIC maps, various defect mechanisms of photovoltaic (PV) cells under concentrated solar irradiance may be identified. The techniques employed to interpret the spatially distributed IV curves as well as initial results are discussed. (author)

Solar Radius at Subterahertz Frequencies and Its Relation to Solar Activity

Science.gov (United States)

Menezes, Fabian; Valio, Adriana

2017-12-01

The Sun emits radiation at several wavelengths of the electromagnetic spectrum. In the optical band, the solar radius is 695 700 km, and this defines the photosphere, which is the visible surface of the Sun. However, as the altitude increases, the electromagnetic radiation is produced at other frequencies, causing the solar radius to change as a function of wavelength. These measurements enable a better understanding of the solar atmosphere, and the radius dependence on the solar cycle is a good indicator of the changes that occur in the atmospheric structure. We measure the solar radius at the subterahertz frequencies of 0.212 and 0.405 THz, which is the altitude at which these emissions are primarily generated, and also analyze the radius variation over the 11-year solar activity cycle. For this, we used radio maps of the solar disk for the period between 1999 and 2017, reconstructed from daily scans made by the Solar Submillimeter-wave Telescope (SST), installed at El Leoncito Astronomical Complex (CASLEO) in the Argentinean Andes. Our measurements yield radii of 966.5'' ±2.8'' for 0.2 THz and 966.5'' ±2.7'' for 0.4 THz. This implies a height of 5.0 ±2.0 ×106 m above the photosphere. Furthermore, we also observed a strong anticorrelation between the radius variation and the solar activity at both frequencies.

La optimización del proceso productivo de centros gastronómicos mediante ecoeficiencia: Estudio del restaurante La Turrialbeña, Costa Rica

Directory of Open Access Journals (Sweden)

Elizabeth Vaughn-Gómez

2016-06-01

Full Text Available En el presente estudio se establecieron medidas para optimizar el proceso productivo para centros gastronómicos utilizando medidas ecoeficientes, las cuales se identificaron para el restaurante La Turrialbeña ubicado en Moín, Limón. Las áreas abarcadas fueron el manejo de agua, energía y residuos sólidos.  En la primera fase se realizó un diagnóstico del local para establecer la línea base. En la segunda fase se identificaron las medidas ecoeficientes que podían ser implementadas y, por último, se realizó un estudio de factibilidad económica, técnica y ambiental de estas, con el propósito de conocer la viabilidad de cada una para su implementación futura. Como resultado del proyecto se  determinó que en términos energéticos la reparación del sistema eléctrico existente era prioritaria para optimizar el consumo de energía, el cual se verá impactado positivamente mediante la implementación de paneles solares. En cuanto al recurso hídrico, la recuperación de agua pluvial para uso del restaurante es viable, así como la implementación de un plan de reciclaje para los residuos sólidos del centro gastronómico. Estas acciones mejorarán el proceso productivo del local, su imagen y su impacto ambiental.

A flat solar collector built from galvanized steel plate, working by thermosyphonic flow, optimized for Mexican conditions; Un colector solar plano construido de lamina de acero galvanizada, operando por flujo termosifonico, optimizado para las condiciones mexicanas

Energy Technology Data Exchange (ETDEWEB)

Marroquin de Jesus, A; Olivares Ramirez, J.M.; Ramos Lopez, G.A.; Pless, R.C. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro (Mexico)]. E-mail: amarroquind@utsjr.edu.mx

2009-07-15

Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled types, the other one flat, which are joined by electric welding. The absorber is connected to a 198-L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m{sup 2}, about 20% smaller than comparable copper-tube-based collectors offered in the market. Temperature measurements conducted over a 30-day period gave values which were a few degrees lower than the theoretically calculated water temperatures. Momentary thermal efficiency values between 35% and 77% were observed. The water temperature achieved the tank at the end of the day averages 65 degrees Celsius in winter weather conditions in the central Mexican highland. This design of solar water heater is well suited to Mexican conditions, as it makes use of the high local intensity of the solar radiation, and as the channel shape of the ducts minimizes bursting during the rare occurrences of freezing temperatures in the region; it also has the advantage of being manufacturable at low cost from simple materials. [Spanish] Se describe el diseno, construccion y pruebas del desempeno termico de un colector solar plano para calentamiento de agua para uso domestico. La placa absorbedora se construyo de materiales facilmente asequibles: dos placas de acero galvanizado, una del tipo acanalado y la otra plana, unidas mediante soldadura de acero electrico. La placa absorbedora esta conectada a un termotanque con capacidad de 198 L, aislado con espuma de poliuretano. La superficie receptora de este prototipo es de 1.35 m{sup 2}, aproximadamente 20% mas pequena comparado con los colectores, basados en tubos de cobre, ofertados en el mercado. Mediciones de temperatura por un periodo de 30 dias, arrojaron valores

Desarrollo de efectos cerámicos como acabados superficiales, mediante tecnología de inyección digital

Directory of Open Access Journals (Sweden)

Spain S.A., Ferro

2012-04-01

Full Text Available Ferro Spain SA has tackled the practical viability of tile surfaces decoration by means of applying layers of reduced thickness by means of the use of digital injection technology by inkjet and, specifically, relating to effects and superficial finishes different from colouring. It has been studied several mechanisms which allow to get those effects and the influence of the main variables. It has also been assessed the obtained results dealing with the current regulations as in the case of non-slip effect.

Ferro Spain, S.A. ha abordado la viabilidad práctica de la decoración de superficies cerámicas mediante la aplicación de capas de muy reducido espesor mediante el uso de la tecnología de inyección digital por chorro de tinta y, específicamente en lo relativo a efectos y acabados superficiales distintos de la coloración. Se han estudiado los diversos mecanismos que permiten obtener dichos efectos y la influencia de las principales variables. También ha evaluado los resultados obtenidos atendiendo a las normativas vigentes como es el caso del efecto antideslizante.

Iowa | Midmarket Solar Policies in the United States | Solar Research |

Science.gov (United States)

Center Solar PV projects are eligible for no-interest financing for up to 50% of the financed project Energy Center administers financing and grant programs for solar photovoltaic (PV) projects. Solar cost (capped at $1,000,000). The Iowa Energy Center also offers several matching grants for project

Solar energy. [New Zealand

Energy Technology Data Exchange (ETDEWEB)

Benseman, R.

1977-10-15

The potential for solar space heating and solar water heating in New Zealand is discussed. Available solar energy in New Zealand is indicated, and the economics of solar space and water heating is considered. (WHK)

Segmentación automática de noticias mediante procesamiento de formas prosódicas

OpenAIRE

Mas Manchón, Lluís

2014-01-01

La segmentación automatizada de noticias en tiempo real es un problema que ha tenido un abordaje fundamentalmente lingüístico y de procesamiento de la señal en los últimos años. El trabajo que presentamos tiene un enfoque sustancialmente diferente: desde una perspectiva comunicológica, se toman las formas prosódicas típicas del discurso informativo y se intentan programar mediante el procesamiento cepstrum en el entorno Labview. Después de numerosas pruebas se fijan los diferentes parámetros ...

Detección de movimiento mediante técnicas radar CW-FM en banda W

OpenAIRE

Vargas González, Daniel

2014-01-01

Aplicació de diverses tècniques de detecció i localització per detectar moviments amb un radar C2-FM que opera en banda W. [ANGLÈS] Integration of a SAR adquisition system using a FM-CW 94 GHz radar and test the system by different measurement campaigns with the aim of detecting micrometic displacements using a phase analysis of the recived signal [CASTELLÀ[ Integración de un sistema de adquisición SAR mediante el uso de un radar FM-CW a 94 GHz y probar la validez del mencionado sistema...

Educación mediante enciclopedias visuales temáticas: INTYPEDIA un caso de éxito.

OpenAIRE

Ramió Aguirre, Jorge; Muñoz Muñoz, Alfonso

2013-01-01

La presente investigación recoge una experiencia de innovación educativa que demuestra la utilidad de las enciclopedias visuales temáticas para la formación académica a través de Internet. Los objetivos de esta experiencia recaen en verificar si es posible crear enciclopedias visuales temáticas que mediante recursos audiovisuales permitan el aprendizaje de aspectos complejos de una manera asequible. Con el interés de obtener datos que permitan comprobar la idoneidad de este tipo de recursos f...

