Reflexions on the expansion of nuclear generation in Brazil

International Nuclear Information System (INIS)

Freitas, Juliana de Moraes Marreco de

2006-01-01

This article analyses the pros and cons of the nuclear generation in Brazil, involving in a large discussion the technological perspectives both economic, social and environmental. The objective is to rise the main questions about the polemical nuclear expansion in Brazil

Enclavado endomedular retrógrado en fracturas diafisarias de fémur: indicaciones, técnica y resultados. [Retrograde­ nailing­ for­ diaphyseal­ femoral­ fracture:­ indications,­ technique­ and­ outcomes

Directory of Open Access Journals (Sweden)

Sebastián Pereira

2014-12-01

Full Text Available In­tro­duc­ción: el enclavado endomedular fresado anterógrado es el método de elección para el tratamiento de las fracturas diafisarias de fémur. Sin embargo, la técnica retrógrada surgió como alternativa para situaciones en las que la técnica anterógrada tiene ciertas desventajas. Materiales ­y ­Métodos:­ entre marzo de 2001 y enero de 2011, se realizaron 110 enclavados retrógrados de fémur, 34 de ellos en pacientes con fracturas diafisarias de fémur. Los mecanismos de lesión fueron: colisión vehicular (15 casos, traumatismo de baja energía (18 casos y proyectil de arma de fuego (1 caso. Once pacientes (31% tenían lesiones asociadas. Resultados:­ treinta y tres pacientes consiguieron la consolidación ósea (97%. El tiempo medio de consolidación fue de 84 días para los clavos fresados y de 112 días para los no fresados. Hubo un caso de retraso de la consolidación. El rango de movilidad de la rodilla promedio fue de 130º de flexión (mínimo 100º y máximo 150º. Seis pacientes (17,6% refirieron dolor de rodilla. Conclusiones:­ el clavo retrógrado para el tratamiento de fracturas diafisarias de fémur consigue resultados de consolidación similares a los del clavo anterógrado de fémur. Sus posibles ventajas son la técnica simple, un menor tiempo quirúrgico y la posibilidad de operar sin el uso de una mesa de tracción.

Utilización del acrílico dental (metil metacrilato) como barra estabilizadora-conectora para reducciones cerradas en fracturas de tibia/peroné o radio/cúbito en caninos

OpenAIRE

Cavero A., Francisco; Fernández A., Víctor

2005-01-01

El metil metacrilato (mmc) es una resina acrílica utilizada en moldes para fabricar prótesis dentales y puede cumplir la función de barra estabilizadora-conectora en la reducción de fracturas, permitiendo la colocación de clavos en planos múltiples. El presente trabajo tuvo como objetivo comprobar que el acrílico dental sirve como barra conectora en la fijación externa esquelética, y demostrar que es posible fijar las fracturas con un método poco traumático, alejado del foco fracturario, para...

UTILIZACIÓN DEL ACRÍLICO DENTAL (metil metacrilato) COMO BARRA ESTABILIZADORA-CONECTORA PARA REDUCCIONES CERRADAS EN FRACTURAS DE TIBIA/PERONÉ O RADIO/CÚBITO EN CANINOS

OpenAIRE

Cavero A., Francisco; Fernández A., Víctor

2012-01-01

El metil metacrilato (mmc) es una resina acrílica utilizada en moldes para fabricar prótesis dentales y puede cumplir la función de barra estabilizadora-conectora en la reducción de fracturas, permitiendo la colocación de clavos en planos múltiples. El presente trabajo tuvo como objetivo comprobar que el acrílico dental sirve como barra conectora en la fijación externa esquelética, y demostrar que es posible fijar las fracturas con un método poco traumático, alejado del foco fracturario, para...

Evaluación de extractos de ocho especies vegetales en el control de mildeo velloso (Peronospora destructor Berk en cebolla de bulbo (Allium cepa L.

Directory of Open Access Journals (Sweden)

Pedro Enrique Cubides-Hernández

2015-01-01

Full Text Available Extractos de ocho especies vegetales: eucalipto (Eucalytus globulus, cola de caballo (Equisetum bogotense, ortiga (Urtica urens, manzanilla (Matricaria chamomilla, caléndula (Calendula officinalis, yerbabuena (Menta viridis, ajo (Allium sativum y clavo (Syzygum aromaticum, preparados por el método de decocción (100 g/l, fueron evaluados en cuanto a su eficiencia en el control de P. destructor en cebolla de bulbo. Se utilizó el diseño experimental de bloques al azar con cuatro repeticiones y siete aplicaciones (52, 60, 68, 76,84, 92 y 100 días después del trasplante, incluyendo un testigo químico Ridomil (metalaxil + mancozeb (2 g/l y el testigo absoluto; se evaluaron la incidencia y severidad de P. destructor, y el número y el peso de bulbos cosechados. El ANOVA mostró que de las siete aplicaciones realizadas, la última presentó efectos estadísticos en el control de la incidencia y severidad de P. destructor. El extracto de manzanilla superó al Ridomil en el control de la incidencia y severidad de P. destructor sin diferencias estadísticas entre sí, y fue significativamente mejor al observado con los extractos de eucalipto, cola de caballo, caléndula y el testigo; el extracto de manzanilla superó al testigo químico en el número y peso de bulbos de cebolla sin presentar diferencias estadísticas, y fue significativamente mejor al obtenido con los extractos de eucalipto, cola de caballo, ortiga, caléndula, yerbabuena, clavo y el testigo absoluto. El extracto de manzanilla es una alternativa ecológica que se debe tener en cuenta en el manejo integrado de P. destructor en cebolla de bulbo.

Obtención de un filtrante de maíz morado (Zea mays L.), evaluación de pérdida de color y degradación de antocianinas en el almacenaje

OpenAIRE

Nolazco C., Diana; Universidad Nacional Agraria la Molina, Lima, Perú.; Araujo V., Miguel; Universidad Nacional Agraria la Molina, Lima, Perú.

2016-01-01

El trabajo de investigación permitió obtener un filtrante de maíz morado, evaluar la pérdida del color y degradación de las antocianinas durante el almacenaje a 70, 80, 90 y 100% de humedad relativa (H.R.). Se obtuvo el filtrante de maíz morado mediante una mezcla de canela 1%, clavo de olor 1%, grano 10% y coronta de maíz morado 88%, con una tamaño de partícula entre 2 y 4mm. La caracterización del filtrante reportó: humedad 7.9%, carbohidratos 74.4%, cenizas 2.4%, grasa 0.2%, proteína 5.1%,...

Allocation of the transmission service cost with base in marginal costs of the transmission network expansion; Asignacion del costo del servicio de transmision con base en costos marginales de expansion de la red de transmision

Energy Technology Data Exchange (ETDEWEB)

Ruiz Casillas, Manuel E.; Nieva Gomez, Rolando [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2001-07-01

The transmission charges to the users must be completely defined in those systems where the restructuring has broken up the traditional functions of the companies; in order to introduce competition in the generation and commercialization segments of the electrical energy. The fundamentals of a method used are explained to assure the transmission service cases between their users. The method is based on the marginal expansion costs of the transmission network. Their more known applications have been in competitive markets of energy, in particular, where the energy price is the same one in all the localities. Nevertheless, it can be used under other forms of organization of the electrical industry. In order to illustrate results, the obtained ones from their application to the most important part of the transmission network of the Mexican system that operates interconnected, are presented. [Spanish] Los cargos de transmision a los usuarios deben estar completamente definidos en aquellos sistemas donde la reestructuracion ha desagregado las funciones tradicionales de las empresas; para introducir competencia en los segmentos de generacion y comercializacion de la energia electrica. Se explican los fundamentos de un metodo utilizado para asegurar los casos del servicio de transmision entre sus usuarios. El metodo se basa en los costos marginales de expansion de la red de transmision. Sus aplicaciones mas conocidas han sido en mercados competitivos de energia, en particular, donde el precio de la energia es el mismo en todas las localidades. Sin embargo, puede utilizarse bajo otras formas de organizacion de la industria electrica. Con el proposito de ilustrar resultados, se muestran los obtenidos de su aplicacion a la parte mas importante de la red de transmision del sistema mexicano que opera interconectada.

Planning the expansion of transmission with evolutionary programming; Planeacion de la expansion de transmision con programacion evolutiva

Energy Technology Data Exchange (ETDEWEB)

Ceciliano Meza, Jose Luis; Nieva Gomez, Rolando [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

1999-07-01

A method of evolutionary programming for the planning of transmission networks in electrical power systems is presented. This is a whole problem mixed and nonlinear, with a combinatory nature that leads to a very large number of possible solutions for electrical systems of medium and large scale. The problem of transmission planning is described briefly and later it is formulated in mathematical terms. The proposed algorithm of evolutionary programming is applied to a large scale network that is representative of the Mexican electrical system. [Spanish] Se presenta un metodo de programacion evolutiva para la planeacion de redes de transmision en sistemas electricos de potencia. Este es un problema entero mixto y no lineal, con una naturaleza combinatoria que conduce a un numero muy grande de soluciones posibles para sistemas electricos de mediana y gran escala. Se describe brevemente el problema de planeacion de transmision y posteriormente se formula en terminos matematicos. El algoritmo propuesto de programacion evolutiva se aplica a una red electrica de gran escala que es representativa del sistema electrico Mexicano.

Behaviour of built light construction on expansible clays. Technical of design and rehabilitation

Directory of Open Access Journals (Sweden)

Arrieta, L.

2003-12-01

Full Text Available The construction pathology of housing built on expansible clays is one of the most requested topics to be investigated in order to obtain solutions mainly in housing of social interest. A vision of the solution alternatives is presented that are being applying in Venezuela and specifically in the cities of Barquisimeto and Coro where the most harmful expansion characteristics are presented registered in the world literature. This population is located to the north of the country in front of the Caribbean Sea with arid climate, deep phreatic level, appreciable loamy profile and water deficit. The investigation methodology and some proven procedures for the design of foundations in light housings and for the rehabilitation of damaged buildings are supported with the results of the researches on the part of the two authors and their research teams coming from two different Universities and with 20 years of experience in the practical field. 3 cases are illustrated, two of them with historical value in the design of housings of social interest and one of severely affected constructions and actually rehabilitated with success. Finally some practical recommendations are provided to be considered in the elaboration of projects related with the construction of light housings on expansible floors.

La patología de construcción de viviendas construidas sobre arcillas expansivas constituye uno de los temas más investigados debido a la gran cantidad de casos identificados con fallos, sobre todo en viviendas de interés social. Se presenta una visión de las alternativas de solución que se vienen aplicando en Venezuela y, específicamente, en las ciudades de Barquisimeto y Coro donde se presentan las características de expansión más perjudiciales registradas en la literatura mundial. Esta población está ubicada al norte del país, frente al mar Caribe, con clima árido, nivel freático profundo, perfil arcilloso apreciable y régimen h

Thermal expansion

International Nuclear Information System (INIS)

Yun, Y.

2015-01-01

Thermal expansion of fuel pellet is an important property which limits the lifetime of the fuels in reactors, because it affects both the pellet and cladding mechanical interaction and the gap conductivity. By fitting a number of available measured data, recommended equations have been presented and successfully used to estimate thermal expansion coefficient of the nuclear fuel pellet. However, due to large scatter of the measured data, non-consensus data have been omitted in formulating the equations. Also, the equation is strongly governed by the lack of appropriate experimental data. For those reasons, it is important to develop theoretical methodologies to better describe thermal expansion behaviour of nuclear fuel. In particular, first-principles and molecular dynamics simulations have been certainly contributed to predict reliable thermal expansion without fitting the measured data. Furthermore, the two theoretical techniques have improved on understanding the change of fuel dimension by describing the atomic-scale processes associated with lattice expansion in the fuels. (author)

Low-temperature thermal expansion

International Nuclear Information System (INIS)

Collings, E.W.

1986-01-01

This chapter discusses the thermal expansion of insulators and metals. Harmonicity and anharmonicity in thermal expansion are examined. The electronic, magnetic, an other contributions to low temperature thermal expansion are analyzed. The thermodynamics of the Debye isotropic continuum, the lattice-dynamical approach, and the thermal expansion of metals are discussed. Relative linear expansion at low temperatures is reviewed and further calculations of the electronic thermal expansion coefficient are given. Thermal expansions are given for Cu, Al and Ti. Phenomenologic thermodynamic relationships are also discussed

Las abejas (Hymenoptera: Apoidea del Parque Nacional Natural Gorgona, Pacífico colombiano

Directory of Open Access Journals (Sweden)

Marcela González-Córdoba

2014-02-01

Full Text Available En este estudio se presenta la diversidad y abundancia de las abejas del PNN Gorgona. En tres visitas en intervalos de tres meses, se muestrearon seis zonas de la isla con cubierta vegetal variable. Los muestreos fueron indirectos usando (i trampas McPhail (cebadas con cineol, silicato de metilo y extracto clavos; (ii trampas Van Someren Rydon (con cebo de pescado o pollo o fruta podridos, (iii trampas Malaise y (iv trampas de luz y directos a lo largo de transectos de longitud indefinida, por períodos de una hora en cada área y se repitieron cuatro veces. Un total de 585 especímenes fueron capturados, de ellos, 443 pertenecen a Apidae (14 géneros, 141 a Halictidae (seis géneros y uno a Megachilidae. Con este informe, el inventario local de Abejas se eleva a 43 especies y 28 géneros. Trigona fulviventris guianae Cockerell, 1910 fue la especie más abundante, Euglossa ignita Smith, 1874 la más atraída por los cebos aromáticos y Megalopta genalis Smith, 1853 dominó durante la noche. Apis mellifera Linnaeus, 1758 no se encontró en los muestreos. La importancia de la Isla Gorgona, como sitio de la diversidad para las especies de abejas es discutida.

Fracturas supracondíleas del húmero en niños entre 2 y 14 años. Perfil demográfico y de tratamiento en el Hospital Pablo Tobón Uribe, Medellín, Colombia = Supracondylar fractures of the humerus in children aged 2-14 years. Demographic profile and therapeutic approach at a third-level hospital in Medellín, Colombia

Directory of Open Access Journals (Sweden)

Valderrama Molina, Carlos Oliver

2011-12-01

Full Text Available Introducción: las fracturas supracondíleas del húmero distal son las lesiones más frecuentes de tratamiento quirúrgico en la población pediátrica. Los informes sobre el perfil demográfico y el enfoque terapéutico de las mismas en Medellín son limitados; este trabajo se llevó a cabo para conocer la epidemiología local de estas lesiones y detectar en el seguimiento los aciertos y errores del tratamiento como base para desarrollar estudios de mayor complejidad.Materiales y métodos: mediante una búsqueda exhaustiva en los registros de historias clíni­cas electrónicas se encontraron 205 casos de fracturas supracondíleas del húmero en niños entre dos y 14 años que ingresaron al Servicio de Urgencias del Hospital Pablo Tobón Uribe entre enero de 2005 y septiembre de 2009. Se analizaron en ellas los aspectos demográficos y terapéuticos.Resultados: el 61,5% de los pacientes fueron varones, la media de la edad fue de 6,6 años, en 62,4% de los casos la fractura afectó el lado izquierdo. La clasificación (Gartland fue como sigue: tipo I: 41,5%; tipo II: 12,2%; tipo III: 46,3%. El 95,6% fueron fracturas cerradas. Se hizo tratamiento quirúrgico en 103 casos (50,2%. El tiempo promedio entre el ingreso y la cirugía fue de 6,7 horas. La técnica quirúrgica más frecuente fue la reducción cerrada con fijación percutánea con clavos cruzados (45,6% de los casos. Se observaron 31 casos (15,1% de le­siones neurológicas, 28 de ellas del nervio ulnar; nueve de las 31 lesiones se registraron en la evaluación posquirúrgica inmediata, todas ellas en pacientes tratados con clavos cruzados. No se registraron lesiones vasculares ni síndromes compartimentales.Conclusión: esta serie presenta el estado actual del perfil demográfico de los pacientes con fracturas supracondíleas del húmero distal en niños y de las modalidades de tratamiento en un hospital de tercer nivel de la ciudad de Medellín. Los resultados pueden ser la base para

Primer registro de Dasypsyllus (Avesopsylla lasius lasius (Siphonaptera: Ceratophyllidae en nidos de golondrina chilena, Tachycineta meyeni (Passeriformes: Hirundinidae, en Ushuaia (Tierra del Fuego, Argentina

Directory of Open Access Journals (Sweden)

Rosana ARAMBURÚ

2009-01-01

Full Text Available La golondrina chilena, Tachycineta meyeni (Cabanis, nidifica en el centro de Chile y suroeste de Argentina. En invierno migra a Bolivia, Paraguay y al sureste de Brasil. Estas golondrinas ocuparon una serie de cajas-nido en Ushuaia, Tierra del Fuego. Luego de la temporada de cría, tratamos los nidos con acetato de etilo y los revisamos en búsqueda de artrópodos hematófagos. Encontramos pulgas adultas, que fueron fijadas, aclaradas, deshidratadas, diafanizadas y montadas en un derivado de clavo de olor para su observación al microsocopio óptico. Identificamos machos y hembras de Dasypsyllus (Avesopsylla lasius lasius (Rothschild. En Argentina, esta pulga es conocida solamente en Sierra de la Ventana (Buenos Aires, donde se la halló parasitando la golondrina barranquera, Notiochelidon cyanoleuca patagonica (Vieillot. La información disponible debería complementarse con prospecciones en localidades intermedias. Otras aves relacionadas con ambas golondrinas por la ocupación de nidos, como el rayadito (Aphrastura spinicauda (Gmelin, ratona común (Troglodytes aedon Vieillot, caminera común (Geositta cunicularia (Vieillot, hornero (Furnarius rufus (Gmelin, podrían contribuir a la dispersión de la pulga entre las dos localidades registradas.

Negative thermal expansion materials: technological key for control of thermal expansion

OpenAIRE

Koshi Takenaka

2012-01-01

Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over −30 ppm K−1. Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining pra...

Following Surgically Assisted Rapid Palatal Expansion, Do Tooth-Borne or Bone-Borne Appliances Provide More Skeletal Expansion and Dental Expansion?

Science.gov (United States)

Hamedi-Sangsari, Adrien; Chinipardaz, Zahra; Carrasco, Lee

2017-10-01

The aim of this study was to compare outcome measurements of skeletal and dental expansion with bone-borne (BB) versus tooth-borne (TB) appliances after surgically assisted rapid palatal expansion (SARPE). This study was performed to provide quantitative measurements that will help the oral surgeon and orthodontist in selecting the appliance with, on average, the greatest amount of skeletal expansion and the least amount of dental expansion. A computerized database search was performed using PubMed, EBSCO, Cochrane, Scopus, Web of Science, and Google Scholar on publications in reputable oral surgery and orthodontic journals. A systematic review and meta-analysis was completed with the predictor variable of expansion appliance (TB vs BB) and outcome measurement of expansion (in millimeters). Of 487 articles retrieved from the 6 databases, 5 articles were included, 4 with cone-beam computed tomographic (CBCT) data and 1 with non-CBCT 3-dimensional cast data. There was a significant difference in skeletal expansion (standardized mean difference [SMD], 0.92; 95% confidence interval [CI], 0.54-1.30; P appliances. However, there was no significant difference in dental expansion (SMD, 0.05; 95% CI, -0.24 to 0.34; P = .03). According to the literature, to achieve more effective skeletal expansion and minimize dental expansion after SARPE, a BB appliance should be favored. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

preescolares desnutridos con madres con obesidad y sin obesidad

Directory of Open Access Journals (Sweden)

Viridiana Vanessa Conzuelo-González

2009-01-01

Full Text Available El primer objetivo fue conocer cuántos menores de cinco años con diferentes grados de desnutrición tienen una madre con sobrepeso/obesidad/ en una comunidad indígena que vive en extrema pobreza y bajo condiciones de migración masculina internacional. El segundo fue comparar tres variables socionutricionales (ingreso familiar, educación de la madre y adecuación nutrimental de la dieta diaria entre estos hogares y los hogares con desnutrición infantil y madres sin obesidad. Se realizó un estudio transversal (2006-2007, en la comunidad mazahua de San Francisco Tepeolulco, Municipio de Temascalcingo; que incluyó a 85 hogares integrados por preescolares con desnutrición inscritos al programa Oportunidades. Se determinó el estado nutrición de los preescolares con indicadores antropométricos y se obtuvo el IMC de las madres de estos infantes. Se aplicó una encuesta socionutricional, incluida el recordatorio de 24 horas, y complementado con la observación participante (cualitativa. Se encontró que 83% de las madres mazahuas presentaron sobrepeso u obesidad. El estado de nutrición de los preescolares con madres con obesidad presentó un porcentaje mayor de desnutrición (76%. En la variable género, se encontró que 54% de los niños con madres con obesidad tenía baja talla. Al relacionar el nivel educativo de la madre, esta variable resultó ser estadísticamente significativa (p=0.015, donde el analfabetismo está más relacionado con la desnutrición infantil que tienen madres de bajo y/o peso normal. La elevada prevalencia de hogares conformados con preescolares con desnutrición y madres con obesidad, es un síntoma más de la pobreza en zonas indígenas en México, con bajo índice de desarrollo humano.

Essential oils from Egyptian aromatic plants as antioxidant and novel anticancer agents in human cancer cell lines

Directory of Open Access Journals (Sweden)

Ramadan, M. M.

2015-06-01

Full Text Available Inhibitors of tumor growth using extracts from aromatic plants are rapidly emerging as important new drug candidates for cancer therapy. The cytotoxicity and in vitro anticancer evaluation of the essential oils from thyme, juniper and clove has been assessed against five different human cancer cell lines (liver HepG2, breast MCF-7, prostate PC3, colon HCT116 and lung A549. A GC/MS analysis revealed that α-pinene, thymol and eugenol are the major components of Egyptian juniper, thyme and clove oils with concentrations of 31.19%, 79.15% and 82.71%, respectively. Strong antioxidant profiles of all the oils are revealed in vitro by DPPH and β-carotene bleaching assays. The results showed that clove oil was similarly potent to the reference drug, doxorubicin in prostate, colon and lung cell lines. Thyme oil was more effective than the doxorubicin in breast and lung cell lines while juniper oil was more effective than the doxorubicin in all the tested cancer cell lines except prostate cancer. In conclusion, the essential oils from Egyptian aromatic plants can be used as good candidates for novel therapeutic strategies for cancer as they possess significant anticancer activity.Los inhibidores de crecimiento de tumores usando extractos de plantas aromáticas están emergiendo con rapidez como nuevos e importantes medicamentos para el tratamiento del cáncer. La citotoxicidad y la acción anticancerígena in vitro de aceites esenciales de tomillo, enebro y clavo han sido evaluadas en cinco líneas celulares de cáncer humano (hígado HepG2, mama MCF-7, próstata PC3, colon HCT116 y pulmón A549. Los análisis de GC/MS mostraron que α-pineno, timol y eugenol son los principales componentes de los aceites egipcios de enebro, tomillo y clavo, con concentraciones de 31,19%, 79,15% y 82,71%, respectivamente. Se demuestra, mediante ensayos in vitro de blanqueo de DPPH y β-caroteno, el enérgico perfil antioxidante de todos los aceites. Los resultados

Cementos con cenizas volantes

Directory of Open Access Journals (Sweden)

Ossa M., Mauricio

1984-03-01

Full Text Available Almost all the studies carried out on cements with the addition of flying ash refer to their characteristics and behaviours in pastes, mortars and concretes, always in relation with Portland cement. This time, there has been developed an experimental work oriented to relate between themselves the cements with additions of flying ash and of natural puzzolan. For this there were manufactured on laboratory scale cements of both types, using the same raw materials, clinker and plaster, and as variables, different percentages of the two additions, which previously complied with the standard requisites concerning their puzzolanic (?? activities. The quality of the cements manufactured was adequate and in accord with that of Portland-puzzolanic (?? cement obtained on an industrial scale with the same clinkers, plaster and natural puzzolan (?? of this study. Later there were determined the characteristics of the experimental cements and normal mortars were prepared for carrying out physical and mechanical tests. The test results indicated that the cements with addition of flying ash (CCV require less water for normal consistency, present greater times of forging and fewer expansions in autoclave than the cements with the addition of puzzolan (CP. The hydration heats at 7 and 28 days were approximately similar for both types of cement. In normal mortars, the CCV cements showed less retraction of drying, greater retentivenness and greater fluidity (for the same quantity of water than the CP cements. In the exudation tests it was observed that this depends more on the fineness than the type of addition. Finally, the mechanical tests showed that the resistances to compression and flexotraction of the mortars with CCV cements are lesser at ages less than 14 days (about 5 to 10% at one day of age, but from then on become greater than those of mortars with CP cements, with growing differences which reach 15% in compression tests, at 120 days of age, for

Negative thermal expansion materials

International Nuclear Information System (INIS)

Evans, J.S.O.

1997-01-01

The recent discovery of negative thermal expansion over an unprecedented temperature range in ZrW 2 O 8 (which contracts continuously on warming from below 2 K to above 1000 K) has stimulated considerable interest in this unusual phenomenon. Negative and low thermal expansion materials have a number of important potential uses in ceramic, optical and electronic applications. We have now found negative thermal expansion in a large new family of materials with the general formula A 2 (MO 4 ) 3 . Chemical substitution dramatically influences the thermal expansion properties of these materials allowing the production of ceramics with negative, positive or zero coefficients of thermal expansion, with the potential to control other important materials properties such as refractive index and dielectric constant. The mechanism of negative thermal expansion and the phase transitions exhibited by this important new class of low-expansion materials will be discussed. (orig.)

Negative thermal expansion materials: technological key for control of thermal expansion.

Science.gov (United States)

Takenaka, Koshi

2012-02-01

Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over -30 ppm K -1 . Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining practical aspects, this review briefly summarizes materials and mechanisms of NTE as well as composites containing NTE materials, based mainly on activities of the last decade.

Negative thermal expansion materials: technological key for control of thermal expansion

Directory of Open Access Journals (Sweden)

Koshi Takenaka

2012-01-01

Full Text Available Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over −30 ppm K−1. Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining practical aspects, this review briefly summarizes materials and mechanisms of NTE as well as composites containing NTE materials, based mainly on activities of the last decade.

Negative thermal expansion materials: technological key for control of thermal expansion

International Nuclear Information System (INIS)

Takenaka, Koshi

2012-01-01

Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over −30 ppm K −1 . Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining practical aspects, this review briefly summarizes materials and mechanisms of NTE as well as composites containing NTE materials, based mainly on activities of the last decade. (topical review)

Optimal expansion planning of stand-alone systems with stochastic simulations

Energy Technology Data Exchange (ETDEWEB)

Hoese, Alejandro [Instituto de Energia Electrica (IEE), Universidad Nacional de San Juan, (Argentina)

1997-12-31

Stand-alone systems in the range of 1 kW - 10 MW are taking relevance in the new (global) liberal concept of energy market. State and private investors are becoming increasingly attention on the use of renewable for these systems, but it must be shown that these non-conventional solutions are competitive with the established conventional ones. The high investment costs and the technical and economic uncertainties coupled with the use of time-dependent energy sources are the mainly inhibiting factors for the decision agents to choose these systems instead of conventional ones. In the paper a new model for optimal expansion planning of hybrid stand-alone generating systems under consideration of uncertainties is presented. This model is at present in {sup d}evelopment state{sup .} Results already obtained in the first steps of this research are promising and some of them are here presented. [Espanol] Los sistemas autocontenidos en el rango de 1 Kw a 10 MW estan tomando importancia en el nuevo (global) concepto liberal del mercado de la energia. Inversionistas privados y del Estado estan poniendo mayor atencion en el uso de energias renovables para estos sistemas, pero debe mostrarse que estas soluciones no-convencionales son competitivas con las convencionales establecidas. Los altos costos de inversion y las incertidumbres tecnicas y economicas aunadamente con el uso de fuentes de energia dependientes del tiempo son los principales factores inhibidores de los factores de decision para escoger estos sistemas en lugar de los convencionales. En este articulo se presenta un nuevo modelo de planeacion de expansion optima de sistemas hibridos autocontenidos de generacion electrica bajo la consideracion de incertidumbres. Este modelo esta actualmente en {sup e}stado de desarrollo{sup .} Los resultados ya obtenidos en las primeras etapas de esta investigacion son prometedores y se presentan algunos de ellos.

Optimal expansion planning of stand-alone systems with stochastic simulations

Energy Technology Data Exchange (ETDEWEB)

Hoese, Alejandro [Instituto de Energia Electrica (IEE), Universidad Nacional de San Juan, (Argentina)

1998-12-31

Stand-alone systems in the range of 1 kW - 10 MW are taking relevance in the new (global) liberal concept of energy market. State and private investors are becoming increasingly attention on the use of renewable for these systems, but it must be shown that these non-conventional solutions are competitive with the established conventional ones. The high investment costs and the technical and economic uncertainties coupled with the use of time-dependent energy sources are the mainly inhibiting factors for the decision agents to choose these systems instead of conventional ones. In the paper a new model for optimal expansion planning of hybrid stand-alone generating systems under consideration of uncertainties is presented. This model is at present in {sup d}evelopment state{sup .} Results already obtained in the first steps of this research are promising and some of them are here presented. [Espanol] Los sistemas autocontenidos en el rango de 1 Kw a 10 MW estan tomando importancia en el nuevo (global) concepto liberal del mercado de la energia. Inversionistas privados y del Estado estan poniendo mayor atencion en el uso de energias renovables para estos sistemas, pero debe mostrarse que estas soluciones no-convencionales son competitivas con las convencionales establecidas. Los altos costos de inversion y las incertidumbres tecnicas y economicas aunadamente con el uso de fuentes de energia dependientes del tiempo son los principales factores inhibidores de los factores de decision para escoger estos sistemas en lugar de los convencionales. En este articulo se presenta un nuevo modelo de planeacion de expansion optima de sistemas hibridos autocontenidos de generacion electrica bajo la consideracion de incertidumbres. Este modelo esta actualmente en {sup e}stado de desarrollo{sup .} Los resultados ya obtenidos en las primeras etapas de esta investigacion son prometedores y se presentan algunos de ellos.

Thermal expansion of coking coals

Energy Technology Data Exchange (ETDEWEB)

Orlik, M.; Klimek, J. (Vyzkumny a Zkusebni Ustav Nova Hut, Ostrava (Czechoslovakia))

1992-12-01

Analyzes expansion of coal mixtures in coke ovens during coking. Methods for measuring coal expansion on both a laboratory and pilot plant scale are comparatively evaluated. The method, developed, tested and patented in Poland by the Institute for Chemical Coal Processing in Zabrze (Polish standard PN-73/G-04522), is discussed. A laboratory device developed by the Institute for measuring coal expansion is characterized. Expansion of black coal from 10 underground mines in the Ostrava-Karvina coal district and from 9 coal mines in the Upper Silesia basin in Poland is comparatively evaluated. Investigations show that coal expansion reaches a maximum for coal types with a volatile matter ranging from 20 to 25%. With increasing volatile matter in coal, its expansion decreases. Coal expansion increases with increasing swelling index. Coal expansion corresponds with coal dilatation. With increasing coal density its expansion increases. Coal mixtures should be selected in such a way that their expansion does not cause a pressure exceeding 40 MPa. 11 refs.

Virial Expansion Bounds

Science.gov (United States)

Tate, Stephen James

2013-10-01

In the 1960s, the technique of using cluster expansion bounds in order to achieve bounds on the virial expansion was developed by Lebowitz and Penrose (J. Math. Phys. 5:841, 1964) and Ruelle (Statistical Mechanics: Rigorous Results. Benjamin, Elmsford, 1969). This technique is generalised to more recent cluster expansion bounds by Poghosyan and Ueltschi (J. Math. Phys. 50:053509, 2009), which are related to the work of Procacci (J. Stat. Phys. 129:171, 2007) and the tree-graph identity, detailed by Brydges (Phénomènes Critiques, Systèmes Aléatoires, Théories de Jauge. Les Houches 1984, pp. 129-183, 1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by doing the actual optimisation and achieving expressions in terms of the Lambert W-function. The different bound from the cluster expansion shows some improvements for bounds on the convergence of the virial expansion in the case of positive potentials, which are allowed to have a hard core.

Ultra-low thermal expansion realized in giant negative thermal expansion materials through self-compensation

Science.gov (United States)

Shen, Fei-Ran; Kuang, Hao; Hu, Feng-Xia; Wu, Hui; Huang, Qing-Zhen; Liang, Fei-Xiang; Qiao, Kai-Ming; Li, Jia; Wang, Jing; Liu, Yao; Zhang, Lei; He, Min; Zhang, Ying; Zuo, Wen-Liang; Sun, Ji-Rong; Shen, Bao-Gen

2017-10-01

Materials with zero thermal expansion (ZTE) or precisely tailored thermal expansion are in urgent demand of modern industries. However, the overwhelming majority of materials show positive thermal expansion. To develop ZTE or negative thermal expansion (NTE) materials as compensators has become an important challenge. Here, we present the evidence for the realization of ultra-low thermal expansion in Mn-Co-Ge-In particles. The bulk with the Ni2In-type hexagonal structure undergoes giant NTE owing to a martensitic magnetostructural transition. The major finding is that the thermal expansion behavior can be totally controlled by modulating the crystallinity degree and phase transition from atomic scale. Self-compensation effect leads to ultra-low thermal expansion with a linear expansion coefficient as small as +0.68 × 10-6/K over a wide temperature range around room temperature. The present study opens an avenue to reach ZTE particularly from the large class of giant NTE materials based on phase transition.

Ultra-low thermal expansion realized in giant negative thermal expansion materials through self-compensation

Directory of Open Access Journals (Sweden)

Fei-Ran Shen

2017-10-01

Full Text Available Materials with zero thermal expansion (ZTE or precisely tailored thermal expansion are in urgent demand of modern industries. However, the overwhelming majority of materials show positive thermal expansion. To develop ZTE or negative thermal expansion (NTE materials as compensators has become an important challenge. Here, we present the evidence for the realization of ultra-low thermal expansion in Mn–Co–Ge–In particles. The bulk with the Ni2In-type hexagonal structure undergoes giant NTE owing to a martensitic magnetostructural transition. The major finding is that the thermal expansion behavior can be totally controlled by modulating the crystallinity degree and phase transition from atomic scale. Self-compensation effect leads to ultra-low thermal expansion with a linear expansion coefficient as small as +0.68 × 10−6/K over a wide temperature range around room temperature. The present study opens an avenue to reach ZTE particularly from the large class of giant NTE materials based on phase transition.

Ultra-low thermal expansion realized in giant negative thermal expansion materials through self-compensation

OpenAIRE

Fei-Ran Shen; Hao Kuang; Feng-Xia Hu; Hui Wu; Qing-Zhen Huang; Fei-Xiang Liang; Kai-Ming Qiao; Jia Li; Jing Wang; Yao Liu; Lei Zhang; Min He; Ying Zhang; Wen-Liang Zuo; Ji-Rong Sun

2017-01-01

Materials with zero thermal expansion (ZTE) or precisely tailored thermal expansion are in urgent demand of modern industries. However, the overwhelming majority of materials show positive thermal expansion. To develop ZTE or negative thermal expansion (NTE) materials as compensators has become an important challenge. Here, we present the evidence for the realization of ultra-low thermal expansion in Mn–Co–Ge–In particles. The bulk with the Ni2In-type hexagonal structure undergoes giant NTE o...

Thermal expansion of granite rocks

International Nuclear Information System (INIS)

Stephansson, O.

1978-04-01

The thermal expansion of rocks is strongly controlled by the thermal expansion of the minerals. The theoretical thermal expansion of the Stripa Granite is gound to be 21 . 10 -6 [deg C] -1 at 25 deg C and 38 . 10 -6 [deg C] -1 at 400 deg C. The difference in expansion for the rock forming minerals causes micro cracking at heating. The expansion due to micro cracks is found to be of the same order as the mineral expansion. Most of the micro cracks will close at pressures of the order of 10 - 20 MPa. The thermal expansion of a rock mass including the effect of joints is determined in the pilot heater test in the Stripa Mine

Molienda asistida con microondas de un coque metalúrgico

Directory of Open Access Journals (Sweden)

Ruisánchez, Esteban

2014-06-01

Full Text Available Metallurgical cokes are composed of graphitic carbon (s2p2 and different inorganic compounds with very different capacities to absorb microwave radiation. Moreover, due to the electric conductivity shown by the metallurgical cokes, microwave radiation produces electric arcs or microplasmas, which gives rise to hot spots. Therefore, when these cokes are irradiated with microwaves some parts of the particle experiment a rapid heating, while some others do not heat at all. As a result of the different expansion and stress caused by thermal the shock, small cracks and micro-fissures are produced in the particle. The weakening of the coke particles, and therefore an improvement of its grindability, is produced. This paper studies the microwave-assisted grinding of metallurgical coke and evaluates the grinding improvement and energy saving.Los coques metalúrgicos están compuestos mayoritariamente de carbono grafítico (s2p2 y diferentes compuestos inorgánicos con distintas capacidades de absorber la radiación de microondas. Cuando se irradian con microondas fragmentos de estos coques, algunas partes de las partículas experimentan un rápido calentamiento, mientras otras no. Además, debido a que el coque presenta una cierta conductividad eléctrica, al ser irradiados con microondas se producen de forma puntual arcos eléctricos o microplasmas, dando lugar a puntos muy calientes. Como consecuencia de las diferentes dilataciones y tensiones producidas por el choque térmico, se producen en las partículas pequeñas grietas y microfisuras. Esto produce una mayor fragilidad en las partículas de coque y un incremento en la molturabilidad de las mismas. En el presente artículo se estudia la molienda de coque asistida con microondas y se evalúan las mejoras en la molturabilidad y el ahorro de energía producido.

Resonant state expansions

International Nuclear Information System (INIS)

Lind, P.

1993-02-01

The completeness properties of the discrete set of bound state, virtual states and resonances characterizing the system of a single nonrelativistic particle moving in a central cutoff potential is investigated. From a completeness relation in terms of these discrete states and complex scattering states one can derive several Resonant State Expansions (RSE). It is interesting to obtain purely discrete expansion which, if valid, would significantly simplify the treatment of the continuum. Such expansions can be derived using Mittag-Leffler (ML) theory for a cutoff potential and it would be nice to see if one can obtain the same expansions starting from an eigenfunction theory that is not restricted to a finite sphere. The RSE of Greens functions is especially important, e.g. in the continuum RPA (CRPA) method of treating giant resonances in nuclear physics. The convergence of RSE is studied in simple cases using square well wavefunctions in order to achieve high numerical accuracy. Several expansions can be derived from each other by using the theory of analytic functions and one can the see how to obtain a natural discretization of the continuum. Since the resonance wavefunctions are oscillating with an exponentially increasing amplitude, and therefore have to be interpreted through some regularization procedure, every statement made about quantities involving such states is checked by numerical calculations.Realistic nuclear wavefunctions, generated by a Wood-Saxon potential, are used to test also the usefulness of RSE in a realistic nuclear calculation. There are some fundamental differences between different symmetries of the integral contour that defines the continuum in RSE. One kind of symmetry is necessary to have an expansion of the unity operator that is idempotent. Another symmetry must be used if we want purely discrete expansions. These are found to be of the same form as given by ML. (29 refs.)

Isotropic Negative Thermal Expansion Metamaterials.

Science.gov (United States)

Wu, Lingling; Li, Bo; Zhou, Ji

2016-07-13

Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale.

Does query expansion limit our learning? A comparison of social-based expansion to content-based expansion for medical queries on the internet.

Science.gov (United States)

Pentoney, Christopher; Harwell, Jeff; Leroy, Gondy

2014-01-01

Searching for medical information online is a common activity. While it has been shown that forming good queries is difficult, Google's query suggestion tool, a type of query expansion, aims to facilitate query formation. However, it is unknown how this expansion, which is based on what others searched for, affects the information gathering of the online community. To measure the impact of social-based query expansion, this study compared it with content-based expansion, i.e., what is really in the text. We used 138,906 medical queries from the AOL User Session Collection and expanded them using Google's Autocomplete method (social-based) and the content of the Google Web Corpus (content-based). We evaluated the specificity and ambiguity of the expansion terms for trigram queries. We also looked at the impact on the actual results using domain diversity and expansion edit distance. Results showed that the social-based method provided more precise expansion terms as well as terms that were less ambiguous. Expanded queries do not differ significantly in diversity when expanded using the social-based method (6.72 different domains returned in the first ten results, on average) vs. content-based method (6.73 different domains, on average).

Energy expansion planning by considering electrical and thermal expansion simultaneously

International Nuclear Information System (INIS)

Abbasi, Ali Reza; Seifi, Ali Reza

2014-01-01

Highlights: • This paper focused on the expansion planning optimization of energy systems. • Employing two form of energy: the expansion of electrical and thermal energies. • The main objective is to minimize the costs. • A new Modified Honey Bee Mating Optimization (MHBMO) algorithm is applied. - Abstract: This study focused on the expansion planning optimization of energy systems employing two forms of energy: the expansion of electrical and thermal energies simultaneously. The main objective of this investigation is confirming network adequacy by adding new equipment to the network, over a given planning horizon. The main objective of the energy expansion planning (EEP) is to minimize the real energy loss, voltage deviation and the total cost of installation equipments. Since the objectives are different and incommensurable, it is difficult to solve the problem by the conventional approaches that may optimize a single objective. So, the meta-heuristic algorithm is applied to this problem. Here, Honey Bee Mating Optimization algorithm (HBMO) as a new evolutionary optimization algorithm is utilized. In order to improve the total ability of HBMO for the global search and exploration, a new modification process is suggested such a way that the algorithm will search the total search space globally. Also, regarding the uncertainties of the new complicated energy systems, in this paper for the first time, the EEP problem is investigated in a stochastic environment by the use of probabilistic load flow technique based on Point Estimate Method (PEM). In order to evaluate the feasibility and effectiveness of the proposed algorithm, two modified test systems are used as case studies

Expansion joints for LMFBR

International Nuclear Information System (INIS)

Dzenus, M.; Hundhausen, W.; Jansing, W.