Polymethylmethacrylate-based luminescent solar concentrators with bottom-mounted solar cells

International Nuclear Information System (INIS)

Zhang, Yi; Sun, Song; Kang, Rui; Zhang, Jun; Zhang, Ningning; Yan, Wenhao; Xie, Wei; Ding, Jianjun; Bao, Jun; Gao, Chen

2015-01-01

Graphical abstract: - Highlights: • Bottom-mounted luminescent solar concentrators on dye-doped plates were studied. • The mechanism of transport process was proposed. • The fabricated luminescent solar concentrator achieved a gain of 1.38. • Power conversion efficiency of 5.03% was obtained with cell area coverage of 27%. • The lowest cost per watt of $1.89 was optimized with cell area coverage of 18%. - Abstract: Luminescent solar concentrators offer an attractive approach to concentrate sunlight economically without tracking, but the narrow absorption band of luminescent materials hinders their further development. This paper describes bottom-mounted luminescent solar concentrators on dye-doped polymethylmethacrylate plates that absorb not only the waveguided light but also the transmitted sunlight and partial fluorescent light in the escape cone. A series of bottom-mounted luminescent solar concentrators with size of 78 mm × 78 mm × 7 mm were fabricated and their gain and power conversion efficiency were investigated. The transport process of the waveguided light and the relationship between the bottom-mounted cells were studied to optimize the performance of the device. The bottom-mounted luminescent solar concentrator with cell area coverage of 9% displayed a cell gain of 1.38, to our best knowledge, which is the highest value for dye-doped polymethylmethacrylate plate luminescent solar concentrators. Power conversion efficiency as high as 5.03% was obtained with cell area coverage of 27%. Furthermore, the bottom-mounted luminescent solar concentrator was found to have a lowest cost per watt of $1.89 with cell area coverage of 18%. These results suggested that the fabricated bottom-mounted luminescent solar concentrator may have a potential in low-cost building integrated photovoltaic application

Solar maximum mission

International Nuclear Information System (INIS)

Ryan, J.

1981-01-01

By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

Texas Solar Collaboration DOE Rooftop Solar Challenge City of Houston Project Summary

Energy Technology Data Exchange (ETDEWEB)

Ronk, Jennifer [Houston Advanced Research Center, TX (United States)

2013-02-14

The City of Houston is committed to achieving a sustainable solar infrastructure. In 2008, Houston was named a United States Department of Energy (DOE) Solar America City. As a Solar America City, Houston teamed with the Houston Advanced Research Center (HARC), Sandia National Laboratory (Sandia), industry, and academia, to implement the Solar Houston Initiative and prepare the Solar Houston Plan. The Solar Houston initiative was focused on identifying and overcoming barriers associated with establishing a solar infrastructure that is incorporated into the City of Houston’s overall energy plan. A broad group of Houston area stakeholders, facilitated by HARC, came together to develop a comprehensive solar plan that went beyond technology to address barriers and establish demonstrations, public outreach, education programs and other activities. The plan included proposed scopes of work in four program areas: policies, solar integration, public outreach, and education. Through the support of the DOE SunShot Rooftop Solar Challenge (RSC) grant to the Texas Collaboration (San Antonio, Austin, and Hosuton), Houston has been able to implement several of the recommendations of the Solar Houston Plan. Specific recommendations that this project was able to support include; Working with the other Texas Solar America Cities (San Antonio and Austin), to harmonize permitting and inspection processes to simplify for installers and lower soft costs of installation; Participating in state level solar policy groups such as the Texas Renewable Energy Industries Association (TRIEA); Continued coordination with the local transmission and distribution utility (CenterPoint) and retail electric providers (REP); Identification of opportunities to improve permitting and interconnection; Providing training on PV systems to City inspectors; Educating the public by continuing outreach, training, and workshops, particularly using the the Green Building Resources Center; Evaluating methods of

Solar Pumping : The Basics

OpenAIRE

World Bank Group

2018-01-01

Solar photovoltaic water pumping (SWP) uses energy from solar photovoltaic (PV) panels to power an electric water pump. The entire process, from sunlight to stored energy, is elegant and simple. Over last seven years, the technology and price of solar pumping have evolved dramatically and hence the opportunities it presents. Solar pumping is most competitive in regions with high solar inso...

Solar thermal aircraft

Science.gov (United States)

Bennett, Charles L.

2007-09-18

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Transient flows of the solar wind associated with small-scale solar activity in solar minimum

Science.gov (United States)

Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the solar wind data obtained in this period by ACE, Wind, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the solar wind (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the solar wind projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow solar wind at solar minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme

Avaliação dos cuidados de proteção solar e prevenção do câncer de pele em pré-escolares Avaluación de los cuidados de protección solar y prevención de cáncer de piel en preescolares Assessment of sun protection and skin cancer prevention among preschool children

Directory of Open Access Journals (Sweden)

Thais Batista

2013-03-01

Full Text Available OBJETIVO: Investigar os cuidados dos pais com a pele de seus filhos, especialmente quanto ao uso do filtro solar e de métodos físicos de proteção solar. MÉTODOS: Estudo transversal com pré-escolares de Tubarão, Santa Catarina, Brasil. Após sorteio de escolas das redes pública e privada e mediante a autorização da direção das entidades, os pais ou responsáveis foram convidados a participarem do estudo. Os questionários foram autoaplicáveis. O instrumento continha dados sobre características demográficas e socioeconômicas, uso de filtro solar, uso de barreiras físicas de proteção solar, além dos horários em que a criança ficava exposta ao sol. Para verificar a associação entre as variáveis de interesse, foram utilizados os testes do qui-quadrado de Pearson ou exato de Fisher, sendo significante pOBJETIVO: Investigar los cuidados de los padres con la piel de sus hijos, en especial el uso de filtro solar y los métodos físicos de protección solar. MÉTODOS: Estudio transversal con preescolares de Tubarão, en Santa Catarina, Brasil. Después del sorteo de las escuelas públicas y privadas y mediante la autorización de la dirección de las entidades, los padres o guardianes fueron invitados a participar del estudio, recibiendo cuestionarios autoaplicables que fueron devueltos a los investigadores durante los días subsiguientes. El instrumento contenía datos sobre características demográficas y socioeconómicas, uso de filtro solar, uso de barreras físicas de protección solar, y también sobre los horarios de exposición al sol del niño. Para verificar la asociación entre las variables de interés, se utilizaron las pruebas chi-cuadrada de Pearson o exacta de Fisher, con significancia estadística preestablecida en 95%. RESULTADOS: Fueron estudiados 361 niños, 228 (63,2% de los cuales inscritos en escuelas públicas. El color de piel blanca fue predominante (78,8%. Del total, 16 (4,4% utilizaban filtro solar

Design and Development of a Solar Thermal Collector with Single Axis Solar Tracking Mechanism

Directory of Open Access Journals (Sweden)

Theebhan Mogana

2016-01-01

Full Text Available The solar energy is a source of energy that is abundant in Malaysia and can be easily harvested. However, because of the rotation of the Earth about its axis, it is impossible to harvest the solar energy to the maximum capacity if the solar thermal collector is placed fix to a certain angle. In this research, a solar thermal dish with single axis solar tracking mechanism that will rotate the dish according to the position of the sun in the sky is designed and developed, so that more solar rays can be reflected to a focal point and solar thermal energy can be harvested from the focal point. Data were collected for different weather conditions and performance of the solar thermal collector with a solar tracker were studied and compared with stationary solar thermal collector.

Seguidor Solar, optimizando el aprovechamiento de la energía solar ; Solar tracker, optimizing ofimprovementof the solar energy

Directory of Open Access Journals (Sweden)

Noel Machado Toranzo

2015-06-01

Full Text Available En este trabajo se realizó el diseño e implementación de un dispositivo encargado de obtener las coordenadas del Sol en cualquier momento del día, es decir, un seguidor solar a dos ejes por punto luminoso. Este seguidor consta de dos bloques principales: la tarjeta controladora y la parte mecánica. Su diseño se basó en el uso de fotorresistencias, microcontroladores y motores de pasos, el mismo posee altas prestaciones y bajo costo. El prototipo construido es utilizado en las investigaciones de aprovechamiento de la energía solar que se realizan en el Grupo de Energía Renovable Aplicadas (GERA de la Universidad de Oriente, particularmente en los paneles fotovoltaicos y los calentadores de agua. Se realizó una prueba experimental en los laboratorios y en el polígono de dicho grupo y se comprobó que el seguidor solar funciona adecuadamente, cumpliendo con las expectativas deseadas.The design and implementation of a device for obtaining the coordinates of the sun at any time during the day, it means, a solar tracker of type two axis by luminous point is developed in this paper. This tracker consists of two main blocks: the controller board and the mechanical part. The design is based on the use of photoresistences, microcontrollers and stepper motors. The prototype is used on investigations about solar energy developed at the GERA (Grupo de Energía Renovable Aplicada of Universidad de Oriente, particularly in photovoltaic panels and water heaters. An experimental test was conducted in the laboratories and at the site of the group and it was found that the solar tracker is functioning properly, meeting the desired expectations.

Solar Irradiance Variability is Caused by the Magnetic Activity on the Solar Surface.

Science.gov (United States)

Yeo, Kok Leng; Solanki, Sami K; Norris, Charlotte M; Beeck, Benjamin; Unruh, Yvonne C; Krivova, Natalie A

2017-09-01

The variation in the radiative output of the Sun, described in terms of solar irradiance, is important to climatology. A common assumption is that solar irradiance variability is driven by its surface magnetism. Verifying this assumption has, however, been hampered by the fact that models of solar irradiance variability based on solar surface magnetism have to be calibrated to observed variability. Making use of realistic three-dimensional magnetohydrodynamic simulations of the solar atmosphere and state-of-the-art solar magnetograms from the Solar Dynamics Observatory, we present a model of total solar irradiance (TSI) that does not require any such calibration. In doing so, the modeled irradiance variability is entirely independent of the observational record. (The absolute level is calibrated to the TSI record from the Total Irradiance Monitor.) The model replicates 95% of the observed variability between April 2010 and July 2016, leaving little scope for alternative drivers of solar irradiance variability at least over the time scales examined (days to years).

Evolution of the solar system in the presence of a solar companion star

International Nuclear Information System (INIS)

Hut, P.

1986-01-01

A review is presented of the dynamical implications of a companion star in a wide orbit around the sun, with a semimajor axis of about half a parsec. The motivation behind the hypothesis of a solar companion star is reviewed briefly along with alternative hypotheses, and the general problem of solar system dynamics with a solar companion star is discussed. Four principal questions are posed and answered concerning the consistency of the solar companion theory in providing the required modulation in comet arrival times: (1) What is the expected lifetime of a solar companion? (2) How stable is the orbital period? (3) Does a single perihelion passage of a solar companion perturb enough comets? (4) Do repeated perihelion passages of a solar companion perturb too many comets? Some applications outside the solar system involving wide binaries, interstellar clouds, and dark matter in the Galactic disk are discussed, and the viability of the solar companion theory is critically assessed

A Preliminary Analysis of Solar Irradiance Measurements at TNB Solar Research Centre for Optimal Orientation of Fixed Solar Panels installed in Selangor Malaysia

International Nuclear Information System (INIS)

Hashim, A M; Ahmad, B; Shafie, R M; Rusli, R; Aziz, M A; Hassan, J; Wanik, M Z C; Ali, M A M

2013-01-01

The well established rule for orienting fixed solar devices is to face south for places in the northern hemisphere and northwards for the southern hemisphere. However for regions near the equator such as in Selangor Malaysia, the position of the sun at solar noon is always near zenith both to the north and south depending on location and month of year. This paper reports an analysis of global solar radiation data taken at TNB Solar Research Centre, Malaysia. The solar radiation is measured using both shaded and exposed pyranometers together with a pyrheliometer which is mounted on a sun-tracker. The analysis on the solar measurements show that a near regular solar irradiation pattern had occurred often enough during the year to recommend an optimum azimuth orientation of installing the fixed solar panels tilted facing towards east. Even though all the solar measurements were done at a single location in TNBR Solar Research Centre at Bangi, for locations near the equator with similar weather pattern, the recommended azimuth direction of installing fixed solar panels and collectors tilted eastward will also be generally valid.

Solar '95: Proceedings of the 20. national passive solar conference. Volume 20

International Nuclear Information System (INIS)

Campbell-Howe, R.; Wilkins-Crowder, B.

1995-01-01

This book contains the proceedings of the 20th National Passive Solar Conference, 1995, of the American Solar Energy Society. The topics of the papers include historical aspects of solar energy, daylighting, examination of passive system designs, sustainability concepts, building components, building design, application of solar architecture, case studies, education, and design tools

Solar variability observed through changes in solar figure and mean diameter

International Nuclear Information System (INIS)

Hill, H.A.

1991-01-01

The work performed on solar variability during 1990 at SCLERA is reviewed. That portion of the SCLERA research program supported by the Department of Energy has been directed toward the detection and monitoring of climatically significant solar variability by accurate measurement of the variability in solar shape and diameter. Observations were obtained in 1990 and results from analysis of earlier observations obtained. The observational evidence of systematic long-term changes in the apparent solar diameter and/or radius has been detected, and these changes continue to strongly correlated with long-term changes in solar total irradiance. Additional evidence for internal gravity modes has been found which may be important to understanding the internal structure of the Sun. Each of these findings shows promise for anticipating future changes in the solar luminosity. Progress has been made in setting up an international network based on SCLERA-type instruments to improve the coverage and quality of the observations. A proposal is made for the continuation of support from the Department of Energy for further studies relevant to solar-variability forecasting

Solar Features

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar feature datasets contributed by a number of national and private solar observatories located worldwide.

Effluents treatment by solar photocatalysis; Tratamiento de efluentes con fotocatalisis solar

Energy Technology Data Exchange (ETDEWEB)

Blanco, J; Malato, S; Richter, C [Plataforma Solar de almeria, Almeria (Spain); Carmona, F; Martinez, F [Deretil, Almeria (Spain)

1996-12-31

A solar photocatalytic system is being developed at the Plataforma Solar De Almeria to destroy organic contaminants in water. Test with common water contaminants were conducted at the Solar Detoxification loop with real sun light and large quantities of water flowing through glass tubes were the solar UV light is concentrated. Experiments at this scale provide verification of laboratory studies and allow the design and operation of real preindustrial detoxification systems. (Author)

Elimination of pathogenic bacteria in sewage sludge during the solar drying; Eliminacion de bacterias patogenas en lodos residuales durante el secado solar

Energy Technology Data Exchange (ETDEWEB)

Cota Espericueta, Alma Delia; Ponce Corral, Carlos [Instituto de Ciencias Biomedicas, Universidad Autonoma de Ciudad Juarez, Ciudad Juarez, Chihuahua, (Mexico)

2008-11-15

Planta de Tratamiento de Aguas Residuales de Ciudad Juarez. El dispositivo solar fue propuesto como una alternativa tecnica factible para la reduccion de volumen de las 135 ton de lodos generadas por dia en esta planta. El prototipo experimental tipo invernadero estuvo constituido por un area de captacion de 4.5 m{sup 2} y un lecho de secado de 1 m{sup 3}, ademas de los sistemas de ventilacion, extraccion y adquisicion de datos. El funcionamiento automatico del dispositivo estuvo regulado por las diferencias entre las condiciones internas y externas de las variables de temperatura y humedad. Ademas, se midieron la radiacion solar, el pH y la humedad del lodo. La efectividad del secador fue determinada en terminos termicos y microbiologicos. La perdida de agua en el lodo durante el tratamiento fue el indicativo de la efectividad termica. La depuracion microbiologica fue cuantificada a diferentes tiempos de residencia, mediante los indicadores de contaminacion: coliformes fecales y Salmonella spp. La cuantificacion de ambas bacterias se realizo a traves de la tecnica microbiologica de tubos de fermentacion multiple expuesta en la Norma Oficial Mexicana NOM-004-SEMARNAT-2002. Los resultados termicos asociados al contenido de agua en el lodo mostraron un decaimiento exponencial hasta lograr el 99 % de reduccion de la misma. En lo referente a la efectividad microbiologica, existio dependencia del contenido de las bacterias indicadoras con la cantidad de agua presente en lodo. Para la remocion del 92 % de agua, se verifico la eliminacion de coliformes fecales desde 3.8x10{sup 6} hasta 1.6 NMP por gramo de lodo seco y para Salmonella spp. dicha reduccion fue desde 1.5x10{sup 1}3 hasta 1.9x10{sup 3} NMP por gramo de lodo seco.