1980-01-01

This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of the development reviewed. Large Na (sodium)-heat transfer systems require a lot of valuable space if the component lay-out does not include compensation devices. So, in order to condense the spatial requirement as much as possible, expansion joints must be integrated into the pipe system. There are two basic types to suit the purpose: axial expansion joints and angular expansion joints. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows. Expansion joints must be designed and mounted in a manner to completely withstand seismic forces. The design must exclude any damage to the bellows during intermittent operations, that is, when sodium is drained the bellows' folds must be completely empty; otherwise residual solidified sodium could destroy the bellows when restarting. The expansion joints must be engineered on the basis of the following design data for the secondary system of the SNR project: working pressure: 16 bar; failure mode pressure: 5 events; failure mode: 5 sec., 28.5 bar, 520 deg. C; working temperature: 520 deg. C; temperature transients: 30 deg. C/sec.; service life: 200,000 h; number of load cycles: 10 4 ; material: 1.4948 or 1.4919; layer thickness of folds: 0.5 mm; angular deflection (DN 800): +3 deg. C or; axial expansion absorption (DN 600): ±80 mm; calculation: ASME class. The bellows' development work is not handled within this scope. The bellows are supplied by leading manufacturers, and warrant highest quality. Multiple bellows were selected on the basis of maximum elasticity - a property

Expansion joints for LMFBR

Energy Technology Data Exchange (ETDEWEB)

Dzenus, M.; Hundhausen, W.; Jansing, W.

1979-10-15

This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of development reviewed. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows.

con dietas suplementadas con Cromo-L-metionina

Directory of Open Access Journals (Sweden)

Ram\\u00F3n Garc\\u00EDa-Castillo

2006-01-01

Full Text Available Un total de 48 cerdos (Sus scrofa domesticus; 24 machos castrados y 24 hembras cruzados (Yorkshire, Hampshire, Duroc y Landrace de 3,5 a 4,0 meses de edad y 60,0 ± 5,0 kg PV en finalización. Se alimentaron con dietas isoproteícas (14,5 % PC e isoenergéticas (3.400 kcal EM/kg de MS, adicionadas con Cr-L-metionina (MiCroPlex® (0, 200, 400 y 600 ppb. El experimento tuvo una duración de 45 días y se realizó de agosto a noviembre del 2002 en las instalaciones de la Universidad Autónoma Agraria Antonio Narro, localizada en Saltillo, Coahuila, México. Al tener los animales aproximadamente 95 kg PV, se tomó muestra de 15 ml de sangre por cada animal para determinar la concentración de glucosa, ácido úrico, creatinina, urea, proteinas totales y colesterol. Se aplicó un diseño completamente al azar con arreglo factorial 2 x 4; dos para el factor sexo y cuatro para nivel de cromo. Los metabolitos en suero no fueron afectados (P>0,05 por el factor sexo. La glucosa en suero disminuyó (P<0,05 y el colesterol incrementó (P<0,05 con cromo en la dieta. Se concluye que el Cr incrementa el metabolismo de glucosa y disminuye el de colesterol, con lo cual puede haber energía disponible para síntesis de proteína la cual es necesaria para el crecimiento de los animales

Expansions for Coulomb wave functions

NARCIS (Netherlands)

Boersma, J.

1969-01-01

In this paper we derive a number of expansions for Whittaker functions, regular and irregular Coulomb wave functions. The main result consists of a new expansion for the irregular Coulomb wave functions of orders zero and one in terms of regular Coulomb wave functions. The latter expansions are

Conformal expansions and renormalons

Energy Technology Data Exchange (ETDEWEB)

Rathsman, J.

2000-02-07

The coefficients in perturbative expansions in gauge theories are factorially increasing, predominantly due to renormalons. This type of factorial increase is not expected in conformal theories. In QCD conformal relations between observables can be defined in the presence of a perturbative infrared fixed-point. Using the Banks-Zaks expansion the authors study the effect of the large-order behavior of the perturbative series on the conformal coefficients. The authors find that in general these coefficients become factorially increasing. However, when the factorial behavior genuinely originates in a renormalon integral, as implied by a postulated skeleton expansion, it does not affect the conformal coefficients. As a consequence, the conformal coefficients will indeed be free of renormalon divergence, in accordance with previous observations concerning the smallness of these coefficients for specific observables. The authors further show that the correspondence of the BLM method with the skeleton expansion implies a unique scale-setting procedure. The BLM coefficients can be interpreted as the conformal coefficients in the series relating the fixed-point value of the observable with that of the skeleton effective charge. Through the skeleton expansion the relevance of renormalon-free conformal coefficients extends to real-world QCD.

Bearing-Mounting Concept Accommodates Thermal Expansion

Science.gov (United States)

Nespodzany, Robert; Davis, Toren S.

1995-01-01

Pins or splines allow radial expansion without slippage. Design concept for mounting rotary bearing accommodates differential thermal expansion between bearing and any structure(s) to which bearing connected. Prevents buildup of thermal stresses by allowing thermal expansion to occur freely but accommodating expansion in such way not to introduce looseness. Pin-in-slot configuration also maintains concentricity.

δ expansion applied to quantum electrodynamics

International Nuclear Information System (INIS)

Bender, C.M.; Boettcher, S.; Milton, K.A.

1992-01-01

A recently proposed technique known as the δ expansion provides a nonperturbative treatment of a quantum field theory. The δ-expansion approach can be applied to electrodynamics in such a way that local gauge invariance is preserved. In this paper it is shown that for electrodynamic processes involving only external photon lines and no external electron lines the δ expansion is equivalent to a fermion loop expansion. That is, the coefficient of δ n in the δ expansion is precisely the sum of all n-electron-loop Feynman diagrams in a conventional weak-coupling approximation. This equivalence does not extend to processes having external electron lines. When external electron lines are present, the δ expansion is truly nonperturbative and does not have a simple interpretation as a resummation of conventional Feynman diagrams. To illustrate the nonperturbative character of the δ expansion we perform a speculative calculation of the fermion condensate in the massive Schwinger model in the limit of large coupling constant

Tratamiento con implantes Leader-Nano en paciente con oligodoncia

Directory of Open Access Journals (Sweden)

Salvador Javier Santos Medina

2015-03-01

Full Text Available Los implantes dentales de titanio han revolucionado el mundo de la rehabilitación desde su surgimiento. De manera particular, el empleo de implantes de carga inmediata acorta el tiempo quirúrgico y protésico, con el consiguiente bienestar estético. Se presenta el caso de una paciente femenina de 32 años de edad, con antecedentes de oligodoncia de ambos incisivos laterales superiores y portadora de prótesis parcial acrílica. Fue atendida por el equipo multidisciplinario de implantes en la Clínica Estomatológica Docente “3 de Octubre” y se le realizó tratamiento de rehabilitación integral con implantes Leader-Nano y prótesis fija con corona acrílica sobre dichos implantes. La implantología fue satisfactoria en la paciente; la mejoría estética y funcional, así como la satisfacción de la paciente, fueron los principales logros obtenidos

Experiencias de haber crecido con un padre/madre con trastorno mental severo (TMS)

OpenAIRE

Vivanco B, Gabriela; Grandón F, Pamela

2016-01-01

Introducción. La experiencia de vivir con personas que presentan un Trastorno Mental Severo (TMS) es difícil para las familias, en especial para los hijos quienes han sido poco estudiados. El objetivo de la investigación fue conocer cómo la experiencia de haber vivido con un padre o madre con un trastorno mental severo influyó en la infancia, adolescencia y adultez joven de sus hijos e hijas. Método. Se analizan las experiencias de convivencia con un padre/madre con TMS en 10 hijos (6 hombres...

Accelerating the loop expansion

International Nuclear Information System (INIS)

Ingermanson, R.

1986-01-01

This thesis introduces a new non-perturbative technique into quantum field theory. To illustrate the method, I analyze the much-studied phi 4 theory in two dimensions. As a prelude, I first show that the Hartree approximation is easy to obtain from the calculation of the one-loop effective potential by a simple modification of the propagator that does not affect the perturbative renormalization procedure. A further modification then susggests itself, which has the same nice property, and which automatically yields a convex effective potential. I then show that both of these modifications extend naturally to higher orders in the derivative expansion of the effective action and to higher orders in the loop-expansion. The net effect is to re-sum the perturbation series for the effective action as a systematic ''accelerated'' non-perturbative expansion. Each term in the accelerated expansion corresponds to an infinite number of terms in the original series. Each term can be computed explicitly, albeit numerically. Many numerical graphs of the various approximations to the first two terms in the derivative expansion are given. I discuss the reliability of the results and the problem of spontaneous symmetry-breaking, as well as some potential applications to more interesting field theories. 40 refs

Thermal expansion data

International Nuclear Information System (INIS)

Taylor, D.

1984-01-01

This paper gives regression data for a modified second order polynomial fitted to the expansion data of, and percentage expansions for dioxides with (a) the fluorite and antifluorite structure: AmO 2 , BkO 2 , CeO 2 , CmO 2 , HfO 2 , Li 2 O, NpO 2 , PrO 2 , PuO 2 , ThO 2 , UO 2 , ZrO 2 , and (b) the rutile structure: CrO 2 , GeO 2 , IrO 2 , MnO 2 , NbO 2 , PbO 2 , SiO 2 , SnO 2 , TeO 2 , TiO 2 and VO 2 . Reduced expansion curves for the dioxides showed only partial grouping into iso-electronic series for the fluorite structures and showed that the 'law of corresponding states' did not apply to the rutile structures. (author)

Thermal expansion of beryllium oxide

International Nuclear Information System (INIS)

Solodukhin, A.V.; Kruzhalov, A.V.; Mazurenko, V.G.; Maslov, V.A.; Medvedev, V.A.; Polupanova, T.I.

1987-01-01

Precise measurements of temperature dependence of the coefficient of linear expansion in the 22-320 K temperature range on beryllium oxide monocrystals are conducted. A model of thermal expansion is suggested; the range of temperature dependence minimum of the coefficient of thermal expansion is well described within the frames of this model. The results of the experiment may be used for investigation of thermal stresses in crystals

Convergence of mayer expansions

International Nuclear Information System (INIS)

Brydges, D.C.

1986-01-01

The tree graph bound of Battle and Federbush is extended and used to provide a simple criterion for the convergence of (iterated) Mayer expansions. As an application estimates on the radius of convergence of the Mayer expansion for the two-dimensional Yukawa gas (nonstable interaction) are obtained

$\\delta$-Expansion at Finite Temperature

OpenAIRE

Ramos, Rudnei O.

1996-01-01

We apply the $\\delta$-expansion perturbation scheme to the $\\lambda \\phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\\delta$-expansion the interaction term is written as $\\lambda (\\phi^{2})^{ 1 + \\delta}$ and $\\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\\delta$. The results are compared with the usual loop-expansion at finite temperature.

Electrical Resistance Alloys and Low-Expansion Alloys

DEFF Research Database (Denmark)

Kjer, Torben

1996-01-01

The article gives an overview of electrical resistance alloys and alloys with low thermal expansion. The electrical resistance alloys comprise resistance alloys, heating alloys and thermostat alloys. The low expansion alloys comprise alloys with very low expansion coefficients, alloys with very low...... thermoelastic coefficients and age hardenable low expansion alloys....

Disjoint sum expansion method in FTA

International Nuclear Information System (INIS)

Ruan Keqiang

1987-01-01

An expansion formula for transforming boolean algebraic expressions into disjoint form was proved. Based on this expansion formula, a method for transforming system failure function into disjoint form was devised. The fact that the expansion can be done for several elements simulatneously makes the method flexible and fast. Some examples from fault tree analysis (FTA) and network analysis were examined by the new method to show its algorithm and its merit. Besides, by means of the proved expansion formula some boolean algebraic relations can proved very easily

Maxwell superalgebras and Abelian semigroup expansion

Directory of Open Access Journals (Sweden)

P.K. Concha

2014-09-01

Full Text Available The Abelian semigroup expansion is a powerful and simple method to derive new Lie algebras from a given one. Recently it was shown that the S-expansion of so(3,2 leads us to the Maxwell algebra M. In this paper we extend this result to superalgebras, by proving that different choices of abelian semigroups S lead to interesting D=4 Maxwell Superalgebras. In particular, the minimal Maxwell superalgebra sM and the N-extended Maxwell superalgebra sM(N recently found by the Maurer–Cartan expansion procedure, are derived alternatively as an S-expansion of osp(4|N. Moreover, we show that new minimal Maxwell superalgebras type sMm+2 and their N-extended generalization can be obtained using the S-expansion procedure.

Maxwell superalgebras and Abelian semigroup expansion

Energy Technology Data Exchange (ETDEWEB)

Concha, P.K.; Rodríguez, E.K. [Departamento de Física, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Dipartimento di Scienza Applicata e Tecnologia (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via Pietro Giuria, 1, 10125 Torino (Italy)

2014-09-15

The Abelian semigroup expansion is a powerful and simple method to derive new Lie algebras from a given one. Recently it was shown that the S-expansion of so(3,2) leads us to the Maxwell algebra M. In this paper we extend this result to superalgebras, by proving that different choices of abelian semigroups S lead to interesting D=4 Maxwell Superalgebras. In particular, the minimal Maxwell superalgebra sM and the N-extended Maxwell superalgebra sM{sup (N)} recently found by the Maurer–Cartan expansion procedure, are derived alternatively as an S-expansion of osp(4|N). Moreover, we show that new minimal Maxwell superalgebras type sM{sub m+2} and their N-extended generalization can be obtained using the S-expansion procedure.

Aspectos Psicosociales Relacionados con el TEPT en Pacientes con Cáncer de Mama

OpenAIRE

Hernández Moreno, Fresia Paloma; Landero Hernández, René

2015-01-01

El objetivo del estudio fue analizar la relación del estrés, la depresión y las estrategias de afrontamiento con el Trastorno de Estrés Postraumático (TEPT) en una muestra de pacientes con cáncer de mama. Se realizó con una muestra no probabilística de 52 mujeres con cáncer de mama. Se encontró una relación entre TEPT y estrés (r= .344, p= .014), TEPT y depresión (rs=.346, p= .013). El TEPT correlacionó con evitación cognitiva (r= .437, p= .001), TEPT y desesperanza (rs= .437, p= .001) y TEPT...

Uniform gradient expansions

CERN Document Server

Giovannini, Massimo

2015-01-01

Cosmological singularities are often discussed by means of a gradient expansion that can also describe, during a quasi-de Sitter phase, the progressive suppression of curvature inhomogeneities. While the inflationary event horizon is being formed the two mentioned regimes coexist and a uniform expansion can be conceived and applied to the evolution of spatial gradients across the protoinflationary boundary. It is argued that conventional arguments addressing the preinflationary initial conditions are necessary but generally not sufficient to guarantee a homogeneous onset of the conventional inflationary stage.

Thin foil expansion into a vacuum

International Nuclear Information System (INIS)

Mora, P.

2005-01-01

Plasma expansion into a vacuum is an old problem which has been renewed recently in various contexts: expansion of ultra-cold plasmas, cluster expansion, of dust grains, expansion of thin foils. In this presentation I will first discuss the physics of the expansion of a thin foil irradiated by an ultra-short ultra-intense laser pulse. The expansion results in the formation of high energy ions. For an infinitely steep plasma-vacuum interface the fastest ions are located in the outer part of the expansion and their velocity is given by ν m ax∼ 2 C s (In ω p it) where c s (Zk B T e /m i )''1/2 is the ion-acoustic velocity ω p i=(n e 0Ze''2/m i e 0 )''1/2 is the ion plasma frequency, n e 0 is the electron density in the unperturbed plasma, Z is the ion charge number. In the above expression, t is either the pulse duration or the effective acceleration time (in particular t∼L/2c s , where L is the width of the foil, when the electron cooling is taken into account). A salient characteristic of the expansion is the occurrence of a double layer structure and a peak of the accelerating electric field at the ion front. I will explain the origin of the peak and predict its temporal behavior. This peak has been diagnosed in recent experiments. I will also discuss the effect of a 2-temperatures electron distribution function on the expansion, showing the dominant role of the hot electron component. Finally I will discuss the occurrence of ion spikes in the expansion when the initial density profile is smooth. The ion spike is due to a wave breaking which cannot be handled in a satisfactory way by a fluid code and requires a kinetic description. A. simple collisionless particle code has been used to treat the evolution of the spike after the wave breaking and the results will be shown. (Author)

Paciente con esquizofrenia tratado con ziprasidona + clozapina

Directory of Open Access Journals (Sweden)

Pol Yanguas E.

2013-05-01

Full Text Available P es un paciente diagnosticado de esquizofrenia, sigue en un piso tutelado un programa de rehabilitación, está medicado con clozapina 500 mg/día y ziprasidona 280 mg/ día. Padece hipercolesterolemia, tabaquismo y sus hábitos alimenticios no son buenos. La medicación que utiliza desde 2007 hasta ahora se refleja en la tabla 1. El último tratamiento se le introdujo el 7 de agosto de 2012, habiendo presentado un electro cardiograma (ECG normal, pero con ligera taquicardia ventricular y prolactinemia de 44,8 ng/ml (valores normales: 2-18 ng/ml.

Comparative studies of antifugal potentialities for some natural plant oils against different fungi isolated from poultry

Directory of Open Access Journals (Sweden)

Ahmed, F. H.

1994-08-01

comportamiento con respecto a los aislados de hongo ya que los aceites crudos y las concentraciones al 10% les afectaron grandemente. Por otro lado aceite de albahaca al 2% no dio ningún efecto. Se calcularon las concentraciones críticas de los aceites con eficacia frente a aislados de hongo. Los aceites más eficaces fueron lemongras frente Aspergillus flavipes, Manzanilla frente a A. fumigatus y comino frente a A. nidulans, mientras que comino frente a A. glaucus, clavo frente a A. flavus, manzanilla frente a A. flavus y clavo frente a A. flavipes fueron los aceites con menor eficiencia.

The Thermal Expansion Of Feldspars

Science.gov (United States)

Hovis, G. L.; Medford, A.; Conlon, M.

2009-12-01

Hovis and others (1) investigated the thermal expansion of natural and synthetic AlSi3 feldspars and demonstrated that the coefficient of thermal expansion (α) decreases significantly, and linearly, with increasing room-temperature volume (VRT). In all such feldspars, therefore, chemical expansion limits thermal expansion. The scope of this work now has been broadened to include plagioclase and Ba-K feldspar crystalline solutions. X-ray powder diffraction data have been collected between room temperature and 925 °C on six plagioclase specimens ranging in composition from anorthite to oligoclase. When combined with thermal expansion data for albite (2,3,4) a steep linear trend of α as a function of VRT emerges, reflecting how small changes in composition dramatically affect expansion behavior. The thermal expansion data for five synthetic Ba-K feldspars ranging in composition from 20 to 100 mole percent celsian, combined with data for pure K-feldspar (3,4), show α-VRT relationships similar in nature to the plagioclase series, but with a slope and intercept different from the latter. Taken as a group all Al2Si2 feldspars, including anorthite and celsian from the present study along with Sr- (5) and Pb-feldspar (6) from other workers, show very limited thermal expansion that, unlike AlSi3 feldspars, has little dependence on the divalent-ion (or M-) site occupant. This apparently is due to the necessitated alternation of Al and Si in the tetrahedral sites of these minerals (7), which in turn locks the tetrahedral framework and makes the M-site occupant nearly irrelevant to expansion behavior. Indeed, in feldspar series with coupled chemical substitution it is the change away from a 1:1 Al:Si ratio that gives feldspars greater freedom to expand. Overall, the relationships among α, chemical composition, and room-temperature volume provide useful predictive tools for estimating feldspar thermal expansion and give insight into the controls of expansion behavior in

Riesgo familiar total en familias con mujeres diagnosticadas con neoplasia de mama

Directory of Open Access Journals (Sweden)

Nancy Cecilia Charrys-Bravo

2017-07-01

Full Text Available Objetivo: Determinar el riesgo familiar total de las familias con mujeres diagnosticadas con cáncer de mama, que asisten a un centro de salud oncológico en la ciudad de Barranquilla. Materiales y Métodos: El estudio fue de tipo descriptivo, transversal con abordaje cuantitativo. Se utilizó el instrumento Riesgo Familiar Total RFT 5-33. El universo estuvo conformado por familias con mujeres diagnosticadas con cáncer en mama. La muestra fue de 41 familias que integraron a 154 miembros; se abordó el estudio de manera censal, y no por medio de una muestra, porque el acceso a la información de la totalidad de las familia fue viable. Resultados: Los resultados mostraron que las familias, en su mayoría, son de tipo 2. El 68 % de las pacientes categorizan sus familias como amenazadas, el 5 % como familias de alto riesgo y un 27 % de las familias con un bajo riesgo. Conclusiones: Los hallazgos encontrados en esta investigación son importantes para las familias, lo cual permitirá establecer acciones y actividades que logren orientar e implementar procesos de atención específicos con el propósito de cuidar a las familias para que se mantengan sanos en un nivel de bajo riesgo; además, desarrollar controles y seguimiento a aquellas familias que se encuentran en un riesgo alto de amenazas, mediante acciones de promoción y prevención de la enfermedad de una manera amplia. Por lo anterior, se deben emprender programas más agresivos de prevención y promoción, especialmente con las familias que asisten en busca de apoyo médico para este padecimiento; de esta forma, se podrán diagnosticar los casos de forma temprana y proceder al respectivo tratamiento.