Kinetic Physics of the Solar Corona and Solar Wind

Directory of Open Access Journals (Sweden)

Marsch Eckart

2006-07-01

Full Text Available Kinetic plasma physics of the solar corona and solar wind are reviewed with emphasis on the theoretical understanding of the in situ measurements of solar wind particles and waves, as well as on the remote-sensing observations of the solar corona made by means of ultraviolet spectroscopy and imaging. In order to explain coronal and interplanetary heating, the microphysics of the dissipation of various forms of mechanical, electric and magnetic energy at small scales (e.g., contained in plasma waves, turbulences or non-uniform flows must be addressed. We therefore scrutinise the basic assumptions underlying the classical transport theory and the related collisional heating rates, and also describe alternatives associated with wave-particle interactions. We elucidate the kinetic aspects of heating the solar corona and interplanetary plasma through Landau- and cyclotron-resonant damping of plasma waves, and analyse in detail wave absorption and micro instabilities. Important aspects (virtues and limitations of fluid models, either single- and multi-species or magnetohydrodynamic and multi-moment models, for coronal heating and solar wind acceleration are critically discussed. Also, kinetic model results which were recently obtained by numerically solving the Vlasov–Boltzmann equation in a coronal funnel and hole are presented. Promising areas and perspectives for future research are outlined finally.

From Solar Cookers Towards Viable Solar Cooking Technology

DEFF Research Database (Denmark)

Ahmad, Bashir

1997-01-01

A broader concept of technology encompassing the technical and the societal aspects is introduced. Viability of technology and technological development process from a socio-technical view- point is discussed. Based on the above, the question of securing viability of solar cooking technology...... is taken up. It is discussed that actor- approach can operationally relate the abstract societal factors with those of technical aspects. Some concrete measures regarding application of solar cooker projects are drawn from the discussion: solar cooking projects should a) be based on user and producer...

GPP Webinar: The Solar Roadmap—Navigating the Evolving Solar Energy Market

Science.gov (United States)

GPP and State & Local Climate and Energy Branch webinar on the Solar Roadmap and the evolving solar energy market. This webinar discussed local and state government’s success stories and opportunities for progress in renewable energy goals using the Solar

Comparison of Artificial Neural Networks and GIS Based Solar Analysis for Solar Potential Estimation

Science.gov (United States)

Konakoǧlu, Berkant; Usta, Ziya; Cömert, Çetin; Gökalp, Ertan

2016-04-01

Nowadays, estimation of solar potential plays an important role in planning process for sustainable cities. The use of solar panels, which produces electricity directly from the sun, has become popular in accordance with developing technologies. Since the use of solar panels enables the users to decrease costs and increase yields, the use of solar panels will be more popular in the future. Production of electricity is not convenient for all circumstances. Shading effects, massive clouds and rainy weather are some factors that directly affect the production of electricity from solar energy. Hence, before the installation of solar panels, it is crucial to conduct spatial analysis and estimate the solar potential of the place that the solar panel will be installed. There are several approaches to determine the solar potential. Examination of the applications in the literature reveals that the applications conducted for determining the solar potential are divided into two main categories. Solar potential is estimated either by using artificial neural network approach in which statistical parameters such as the duration of sun shine, number of clear days, solar radiation etc. are used, or by spatial analysis conducted in GIS approaches in which spatial parameters such as, latitude, longitude, slope, aspect etc. are used. In the literature, there are several studies that use both approaches but the literature lacks of a study related to the comparison of these approaches. In this study, Karadeniz Technical University campus has been selected as study area. Monthly average values of the number of clear sky days, air temperature, atmospheric pressure, relative humidity, sunshine duration and solar radiation parameters obtained for the years between 2005 and 2015 will be used to perform artificial neural network analysis to estimate the solar potential of the study area. The solar potential will also be estimated by using GIS-based solar analysis modules. The results of

Solar Photovoltaic Cells.

Science.gov (United States)

Mickey, Charles D.

1981-01-01

Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

Solar Photovoltaic

OpenAIRE

Wang, Chen; Lu, Yuefeng

2016-01-01

In the 21st century, human demand for new energy sources is urgent, because the traditional fossil energy is unable to meet human needs, and the fossil resource will make pollution, in this situation, solar energy gradually into the vision of scientists. As science advances, humans can already extensive use of solar energy to generate electricity. Solar energy is an inexhaustible and clean energy. In the global energy crisis, environmental pollution is the growing problem of today. The us...

Solar Imagery

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar photographic and illustrated datasets contributed by a number of national and private solar observatories located worldwide....

Solar weather monitoring

Directory of Open Access Journals (Sweden)

J.-F. Hochedez

2005-11-01

Full Text Available Space Weather nowcasting and forecasting require solar observations because geoeffective disturbances can arise from three types of solar phenomena: coronal mass ejections (CMEs, flares and coronal holes. For each, we discuss their definition and review their precursors in terms of remote sensing and in-situ observations. The objectives of Space Weather require some specific instrumental features, which we list using the experience gained from the daily operations of the Solar Influences Data analysis Centre (SIDC at the Royal Observatory of Belgium. Nowcasting requires real-time monitoring to assess quickly and reliably the severity of any potentially geoeffective solar event. Both research and forecasting could incorporate more observations in order to feed case studies and data assimilation respectively. Numerical models will result in better predictions of geomagnetic storms and solar energetic particle (SEP events. We review the data types available to monitor solar activity and interplanetary conditions. They come from space missions and ground observatories and range from sequences of dopplergrams, magnetograms, white-light, chromospheric, coronal, coronagraphic and radio images, to irradiance and in-situ time-series. Their role is summarized together with indications about current and future solar monitoring instruments.

Solar-hydrogen generation and solar concentration (Conference Presentation)

NARCIS (Netherlands)

Sulima, Oleg V.; Chinello, Enrico; Conibeer, Gavin; Modestino, Miquel A.; Schüttauf, Jan-Willem; Lambelet, David; Delfino, Antonio; Domine, Didier; Faes, Antonin; Despeisse, Matthieu; Bailat, Julien; Psaltis, Demetri; Fernandez Rivas, David; Ballif, Christophe; Moser, Christophe

2016-01-01

We successfully demonstrated and reported the highest solar-to-hydrogen efficiency with crystalline silicon cells and Earth-abundant electrocatalysts under unconcentrated solar radiation. The combination of hetero-junction silicon cells and a 3D printed Platinum/Iridium-Oxide electrolyzer has been

Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

Science.gov (United States)

Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

2002-01-01

Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

Solar Research | NREL

Science.gov (United States)

Research Photo of a city landscape with a sun in the background. Solar energy research at NREL includes photovoltaics, concentrating solar power, solar grid and systems integration, and market research and analysis. Photovoltaic Research Photo of a roof-mounted PV array on the NREL campus. NREL's

Solar Indices

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

Solar heating and cooling.

Science.gov (United States)

Duffie, J A

1976-01-01

Solar energy is discussed as an energy resource that can be converted into useful energy forms to meet a variety of energy needs. The review briefly explains the nature of this energy resource, the kinds of applications that can be made useful, and the status of several systems to which it has been applied. More specifically, information on solar collectors, solar water heating, solar heating of buildings, solar cooling plus other applications, are included.