REDUCCIÓN DE ÓXIDOSDE NITROGENO CON CATALIZADORES ZEOLÍTICOS INTERCAMBIADOS CON COBALTO

Directory of Open Access Journals (Sweden)

Enrique Alexis García Moya

2012-10-01

Full Text Available Se presenta un estudio sobre la reducción catalítica selectiva (RCS de NOx con metano en presencia de oxígeno en exceso con varios catalizadores a base de las zeolitas mordenita, ferrierita y ZSM-5 intercambiadas con diferentes cargas de cobalto y con las correspondientes zeolitas en forma acida. Cuando la mezcla reactiva contenía mayormente NO2 en lugar de NO, los catalizadores ácidos mostraron las más altas velocidades de formación de N2 en condiciones secas. Las mayores actividades se obtuvieron con los catalizadores Co-mordenita, siguiendo en orden de actividad los catalizadores Co-Ferrierita y Co-ZSM-5. El catalizador Co-Mordenita más activo se ensayó con una mezcla reactiva donde predominó el NO en lugar del NO2 bajo condiciones secas e hidrotérmicas y en presencia de SO2. Con la adición de 8% de agua a la mezcla de reacción se observó desactivación reversible, especialmente a bajas temperaturas. La adición de 60 ppm de SO2 disminuyó la velocidad de reacción aproximadamente a la mitad debido posiblemente al envenenamiento de algunos sitios activos.

Thermal expansion of L-ascorbic acid

Science.gov (United States)

Nicolaï, B.; Barrio, M.; Tamarit, J.-Ll.; Céolin, R.; Rietveld, I. B.

2017-04-01

The specific volume of vitamin C has been investigated by X-ray powder diffraction as a function of temperature from 110 K up to complete degradation around 440 K. Its thermal expansion is relatively small in comparison with other organic compounds with an expansivity α v of 1.2(3) × 10-4 K-1. The structure consists of strongly bound molecules in the ac plane through a dense network of hydrogen bonds. The thermal expansion is anisotropic. Along the b axis, the expansion has most leeway and is about 10 times larger than in the other directions.

Chemical graph-theoretic cluster expansions

International Nuclear Information System (INIS)

Klein, D.J.

1986-01-01

A general computationally amenable chemico-graph-theoretic cluster expansion method is suggested as a paradigm for incorporation of chemical structure concepts in a systematic manner. The cluster expansion approach is presented in a formalism general enough to cover a variety of empirical, semiempirical, and even ab initio applications. Formally such approaches for the utilization of chemical structure-related concepts may be viewed as discrete analogues of Taylor series expansions. The efficacy of the chemical structure concepts then is simply bound up in the rate of convergence of the cluster expansions. In many empirical applications, e.g., boiling points, chromatographic separation coefficients, and biological activities, this rate of convergence has been observed to be quite rapid. More note will be made here of quantum chemical applications. Relations to questions concerning size extensivity of energies and size consistency of wave functions are addressed

Defining chemical expansion: the choice of units for the stoichiometric expansion coefficient

DEFF Research Database (Denmark)

Marrocchelli, Dario; Chatzichristodoulou, Christodoulos; Bishop, Sean R.

2014-01-01

Chemical expansion refers to the spatial dilation of a material that occurs upon changes in its composition. When this dilation is caused by a gradual, iso-structural increase in the lattice parameter with composition, it is related to the composition change by the stoichiometric expansion coeffi...... are provided for changes in oxygen content in fluorite, perovskite, and Ruddlesden-Popper (K2NiF4) phase materials used in solid oxide fuel cells....

Terapias alternativas con animales para niños con necesidades especiales

OpenAIRE

Cea-Chueca, Aihnoa

2014-01-01

El presente trabajo de fin de grado consiste en la realización de un análisis y descripción de la literatura acerca de las distintas terapias animales, destinadas a niños con necesidades especiales: cómo y por qué surgieron, en qué consisten las terapias, cómo podemos utilizarlas, etc. Las terapias alternativas con animales se conocen como una alternativa terapéutica, donde se utiliza a un animal como co-terapeuta para poder desarrollar diferentes capacidades de los niños con necesidades espe...

Edgeworth expansion for functionals of continuous diffusion processes

DEFF Research Database (Denmark)

Podolskij, Mark; Yoshida, Nakahiro

This paper presents new results on the Edgeworth expansion for high frequency functionals of continuous diffusion processes. We derive asymptotic expansions for weighted functionals of the Brownian motion and apply them to provide the Edgeworth expansion for power variation of diffusion processes....... Our methodology relies on martingale embedding, Malliavin calculus and stable central limit theorems for semimartingales. Finally, we demonstrate the density expansion for studentized statistics of power variations.......This paper presents new results on the Edgeworth expansion for high frequency functionals of continuous diffusion processes. We derive asymptotic expansions for weighted functionals of the Brownian motion and apply them to provide the Edgeworth expansion for power variation of diffusion processes...

Expansion lyre-shaped tube

International Nuclear Information System (INIS)

Andro, Jean.

1973-01-01

The invention relates the expansion lyre-shaped tube portions formed in dudgeoned tubular bundles between two bottom plates. An expansion lyre comprises at least two sets of tubes of unequal lengths coplanar and symmetrical with respect to the main tube axis, with connecting portions between the tubes forming said sets. The invention applies to apparatus such as heat exchangers, heaters, superheaters or breeders [fr

Optimization of a water resource system expansion using the Genetic Algorithm and Simulated Annealing methods; Optimizacion de la expansion de un sistema de recursos hidricos utilizados las metodologias del algoritmo genetico y el recocido simulado

Energy Technology Data Exchange (ETDEWEB)

Sanchez Camacho, Enrique; Andreu Alvarez, Joaquin [Universidad Politecnica de Valencia (Spain)

2001-06-01

Two numerical procedures, based on the Genetic Algorithm (GA) and the Simulated Annealing (SA), are developed to solve the problem of the expansion of capacity of a water resource system. The problem was divided into two subproblems: capital availability and operation policy. Both are optimisation-simulation models, the first one is solved by means of the GA and SA, in each case, while the second one is solved using the Out-of-kilter algorithm (OKA), in both models. The objective function considers the usual benefits and costs in this kind of systems, such as irrigation and hydropower benefits, costs of dam construction and system maintenance. The strength and weakness of both models are evaluated by comparing their results with those obtained with the branch and bound technique, which was classically used to solve this kind of problems. [Spanish] Un par de metodos numericos fundamentados en dos tecnicas de busqueda globales. Algoritmos Genetico (AG) y Recocido Simulado (RS), son desarrollados para resolver el problema de expansion de capacidad de un sistema de recursos hidricos. La estrategia ha sido dividir al problema en dos subproblemas: el de disponibilidad de capital y el de la politica de operacion. Ambos modelos son de optimizacion-simulacion, el primero se realiza mediante los algoritmos del RS y el AG en cada caso, en tanto que el segundo lleva a cabo a traves del algoritmo del Out-of-kilter (AOK) en los dos modelos. La funcion objetivo con que se trabaja considera los beneficios y costos mas comunes en este tipo de sistema, tales como beneficios por riego, por hidroelectricidad y costos de construccion de los embalses y mantenimiento del sistema. La potencia y debilidades delos dos modelos se evaluan mediante la comparacion con los resultados obtenidos a traves de una de las tecnicas mas usadas en este tipo de problemas: la de ramificacion y acotacion.

On the Equisummability of Hermite and Fourier Expansions

Indian Academy of Sciences (India)

We prove an equisummability result for the Fourier expansions and Hermite expansions as well as special Hermite expansions. We also prove the uniform boundedness of the Bochner-Riesz means associated to the Hermite expansions for polyradial functions.

Variables socionutricionales de hogares mazahuas integrados por preescolares desnutridos con madres con obesidad y sin obesidad

Directory of Open Access Journals (Sweden)

Conzuelo González, Viridiana Vanessa

2009-01-01

Full Text Available El primer objetivo fue conocer cuántos menores de cinco años con diferentes grados de desnutrición tienen una madre con sobrepeso/obesidad/ en una comunidad indígena que vive en extrema pobreza y bajo condiciones de migración masculina internacional. El segundo fue comparar tres variables socionutricionales (ingreso familiar, educación de la madre y adecuación nutrimental de la dieta diaria entre estos hogares y los hogares con desnutrición infantil y madres sin obesidad. Se realizó un estudio transversal (2006-2007, en la comunidad mazahua de San Francisco Tepeolulco, Municipio de Temascalcingo; que incluyó a 85 hogares integrados por preescolares con desnutrición inscritos al programa Oportunidades. Se determinó el estado nutrición de los preescolares con indicadores antropométricos y se obtuvo el IMC de las madres de estos infantes. Se aplicó una encuesta socionutricional, incluida el recordatorio de 24 horas, y complementado con la observación participante (cualitativa. Se encontró que 83% de las madres mazahuas presentaron sobrepeso u obesidad. El estado de nutrición de los preescolares con madres con obesidad presentó un porcentaje mayor de desnutrición (76%. En la variable género, se encontró que 54% de los niños con madres con obesidad tenía baja talla. Al relacionar el nivel educativo de la madre, esta variable resultó ser estadísticamente significativa (p=0.015, donde el analfabetismo está más relacionado con la desnutrición infantil que tienen madres de bajo y/o peso normal. La elevada prevalencia de hogares conformados con preescolares con desnutrición y madres con obesidad, es un síntoma más de la pobreza en zonas indígenas en México, con bajo índice de desarrollo humano.

Plasma expansion: fundamentals and applications

International Nuclear Information System (INIS)

Engeln, R; Mazouffre, S; Vankan, P; Bakker, I; Schram, D C

2002-01-01

The study of plasma expansion is interesting from a fundamental point of view as well as from a more applied point of view. We here give a short overview of the way properties like density, velocity and temperature behave in an expanding thermal plasma. Experimental data show that the basic phenomena of plasma expansion are to some extent similar to those of the expansion of a hot neutral gas. From the application point of view, we present first results on the use of an expanding thermal plasma in the plasma-activated catalysis of ammonia, from N 2 -H 2 mixtures

On genus expansion of superpolynomials

Energy Technology Data Exchange (ETDEWEB)

Mironov, Andrei, E-mail: mironov@itep.ru [Lebedev Physics Institute, Moscow 119991 (Russian Federation); ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Morozov, Alexei, E-mail: morozov@itep.ru [ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Sleptsov, Alexei, E-mail: sleptsov@itep.ru [ITEP, Moscow 117218 (Russian Federation); Laboratory of Quantum Topology, Chelyabinsk State University, Chelyabinsk 454001 (Russian Federation); KdVI, University of Amsterdam (Netherlands); Smirnov, Andrey, E-mail: asmirnov@math.columbia.edu [ITEP, Moscow 117218 (Russian Federation); Columbia University, Department of Mathematics, New York (United States)

2014-12-15

Recently it was shown that the (Ooguri–Vafa) generating function of HOMFLY polynomials is the Hurwitz partition function, i.e. that the dependence of the HOMFLY polynomials on representation R is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and expansion through Vassiliev invariants explicitly demonstrate this phenomenon. In the present paper we claim that the superpolynomials are not functions of such a type: symmetric group characters do not provide an adequate linear basis for their expansions. Deformation to superpolynomials is, however, straightforward in the multiplicative basis: the Casimir operators are β-deformed to Hamiltonians of the Calogero–Moser–Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is fully straightforward only for the thin knots. Beyond the family of thin knots additional algebraically independent terms appear in the Vassiliev and genus expansions. This can suggest that the superpolynomials do in fact contain more information about knots than the colored HOMFLY and Kauffman polynomials. However, even for the thin knots the beta-deformation is non-innocent: already in the simplest examples it seems inconsistent with the positivity of colored superpolynomials in non-(anti)symmetric representations, which also happens in I. Cherednik's (DAHA-based) approach to the torus knots.

On summation of perturbation expansions

International Nuclear Information System (INIS)

Horzela, A.

1985-04-01

The problem of the restoration of physical quantities defined by divergent perturbation expansions is analysed. The Pad'e and Borel summability is proved for alternating perturbation expansions with factorially growing coefficients. The proof is based on the methods of the classical moments theory. 17 refs. (author)

OPEC future capacity expansions

International Nuclear Information System (INIS)

Sandrea, I.

2005-01-01

This conference presentation examined OPEC future capacity expansions including highlights from 2000-2004 from the supply perspective and actions by OPEC; OPEC spare capacity in 2005/2006; medium-term capacity expansion and investments; long-term scenarios, challenges and opportunities; and upstream policies in member countries. Highlights from the supply perspective included worst than expected non-OPEC supply response; non-OPEC supply affected by a number of accidents and strikes; geopolitical tensions; and higher than expected demand for OPEC crude. OPEC's actions included closer relationship with other producers and consumers; capacity expansions in 2004 and 2005/2006; and OPEC kept the market well supplied with crude in 2004. The presentation also provided data using graphical charts on OPEC net capacity additions until 2005/2006; OPEC production versus spare capacity from 2003 to 2005; OPEC production and capacity to 2010; and change in required OPEC production from 2005-2020. Medium term expansion to 2010 includes over 60 projects. Medium-term risks such as project execution, financing, costs, demand, reserves, depletion, integration of Iraq, and geopolitical tensions were also discussed. The presentation concluded that in the long term, large uncertainties remain; the peak of world supply is not imminent; and continued and enhanced cooperation is essential to market stability. tabs., figs

Terapia regenerativa con plasma rico en plaquetas en pacientes con quemaduras

Directory of Open Access Journals (Sweden)

María del Carmen Franco Mora

2015-10-01

Full Text Available Se realizó un estudio comparativo, longitudinal y prospectivo de 60 adultos con quemaduras profundas, atendidos en el Hospital General docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, desde febrero de 2013 hasta igual mes de 2014, para evaluar la efectividad de la terapia regenerativa con plasma rico en plaquetas para la cicatrización de estas lesiones. La muestra fue dividida en 2 grupos de 30 integrantes cada uno: a los del primero se les aplicó plasma rico en plaquetas y a los del segundo sulfadiazina de plata. Se utilizaron las frecuencias absolutas y el porcentaje como medidas de resumen para variables cualitativos, así como la media aritmética y la desviación estándar para las cuantitativas. Con el proceder aplicado la cicatrización se completó en un tiempo menor, de manera que se demostró la efectividad de esta alternativa terapéutica en relación con el tratamiento convencional

On Learning Ring-Sum-Expansions

DEFF Research Database (Denmark)

Fischer, Paul; Simon, H. -U.

1992-01-01

The problem of learning ring-sum-expansions from examples is studied. Ring-sum-expansions (RSE) are representations of Boolean functions over the base {#123;small infinum, (+), 1}#125;, which reflect arithmetic operations in GF(2). k-RSE is the class of ring-sum-expansions containing only monomials...... of length at most k:. term-RSE is the class of ring-sum-expansions having at most I: monomials. It is shown that k-RSE, k>or=1, is learnable while k-term-RSE, k>2, is not learnable if RPnot=NP. Without using a complexity-theoretical hypothesis, it is proven that k-RSE, k>or=1, and k-term-RSE, k>or=2 cannot...... be learned from positive (negative) examples alone. However, if the restriction that the hypothesis which is output by the learning algorithm is also a k-RSE is suspended, then k-RSE is learnable from positive (negative) examples only. Moreover, it is proved that 2-term-RSE is learnable by a conjunction...

The bootstrap and edgeworth expansion

CERN Document Server

Hall, Peter

1992-01-01

This monograph addresses two quite different topics, in the belief that each can shed light on the other. Firstly, it lays the foundation for a particular view of the bootstrap. Secondly, it gives an account of Edgeworth expansion. Chapter 1 is about the bootstrap, witih almost no mention of Edgeworth expansion; Chapter 2 is about Edgeworth expansion, with scarcely a word about the bootstrap; and Chapters 3 and 4 bring these two themes together, using Edgeworth expansion to explore and develop the properites of the bootstrap. The book is aimed a a graduate level audience who has some exposure to the methods of theoretical statistics. However, technical details are delayed until the last chapter (entitled "Details of Mathematical Rogour"), and so a mathematically able reader without knowledge of the rigorous theory of probability will have no trouble understanding the first four-fifths of the book. The book simultaneously fills two gaps in the literature; it provides a very readable graduate level account of t...

Fuel Thermal Expansion (FTHEXP)

International Nuclear Information System (INIS)

Reymann, G.A.

1978-07-01

A model is presented which deals with dimensional changes in LWR fuel pellets caused by changes in temperature. It is capable of dealing with any combination of UO 2 and PuO 2 in solid, liquid or mixed phase states, and includes expansion due to the solid-liquid phase change. The function FTHEXP models fuel thermal expansion as a function of temperature, fraction of PuO 2 , and the fraction of fuel which is molten

Node-Expansion Operators for the UCT Algorithm

Science.gov (United States)

Yajima, Takayuki; Hashimoto, Tsuyoshi; Matsui, Toshiki; Hashimoto, Junichi; Spoerer, Kristian

Recent works on the MCTS and UCT framework in the domain of Go focused on introducing knowledge to the playout and on pruning variations from the tree, but so far node expansion has not been investigated. In this paper we show that delaying expansion according to the number of the siblings delivers a gain of more than 92% when compared to normal expansion. We propose three improvements; one that uses domain knowledge and two that are domain-independent methods. Experimental results show that all advanced operators significantly improve the UCT performance when compared to the basic delaying expansion. From the results we may conclude that the new expansion operators are an appropriate means to improve the UCT algorithm.

RadConEd: A Graphical Data Editor for the Radiological Consequences Model, RadCon

International Nuclear Information System (INIS)

Crawford, J.; Domel, R.U.

2000-05-01

This document describes the application, RadConEd, which has been designed and implemented to enable users of the RadCon system to update these parameter files. The RadCon system is written in the Java programming language, and as such provides portability across computer platforms. The software described in this report was developed in line with the portability requirements of RadCon, thus providing a uniform user interface across computer platforms and bypassing the need of using system editors. In addition a number of data integrity measures were implemented

Thermal expansion in small metallic particles

International Nuclear Information System (INIS)

Ivanov, A.S.

1985-01-01

An anomalously low thermal expansion observable in small particles is attributed to extending effect of the shell. It is shown that the coefficient of thermal expansion of the oxide-film-coated aluminium particles calculated using elastic constants and coefficients of thermal expansion of massive materials agres well with those measured experimentally. The linear dilatation of the shell, its stress to rupture and the values of the structural tension are estimated vs the temperature

Calidad de vida, satisfacción con el tratamiento y bienestar emocional en pacientes con diabetes LADA

OpenAIRE

Granado Casas, Minerva

2014-01-01

Introducción: La calidad de vida, satisfacción con el tratamiento y bienestar emocional en pacientes con diabetes mellitus están relacionados con el control metabólico, las complicaciones y algunas variables socioeconómicas. Actualmente, no existe ningún estudio científico que analice la calidad de vida, satisfacción con el tratamiento y bienestar emocional en pacientes con diabetes LADA. Objetivos: Los objetivos principales fueron conocer la calidad de vida, satisfacción con el tratamient...

[Tissular expansion in giant congenital nevi treatment].

Science.gov (United States)

Nguyen Van Nuoi, V; Francois-Fiquet, C; Diner, P; Sergent, B; Zazurca, F; Franchi, G; Buis, J; Vazquez, M-P; Picard, A; Kadlub, N

2014-08-01

Surgical management of giant melanotic naevi remains a surgical challenge. Tissue expansion provides tissue of the same quality for the repair of defects. The aim of this study is to review tissular expansion for giant melanotic naevi. We conducted a retrospective study from 2000 to 2012. All children patients who underwent a tissular expansion for giant congenital naevi had been included. Epidemiological data, surgical procedure, complication rate and results had been analysed. Thirty-tree patients had been included; they underwent 61 procedures with 79 tissular-expansion prosthesis. Previous surgery, mostly simple excision had been performed before tissular expansion. Complete naevus excision had been performed in 63.3% of the cases. Complications occurred in 45% of the cases, however in 50% of them were minor. Iterative surgery increased the complication rate. Tissular expansion is a valuable option for giant congenital naevus. However, complication rate remained high, especially when iterative surgery is needed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Negative thermal expansion in functional materials: controllable thermal expansion by chemical modifications.

Science.gov (United States)

Chen, Jun; Hu, Lei; Deng, Jinxia; Xing, Xianran

2015-06-07

Negative thermal expansion (NTE) is an intriguing physical property of solids, which is a consequence of a complex interplay among the lattice, phonons, and electrons. Interestingly, a large number of NTE materials have been found in various types of functional materials. In the last two decades good progress has been achieved to discover new phenomena and mechanisms of NTE. In the present review article, NTE is reviewed in functional materials of ferroelectrics, magnetics, multiferroics, superconductors, temperature-induced electron configuration change and so on. Zero thermal expansion (ZTE) of functional materials is emphasized due to the importance for practical applications. The NTE functional materials present a general physical picture to reveal a strong coupling role between physical properties and NTE. There is a general nature of NTE for both ferroelectrics and magnetics, in which NTE is determined by either ferroelectric order or magnetic one. In NTE functional materials, a multi-way to control thermal expansion can be established through the coupling roles of ferroelectricity-NTE, magnetism-NTE, change of electron configuration-NTE, open-framework-NTE, and so on. Chemical modification has been proved to be an effective method to control thermal expansion. Finally, challenges and questions are discussed for the development of NTE materials. There remains a challenge to discover a "perfect" NTE material for each specific application for chemists. The future studies on NTE functional materials will definitely promote the development of NTE materials.

Applications of the large mass expansion

International Nuclear Information System (INIS)

Fleischer, J.; Kotikov, A.V.; ); Veretin, O.L.

1998-01-01

The method of the large mass expansion (LME) is investigated for selfenergy and vertex functions in two-loop order. It has the technical advantage that in many cases the expansion coefficients can be expressed analytically. As long as only one non-zero external momentum squared, q 2 , is involved also the Taylor expansion (TE) w.r.t. small q 2 yields high precision results in a domain sufficient for most applications. In the case of only one non-zero mass M and only one external momentum squared, the expansion w.r.t. q 2 /M 2 is identical for the TE and the LME. In this case the combined techniques yield analytic expressions for many diagrams, which are quite easy to handle numerically. (author)

Hematoma Expansion Following Acute Intracerebral Hemorrhage

Science.gov (United States)

Brouwers, H. Bart; Greenberg, Steven M.

2013-01-01

Intracerebral hemorrhage, the most devastating form of stroke, has no specific therapy proven to improve outcome by randomized controlled trial. Location and baseline hematoma volume are strong predictors of mortality, but are non-modifiable by the time of diagnosis. Expansion of the initial hematoma is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for hematoma expansion have been identified, including baseline ICH volume, early presentation after symptom onset, anticoagulation, and the CT angiography spot sign. Although the biological mechanisms of hematoma expansion remain unclear, accumulating evidence supports a model of ongoing secondary bleeding from ruptured adjacent vessels surrounding the initial bleeding site. Several large clinical trials testing therapies aimed at preventing hematoma expansion are in progress, including aggressive blood pressure reduction, treatment with recombinant factor VIIa guided by CT angiography findings, and surgical intervention for superficial hematomas without intraventricular extension. Hematoma expansion is so far the only marker of outcome that is amenable to treatment and thus a potentially important therapeutic target. PMID:23466430

Renormalization group and mayer expansions

International Nuclear Information System (INIS)

Mack, G.

1984-01-01

Mayer expansions promise to become a powerful tool in exact renormalization group calculations. Iterated Mayer expansions were sucessfully used in the rigorous analysis of 3-dimensional U (1) lattice gauge theory by Gopfert and the author, and it is hoped that they will also be useful in the 2-dimensional nonlinear σ-model, and elsewhere

Mastopexia con prótesis: técnica triplanar con colgajo en cola de pez para mamas con pobre calidad de cobertura

Directory of Open Access Journals (Sweden)

M. Berrocal-Revueltas

2013-12-01

Full Text Available La mastopexia con implantes de silicona, es uno de los procedimientos más frecuentes en la práctica diaria en Cirugía Plástica. Sin embargo, la pobre calidad de la cobertura de las mamas, relacionada con piel estriada, escaso tejido subcutáneo y pérdida del parénquima mamario secundarios a la lactancia prolongada y a la pérdida masiva de peso, son causa del incremento progresivo de resultados insatisfactorios a medio y largo plazo que han sido evaluados, analizados y discutidos por los especialistas. Los resultados insatisfactorios más frecuentes en mastopexia con implantes en posición retromuscular son: doble contorno mamario, asimetrías y desplazamiento de los implantes. Los objetivos del presente estudio son: describir el nuevo método triplanar como alternativa útil para lograr mejores resultados en pacientes con mala calidad de cobertura y analizar los resultados obtenidos con el mismo. Realizamos un estudio observacional, descriptivo, prospectivo, en un grupo de 268 pacientes con diagnóstico de ptosis mamaria con hipotrofia y mala calidad de cobertura por piel estriada, escaso tejido celular subcutáneo y pérdida del parénquima mamario, secundarios a lactancia prolongada y pérdida masiva de peso, entre otros, a las que se les practicó mamoplastia de aumento con implantes de silicona mediante la aplicación del método triplanar descrito por la autora, entre enero del 2004 y enero del 2013 en el Hospital de Bocagrande de Cartagena, Colombia. El diseño de la técnica se basa en los principios de cicatriz vertical descrita por Lassus o Lejour o mediante cicatriz en "J", descrita por la autora. El método triplanar se basa en tres planos de cobertura del implante. Plano I: submuscular, para cubrir los dos tercios superiores del implante. Plano II: colgajo dermoglandular con dos prolongaciones distales triangulares de tejido adiposo, en forma de pez, para cubrir el tercio inferior del implante y el borde libre del m

Asymptotic expansions for high-contrast elliptic equations

KAUST Repository

Calo, Victor M.; Efendiev, Yalchin R.; Galvis, Juan

2014-01-01

In this paper, we present a high-order expansion for elliptic equations in high-contrast media. The background conductivity is taken to be one and we assume the medium contains high (or low) conductivity inclusions. We derive an asymptotic expansion with respect to the contrast and provide a procedure to compute the terms in the expansion. The computation of the expansion does not depend on the contrast which is important for simulations. The latter allows avoiding increased mesh resolution around high conductivity features. This work is partly motivated by our earlier work in [Domain decomposition preconditioners for multiscale flows in high-contrast media, Multiscale Model Simul. 8 (2010) 1461-1483] where we design efficient numerical procedures for solving high-contrast problems. These multiscale approaches require local solutions and our proposed high-order expansion can be used to approximate these local solutions inexpensively. In the case of a large-number of inclusions, the proposed analysis can help to design localization techniques for computing the terms in the expansion. In the paper, we present a rigorous analysis of the proposed high-order expansion and estimate the remainder of it. We consider both high-and low-conductivity inclusions. © 2014 World Scientific Publishing Company.

Asymptotic expansions for high-contrast elliptic equations

KAUST Repository

Calo, Victor M.

2014-03-01

In this paper, we present a high-order expansion for elliptic equations in high-contrast media. The background conductivity is taken to be one and we assume the medium contains high (or low) conductivity inclusions. We derive an asymptotic expansion with respect to the contrast and provide a procedure to compute the terms in the expansion. The computation of the expansion does not depend on the contrast which is important for simulations. The latter allows avoiding increased mesh resolution around high conductivity features. This work is partly motivated by our earlier work in [Domain decomposition preconditioners for multiscale flows in high-contrast media, Multiscale Model Simul. 8 (2010) 1461-1483] where we design efficient numerical procedures for solving high-contrast problems. These multiscale approaches require local solutions and our proposed high-order expansion can be used to approximate these local solutions inexpensively. In the case of a large-number of inclusions, the proposed analysis can help to design localization techniques for computing the terms in the expansion. In the paper, we present a rigorous analysis of the proposed high-order expansion and estimate the remainder of it. We consider both high-and low-conductivity inclusions. © 2014 World Scientific Publishing Company.

Crude oil pipeline expansion summary

International Nuclear Information System (INIS)

2005-02-01

The Canadian Association of Petroleum Producers has been working with producers to address issues associated with the development of new pipeline capacity from western Canada. This document presents an assessment of the need for additional oil pipeline capacity given the changing mix of crude oil types and forecasted supply growth. It is of particular interest to crude oil producers and contributes to current available information for market participants. While detailed, the underlying analysis does not account for all the factors that may come into play when individual market participants make choices about which expansions they may support. The key focus is on the importance of timely expansion. It was emphasized that if pipeline expansions lags the crude supply growth, then the consequences would be both significant and unacceptable. Obstacles to timely expansion are also discussed. The report reviews the production and supply forecasts, the existing crude oil pipeline infrastructure, opportunities for new market development, requirements for new pipeline capacity and tolling options for pipeline development. tabs., figs., 1 appendix

Expansion dynamics

International Nuclear Information System (INIS)

Knoll, J.

1985-10-01

A quantum dynamical model is suggested which describes the expansion and disassembly phase of highly excited compounds formed in energetic heavy-ion collisions. First applications in two space and one time dimensional model world are discussed and qualitatively compared to standard freeze-out concepts. (orig.)

Spatial Linkage and Urban Expansion: AN Urban Agglomeration View

Science.gov (United States)

Jiao, L. M.; Tang, X.; Liu, X. P.

2017-09-01

Urban expansion displays different characteristics in each period. From the perspective of the urban agglomeration, studying the spatial and temporal characteristics of urban expansion plays an important role in understanding the complex relationship between urban expansion and network structure of urban agglomeration. We analyze urban expansion in the Yangtze River Delta Urban Agglomeration (YRD) through accessibility to and spatial interaction intensity from core cities as well as accessibility of road network. Results show that: (1) Correlation between urban expansion intensity and spatial indicators such as location and space syntax variables is remarkable and positive, while it decreases after rapid expansion. (2) Urban expansion velocity displays a positive correlation with spatial indicators mentioned above in the first (1980-1990) and second (1990-2000) period. However, it exhibits a negative relationship in the third period (2000-2010), i.e., cities located in the periphery of urban agglomeration developing more quickly. Consequently, the hypothesis of convergence of urban expansion in rapid expansion stage is put forward. (3) Results of Zipf's law and Gibrat's law show urban expansion in YRD displays a convergent trend in rapid expansion stage, small and medium-sized cities growing faster. This study shows that spatial linkage plays an important but evolving role in urban expansion within the urban agglomeration. In addition, it serves as a reference to the planning of Yangtze River Delta Urban Agglomeration and regulation of urban expansion of other urban agglomerations.

Magnetized relativistic electron-ion plasma expansion

Science.gov (United States)

Benkhelifa, El-Amine; Djebli, Mourad

2016-03-01

The dynamics of relativistic laser-produced plasma expansion across a transverse magnetic field is investigated. Based on a one dimensional two-fluid model that includes pressure, enthalpy, and rest mass energy, the expansion is studied in the limit of λD (Debye length) ≤RL (Larmor radius) for magnetized electrons and ions. Numerical investigation conducted for a quasi-neutral plasma showed that the σ parameter describing the initial plasma magnetization, and the plasma β parameter, which is the ratio of kinetic to magnetic pressure are the key parameters governing the expansion dynamics. For σ ≪ 1, ion's front shows oscillations associated to the break-down of quasi-neutrality. This is due to the strong constraining effect and confinement of the magnetic field, which acts as a retarding medium slowing the plasma expansion.

Renormalization group and Mayer expansions

International Nuclear Information System (INIS)

Mack, G.

1984-02-01

Mayer expansions promise to become a powerful tool in exact renormalization group calculations. Iterated Mayer expansions were sucessfully used in the rigorous analysis of 3-dimensional U(1) lattice gauge theory by Goepfert and the author, and it is hoped that they will also be useful in the 2-dimensional nonlinear sigma-model, and elsewhere. (orig.)

Estudio comparativo del efecto del cepillado con una crema dental con propóleos rojos y de un gel con clorofila

OpenAIRE

Estela Gispert Abreu; Elena Cantillo Estrada; Aracelys Rivero López; Berta Oramas Rodríguez

1998-01-01

Se analiza comparativamente el efecto de un gel dental de clorofila y de una crema dental con propóleos rojos sobre varios parámetros relacionados con la caries dental, en escolares que se cepillaron durante 21 días con dichos productos. Se obtuvieron resultados favorables principalmente en la disminución del grado de infección por Streptococcus mutans y la elevación de la capacidad individual de remineralización; salvo en este último no hubo diferencias estadísticamente significativas.Author...

expansion method

Indian Academy of Sciences (India)

of a system under investigation is to model the system in terms of some ... The organization of the paper is as follows: In §2, a brief account of the (G /G)- expansion ...... It is interesting to note that from the general results, one can easily recover.

Expansion of Tubular with Elastomers in Multilateral Wells

Directory of Open Access Journals (Sweden)

Md Velden

2013-06-01

Full Text Available The use of solid expandable tubular technology during the last decade has focused on solving many challenges in well drilling and delivery including zonal isolation, deep drilling, conservation of hole sizes, etc. not only as pioneered solution but also providing cost effective and long lasting solutions. Concurrently, the technology was extended for construction of multilateral in typical wells. The process of horizontal tubular expansion is similar to the vertical expansion of expandable tubular in down-hole environment with the addition of uniformly distributed force due to its weight. The expansion is targeted to increase its diameter such that post expansion characteristics remain within allowable limits. In this study a typical expandable tubular of 57.15 mm outer diameter and 6.35 mm wall thickness was used with two different elastomer seals of 5 and 7 mm thickness placed at equal spacing of 200 mm. The developed stress contours during expansion process clearly showed the high stress areas in the vicinity of expansion region which lies around the mandrel. These high stresses may result in excessive wear of the mandrel. It was also found out that the drawing force increases as the mandrel angle, expansion ratio, and friction coefficient increases. A mandrel angle of 20o  requires minimum expansion force and can be considered as an optimum geometrical parameter to lower the power required for expansion.

Adiabatic supernova expansion into the circumstellar medium

International Nuclear Information System (INIS)

Band, D.L.; Liang, E.P.

1987-01-01

We perform one dimensional numerical simulations with a Lagrangian hydrodynamics code of the adiabatic expansion of a supernova into the surrounding medium. The early expansion follows Chevalier's analytic self-similar solution until the reverse shock reaches the ejecta core. We follow the expansion as it evolves towards the adiabatic blast wave phase. Some memory of the earlier phases of expansion is retained in the interior even when the outer regions expand as a blast wave. We find the results are sensitive to the initial configuration of the ejecta and to the placement of gridpoints. 6 refs., 2 figs

Decennial plan of expansion 1994-2003

International Nuclear Information System (INIS)

1993-12-01

The Decennial Plan of Expansion 1994-2003 of Electric sector reproduces the results of the studies occurred during the planning cycle of 1992/93 from the Coordinator Groups of the Electric System Planning. Based in the market forecasting, economic-financier and time for finishing the the works, the Decennial Plan of Expansion presents the schedule of the main generation and transmission works for the next ten years, the annual spend in generation, transmission and distribution, the costs of expansion and the evaluation of attending conditions in electric system in Brazil. (C.G.C.)

In vitro evaluation of force-expansion characteristics in a newly designed orthodontic expansion screw compared to conventional screws

Directory of Open Access Journals (Sweden)

Oshagh Morteza

2009-01-01

Full Text Available Objective : Expansion screws like Hyrax, Haas and other types, produce heavy interrupted forces which are unfavorable for dental movement and could be harmful to the tooth and periodontium. The other disadvantage of these screws is the need for patient cooperation for their regular activation. The purpose of this study was to design a screw and compare its force- expansion curve with other types. Materials and Methods : A new screw was designed and fabricated in the same dimension, with conventional types, with the ability of 8 mm expansion (Free wire length: 12 mm, initial compression: 4.5 mm, spring wire diameter: 0.4 mm, spring diameter: 3 mm, number of the coils: n0 ine, material: s0 tainless steel. In this in vitro study, the new screw was placed in an acrylic orthodontic appliance, and after mounting on a stone cast, the force-expansion curve was evaluated by a compression test machine and compared to other screws. Results : Force-expansion curve of designed screw had a flatter inclination compared to other screws. Generally it produced a light continuous force (two to 3.5 pounds for every 4 mm of expansion. Conclusion : In comparison with heavy and interrupted forces of other screws, the newly designed screw created light and continuous forces.

Financing electricity expansion

International Nuclear Information System (INIS)

Hyman, L.S.

1994-01-01

Expansion of electricity supply is associated with economic development. The installation and enlargement of power systems in developing countries entails a huge financial burden, however. Energy consumers in such countries must pay not only for supplies but for the cost of raising the capital for expansion on the international markets. Estimates are presented for the capital expenditure for electricity supply over the period 1990 to 2020 for the major world regions, using approximations for the cost of plant and capital and for the returns earned. These data lead to the conclusion that the five regions with the lowest per capita incomes are those which will need the major part of the capital expenditure and the highest percentage of external finance. (6 tables) (UK)

Preparation of Shrinkage Compensating Concrete with HCSA Expansive Agent

Science.gov (United States)

Li, Changcheng; Jia, Fujia

2017-10-01

Shrinkage compensating concrete (SCC) has become one of the best effective methods of preventing and reducing concrete cracking. SCC is prepared by HCSA high performance expansive agent for concrete which restrained expansion rate is optimized by 0.057%. Slump, compressive strength, restrained expansion rate and cracking resistance test were carried out on SCC. The results show that the initial slump of fresh SCC was about 220mm-230mm, while slump after 2 hours was 180mm-200mm. The restrained expansion rate of SCC increased with the mixing amount of expansive agent. After cured in water for 14 days, the restrained expansion rate of C35 and C40 SCC were 0.020%-0.032%. With the dosage of expansive agent increasing, restrained expansion rate of SCC increased, maximum compressive stress and cracking stress improved, cracking temperature fell, thus cracking resistance got effectively improvement.

Use of expansion joints in power stations

International Nuclear Information System (INIS)

Birker; Rommerswinkel.

1976-01-01

The paper discusses the mode of action of different systems of expansion joints. Special regard is given to the problems of expansion of pipelines of high rated diameter as employed in today's large power plant turbines. Due to the limited space available, the important role of the spring rate of the bellows for the reaction forces and moments acting on the connection points is pointed out. Apart from this details are given on the fabrication and materials selection of expansion joint bellows, and problems are discussed which arise in connection with the mechanical or hydraulic deformation of bellows with one or more walls. The non-destructive methods now in use for the testing of expansion pipe joints are mentioned along with experiments to test their behaviour under changing loads. The paper concludes on some remarks concerning proper transport, storage and installation of expansion pipe joints. (orig./AK) [de

Chromatic Derivatives, Chromatic Expansions and Associated Spaces

OpenAIRE

Ignjatovic, Aleksandar

2009-01-01

This paper presents the basic properties of chromatic derivatives and chromatic expansions and provides an appropriate motivation for introducing these notions. Chromatic derivatives are special, numerically robust linear differential operators which correspond to certain families of orthogonal polynomials. Chromatic expansions are series of the corresponding special functions, which possess the best features of both the Taylor and the Shannon expansions. This makes chromatic derivatives and ...

Warp drive with zero expansion

Energy Technology Data Exchange (ETDEWEB)

Natario, Jose [Department of Mathematics, Instituto Superior Tecnico (Portugal)

2002-03-21

It is commonly believed that Alcubierre's warp drive works by contracting space in front of the warp bubble and expanding the space behind it. We show that this contraction/expansion is but a marginal consequence of the choice made by Alcubierre and explicitly construct a similar spacetime where no contraction/expansion occurs. Global and optical properties of warp-drive spacetimes are also discussed.

Investigando con personas con dificultades de aprendizaje

Directory of Open Access Journals (Sweden)

Borja González Luna

2013-12-01

Full Text Available El artículo muestra los orígenes de lo que Walmsley (2008 denomina «investigación inclusiva». Para comprender qué se entiende por investigación inclusiva tenemos que remontarnos a los debates epistemológicos sobre las metodologías cuantitativas y cualitativas, acontecidos en la década de los 90, en torno a la revista Disability & Society. A partir de una síntesis de dichos debates, focalizados en el ámbito de la «discapacidad intelectual y del desarrollo», se exponen dos estrategias de colaboración con dicha población: a una aproximación etnográfica (de trabajo grupal, y b una aproximación biográfica (de trabajo individual. A continuación se esboza un posible diseño de trabajo de campo que intenta superar el paradigma cualitativo «clásico» con el objetivo de incluir a dicho colectivo más allá del rol de «sujetos de la investigación». Para finalizar se recoge el debate sobre la accesibilidad de los resultados de la investigación a los participantes en dichas investigaciones, y con ello la necesaria innovación en el ámbito de las «devoluciones» de los resultados, cuando se trata de incluir a personas que presentan limitaciones para la comprensión del lenguaje abstracto oral y/o escrito.

MODELADO CON REDES DE PETRI E IMPLEMENTACIÓN CON GRAFCET DE UN SISTEMA DE MANUFACTURA FLEXIBLE CON PROCESOS CONCURRENTES Y RECURSOS COMPARTIDOS

OpenAIRE

Johanna Stella Castellanos Arias; Leonardo Enrique Solaque Guzmán

2010-01-01

En este trabajo, se presenta el modelado de un Sistema de Manufactura Flexible (SMF), con procesos concurrentes y recursos compartidos mediante Sistemas a Eventos Discretos (SED), específicamente Redes de Petri (RdP), y GRAFCET. El SMF se plantea como un modelo hipotético que se modela con una RdP con el objeto de identificar su dinámica y hallar la secuencia óptima de funcionamiento del sistema. Se desarrolló un modelo matemático que permite estimar el vector de tiempo acumulado de un proces...

The δ expansion for stochastic quantization

International Nuclear Information System (INIS)

Bender, C.M.; Cooper, F.; Milton, K.A.; Department of Physics, Brown University, Providence, Rhode Island 02912; Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexic o 87545; Department of Physics, The Ohio State University, Columbus, Ohio 43210; Department of Physics and Astronomy, University of Oklahoma, Norman, Oklaho ma 73019)

1989-01-01

Using a recently proposed perturbation expansion called the δ expansion, we show how to solve the Langevin equation associated with a gphi 4 field theory. We illustrate the technique in zero- and one-dimensional space-time, and then generalize this approach to d dimensions

A meta-analysis of global urban land expansion.

Science.gov (United States)

Seto, Karen C; Fragkias, Michail; Güneralp, Burak; Reilly, Michael K

2011-01-01

The conversion of Earth's land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It drives the loss of farmland, affects local climate, fragments habitats, and threatens biodiversity. Here we present a meta-analysis of 326 studies that have used remotely sensed images to map urban land conversion. We report a worldwide observed increase in urban land area of 58,000 km(2) from 1970 to 2000. India, China, and Africa have experienced the highest rates of urban land expansion, and the largest change in total urban extent has occurred in North America. Across all regions and for all three decades, urban land expansion rates are higher than or equal to urban population growth rates, suggesting that urban growth is becoming more expansive than compact. Annual growth in GDP per capita drives approximately half of the observed urban land expansion in China but only moderately affects urban expansion in India and Africa, where urban land expansion is driven more by urban population growth. In high income countries, rates of urban land expansion are slower and increasingly related to GDP growth. However, in North America, population growth contributes more to urban expansion than it does in Europe. Much of the observed variation in urban expansion was not captured by either population, GDP, or other variables in the model. This suggests that contemporary urban expansion is related to a variety of factors difficult to observe comprehensively at the global level, including international capital flows, the informal economy, land use policy, and generalized transport costs. Using the results from the global model, we develop forecasts for new urban land cover using SRES Scenarios. Our results show that by 2030, global urban land cover will increase between 430,000 km(2) and 12,568,000 km(2), with an estimate of 1,527,000 km(2) more likely.