Midmarket Solar Policies in the United States: A Guide for Midsized Solar Customers

Energy Technology Data Exchange (ETDEWEB)

Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Liu, Chang [National Renewable Energy Lab. (NREL), Golden, CO (United States); O' Shaughnessy, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mathur, Shivani [National Renewable Energy Lab. (NREL), Golden, CO (United States); Holm, Alison [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, John [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

The midscale market for solar photovoltaics (PV) has not experienced the same high growth rate as residential- or utility-scale market segments in the past five years when solar PV deployment increased rapidly. Midscale solar can be defined as behind-the-meter solar PV between 50 kilowatts and 2 megawatts adopted by multi-housing residential, commercial, industrial, non-profit, and other entities. A number of challenges face the midscale segment, including difficulties in contracting, mismatch between tenant lease and PV financing terms, high transaction costs relative to project sizes, and inefficiencies in matching prospective projects with capital. The changing policy landscape across U.S. states provides both opportunities and challenges to midmarket solar. Some states, such as California, are expanding system capacity limits for policies such as net metering, thus enabling a wider range of customers to benefit from excess generation. A number of states and utilities are making changes to rate design to introduce new or higher user fees for solar customers or reduced tariffs for net metering, which decrease the value of solar generation. An understanding of these policies relative to project feasibility and economics is important for prospective customers to make informed decisions to adopt solar PV. This guide complements existing solar policy resources to help potential customers navigate through the policy landscape in order to make informed decisions for their solar investment. The first part of this guide introduces the key solar policies necessary for policy-based decision-making, which involves using knowledge of a solar policy to improve project economics and efficiency. Policies that could result in policy-based decisions include interconnection standards, net metering, user fees, incentives, and third-party ownership policies. The goal of this section is to equip prospective customers and project developers with the tools necessary to understand and

Solar Flares and the High Energy Solar Spectroscopic Imager (HESSI)

Science.gov (United States)

Holman, Gordon D.; Fisher, Richard R. (Technical Monitor)

2001-01-01

Solar flares are the biggest explosions in the solar system. They are important both for understanding explosive events in the Universe and for their impact on human technology and communications. The satellite-based HESSI is designed to study the explosive release of energy and the acceleration of electrons, protons, and other charged particles to high energies in solar flares. HESSI produces "color" movies of the Sun in high-energy X rays and gamma rays radiated by these energetic particles. HESSI's X-ray and gamma-ray images of flares are obtained using techniques similar to those used in radio interferometry. Ground-based radio observations of the Sun provide an important complement to the HESSI observations of solar flares. I will describe the HESSI Project and the high-energy aspects of solar flares, and how these relate to radio astronomy techniques and observations.

The SOLAR-C Mission

Science.gov (United States)

Suematsu, Y.

2015-12-01

The Solar-C is a Japan-led international solar mission planned to be launched in mid2020. It is designed to investigate the magnetic activities of the Sun, focusing on the study in heating and dynamical phenomena of the chromosphere and corona, and also to develop an algorithm for predicting short and long term solar evolution. Since it has been revealed that the different parts of the magnetized solar atmosphere are essentially coupled, the SOLAR-C should tackle the spatial scales and temperature regimes that need to be observed in order to achieve a comprehensive physical understanding of this coupling. The science of Solar-C will greatly advance our understanding of the Sun, of basic physical processes operating throughout the universe. To dramatically improve the situation, SOLAR-C will carry three dedicated instruments; the Solar UV-Vis-IR Telescope (SUVIT), the EUV Spectroscopic Telescope (EUVST) and the High Resolution Coronal Imager (HCI), to jointly observe the entire visible solar atmosphere with essentially the same high spatial resolution (0.1-0.3 arcsec), performing high resolution spectroscopic measurements over all atmospheric regions and spectro-polarimetric measurements from the photosphere through the upper chromosphere. In addition, Solar-C will contribute to our understanding on the influence of the Sun-Earth environments with synergetic wide-field observations from ground-based and other space missions. Some leading science objectives and the mission concept, including designs of the three instruments aboard SOLAR-C will be presented.

Solar thermal and concentrated solar power barometer

International Nuclear Information System (INIS)

2013-01-01

The European concentrated solar power plant market is steeling itself for tough time ahead. The number of projects under construction is a pittance compared with 2012 that was an excellent year for installations (an additional 802.5 MW of capacity recorded). This drop is the result of the moratorium on renewable energy power plants introduced by the Spanish government. The European solar thermal market is hardly any more encouraging . EurObserv'ER holds that it slipped for the fourth year in a row (it dropped 5.5% between 2011 and 2012). The newly-installed solar thermal collector surface area in the EU now stands at 3.4 million m 2 , far short of its 2008 installation record of 4.6 million m 2 . The EU's solar thermal base to date at the end of 2012 is 29.6 GWth with 2.4 GWth installed during the year 2012. This article gives tables gathering the figures of the production for every European country for 2012 and describes the market and the general trend for every EU member

Solar energy: a UK assessment

Energy Technology Data Exchange (ETDEWEB)

1976-01-01

A panel convened by UK-ISES to analyze all aspects of solar energy systems and to assess the potential for solar energy utilization and research and development needs in the UK and for export is reported. Topics covered include: solar energy in relation to other energy sources; international solar energy research and development program; the physical nature of solar energy and its availability in the UK and other countries; thermal collection, storage, and low-temperature applications; solar energy and architecture; solar thermal power systems; solar cells; agricultural and biological systems; photochemical systems; social, legal, and political considerations with particular reference to the UK; and future policy on solar research and development for the UK. (WDM)

Manifestation of solar activity in solar wind particle flux density

International Nuclear Information System (INIS)

Kovalenko, V.A.

1988-01-01

An analysis has been made of the origin of long-term variations in flux density of solar wind particles (nv) for different velocity regimes. The study revealed a relationship of these variations to the area of the polar coronal holes (CH). It is shown that within the framework of the model under development, the main longterm variations of nv are a result of the latitude redistribution of the solar wind mass flux in the heliosphere and are due to changes in the large-scale geometry of the solar plasma flow in the corona. A study has been made of the variations of nv for high speed solar wind streams. It is found that nv in high speed streams which are formed in CH, decreases from minimum to maximum solar activity. The analysis indicates that this decrease is attributable to the magnetic field strength increase in coronal holes. It has been found that periods of rapid global changes of background magnetic fields on the Sun are accompanied by a reconfiguration of coronal magnetic fields, rapid changes in the length of quiescent filaments, and by an increase in the density of the particle flux of a high speed solar wind. It has been established that these periods precede the formation of CH, corresponding to the increase in solar wind velocity near the Earth and to enhancement of the level of geomagnetic disturbance. (author)

A comparison of solar wind streams and coronal structure near solar minimum

Science.gov (United States)

Nolte, J. T.; Davis, J. M.; Gerassimenko, M.; Lazarus, A. J.; Sullivan, J. D.

1977-01-01

Solar wind data from the MIT detectors on the IMP 7 and 8 satellites and the SOLRAD 11B satellite for the solar-minimum period September-December, 1976, were compared with X-ray images of the solar corona taken by rocket-borne telescopes on September 16 and November 17, 1976. There was no compelling evidence that a coronal hole was the source of any high speed stream. Thus it is possible that either coronal holes were not the sources of all recurrent high-speed solar wind streams during the declining phase of the solar cycle, as might be inferred from the Skylab period, or there was a change in the appearance of some magnetic field regions near the time of solar minimum.

Solar Energy Perspectives In Egypt

International Nuclear Information System (INIS)

Comsan, M.N.H.

2010-01-01

Egypt belongs to the global sun-belt. The country is in advantageous position with solar energy. In 1991 solar atlas for Egypt was issued indicating that the country enjoys 2900-3200 hours of sunshine annually with annual direct normal energy density 1970-3200 kWh/m2 and technical solar-thermal electricity generating potential of 73.6 Peta watt hour (PWh). Egypt was among the first countries to utilize solar energy. In 1910, a practical industrial scale solar system engine was built at Maadi south to Cairo using solar thermal parabolic collectors. The engine was used to produce steam which drove a series of large water pumps for irrigation. Nowadays utilization of solar energy includes use of photovoltaic cells, solar water heating and solar thermal power. Use of solar thermal technology may include both electricity generation and water desalination, which is advantageous for Egypt taking in consideration its shortage in water supply. The article discusses perspectives of solar energy in Egypt and developmental trends till 2050

Rectenna solar cells

CERN Document Server

Moddel, Garret

2013-01-01

Rectenna Solar Cells discusses antenna-coupled diode solar cells, an emerging technology that has the potential to provide ultra-high efficiency, low-cost solar energy conversion. This book will provide an overview of solar rectennas, and provide thorough descriptions of the two main components: the diode, and the optical antenna. The editors discuss the science, design, modeling, and manufacturing of the antennas coupled with the diodes. The book will provide concepts to understanding the challenges, fabrication technologies, and materials required to develop rectenna structures. Written by e

Distinción de especies del género Persea mediante RAPD e ISSR de ADN

OpenAIRE

Reyes-Alemán, Juan Carlos; Valadez-Moctezuma, Ernestina; Simuta-Velázco, Lisandro; Barrientos-Priego, Alejandro Facundo; Gallegos-Vázquez, Clemente

2013-01-01

Con la finalidad de establecer bases para diferenciar parte de la diversidad genética de Persea y en especial del subgénero Persea resguardado en la colección nacional de germoplasma de aguacate de México, se estudiaron ocho especies (P. americana, P. steyermarkii, P. schiedeana, P. lingue, P. nubigena, P. floccosa, P. cinerascens y P. indica) con marcadores moleculares mediante las técnicas de RAPD e ISSR, donde los productos de PCR fueron separados en geles de acrilamida. Las huellas de ADN...