Considering FACTS in Optimal Transmission Expansion Planning

Directory of Open Access Journals (Sweden)

K. Soleimani

2017-10-01

Full Text Available The expansion of power transmission systems is an important part of the expansion of power systems that requires enormous investment costs. Since the construction of new transmission lines is very expensive, it is necessary to choose the most efficient expansion plan that ensures system security with a minimal number of new lines. In this paper, the role of Flexible AC Transmission System (FACTS devices in the effective operation and expansion planning of transmission systems is examined. Effort was taken to implement a method based on sensitivity analysis to select the optimal number and location of FACTS devices, lines and other elements of the transmission system. Using this method, the transmission expansion plan for a 9 and a 39 bus power system was performed with and without the presence of FACTS with the use of DPL environment in Digsilent software 15.1. Results show that the use of these devices reduces the need for new transmission lines and minimizes the investment cost.

Simulation program for multiple expansion Stirling machines

International Nuclear Information System (INIS)

Walker, G.; Weiss, M.; Fauvel, R.; Reader, G.; Bingham, E.R.

1992-01-01

Multiple expansion Stirling machines have been a topic of interest at the University of Calgary for some years. Recently a second-order computer simulation program with integral graphics package for Stirling cryocoolers with up to four stages of expansion were developed and made available to the Stirling community. Adaptation of the program to multiple expansion Stirling power systems is anticipated. This paper briefly introduces the program and presents a specimen result

con mala calidad de vida

Directory of Open Access Journals (Sweden)

Agustín Martín-Rodríguez

2007-01-01

Full Text Available En este estudio ex post facto se ha analizado si los familiares de pacientes con mala calidad de vida presentan diferencias en las variables clínicas de personalidad y relaciones familiares en función de que el paciente haya estado o no ingresado en una Unidad de Cuidados Intensivos. Seleccionamos dos grupos: 29 familiares de pacientes traumatizados graves transcurridos cuatro años de su ingreso en una UCI de Traumatología y con mala calidad de vida (debido a secuelas físicas y/o psicológicas tras el ingreso, tales como traumatismos craneoencefálicos, politraumatismos y tetraplejias traumáticas y 32 familiares de pacientes con mala calidad de vida con cuatro años de evolución de su enfermedad física (hipertensión, diabetes, artritis reumatoide y síndrome de intestino irritable que no han estado ingresados en la UCI. Para alcanzar nuestro objetivo empleamos una Encuesta Psicosocial y los siguientes instrumentos: Cuestionario de Análisis Clínico, Escala de Clima Social en la Familia y Escala de Adaptación Psicosocial de la Enfermedad. Los resultados mostraron que los familiares de pacientes con mala calidad de vida que estuvieron ingresados en la UCI hace cuatro años, presentan diferencias significativas en las variables agitación y expresividad comparados con los familiares de pacientes con mala calidad de vida que no han estado ingresados en la UCI.

Controlling Thermal Expansion: A Metal-Organic Frameworks Route.

Science.gov (United States)

Balestra, Salvador R G; Bueno-Perez, Rocio; Hamad, Said; Dubbeldam, David; Ruiz-Salvador, A Rabdel; Calero, Sofia

2016-11-22

Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal-organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model material, along with three molecules of similar size and known differences in terms of the nature of host-guest interactions. It has been shown that adsorbate molecules can control, in a colligative way, the thermal expansion of the solid, so that changing the adsorbate molecules induces the solid to display positive, zero, or negative thermal expansion. We analyze in depth the distortion mechanisms, beyond the ligand metal junction, to cover the ligand distortions, and the energetic and entropic effect on the thermo-structural behavior. We provide an unprecedented atomistic insight on the effect of adsorbates on the thermal expansion of MOFs as a basic tool toward controlling the thermal expansion.

The Economic Impact of Medicaid Expansion on Pennsylvania.

Science.gov (United States)

Price, Carter C; Donohue, Julie M; Saltzman, Evan; Woods, Dulani; Eibner, Christine

2013-01-01

The Affordable Care Act is a substantial reform of the U.S. health care insurance system. Using the RAND COMPARE model, researchers assessed the act's potential economic effects on Pennsylvania, factoring in an optional expansion of Medicaid, and found the state would enjoy significant net benefits. With or without the expansion of Medicaid, the act will increase insurance coverage to hundreds of thousands of Pennsylvanians, but the COMPARE model estimates that the expansion of Medicaid eligibility would cover an additional 350,000 people and bring more than $2 billion in federal spending into the state annually than if the state did not expand. Should the state expand Medicaid, the additional spending will add more than $3 billion a year to the state's GDP and support 35,000 jobs. But Medicaid expansion is not without cost for the state; the estimated cumulative effect on Pennsylvania's Medicaid spending will be $180 million higher with the expansion than without between 2014 and 2020. Substantial reductions in uncompensated care costs for hospitals are possible even without expansion, but savings to hospitals for uncompensated care funding are even larger with the Medicaid expansion, amounting to $550 million or more each year.

Controlling Thermal Expansion: A Metal–Organic Frameworks Route

Science.gov (United States)

2016-01-01

Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal–organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model material, along with three molecules of similar size and known differences in terms of the nature of host–guest interactions. It has been shown that adsorbate molecules can control, in a colligative way, the thermal expansion of the solid, so that changing the adsorbate molecules induces the solid to display positive, zero, or negative thermal expansion. We analyze in depth the distortion mechanisms, beyond the ligand metal junction, to cover the ligand distortions, and the energetic and entropic effect on the thermo-structural behavior. We provide an unprecedented atomistic insight on the effect of adsorbates on the thermal expansion of MOFs as a basic tool toward controlling the thermal expansion. PMID:28190918

Platform Expansion Design as Strategic Choice

DEFF Research Database (Denmark)

Staykova, Kalina S.; Damsgaard, Jan

2016-01-01

In this paper, we address how the strategic choice of platform expansion design impacts the subse-quent platform strategy. We identify two distinct approaches to platform expansion – platform bun-dling and platform constellations, which currently co-exist. The purpose of this paper is to outline...

Thermal expansion behavior in fabricated cellular structures

International Nuclear Information System (INIS)

Oruganti, R.K.; Ghosh, A.K.; Mazumder, J.

2004-01-01

Thermal expansion behavior of cellular structures is of interest in applications where undesirable deformation and failure are caused by thermal expansion mismatch. This report describes the role of processing-induced effects and metallurgical aspects of melt-processed cellular structures, such as a bi-material structure designed to contract on heating, as well as uni-material structures of regular and stochastic topology. This bi-material structure utilized the principle of internal geometric constraints to alter the expansion behavior of the internal ligaments to create overall contraction of the structure. Homogenization design method was used to design the structure, and fabrication was by direct metal deposition by laser melting of powder in another part of a joint effort. The degree of porosity and grain size in the fabricated structure are characterized and related to the laser deposition parameters. The structure was found to contract upon heating over a short range of temperature subsequent to which normal expansion ensued. Also examined in this report are uni-material cellular structures, in which internal constraints arise from residual stress variations caused by the fabrication process, and thereby alter their expansion characteristics. A simple analysis of thermal strain of this material supports the observed thermal expansion behavior

Secret-key expansion from covert communication

Science.gov (United States)

Arrazola, Juan Miguel; Amiri, Ryan

2018-02-01

Covert communication allows the transmission of messages in such a way that it is not possible for adversaries to detect that the communication is occurring. This provides protection in situations where knowledge that two parties are talking to each other may be incriminating to them. In this work, we study how covert communication can be used for a different purpose: secret key expansion. First, we show that any message transmitted in a secure covert protocol is also secret and therefore unknown to an adversary. We then propose a covert communication protocol where the amount of key consumed in the protocol is smaller than the transmitted key, thus leading to secure secret key expansion. We derive precise conditions for secret key expansion to occur, showing that it is possible when there are sufficiently low levels of noise for a given security level. We conclude by examining how secret key expansion from covert communication can be performed in a computational security model.

From greedy to lazy expansions and their driving dynamics

NARCIS (Netherlands)

Dajani, K.; Kraaikamp, C.

2001-01-01

In this paper we study the ergodic properties of non-greedy series expansions to non-integer bases β > 1. It is shown that the so-called 'lazy' expansion is isomorphic to the 'greedy' expansion. Furthermore, a class of expansions to base β > 1, β =2 Z, 'in between' the lazy and the greedy

RTEL1 Inhibits Trinucleotide Repeat Expansions and Fragility

Directory of Open Access Journals (Sweden)

Aisling Frizzell

2014-03-01

Full Text Available Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG repeat expansions and fragility, likely by unwinding problematic hairpins.

Thermal expansion studies on Hafnium titanate (HfTiO4)

International Nuclear Information System (INIS)

Panneerselvam, G.; Subramanian, G.G.S.; Antony, M.P.

2006-01-01

The lattice thermal expansion characteristics of hafnium titanate (HfTiO 4 ) have been studied by measuring the lattice parameter as a function of temperature by high temperature X-ray diffraction technique (HT-XRD) in the temperature range 298-1973K. Percentage linear thermal expansion and mean linear thermal expansion coefficients were computed from the lattice parameter data. The thermal expansion of HfTiO 4 is highly anisotropic. The expansivity along 'a' axis is large; as compared to the expansivity along 'b' axis which is negative below 1073 K. The percentage linear thermal expansion in the temperature range 298-1973 K along a, b and c axis are 2.74, 0.901 and 1.49 respectively. Thermal expansion values obtained in the present study are in reasonable agreement with the existing thermal expansion data. (author)

Hypersonic expansion of the Fokker--Planck equation

International Nuclear Information System (INIS)

Fernandez-Feria, R.

1989-01-01

A systematic study of the hypersonic limit of a heavy species diluted in a much lighter gas is made via the Fokker--Planck equation governing its velocity distribution function. In particular, two different hypersonic expansions of the Fokker--Planck equation are considered, differing from each other in the momentum equation of the heavy gas used as the basis of the expansion: in the first of them, the pressure tensor is neglected in that equation while, in the second expansion, the pressure tensor term is retained. The expansions are valid when the light gas Mach number is O(1) or larger and the difference between the mean velocities of light and heavy components is small compared to the light gas thermal speed. They can be applied away from regions where the spatial gradient of the distribution function is very large, but it is not restricted with respect to the temporal derivative of the distribution function. The hydrodynamic equations corresponding to the lowest order of both expansions constitute two different hypersonic closures of the moment equations. For the subsequent orders in the expansions, closed sets of moment equations (hydrodynamic equations) are given. Special emphasis is made on the order of magnitude of the errors of the lowest-order hydrodynamic quantities. It is shown that if the heat flux vanishes initially, these errors are smaller than one might have expected from the ordinary scaling of the hypersonic closure. Also it is found that the normal solution of both expansions is a Gaussian distribution at the lowest order

14 CFR 23.969 - Fuel tank expansion space.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 23.969 Section 23.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT....969 Fuel tank expansion space. Each fuel tank must have an expansion space of not less than two...

Calidad de vida relacionada con la salud del niño y del adolescente con obesidad

OpenAIRE

Hurtado-Valenzuela, Jaime Gabriel; Álvarez-Hernández, Gerardo

2014-01-01

Objetivo Estimar la calidad de vida relacionada con la salud (CVRS) en un grupo de niños y adolescentes con obesidad de la ciudad de Hermosillo, Sonora, México. Métodos Se realizó un estudio transversal utilizando el cuestionario PedsQL® para comparar la CVRS de 200 niños y adolescentes con obesidad al igual que a sus padres, con dos grupos de control, uno de la comunidad (n=400) y otro grupo de usuarios (n=200) del Hospital Infantil del Estado de Sonora. Las diferencias en la CVRS fueron eva...

Research progress on expansive soil cracks under changing environment.

Science.gov (United States)

Shi, Bei-xiao; Zheng, Cheng-feng; Wu, Jin-kun

2014-01-01

Engineering problems shunned previously rise to the surface gradually with the activities of reforming the natural world in depth, the problem of expansive soil crack under the changing environment becoming a control factor of expansive soil slope stability. The problem of expansive soil crack has gradually become a research hotspot, elaborates the occurrence and development of cracks from the basic properties of expansive soil, and points out the role of controlling the crack of expansive soil strength. We summarize the existing research methods and results of expansive soil crack characteristics. Improving crack measurement and calculation method and researching the crack depth measurement, statistical analysis method, crack depth and surface feature relationship will be the future direction.

Pulpotomía con electrocauterio en pacientes con hemofilia A

OpenAIRE

Carbonell Rodriguez, Rosario

2017-01-01

Rehabilita la salud oral de un niños con Hemofilia A, empleando el Electrocauterio como una alternativa en la terapia pulpar, específicamente en la pulpotomía, para lo cual se realiza un minucioso examen clínico y anamnesis, que respaldados con exámenes complementarios, permite determinar el plan de tratamiento. La rehabilitación integral se llevó a cabo, previo consentimiento informado del padre, en sala de operaciones bajo anestesia general, debido a la condición sistémica del niño. Incl...

Intervención con menores con adicciones desde Proyecto Hombre

OpenAIRE

Pardo-Esteban, Belén; Escalza-González, Amaia

2015-01-01

En el citado seminario informaremos del programa de atención y prevención de las toxicomanías y otras adicciones, llevado a cabo por la Asociación Proyecto hombre. A continuación, trataremos la formación en adicciones y toxicomanía con los estudiantes, mediante charla, cuestionarios sobre conocimientos básicos en prevención de toxicomanía en menores y los diferentes programas de intervención posibles aducados a los perfiles de los usuarios. Terminaremos con un debate sobre los temas tra...

NARRATIVAS CONVERSACIONALES CON FAMILIAS Y DOCENTES DE NIÑOS Y NIÑAS CON DISCAPACIDAD: UN APORTE METODOLÓGICO

Directory of Open Access Journals (Sweden)

NORA ANETH PAVA-RIPOLL

2015-01-01

Full Text Available Se presentan algunas ventajas y limitaciones de las narrativas conversacionales como estrategia de investigación para el trabajo con familias y docentes de niños con discapacidad. La narración realizada por muchas voces, como sucede en una conversación, privilegia la relación y el discurso entre las personas como fuente de construcción consensuada de significados. La interacción triádica entre familia, inclusión educativa y salud orientó los encuentros conversacionales con padres, acudientes y profesores de estos niños en la ciudad de Manizales (Colombia. Los participantes conformaron equipos conversacionales y equipos reflexivos y conversaron sobre preguntas propuestas, previamente elaboradas. Con este ejercicio investigativo se resalta el valor interaccional de esta estrategia desde tres ámbitos: entre los par ticipantes, con el investigador y con el contexto situacional. Se argumenta que la reflexividad está más relacionada con el hacer que con el ser y el sentir de las personas, las cuales no necesariamente se transforman en la narrativa...

Principles of Thermal Expansion in Feldspars

Science.gov (United States)

Hovis, Guy; Medford, Aaron; Conlon, Maricate; Tether, Allison; Romanoski, Anthony

2010-05-01

Following the recent thermal expansion work of Hovis et al. (1) on AlSi3 feldspars, we have investigated the thermal expansion of plagioclase, Ba-K, and Ca-K feldspar crystalline solutions. X-ray powder diffraction data were collected between room temperature and 925 °C on six natural plagioclase specimens ranging in composition from anorthite to oligoclase, the K-exchanged equivalents of these plagioclase specimens, and five synthetic Ba-K feldspars with compositions ranging from 25 to 99 mol % BaAl2Si2O8. The resulting thermal expansion coefficients (α) for volume have been combined with earlier results for end-member Na- and K-feldspars (2,3). Unlike AlSi3 feldspars, Al2Si2 feldspars, including anorthite and celsian from the present study plus Sr- and Pb-feldspar from other workers (4,5), show essentially constant and very limited thermal expansion, regardless of divalent cation size. In the context of structures where the Lowenstein rule (6) requires Al and Si to alternate among tetrahedra, the proximity of bridging Al-O-Si oxygen ions to divalent neighbors (ranging from 0 to 2) produces short Ca-O (or Ba-O) bonds (7,8) that apparently are the result of local charge-balance requirements (9). Gibbs et al. (10) suggest that short bonds such as these have a partially covalent character. This in turn stiffens the structure. Thus, for feldspar series with coupled substitution the change away from a purely divalent M-site occupant gives the substituting (less strongly bonded) monovalent cations increasingly greater influence on thermal expansion. Overall, then, thermal expansion in the feldspar system is well represented on a plot of α against room-temperature volume, where one sees a quadrilateral bounded by data for (A) AlSi3 feldspars whose expansion behavior is controlled largely by the size of the monovalent alkali-site occupant, (B) Al2Si2 feldspars whose expansion is uniformly limited by partially-covalent bonds between divalent M-site occupants and

Zirconium titanate: stability and thermal expansion; Titanato de circonio: estabilidad termodinamica y expansion termica

Energy Technology Data Exchange (ETDEWEB)

Lopez-Lopez, E.; Moreno, R.; Baudin, C.

2011-07-01

Zirconium titanate is a well known compound in the field of electro ceramics, although it has also been used in catalyst and sensors applications. The crystallographic thermal expansion anisotropy of this compound makes it a potential candidate as constituent of structural components. In general, to assure the structural integrity and microstructural homogeneity of a ceramic piece, relatively low cooling rates from the fabrication temperature are required. This requirement is essential for zirconium titanate because thermal expansion as well as phase distribution is affected by small variations in the composition and cooling rate. This work reviews the available data on the phase equilibrium relationships in the systems ZrO{sub 2}-TiO{sub 2} and ZrO{sub 2}-TiO{sub 2}-Y{sub 2}O{sub 3}. The main discrepancies as well as the possible origins of them are discussed. Additionally, the crystallographic thermal expansion data in the current literature are reviewed. (Author) 56 refs.

Semiclassical expansions on and near caustics

International Nuclear Information System (INIS)

Meetz, K.

1984-09-01

We show that the standard WKB expansion can be generalized so that it reproduces the behavior of the wave function on and near a caustic in two-dimensional space time. The expansion is related to the unfolding polynomials of the elementary catastrophes occurring in two dimensions: the fold and the cusp catastrophe. The method determines control parameters and transport coefficients in a self-consistent way from differential equations and does not refer to the asymptotic expansion of Feynman path integrals. The lowest order equations are solved explicitly in terms of the multivalued classical action. The result is a generalized semiclassical approximation on and beyond a caustic. (orig.)

Interbasis expansions for isotropic harmonic oscillator

Energy Technology Data Exchange (ETDEWEB)

Dong, Shi-Hai, E-mail: dongsh2@yahoo.com [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Edificio 9, Unidad Profesional Adolfo López Mateos, Mexico D.F. 07738 (Mexico)

2012-03-12

The exact solutions of the isotropic harmonic oscillator are reviewed in Cartesian, cylindrical polar and spherical coordinates. The problem of interbasis expansions of the eigenfunctions is solved completely. The explicit expansion coefficients of the basis for given coordinates in terms of other two coordinates are presented for lower excited states. Such a property is occurred only for those degenerated states for given principal quantum number n. -- Highlights: ► Exact solutions of harmonic oscillator are reviewed in three coordinates. ► Interbasis expansions of the eigenfunctions is solved completely. ► This is occurred only for those degenerated states for given quantum number n.

Cosmic growth history and expansion history

International Nuclear Information System (INIS)

Linder, Eric V.

2005-01-01

The cosmic expansion history tests the dynamics of the global evolution of the universe and its energy density contents, while the cosmic growth history tests the evolution of the inhomogeneous part of the energy density. Precision comparison of the two histories can distinguish the nature of the physics responsible for the accelerating cosmic expansion: an additional smooth component--dark energy--or a modification of the gravitational field equations. With the aid of a new fitting formula for linear perturbation growth accurate to 0.05%-0.2%, we separate out the growth dependence on the expansion history and introduce a new growth index parameter γ that quantifies the gravitational modification

MODELADO CON REDES DE PETRI E IMPLEMENTACIÓN CON GRAFCET DE UN SISTEMA DE MANUFACTURA FLEXIBLE CON PROCESOS CONCURRENTES Y RECURSOS COMPARTIDOS

Directory of Open Access Journals (Sweden)

Johanna Stella Castellanos Arias

2010-01-01

Full Text Available En este trabajo, se presenta el modelado de un Sistema de Manufactura Flexible (SMF, con procesos concurrentes y recursos compartidos mediante Sistemas a Eventos Discretos (SED, específicamente Redes de Petri (RdP, y GRAFCET. El SMF se plantea como un modelo hipotético que se modela con una RdP con el objeto de identificar su dinámica y hallar la secuencia óptima de funcionamiento del sistema. Se desarrolló un modelo matemático que permite estimar el vector de tiempo acumulado de un proceso modelado mediante una RdP, el cual constituye la base para hallar la mejor secuencia posible del sistema modelado. Por último, se realizó una implementación en el Laboratorio de Automatización de la Universidad Militar Nueva Granada, que simula el funcionamiento del SMF modelado por un montaje electrohidroneumático controlado con GRAFCET mediante PLC.