Generación de escenarios de planificación de redes mediante técnicas OLAP

OpenAIRE

Ramos García, Jesús

2015-01-01

RESUMEN: Debido a la gran cantidad de datos que a veces se tienen que manejar, es necesario el uso de herramientas que se encarguen de almacenar, reducir, extraer, analizar, procesar o modificar dichos datos de la forma más rápida y sencilla posible. Las bases de datos multidimensionales, con el nombre de cubo OLAP (On-Line Analytical Processing) se encargan de representar la información elegida de forma multidimensional, es decir, mediante cubos de varias dimensiones, haciendo que dicha info...

Teleoperación de un robot mindstorm mediante técnicas de visión artificial

OpenAIRE

Méndez Rodríguez, Eduardo

2011-01-01

Las tres partes tratadas son la teleoperacióon (principalmente con comunicaciones mediante bluetooth), la visión arti cial para elementos móviles en tiempo real y proyectos realizados con el Mindstorm NXT. Hay que destacar que en los dos primeros campos hay innumerables aplicaciones debido a que ambos campos siguen hoy en día bajo invetigación en busca de lograr mejoras tecnológicas, también los proyectos con el Mindstorm están creciendo exponencialmente, mayormente debido a...

Solar and Hydrogen

International Nuclear Information System (INIS)

Kadirgan, F.; Beyhan, S.; Oezenler, S.

2006-01-01

It has been widely accepted that the only sustainable and environmentally friendly energy is the solar energy and hydrogen energy, which can meet the increasing energy demand in the future. Solar Energy may be used either for solar thermal or for solar electricity conversion. Solar thermal collectors represent a wide-spread type of system for the conversion of solar energy. Radiation, convection and conduction are strongly coupled energy transport mechanisms in solar collector systems. The economic viability of lower temperature applications of solar energy may be improved by increasing the quantity of usable energy delivered per unit area of collector. This can be achieved by the use of selective black coatings which have a high degree of solar absorption, maintaining high energy input to the solar system while simultaneously suppressing the emission of thermal infrared radiation. Photovoltaic solar cells and modules are produced for: (1) large scale power generation, most commonly when modules are incorporated as part of a building (building integrated photovoltaic s) but also in centralised power stations, (2) supplying power to villages and towns in developing countries that are not connected to the supply grid, e.g. for lighting and water pumping systems, (3) supplying power in remote locations, e.g. for communications or weather monitoring equipment, (4) supplying power for satellites and space vehicles, (5) supplying power for consumer products, e.g. calculators, clocks, toys and night lights. In hydrogen energy systems, Proton exchange membrane (PEMFC) fuel cells are promising candidates for applications ranging from portable power sources (battery replacement applications) to power sources for future electric vehicles because of their safety, elimination of fuel processor system, thus, simple device fabrication and low cost. Although major steps forward have been achieved in terms of PEMFC design since the onset of research in this area, further

Semiconductor-based Multilayer Selective Solar Absorber for Unconcentrated Solar Thermal Energy Conversion.

Science.gov (United States)

Thomas, Nathan H; Chen, Zhen; Fan, Shanhui; Minnich, Austin J

2017-07-13

Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths. In field tests, we obtain a peak temperature of 225 °C, comparable to that achieved with state-of-the-art selective surfaces. With straightforward optimization to improve solar absorption, our work shows the potential for unconcentrated solar thermal systems to reach stagnation temperatures exceeding 300 °C, thereby eliminating the need for solar concentrators for mid-temperature solar applications such as supplying process heat.

The Solar Wind from Pseudostreamers and their Environs: Opportunities for Observations with Parker Solar Probe and Solar Orbiter

Science.gov (United States)

Panasenco, O.; Velli, M.; Panasenco, A.; Lionello, R.

2017-12-01

The solar dynamo and photospheric convection lead to three main types of structures extending from the solar surface into the corona - active regions, solar filaments (prominences when observed at the limb) and coronal holes. These structures exist over a wide range of scales, and are interlinked with each other in evolution and dynamics. Active regions can form clusters of magnetic activity and the strongest overlie sunspots. In the decay of active regions, the boundaries separating opposite magnetic polarities (neutral lines) develop specific structures called filament channels above which filaments form. In the presence of flux imbalance decaying active regions can also give birth to lower latitude coronal holes. The accumulation of magnetic flux at coronal hole boundaries also creates conditions for filament formation: polar crown filaments are permanently present at the boundaries of the polar coronal holes. Mid-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers if other coronal holes of the same polarity are present. While helmet streamers form between open fields of opposite polarities, the pseudostreamer, characterized by a smaller coronal imprint, typically shows a more prominent straight ray or stalk extending from the corona. The pseudostreamer base at photospheric heights is multipolar; often one observes tripolar magnetic configurations with two neutral lines - where filaments can form - separating the coronal holes. Here we discuss the specific role of filament channels on pseudostreamer topology and on solar wind properties. 1D numerical analysis of pseudostreamers shows that the properties of the solar wind from around PSs depend on the presence/absence of filament channels, number of channels and chirality at thepseudostreamer base low in the corona. We review and model possible coronal magnetic configurations and solar wind plasma properties at different distances from the solar surface that

Magnetohydrodynamic process in solar activity

Directory of Open Access Journals (Sweden)

Jingxiu Wang

2014-01-01

Full Text Available Magnetohydrodynamics is one of the major disciplines in solar physics. Vigorous magnetohydrodynamic process is taking place in the solar convection zone and atmosphere. It controls the generating and structuring of the solar magnetic fields, causes the accumulation of magnetic non-potential energy in the solar atmosphere and triggers the explosive magnetic energy release, manifested as violent solar flares and coronal mass ejections. Nowadays detailed observations in solar astrophysics from space and on the ground urge a great need for the studies of magnetohydrodynamics and plasma physics to achieve better understanding of the mechanism or mechanisms of solar activity. On the other hand, the spectacular solar activity always serves as a great laboratory of magnetohydrodynamics. In this article, we reviewed a few key unresolved problems in solar activity studies and discussed the relevant issues in solar magnetohydrodynamics.

Large-scale solar purchasing

International Nuclear Information System (INIS)

1999-01-01

The principal objective of the project was to participate in the definition of a new IEA task concerning solar procurement (''the Task'') and to assess whether involvement in the task would be in the interest of the UK active solar heating industry. The project also aimed to assess the importance of large scale solar purchasing to UK active solar heating market development and to evaluate the level of interest in large scale solar purchasing amongst potential large scale purchasers (in particular housing associations and housing developers). A further aim of the project was to consider means of stimulating large scale active solar heating purchasing activity within the UK. (author)

Elemental composition and ionization state of the solar atmosphere and solar wind

International Nuclear Information System (INIS)

Joselyn, J.A.C.