Correlation expansion: a powerful alternative multiple scattering calculation method

International Nuclear Information System (INIS)

Zhao Haifeng; Wu Ziyu; Sebilleau, Didier

2008-01-01

We introduce a powerful alternative expansion method to perform multiple scattering calculations. In contrast to standard MS series expansion, where the scattering contributions are grouped in terms of scattering order and may diverge in the low energy region, this expansion, called correlation expansion, partitions the scattering process into contributions from different small atom groups and converges at all energies. It converges faster than MS series expansion when the latter is convergent. Furthermore, it takes less memory than the full MS method so it can be used in the near edge region without any divergence problem, even for large clusters. The correlation expansion framework we derive here is very general and can serve to calculate all the elements of the scattering path operator matrix. Photoelectron diffraction calculations in a cluster containing 23 atoms are presented to test the method and compare it to full MS and standard MS series expansion

Treatment of divergent expansions in scattering theory

International Nuclear Information System (INIS)

Gersten, A.; Malin, S.

1978-01-01

One of the biggest obstacles in applying quantum field theory to realistic scattering problems are the divergencies of pertubation expansions for large coupling constants and the divergencies of partial wave expansions for massless particles exchanges. There exist, however, methods of summation of the divergent expansions which can lead to significant application in physics. In this paper we treat the problem of summing such expansions using three methods: (i) a generalization of the Pade approximation to the multivariable case. The suggested definition is unique and preserves unitarity. (ii) The summation of divergent partial waves for arbitrary spins. (iii) A successful application of a series inversion to the 3 P 1 nucleon-nucleon phase shift up to 200 MeV. (orig./WL) [de

Relación del perfil salival con el grado de inmunosupresión en pacientes infectados con VIH con y sin tratamiento antirretroviral

OpenAIRE

Vera Cruz, Moisés; Cornejo Salaza, José; Chiyong, Teresa Evaristo; Arevalo Abanto, Jorge A.; Villanueva Vílchez, Hugo G.

2014-01-01

El objetivo del estudio fue evaluar el perfil salival de pacientes con infección por VIH con y sin Tratamiento Antirretroviral de Gran Actividad (TARGA), por medio de la evaluación de los síntomas de hipofunción salival (Xerostomía, Disgeusia, Disfagia y Susceptibilidad de desarrollar úlceras orales), la Tasa de Flujo salival no estimulado, el pH salival y la viscosidad salival; estableciendo su relación con el Grado de Inmunosupresión, evaluado por medio del Recuento de Linfocitos CD4/μl. Se...

The loop expansion as a divergent-power-series expansion

International Nuclear Information System (INIS)

Murai, N.

1981-01-01

The loop expansion should be divergent, possibly an asymptotic one, in the Euclidean path integral formulation. This consideration is important in applications of the symmetric and mass-independent renormalization. The [1,1] Pade approximant is calculated in a PHI 4 model. Its classical vacua may be not truely stable for nonzero coupling constant. (author)

The heavy quark expansion of QCD

Energy Technology Data Exchange (ETDEWEB)

Falk, A.F. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Physics and Astronomy

1997-06-01

These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic B decays are included. Heavy hadron production via nonperturbative fragmentation processes is also discussed. 54 refs., 7 figs.

The heavy quark expansion of QCD

International Nuclear Information System (INIS)

Falk, A.F.

1997-01-01

These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic B decays are included. Heavy hadron production via nonperturbative fragmentation processes is also discussed. 54 refs., 7 figs

Thermal expansion of doped lanthanum gallates

Indian Academy of Sciences (India)

Administrator

Since the components are in intimate mechanical contact, any stress generated due to their thermal expansion mis- match during thermal cycling could lead to catastrophic failure of the cell. The functional materials must have similar thermal expansions to avoid mechanical stresses. Hence it is useful to study the thermal ...

Thermal and hygroscopic expansion characteristics of bamboo

OpenAIRE

Huang, Puxi; Chang, Wen-shao; Ansell, Martin P.; Bowen, Chris R.; Chew, John Y. M.; Adamak, Vana i

2017-01-01

The expansion and contraction of bamboo caused by temperature and moisture variations must be evaluated\\ud if bamboo is to be utilised as a building material. However, detailed expansion data, especially data in the ascent and\\ud descent processes of temperature and moisture are unexplored. The aim of this study is to investigate the expansion\\ud characteristics of Phyllostachys edulis (Moso bamboo) in ascent and descent processes of temperature and moisture.\\ud The measurement of linear ther...

Semiclassical expansions for confined N fermion systems

International Nuclear Information System (INIS)

Krivine, H.; Martorell, J.; Casas, M.

1989-01-01

A new derivation of the Wigner Kirkwood expansion for N-fermion systems is presented, showing explicitly the connection to the WKB approximation for a single level. This allows to study separately the two ansatz required to obtain the semiclassical expansions: the asymptotic expansions in powers of ℎ and the smoothing of quantal effects. We discuss the one dimensional and three dimensional, with spherical symmetry, cases. Applications for standard potentials used in nuclear physics are described in detail

Breaking the Link between Environmental Degradation and Oil Palm Expansion: A Method for Enabling Sustainable Oil Palm Expansion

Science.gov (United States)

Smit, Hans Harmen; Meijaard, Erik; van der Laan, Carina; Mantel, Stephan; Budiman, Arif; Verweij, Pita

2013-01-01

Land degradation is a global concern. In tropical areas it primarily concerns the conversion of forest into non-forest lands and the associated losses of environmental services. Defining such degradation is not straightforward hampering effective reduction in degradation and use of already degraded lands for more productive purposes. To facilitate the processes of avoided degradation and land rehabilitation, we have developed a methodology in which we have used international environmental and social sustainability standards to determine the suitability of lands for sustainable agricultural expansion. The method was developed and tested in one of the frontiers of agricultural expansion, West Kalimantan province in Indonesia. The focus was on oil palm expansion, which is considered as a major driver for deforestation in tropical regions globally. The results suggest that substantial changes in current land-use planning are necessary for most new plantations to comply with international sustainability standards. Through visualizing options for sustainable expansion with our methodology, we demonstrate that the link between oil palm expansion and degradation can be broken. Application of the methodology with criteria and thresholds similar to ours could help the Indonesian government and the industry to achieve its pro-growth, pro-job, pro-poor and pro-environment development goals. For sustainable agricultural production, context specific guidance has to be developed in areas suitable for expansion. Our methodology can serve as a template for designing such commodity and country specific tools and deliver such guidance. PMID:24039700

Mechanism of actuation in conducting polymers: Osmotic expansion

DEFF Research Database (Denmark)

Bay, Lasse; Jacobsen, Torben; West, Keld

2001-01-01

Conducting polymers expand or contract when their redox state is changed. This expansion/contraction effect can be separated in an intrinsic part because of changes of the polymer backbone on reduction/oxidation and a part depending on the surrounding electrolyte phase, because of osmotic expansion...... is compared with measurements on PPy(DBS) films. The experiments show that the expansion decreases as the electrolyte concentration is increased. This means that a considerable part of the total expansion is due to the osmotic effect. The osmotic effect should be taken into account when interpreting...

Mapping Brazilian Cropland Expansion, 2000-2013

Science.gov (United States)

Zalles, V.; Hansen, M.; Potapov, P.

2016-12-01

Brazil is one of the world's leading producers and exporters of agricultural goods. Despite undergoing significant increases in its cropland area in the last decades, it remains one of the countries with the most potential for further agricultural expansion. Most notably, the expansion in production areas of commodity crops such as soybean, corn, and sugarcane has become the leading cause of land cover conversion in Brazil. Natural land covers, such as the Amazon and Cerrado forests, have been negatively affected by this agricultural expansion, causing carbon emissions, biodiversity loss, altered water cycles, and many other disturbances to ecosystem services. Monitoring of change in cropland area extent can provide relevant information to decision makers seeking to understand and manage land cover change drivers and their impacts. In this study, the freely-available Landsat archive was leveraged to produce a large-scale, methodologically consistent map of cropland cover at 30 m. resolution for the entire Brazilian territory in the year 2000. Additionally, we mapped cropland expansion from 2000 to 2013, and used statistical sampling techniques to accurately estimate cropland area per Brazilian state. Using the Global Forest Change product produced by Hansen et al. (2013), we can disaggregate forest cover loss due to cropland expansion by year, revealing spatiotemporal trends that could advance our understanding of the drivers of forest loss.

Thermal expansion of fibre-reinforced composites

International Nuclear Information System (INIS)

Schneider, B.

1991-07-01

The integral thermal expansion and the coefficient of thermal expansion (CTE) of carbon and Kevlar fibre-reinforced composites were measured with high accuracy from 5 K to room temperature. For this, a laser dilatometer and a sophisticated measuring procedure were used. CTE dependence on the orientation angle ω of angle-ply laminates was determined for samples with 5 different fibre alignments (UD 0deg, +/-30deg, +/-45deg, +/-60deg and UD 90deg). A high variability of the CTE with the orientation angle was shown. At angles of approximately +/-30deg even negative CTEs were found. With suitable reinforcing fibres being selected, their absolute values rose up to 30-100% of the positive CTEs of metals. Hence, composites of this type would be suitable as compensating materials in metal constructions where little thermal expansion is desired. To check the lamination theory, theoretical computations of the CTE- ω -dependence were compared with the measured values. An excellent agreement was found. Using the lamination theory, predictions about the expansion behaviour of angle-ply laminates can be made now, if the thermal and mechanical properties of the unidirectional (UD) laminate are known. Furthermore, it is possible to carry out simulation computations aimed at investigating the influence of a single parameter of the UD-laminate (e.g. shear modulus) on the expansion of the angle-ply laminate. (orig.) [de

On equivalence of high temperature series expansion and coupling parameter series expansion in thermodynamic perturbation theory of fluids

International Nuclear Information System (INIS)

Sai Venkata Ramana, A.

2014-01-01

The coupling parameter series expansion and the high temperature series expansion in the thermodynamic perturbation theory of fluids are shown to be equivalent if the interaction potential is pairwise additive. As a consequence, for the class of fluids with the potential having a hardcore repulsion, if the hard-sphere fluid is chosen as reference system, the terms of coupling parameter series expansion for radial distribution function, direct correlation function, and Helmholtz free energy follow a scaling law with temperature. The scaling law is confirmed by application to square-well fluids

SATISFACCIÓN CON EL TRATAMIENTO EN PACIENTES DE ATENCIÓN PRIMARIA CON ARTROSIS

Directory of Open Access Journals (Sweden)

Carmen Llanos Val Jiménez

2017-01-01

Full Text Available Fundamentos: Al igual que en otros problemas crónicos, en el abor - daje del paciente con artrosis se tiende a un modelo de toma de decisiones compartidas, en el que el punto de vista del paciente debe ser considerado en la elección del tratamiento. El objetivo de este trabajo fue evaluar la sa - tisfacción con el tratamiento en pacientes diagnosticados de osteoartrosis y comprobar si existen diferencias entre diferentes opciones farmacológicas, así como determinar si existe asociación con el estado funcional y las carac - terísticas clínicas y sociodemográficas. Métodos: Se realizó un estudio observacional transversal en una muestra de 487 pacientes seleccionados mediante muestreo consecutivo. La variable principal fue el nivel de satisfacción con el tratamiento (cuestionario ARTS. El estado funcional de los pacientes fue evaluado mediante la escala WO - MAC. Otras variables fueron: características del tratamiento, adherencia te - rapéutica, eventos adversos, y variables clínicas y sociodemográficas. Resultados: En el cuestionario ARTS los pacientes, en un rango entre 28 y 87, obtuvieron una puntuación media de 65,3 (DE: 9,9. La puntuación no fue significativamente diferente en consumidores de 1, 2 o más fármacos. Entre quienes consumían un solo fármaco, no hubo diferencias entre los di - ferentes tipos de fármacos. En el estado funcional se obtuvo una puntuación media de 30,2 puntos (DE: 20,8 y se observó una débil correlación negativa con el nivel de satisfacción (r= - 0,252; p<0,001. Mediante regresión lineal múltiple, se observó mayor puntuación en la escala ARTS (p<0,05 en pa - cientes con menor puntuación en la escala WOMAC, mayor edad y ausencia de eventos adversos. Conclusión : En pacientes con osteoartritis se observa un nivel mode - rado de satisfacción con el tratamiento farmacológico, condicionado por su situación funcional, sus características sociodemográficas y por la presencia de eventos

Estimates of expansion time scales

International Nuclear Information System (INIS)

Jones, E.M.

1979-01-01

Monte Carlo simulations of the expansion of a spacefaring civilization show that descendants of that civilization should be found near virtually every useful star in the Galaxy in a time much less than the current age of the Galaxy. Only extreme assumptions about local population growth rates, emigration rates, or ship ranges can slow or halt an expansion. The apparent absence of extraterrestrials from the solar system suggests that no such civilization has arisen in the Galaxy. 1 figure

Strategic Complexity and Global Expansion

DEFF Research Database (Denmark)

Oladottir, Asta Dis; Hobdari, Bersant; Papanastassiou, Marina

2012-01-01

The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish....... The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness....

Range expansion of heterogeneous populations.

Science.gov (United States)

Reiter, Matthias; Rulands, Steffen; Frey, Erwin

2014-04-11

Risk spreading in bacterial populations is generally regarded as a strategy to maximize survival. Here, we study its role during range expansion of a genetically diverse population where growth and motility are two alternative traits. We find that during the initial expansion phase fast-growing cells do have a selective advantage. By contrast, asymptotically, generalists balancing motility and reproduction are evolutionarily most successful. These findings are rationalized by a set of coupled Fisher equations complemented by stochastic simulations.

Hidroxilación de fenol con catalizadores ZSM-5 modificado con cobre

Directory of Open Access Journals (Sweden)

César Augusto Caro

2005-01-01

Full Text Available Se sintetizaron varios catalizadores Cu-ZSM-5 con diferentes relaciones Si/Al y Si/Cu. Usando metilamina o hidróxido de sodio como agente mineralizante. Los catalizadores se caracterizaron por DRX, IR, análisis BET, UV-VIS y análisis elemental. El desempeño catalítico de los catalizadores sintetizados se evaluó en la hidroxilación de fenol con H2O2. Se encontró que la relación catecol (CAT/(hidroquinona (HQ + p-benzoquinona (PBQ aumentó con el contenido de agua, presentó un máximo cuando la relación en peso de agua/fenol fue de 53/1 y se favoreció a altas temperaturas, con el aumento del contenido de aluminio o con la disminución en el contenido de catalizador. El contenido de cobre no fue un factor determinante para la conversión ni para la selectividad en la hidroxilación de fenol. La producción de la p-benzoquinona (PBQ, producto de oxidación de la hidroquinona, fue mínimo cuando se usaron las siguientes condiciones: 80 ºC, fenol: 1 mmol, relación molar fenol/H2O2 de 3/1, catalizador: 20 mg, agua: 5 g, tiempo de reacción: 4 h.

Low Thermal Expansion Glass Ceramics

CERN Document Server

Bach, Hans

2005-01-01

This book appears in the authoritative series reporting the international research and development activities conducted by the Schott group of companies. This series provides an overview of Schott's activities for scientists, engineers, and managers from all branches of industry worldwide in which glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This new extended edition describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus g...

Low thermal expansion glass ceramics

CERN Document Server

1995-01-01

This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

Regulation of gas infrastructure expansion

International Nuclear Information System (INIS)

De Joode, J.

2012-01-01

The topic of this dissertation is the regulation of gas infrastructure expansion in the European Union (EU). While the gas market has been liberalised, the gas infrastructure has largely remained in the regulated domain. However, not necessarily all gas infrastructure facilities - such as gas storage facilities, LNG import terminals and certain gas transmission pipelines - need to be regulated, as there may be scope for competition. In practice, the choice of regulation of gas infrastructure expansion varies among different types of gas infrastructure facilities and across EU Member States. Based on a review of economic literature and on a series of in-depth case studies, this study explains these differences in choices of regulation from differences in policy objectives, differences in local circumstances and differences in the intrinsic characteristics of the infrastructure projects. An important conclusion is that there is potential for a larger role for competition in gas infrastructure expansion.

RTEL1 inhibits trinucleotide repeat expansions and fragility.

Science.gov (United States)

Frizzell, Aisling; Nguyen, Jennifer H G; Petalcorin, Mark I R; Turner, Katherine D; Boulton, Simon J; Freudenreich, Catherine H; Lahue, Robert S

2014-03-13

Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG) repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG) repeat expansions and fragility, likely by unwinding problematic hairpins. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

ESTUDIO DE LA DIGESTION HUMANA CON ALUMNOS CON DIFICULTADES DE APRENDIZAJE

Directory of Open Access Journals (Sweden)

Mª Begoña Carretero Gómez

2009-01-01

Full Text Available En esta experiencia se han seleccionado una serie de actividades relacionadas con la digestión con el fin de lograr una reestructuración de ideas y cambios conceptuales, y así con la conseguir que el alumnado aprenda a construir sus propios conocimientos acerca de cómo y donde se dan los procesos de digestión necesarios para la nutrición del organismo. El trabajo se ha llevado a cabo con alumnos de 3º de Educación Secundaria Obligatoria, pertenecientesal programa de diversificación curricular. Hemos querido hacer la ciencia más cercana para que comprendan que algunos procesos tienen su explicación científica y que la ciencia forma parte de nuestro día a día, fomentando el interés del estudiante así como su implicación en el proceso de enseñanza-aprendizaje. Por ello hemos trabajado a base de pequeñas investigaciones, donde es el alumno el que marca su ritmo de trabajo, investiga y hace sus aportaciones. Han aprendido a trabajar de una forma meticulosa donde el rigor esfundamental, contagiándose del afán investigador de manera que al realizar las experiencias se han aproximado al trabajo científico a la vez que aclaran y reestructuran conocimientos.

Longitudinal expansion of field line dipolarization

Science.gov (United States)

Saka, O.; Hayashi, K.

2017-11-01

We examine the substorm expansions that started at 1155 UT 10 August 1994 in the midnight sector focusing on the longitudinal (eastward) expansion of field line dipolarization in the auroral zone. Eastward expansion of the dipolarization region was observed in all of the H, D, and Z components. The dipolarization that started at 1155 UT (0027 MLT) from 260° of geomagnetic longitude (CMO) expanded to 351°(PBQ) in about 48 min. The expansion velocity was 0.03-0.04°/s, or 1.9 km/s at 62°N of geomagnetic latitude. The dipolarization region expanding to the east was accompanied by a bipolar event at the leading edge of the expansion in latitudes equatorward of the westward electrojet (WEJ). In the midnight sector at the onset meridian, the Magnetospheric Plasma Analyzer (MAP) on board geosynchronous satellite L9 measured electrons and ions between 10 eV and 40 keV. We conclude from the satellite observations that this dipolarization was characterized by the evolution of temperature anisotropies, an increase of the electron and ion temperatures, and a rapid change in the symmetry axis of the temperature tensor. The field line dipolarization and its longitudinal expansion were interpreted in terms of the slow MHD mode triggered by the current disruption. We propose a new magnetosphere-ionosphere coupling (MI-coupling) mechanism based on the scenario that transmitted westward electric fields from the magnetosphere in association with expanding dipolarization produced electrostatic potential (negative) in the ionosphere through differences in the mobility of collisional ions and collisionless electrons. The field-aligned currents that emerged from the negative potential region are arranged in a concentric pattern around the negative potential region, upward toward the center and downward on the peripheral.

Wilson expansion in the minimal subtraction scheme

International Nuclear Information System (INIS)

Smirnov, V.A.

1989-01-01

The small distance expansion of the product of composite fields is constructed for an arbitrary renormalization procedure of the type of minimal subtraction scheme. Coefficient functions of the expansion are expressed explicitly through the Green functions of composite fields. The expansion has the explicity finite form: the ultraviolet (UV) divergences of the coefficient functions and composite fields are removed by the initial renormalization procedure while the infrared (IR) divergences in massless diagrams with nonvanishing contribution into the coefficient functions are removed by the R-operation which is the IR part of the R-operation. The latter is the generalization of the dimensional renormalization in the case when both UV and IR divergences are present. To derive the expansion, a ''pre-subtracting operator'' is introduced and formulas of the counter-term technique are exploited

Thermal Expansion Anomaly Regulated by Entropy

Science.gov (United States)

Liu, Zi-Kui; Wang, Yi; Shang, Shunli

2014-11-01

Thermal expansion, defined as the temperature dependence of volume under constant pressure, is a common phenomenon in nature and originates from anharmonic lattice dynamics. However, it has been poorly understood how thermal expansion can show anomalies such as colossal positive, zero, or negative thermal expansion (CPTE, ZTE, or NTE), especially in quantitative terms. Here we show that changes in configurational entropy due to metastable micro(scopic)states can lead to quantitative prediction of these anomalies. We integrate the Maxwell relation, statistic mechanics, and first-principles calculations to demonstrate that when the entropy is increased by pressure, NTE occurs such as in Invar alloy (Fe3Pt, for example), silicon, ice, and water, and when the entropy is decreased dramatically by pressure, CPTE is expected such as in anti-Invar cerium, ice and water. Our findings provide a theoretic framework to understand and predict a broad range of anomalies in nature in addition to thermal expansion, which may include gigantic electrocaloric and electromechanical responses, anomalously reduced thermal conductivity, and spin distributions.

Territorial expansion and primary state formation.