1978-01-01

Abundance measurements have always proved useful in generating and refining astrophysical theories. Some of the classical problems of astrophysics involve determining the relative abundances of elements in the atmosphere of a star from observations of its line spectrum, and then synthesizing the physical processes which would produce such abundances. Theories of the formation of the solar system are critically tested by their ability to explain observed abundances, and, elemental abundances can serve as tracers, helping to determine the origin and transport of ions. Since the solar wind originates at the sun, it can act as a diagnostic probe of solar conditions. In particular, measurements of the composition of the solar wind should be related to the solar composition. And, assuming ionization equilibrium, measurements of the relative abundances of the ionization states in the solar wind should infer coronal temperatures and temperature gradients. However, most spherically symmetric models of the solar wind are unable to explain the relationship between the composition estimated from solar observations and as measured at 1 AU; and, recent observations of significant flow speeds in the transition region raise doubts about the validity of the assumption of ionization equilibrium

Solar-system Education for the 2017 Total Solar Eclipse

Science.gov (United States)

Pasachoff, Jay M.

2017-10-01

I describe an extensive outreach program about the Sun, the silhouette of the Moon, and the circumstances both celestial and terrestrial of the August 21, 2017, total solar eclipse. Publications included a summary of the last decade of solar-eclipse research for Nature Astronomy, a Resource Letter on Observing Solar Eclipses for the American Journal of Physics, and book reviews for Nature and for Phi Beta Kappa's Key Reporter. Symposia arranged include sessions at AAS, APS, AGU, and AAAS. Lectures include all ages from pre-school through elementary school to high school to senior-citizen residences. The work, including the scientific research about the solar corona that is not part of this abstract, was supported by grants from the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of NSF and from the Committee for Research and Exploration of the National Geographic Society. Additional student support was received from NSF, NASA's Massachusetts Space Grant Consortium, the Honorary Research Society Sigma Xi, the Clare Booth Luce Foundation, and funds at Williams College.

Proyectar con la naturaleza mediante la Metodología de los Estudios de Impacto Ambiental en ordenaciones residenciales

OpenAIRE

Higueras García, Esther

2013-01-01

Proyectar con la naturaleza mediante la Metodología de los Estudios de Impacto Ambiental en ordenaciones residenciales .- Procedimiento de acción en la planificación ambiental .- Las técnicas de agregación de impactos .- Las afecciones de los planes de ordenación sobre el territorio. .- Las medidas preventivas y correctoras de planes .- Evaluación critica de los estudios de impacto ambiental

Energetic solar particles

International Nuclear Information System (INIS)

Biswas, M.

1975-01-01

In this review, some of the important aspects of energetic solar particles and their relation to solar physics are discussed. The major aspects of solar cosmic ray studies currently under investigation are identified and attention is focussed on the problems of the physical processes in the sun which may be responsible for these phenomena. The studies of the composition and energy spectra of solar cosmic ray nuclei are related to the basic problem of particle acceleration process in sun and to the composition of elements in solar atmosphere. The composition of higher energy (>20 MeV/amu) multiply charged nuclei of He, C, N, O, Ne, Mg, Si and Fe give information on the abundance of elements in the solar atmosphere. At lower energies (approximately 1-10 MeV/amu), the abundances of these elements show enhancements relative to solar abundances and these enhancements are believed to be due to particle acceleration mechanisms operative in the sun which are not fully understood at present. Studies of the relative abundances of H 2 , H 3 and He 3 isotopes and Li, Be, B nuclei in the solar cosmic rays can also be studied. The question of the relationship of the accelerated particles in the sun to the optical flare phenomena is discussed. Further studies of different aspects of these phenomena may give important clues to a wide ranging phenomena in the active sun. The observational methods employed for these studies are mentioned. (A.K.)

Solar atmospheric neutrinos and the sensitivity floor for solar dark matter annihilation searches

Energy Technology Data Exchange (ETDEWEB)

Argüelles, C.A. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA (United States); De Wasseige, G. [Vrije Universiteit Brussel, Pleinlaan 2, 1050 Elsene, Brussels (Belgium); Fedynitch, A. [Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Jones, B.J.P., E-mail: caad@mit.edu, E-mail: gdewasse@vub.ac.be, E-mail: anatoli.fedynitch@desy.de, E-mail: ben.jones@uta.edu [University of Texas at Arlington, 108 Science Hall, 502 Yates St, Arlington TX (United States)

2017-07-01

Cosmic rays interacting in the solar atmosphere produce showers that result in a flux of high-energy neutrinos from the Sun. These form an irreducible background to indirect solar WIMP self-annihilation searches, which look for heavy dark matter particles annihilating into final states containing neutrinos in the Solar core. This background will eventually create a sensitivity floor for indirect WIMP self-annihilation searches analogous to that imposed by low-energy solar neutrino interactions for direct dark matter detection experiments. We present a new calculation of the flux of solar atmospheric neutrinos with a detailed treatment of systematic uncertainties inherent in solar atmospheric shower evolution, and we use this to derive the sensitivity floor for indirect solar WIMP annihilation analyses. We find that the floor lies less than one order of magnitude beyond the present experimental limits on spin-dependent WIMP-proton cross sections for some mass points, and that the high-energy solar atmospheric neutrino flux may be observable with running and future neutrino telescopes.

Hawaii Solar Integration Study: Solar Modeling Developments and Study Results; Preprint

Energy Technology Data Exchange (ETDEWEB)

Orwig, K.; Corbus, D.; Piwko, R.; Schuerger, M.; Matsuura, M.; Roose, L.

2012-12-01

The Hawaii Solar Integration Study (HSIS) is a follow-up to the Oahu Wind Integration and Transmission Study completed in 2010. HSIS focuses on the impacts of higher penetrations of solar energy on the electrical grid and on other generation. HSIS goes beyond the island of Oahu and investigates Maui as well. The study examines reserve strategies, impacts on thermal unit commitment and dispatch, utilization of energy storage, renewable energy curtailment, and other aspects of grid reliability and operation. For the study, high-frequency (2-second) solar power profiles were generated using a new combined Numerical Weather Prediction model/ stochastic-kinematic cloud model approach, which represents the 'sharp-edge' effects of clouds passing over solar facilities. As part of the validation process, the solar data was evaluated using a variety of analysis techniques including wavelets, power spectral densities, ramp distributions, extreme values, and cross correlations. This paper provides an overview of the study objectives, results of the solar profile validation, and study results.

Virginia Solar Pathways Project: Economic Study of Utility-Administered Solar Programs: Soft Costs, Community Solar, and Tax Normalization Considerations

Energy Technology Data Exchange (ETDEWEB)

Reiter, Emerson [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lowder, Travis [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mathur, Shivani [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mercer, Megan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-06-23

This report presents economic considerations for solar development in support of the Virginia Solar Pathways Project (VSPP), an effort funded by the U.S. Department of Energy (DOE) SunShot Initiative that seeks to develop a collaborative utility-administered solar strategy for the Commonwealth of Virginia. The results presented are intended to be considered alongside the results of other studies conducted under the VSPP that evaluate the impacts of solar energy on the electric distribution, transmission, and generation systems in Virginia.

National Community Solar Platform

Energy Technology Data Exchange (ETDEWEB)

Rupert, Bart [Clean Energy Collective, Louisville, CO (United States)

2016-06-30

This project was created to provide a National Community Solar Platform (NCSP) portal known as Community Solar Hub, that is available to any entity or individual who wants to develop community solar. This has been done by providing a comprehensive portal to make CEC’s solutions, and other proven community solar solutions, externally available for everyone to access – making the process easy through proven platforms to protect subscribers, developers and utilities. The successful completion of this project provides these tools via a web platform and integration APIs, a wide spectrum of community solar projects included in the platform, multiple groups of customers (utilities, EPCs, and advocates) using the platform to develop community solar, and open access to anyone interested in community solar. CEC’s Incubator project includes web-based informational resources, integrated systems for project information and billing systems, and engagement with customers and users by community solar experts. The combined effort externalizes much of Clean Energy Collective’s industry-leading expertise, allowing third parties to develop community solar without duplicating expensive start-up efforts. The availability of this platform creates community solar projects that are cheaper to build and cheaper to participate in, furthering the goals of DOE’s SunShot Initiative. Final SF 425 Final SF 428 Final DOE F 2050.11 Final Report Narrative

Bright Idea: Solar Energy Primer.

Science.gov (United States)

Missouri State Dept. of Natural Resources, Jefferson City.

This booklet is intended to address questions most frequently asked about solar energy. It provides basic information and a starting point for prospective solar energy users. Information includes discussion of solar space heating, solar water heating, and solar greenhouses. (Author/RE)

Solar engineering of thermal processes

CERN Document Server

Duffie, John A

2013-01-01

The updated fourth edition of the ""bible"" of solar energy theory and applications Over several editions, Solar Engineering of Thermal Processes has become a classic solar engineering text and reference. This revised Fourth Edition offers current coverage of solar energy theory, systems design, and applications in different market sectors along with an emphasis on solar system design and analysis using simulations to help readers translate theory into practice. An important resource for students of solar engineering, solar energy, and alternative energy as well

Advanced solar energy conversion. [solar pumped gas lasers

Science.gov (United States)

Lee, J. H.

1981-01-01

An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

Solar saddle bags. Solar-Fahrradpacktaschen

Energy Technology Data Exchange (ETDEWEB)

Willems, M

1991-09-12

The invention consists of the arrangement of solar cells on the upper side of saddle bags of every design (handle bar pocket, bicycle saddle bag etc.) which charge the accumulators in the pack pocket. One can drive the alternator of the bicycle, a transistor radio, a cassette tape recorder, or similar, with the power from the accumulators. The lamp and the taillight of the bicycle can still be used. The solar cells can be attached firmly to the pack pocket. However, they can also be assembled detachably, e.g. by push-buttons or zip-fasteners.

Solar energy storage

CERN Document Server

Sorensen, Bent

2015-01-01

While solar is the fastest-growing energy source in the world, key concerns around solar power's inherent variability threaten to de-rail that scale-up . Currently, integration of intermittent solar resources into the grid creates added complication to load management, leading some utilities to reject it altogether, while other operators may penalize the producers via rate increases or force solar developers to include storage devices on-site to smooth out power delivery at the point of production. However these efforts at mitigation unfold, it is increasingly clear to parties on all sides th

Solar neutrino experiments

International Nuclear Information System (INIS)

Hampel, W.

1996-01-01

The present status of experimental solar neutrino research is reviewed. Updated results from the Homestake, Kamiokande, GALLEX and SAGE detectors all show a deficit when compared to recent standard solar model calculations. Two of these detectors, GALLEX and SAGE, have recently been checked with artificial 51 Cr neutrino sources. It is shown that astrophysical scenarios to solve the solar neutrino problems are not favoured by the data. There is hope that the results of forthcoming solar neutrino experiments can provide the answers to the open questions. (author) 6 figs., 3 tabs., 36 refs

Solar neutrino experiments

Energy Technology Data Exchange (ETDEWEB)

Hampel, W [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

1996-11-01

The present status of experimental solar neutrino research is reviewed. Updated results from the Homestake, Kamiokande, GALLEX and SAGE detectors all show a deficit when compared to recent standard solar model calculations. Two of these detectors, GALLEX and SAGE, have recently been checked with artificial {sup 51}Cr neutrino sources. It is shown that astrophysical scenarios to solve the solar neutrino problems are not favoured by the data. There is hope that the results of forthcoming solar neutrino experiments can provide the answers to the open questions. (author) 6 figs., 3 tabs., 36 refs.

Passive solar technology

Energy Technology Data Exchange (ETDEWEB)

Watson, D

1981-04-01

The present status of passive solar technology is summarized, including passive solar heating, cooling and daylighting. The key roles of the passive solar system designer and of innovation in the building industry are described. After definitions of passive design and a summary of passive design principles are given, performance and costs of passive solar technology are discussed. Passive energy design concepts or methods are then considered in the context of the overall process by which building decisions are made to achieve the integration of new techniques into conventional design. (LEW).

Solar Energy Basics | NREL

Science.gov (United States)

Solar Energy Basics Solar Energy Basics Solar is the Latin word for sun-a powerful source of energy that can be used to heat, cool, and light our homes and businesses. That's because more energy from the technologies convert sunlight to usable energy for buildings. The most commonly used solar technologies for

Solar Deployment System (SolarDS) Model: Documentation and Sample Results

Energy Technology Data Exchange (ETDEWEB)

Denholm, P.; Drury, E.; Margolis, R.

2009-09-01

The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

The turbulent cascade and proton heating in the solar wind during solar minimum

International Nuclear Information System (INIS)

Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

2013-01-01

Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

Solar energy conversion systems

CERN Document Server

Brownson, Jeffrey R S

2013-01-01

Solar energy conversion requires a different mind-set from traditional energy engineering in order to assess distribution, scales of use, systems design, predictive economic models for fluctuating solar resources, and planning to address transient cycles and social adoption. Solar Energy Conversion Systems examines solar energy conversion as an integrative design process, applying systems thinking methods to a solid knowledge base for creators of solar energy systems. This approach permits different levels of access for the emerging broad audience of scientists, engineers, architects, planners

Solar: California, not dreaming

Energy Technology Data Exchange (ETDEWEB)

Jones, J.

2006-03-15

The California Solar Initiative (CSI) was approved by the California Public Utilities Commission (PUC) in January 2006. The CSI is the largest solar programme of this kind ever in the USA and provides for $3.2 billion in incentives for solar projects between 2007 and 2017. The PUC will oversee a $2.5 billion programme to provide funding for solar installations on commercial and existing residential buildings, while the California Energy Commission (CEC) will manage a separate $350 million fund targeted at new residential building. Existing solar programmes operated by the PUC and CEC will be consolidated into the CSI. The CEC programme will use already allocated funding, but the PUC programme will be funded through revenues collected from customers of the main gas and electric utilities in California. Funds will be distributed via rebates to householders or companies that install solar. As well as solar photovoltaics (PV), rebates will also go to solar thermal power (concentrating solar power) and solar heating and cooling. CSI funding can be used in combination with existing federal tax credits. The aim is a gradual increase from installation of 40 MW of PV in 2005 to 100 MW by 2009. The CSI is also expected to create favourable market conditions for PV manufacturers in California and to encourage investment in production of solar-grade silicon in or near California. Objections from the International Brotherhood of Electrical Workers (IBEW) appear to have been overcome but a number of other potential snags remain. CSI is expected to be replicated in other US states.

Job creation potential of solar

International Nuclear Information System (INIS)

McMonagle, R.

2005-01-01

This document defines the size of the job market within Canada's solar industry and presents a preliminary forecast of the employment opportunities through to 2025. The issue of job potential within Canada's solar technologies is complicated by the wide range of different fields and technologies within the solar industry. The largest energy generator of the solar technologies is passive solar, but the jobs in this sector are generally in the construction trades and window manufacturers. The Canadian Solar Industries Association estimates that there are about 360 to 500 firms in Canada with the primary business of solar technologies, employing between 900 to 1,200 employees. However, most solar manufacturing jobs in Canada are for products exports as demonstrated by the 5 main solar manufacturers in Canada who estimate that 50 to 95 per cent of their products are exported. The main reason for their high export ratio is the lack of a Canadian market for their products. The 3 categories of job classifications within the solar industry include manufacturing, installation, and operations and maintenance. The indirect jobs include photovoltaic system hardware, solar hot water heating, solar air ventilation, and glass/metal framing. 17 refs., 3 tabs., 2 figs

Optimización topológica y fabricación aditiva de un soporte aeronáutico mediante sinterizado láser de acero inoxidable 15-5PH

OpenAIRE

Marchal Montes, Álvaro

2016-01-01

El objetivo de este trabajó será la aplicación de la optimización topológica a un soporte usado en el sector aeronáutico para reducir su masa que posteriormente se fabricará mediante fabricación aditiva con tecnología DMLS (Direct Metal Laser Sintering) en acero inoxidable 15-5PH. Para llegar a una buena optimización topológica será necesario estudiar todos los caminos de optimización posibles hasta llegar a una correcta mediante softwares adecuados además de adaptarla a la fabricación ad...

Medium level of direct solar radiation and energetic potential of solar concentrator in Minas Gerais State, Brazil; Niveis medios de radiacao solar direta e potencial energetico dos concentradores solares em Minas Gerais

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-07-01

Basic concepts of solar energy, technical description of solar concentrators, its orientation and methodology of direct solar radiation measurement are discussed. An comparison of different solar radiation measurements methods, its methodology and its calculation steps are reported. Calculus and tables of the electric and thermal energy generation potential, through solar concentrators, on the state of Minas Gerais are also presented. 18 figs., 90 tabs., 12 refs.