Science.gov (United States)

Spencer, Charles S

2010-04-20

A major research problem in anthropology is the origin of the state and its bureaucratic form of governance. Of particular importance for evaluating theories of state origins are cases of primary state formation, whereby a first-generation state evolves without contact with any preexisting states. A general model of this process, the territorial-expansion model, is presented and assessed with archaeological data from six areas where primary states emerged in antiquity: Mesoamerica, Peru, Egypt, Mesopotamia, the Indus Valley, and China. In each case, the evidence shows a close correspondence in time between the first appearance of state institutions and the earliest expansion of the state's political-economic control to regions lying more than a day's round-trip from the capital. Although additional research will add detail and clarity to the empirical record, the results to date are consistent with the territorial-expansion model, which argues that the success of such long-distance expansion not only demanded the bureaucratization of central authority but also helped provide the resources necessary to underwrite this administrative transformation.

Thermal expansion of quaternary nitride coatings

Science.gov (United States)

Tasnádi, Ferenc; Wang, Fei; Odén, Magnus; Abrikosov, Igor A.

2018-04-01

The thermal expansion coefficient of technologically relevant multicomponent cubic nitride alloys are predicted using the Debye model with ab initio elastic constants calculated at 0 K and an isotropic approximation for the Grüneisen parameter. Our method is benchmarked against measured thermal expansion of TiN and Ti(1-x)Al x N as well as against results of molecular dynamics simulations. We show that the thermal expansion coefficients of Ti(1-x-y)X y Al x N (X  =  Zr, Hf, Nb, V, Ta) solid solutions monotonously increase with the amount of alloying element X at all temperatures except for Zr and Hf, for which they instead decrease for y≳ 0.5 .

Esporotricosis cutánea diseminada con compromiso articular en una mujer con diabetes tipo 2

Directory of Open Access Journals (Sweden)

Sendy Solorzano

Full Text Available La esporotricosis diseminada es una presentación infrecuente de esta micosis. Aunque ha sido descrita en sujetos inmunocompetentes, con frecuencia existe compromiso de la inmunidad mediada por células T. Reportamos el caso de una mujer con diabetes tipo 2 no controlada que desarrolló esporotricosis cutánea diseminada. El curso de la enfermedad presentó varias complicaciones que incluyeron hepatitis secundaria a itraconazol y artritis de la rodilla con cultivo positivo para Sporothrix schenckii durante el tratamiento con solución saturada de ioduro de potasio. La discusión del caso incluye aspectos de la patogénesis de la esporotricosis diseminada y el manejo de la infección y sus complicaciones.

Thermal and Hygric Expansion of High Performance Concrete

Directory of Open Access Journals (Sweden)

J. Toman

2001-01-01

Full Text Available The linear thermal expansion coefficient of two types of high performance concrete was measured in the temperature range from 20 °C to 1000 °C, and the linear hygric expansion coefficient was determined in the moisture range from dry material to saturation water content. Comparative methods were applied for measurements of both coefficients. The experimental results show that both the effect of temperature on the values of linear thermal expansion coefficients and the effect of moisture on the values of linear hygric expansion coefficients are very significant and cannot be neglected in practical applications.

Parabolic cyclinder functions : examples of error bounds for asymptotic expansions

NARCIS (Netherlands)

R. Vidunas; N.M. Temme (Nico)

2002-01-01

textabstractSeveral asymptotic expansions of parabolic cylinder functions are discussedand error bounds for remainders in the expansions are presented. Inparticular Poincaré-type expansions for large values of the argument$z$ and uniform expansions for large values of the parameter areconsidered.

A unification of boson expansion theories. (III) Applications

International Nuclear Information System (INIS)

Dobaczewski, J.

1981-10-01

A general scheme of constructing boson expansions that was proposed in earlier work is applied to a number or examples. The Fukutome expansion is obtained by considering the spinor representation of the SO(2N+1) group. Its hermitian, Holstein-Primakofr-type version is also derived. The generalized Dyson expansions for even and odd fermion systems are given in terms of two spinor representations of the SO(2N) group. For fixed fermion number systems the relevant boson expansions are obtained by considering the fundamental representations of SU(N) while for fixed seniority those of Sp(N) are concerned. The collective boson expansions corresponding to the Ginocchio model, the interacting boson model of Arima and Iachello and the Elliot model are given for the symmetric representations of SO(8) and SU(1+1) and any representation of SU(3)

Discrete expansions of continuum functions. General concepts

International Nuclear Information System (INIS)

Bang, J.; Ershov, S.N.; Gareev, F.A.; Kazacha, G.S.

1979-01-01

Different discrete expansions of the continuum wave functions are considered: pole expansion (according to the Mittag-Lefler theorem), Weinberg states. The general property of these groups of states is their completeness in the finite region of space. They satisfy the Schroedinger type equations and are matched with free solutions of the Schroedinger equation at the boundary. Convergence of expansions for the S matrix, the Green functions and the continuous-spectrum wave functions is studied. A new group of states possessing the best convergence is introduced

Edgeworth expansion for the pre-averaging estimator

DEFF Research Database (Denmark)

Podolskij, Mark; Veliyev, Bezirgen; Yoshida, Nakahiro

In this paper, we study the Edgeworth expansion for a pre-averaging estimator of quadratic variation in the framework of continuous diffusion models observed with noise. More specifically, we obtain a second order expansion for the joint density of the estimators of quadratic variation and its...... asymptotic variance. Our approach is based on martingale embedding, Malliavin calculus and stable central limit theorems for continuous diffusions. Moreover, we derive the density expansion for the studentized statistic, which might be applied to construct asymptotic confidence regions....

Oblique photon expansion of QED structure functions

International Nuclear Information System (INIS)

Chahine, C.

1986-01-01

In the oblique photon expansion, the collinear part of photon emission is summed up to all orders in perturbation theory. The number of oblique or non-collinear photons is the expansion order. Unlike in perturbation theory, every term of the expansion is both infrared finite and gauge invariant. The zero oblique photon contribution to the electromagnetic structure tensor in QED is computed in detail. The behaviors of the structure functions F1 and F2 are discussed in the soft and ultra-soft limits

AUTO-EXPANSIVE FLOW

Science.gov (United States)

Physics suggests that the interplay of momentum, continuity, and geometry in outward radial flow must produce density and concomitant pressure reductions. In other words, this flow is intrinsically auto-expansive. It has been proposed that this process is the key to understanding...

Studies of Expansive Learning: Foundations, Findings and Future Challenges

Directory of Open Access Journals (Sweden)

Yrjö Engeström

2013-07-01

Full Text Available The paper examines studies based on the theory of expansive learning, formulated in 1987. In recent years the theory has been used in a wide variety of studies and interventions. The theory builds on foundational ideas put forward by Vygotsky, Leont’ev, Il’enkov, and Davydov, key figures in the Russian school of cultural-historical activity theory. Studies based on the theory are reviewed in six sections: expansive learning as transformation of the object, expansive learning as movement in the zone of proximal development, expansive learning as cycles of learning actions, expansive learning as boundary crossing and network building, expansive learning as distributed and discontinuous movement, and formative interventions.A separate section is devoted to critiques of expansive learning. It is concluded that the ultimate test of learning theories is how they help practitioners to generate learning that grasps pressing issues the humankind is facing. The theory of expansive learning currently expands its analyses both up and down, outward and inward. Moving up and outward, it tackles learning in fields or networks of interconnected activity systems with their partially shared and often contested objects. Moving down and inward, it tackles issues of subjectivity, experiencing, personal sense, emotion, embodiment, identity, and moral commitment.

A Power Series Expansion and Its Applications

Science.gov (United States)

Chen, Hongwei

2006-01-01

Using the power series solution of a differential equation and the computation of a parametric integral, two elementary proofs are given for the power series expansion of (arcsin x)[squared], as well as some applications of this expansion.

Expansion Under Climate Change: The Genetic Consequences.

Science.gov (United States)

Garnier, Jimmy; Lewis, Mark A

2016-11-01

Range expansion and range shifts are crucial population responses to climate change. Genetic consequences are not well understood but are clearly coupled to ecological dynamics that, in turn, are driven by shifting climate conditions. We model a population with a deterministic reaction-diffusion model coupled to a heterogeneous environment that develops in time due to climate change. We decompose the resulting travelling wave solution into neutral genetic components to analyse the spatio-temporal dynamics of its genetic structure. Our analysis shows that range expansions and range shifts under slow climate change preserve genetic diversity. This is because slow climate change creates range boundaries that promote spatial mixing of genetic components. Mathematically, the mixing leads to so-called pushed travelling wave solutions. This mixing phenomenon is not seen in spatially homogeneous environments, where range expansion reduces genetic diversity through gene surfing arising from pulled travelling wave solutions. However, the preservation of diversity is diminished when climate change occurs too quickly. Using diversity indices, we show that fast expansions and range shifts erode genetic diversity more than slow range expansions and range shifts. Our study provides analytical insight into the dynamics of travelling wave solutions in heterogeneous environments.

Improvement of Expansive Soils Using Chemical Stabilizers

Science.gov (United States)

Ikizler, S. B.; Senol, A.; Khosrowshahi, S. K.; Hatipoğlu, M.

2014-12-01

The aim of this study is to investigate the effect of two chemical stabilizers on the swelling potential of expansive soil. A high plasticity sodium bentonite was used as the expansive soil. The additive materials including fly ash (FA) and lime (L) were evaluated as potential stabilizers to decrease the swelling pressure of bentonite. Depending on the type of additive materials, they were blended with bentonite in different percentages to assess the optimum state and approch the maximum swell pressure reduction. According to the results of swell pressure test, both fly ash and lime reduce the swelling potential of bentonite but the maximum improvement occurs using bentonite-lime mixture while the swelling pressure reduction approaches to 49%. The results reveal a significant reduction of swelling potential of expansive soil using chemical stabilizers. Keywords: Expansive soil; swell pressure; chemical stabilization; fly ash; lime

Thermal expansion: Metallic elements and alloys. [Handbook

Science.gov (United States)

Touloukian, Y. S.; Kirby, R. K.; Taylor, R. E.; Desai, P. D.

1975-01-01

The introductory sections of the work are devoted to the theory of thermal expansion of solids and to methods for the measurement of the linear thermal expansion of solids (X-ray methods, high speed methods, interferometry, push-rod dilatometry, etc.). The bulk of the work is devoted to numerical data on the thermal linear expansion of all the metallic elements, a large number of intermetallics, and a large number of binary alloy systems and multiple alloy systems. A comprehensive bibliography is provided along with an index to the materials examined.

Some Improved Nonperturbative Bounds for Fermionic Expansions

Energy Technology Data Exchange (ETDEWEB)

Lohmann, Martin, E-mail: marlohmann@gmail.com [Universita di Roma Tre, Dipartimento di Matematica (Italy)

2016-06-15

We reconsider the Gram-Hadamard bound as it is used in constructive quantum field theory and many body physics to prove convergence of Fermionic perturbative expansions. Our approach uses a recursion for the amplitudes of the expansion, discovered in a model problem by Djokic (2013). It explains the standard way to bound the expansion from a new point of view, and for some of the amplitudes provides new bounds, which avoid the use of Fourier transform, and are therefore superior to the standard bounds for models like the cold interacting Fermi gas.

Efectos del tratamiento con litio sobre las funciones neurosicológicas de pacientes con trastorno bipolar de tipo I

Directory of Open Access Journals (Sweden)

Anabel Martínez Aran

2008-11-01

Full Text Available OBJETIVO: determinar si el tratamiento continuo con litio influye en el desempeño cognitivo de un grupo de pacientes eutímicos con trastorno afectivo bipolar I. MÉTODO: se evaluó el desempeño cognitivo usando pruebas neurosicológicas de atención, memoria y función ejecutiva en 20 pacientes eutímicos con trastorno afectivo bipolar I que no tomaban medicación, 20 pacientes eutímicos con trastorno afectivo bipolar I quienes continuaban regularmente el tratamiento con carbonato de litio, y un tercer grupo de 20 pacientes control. RESULTADOS: no se encontraron diferencias estadísticamente significativas entre los dos grupos de pacientes con trastorno afectivo bipolar. Sin embargo, al compararlos con el grupo control, su desempeño en términos de memoria verbal, viso-verbal y asociación semántica medida fue menor. DISCUSIÓN: los pacientes con trastorno afectivo bipolar I muestran deficiencias en términos de memoria verbal y viso-verbal que no pueden ser atribuidos al tratamiento regular con carbonato de litio. Por el contrario, estas deficiencias podrían ser consideradas como características de rasgo de este trastorno.

A non-uniform expansion mechanical safety model of the stent.

Science.gov (United States)

Yang, J; Huang, N; Du, Q

2009-01-01

Stents have a serial unstable structure that readily leads to non-uniform expansion. Non-uniform expansion in turn creates a stent safety problem. We explain how a stent may be simplified to a serial unstable structure, and present a method to calculate the non-uniform expansion of the stent on the basis of the serial unstable structure. We propose a safety criterion based on the expansion displacement instead of the strain, and explain that the parameter Rd, the ratio of the maximum displacement of the elements to normal displacement, is meaningful to assess the safety level of the stent. We also examine how laser cutting influences non-uniform expansion. The examples illustrate how to calculate the parameter Rd to assess non-uniform expansion of the stent, and demonstrate how the laser cutting offset and strengthening coefficient of the material influence the stent expansion behaviour. The methods are valuable for assessing stent safety due to non-uniform expansion.

Acne polimorfo: tratamiento con Implacen

Directory of Open Access Journals (Sweden)

Rubén Pérez Armas

1995-06-01

Full Text Available Se realiza el estudio de 40 pacientes con acné polimorfo, los que fueron atendidos en la Consulta de Dermatología del Hospital Provincial Clinicoquirúrgico Docente "Celia Sánchez Manduley", en el período comprendido de enero de 1988 a diciembre de 1989. Se revisa la literatura médica sobre los diversos métodos y medicamentos utilizados en la terapéutica de esta dermatosis. Se describe el esquema de tratamiento empleado con implacén en 30 pacientes; los 10 restantes se trataron con placebo; se compara dicho esquema con los tradicionales y se observan mejores resultados con nuestro estudio. Se destaca la ausencia de recaídas, así como el resultado del tratamiento de acuerdo con el sexo.A study was performed in 40 patients presenting with polymorphic acne who were attended in the Dermatology Department of "Celia Sánchez Manduley" Clinicosurgical and Teaching Hospital from January, 1988 to December, 1989. A review of the literature was made seeking for the different methods and drugs used for the treatment of this dermatosis. The treatment schedule with the use of implacen in 30 patients is described. Such therapeutic schedule was compared with traditional ones and better results were observed with the use of implacen. The fact that there were no relapses is highlighted, as well as the result of treatment according to sex.

Synthesis, microstructure and thermal expansion studies

Indian Academy of Sciences (India)

Abstract. We report on the synthesis, microstructure and thermal expansion studies on Ca0.5+/2Sr0.5+/2Zr4P6−2Si2O24 ( = 0.00 to 1.00) system which belongs to NZP family of low thermal expansion ceramics. The ceramics synthesized by co-precipitation method at lower calcination and the sintering temperatures ...

Operator expansion in quantum chromodynamics beyond perturbation theory

International Nuclear Information System (INIS)

Novikov, V.A.; Shifman, M.A.; Vainshtejn, A.I.; Zakharov, V.I.

1980-01-01

The status of operator expansion at short distances is descussed within the frameworks of nonperturbatue QCD. The question of instanton effects is investigated in various aspects. Two-point functions induced by the gluonic currents are considered. It is shown that certain gluonic correlations vanish in the field of definite duality. It is proved that there does exist a very special relation between the expansion coefficients required by consistancy between instanton calculations and the general operator expansion. At last a certain modification of the naive version of operator expansion is proposed, which allows one to go beyond the critical power and construct, if necessary, an infinite series

Studying medium effects with the optimized δ expansion

International Nuclear Information System (INIS)

Krein, G.; Menezes, D.P.; Nielsen, M.; Pinto, M.B.

1995-04-01

The possibility of using the optimized δ expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The δ expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the δ expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the δ expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs

Studying medium effects with the optimized {delta} expansion

Energy Technology Data Exchange (ETDEWEB)

Krein, G [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Menezes, D P [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Fisica; Nielsen, M [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Pinto, M B [Montpellier-2 Univ., 34 (France). Lab. de Physique Mathematique

1995-04-01

The possibility of using the optimized {delta} expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The {delta} expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the {delta} expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the {delta} expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs.

Bike2Work: Rolling in the SNOW

CERN Document Server

2018-01-01

This team is obviously cycling around the year! Unless the association to snow is purely linked to the fact that the team works in Service Management providing support for the ServiceNow, which computer platform is known as SNOW. The team members are from left to right Iban Eguia Moraza, Petar Tonkovic and Africa Santos. David Martin Clavo, the forth member, was absent on the day of the photo.

Reducción de color con cloruro de magnesio en soluciones con colorantes comerciales

Directory of Open Access Journals (Sweden)

Mercedes Lucero Chávez

2017-01-01

Full Text Available Se experimentó con diferentes concentraciones de cloruro de magnesio (MgCl2 como coagulante para reducir el color en soluciones con colorantes comerciales: negro, azul y café. Los parámetros analizados fueron pH, color, demanda química de oxígeno ( dqo y sólidos suspendidos totales (sst de acuerdo con las Normas Mexicanas. Como prueba complementaria se agregó carbón activado a las muestras para reducir el color residual después de la coagulación-floculación. La reducción de los valores de color y dqo fue mayor cuando se adicionó más cantidad de MgCl2 (1.8 g/L. Los porcentajes de reducción fueron ≥90% para el color y >50% para la dqo. Los sst aumentaron con la adición de MgCl2. El carbón activado eliminó el color residual.

Origami structures for tunable thermal expansion

Science.gov (United States)

Boatti, Elisa; Bertoldi, Katia

Materials with engineered thermal expansion, capable of achieving targeted and extreme area/volume changes in response to variations in temperature, are important for a number of aerospace, optical, energy, and microelectronic applications. While most of the proposed structures with tunable coefficient of thermal expansion consist of bi-material 2D or 3D lattices, here we propose a periodic metastructure based on a bilayer Miura-Ori origami fold. We combine experiments and simulations to demonstrate that by tuning the geometrical and mechanical parameters an extremely broad range of thermal expansion coefficients can be obtained, spanning both negative and positive values. Additionally, the thermal properties along different directions can be adjusted independently. Differently from all previously reported systems, the proposed structure is non-porous.

Anisotropic thermal expansion in flexible materials

Science.gov (United States)

Romao, Carl P.

2017-10-01

A definition of the Grüneisen parameters for anisotropic materials is derived based on the response of phonon frequencies to uniaxial stress perturbations. This Grüneisen model relates the thermal expansion in a given direction (αi i) to one element of the elastic compliance tensor, which corresponds to the Young's modulus in that direction (Yi i). The model is tested through ab initio prediction of thermal expansion in zinc, graphite, and calcite using density functional perturbation theory, indicating that it could lead to increased accuracy for structurally complex systems. The direct dependence of αi i on Yi i suggests that materials which are flexible along their principal axes but rigid in other directions will generally display both positive and negative thermal expansion.

Aprende Ajedrez con Rey - Parte 2

OpenAIRE

ESTÉVEZ MONTERO, RAÚL; Lloret Mauri, Jaime

2016-01-01

Es una pieza audiovisual creada con el objeto de atraer la atención de los niños de muy corta edad con el ajedrez y familiarizarlos con todas sus piezas y movimientos. Es una animación dirigida a un público infantil presentada por dibujos animados en 2D, en la que se ha intentado respetar en todo momento el argot de la comunidad ajedredística. En este video se presenta la segunda parte. Estévez Montero, R.; Lloret Mauri, J. (2016). Aprende Ajedrez con Rey - Parte 2. http://hdl.handle.net/1...

Aprende Ajedrez con Rey - Parte 1

OpenAIRE

ESTÉVEZ MONTERO, RAÚL; Lloret Mauri, Jaime

2016-01-01

Es una pieza audiovisual creada con el objeto de atraer la atención de los niños de muy corta edad con el ajedrez y familiarizarlos con todas sus piezas y movimientos. Es una animación dirigida a un público infantil presentada por dibujos animados en 2D, en la que se ha intentado respetar en todo momento el argot de la comunidad ajedredística. En este video se presenta la primera parte. Estévez Montero, R.; Lloret Mauri, J. (2016). Aprende Ajedrez con Rey - Parte 1. http://hdl.handle.net/1...

Cluster expansion of the wavefunction. Symmetry-adapted-cluster expansion, its variational determination, and extension of open-shell orbital theory

International Nuclear Information System (INIS)

Nakatsuji, H.; Hirao, K.

1978-01-01

The symmetry-adapted-cluster (SAC) expansion of an exact wavefunction is given. It is constructed from the generators of the symmetry-adapted excited configurations having the symmetry under consideration, and includes their higher-order effect and self-consistency effect. It is different from the conventional cluster expansions in several important points, and is suitable for applications to open-shell systems as well as closed-shell systems. The variational equation for the SAC wavefunction has a form similar to the generalized Brillouin theorem in accordance with the inclusion of the higher-order effect and the self-consistency effect. We have expressed some existing open-shell orbital theories equivalently in the conventional cluster expansion formulas, and on this basis, we have given the pseudo-orbital theory which is an extension of open-shell orbital theory in the SAC expansion formula

Elastic-plastic analysis of tube expansion in tubesheets

International Nuclear Information System (INIS)

Kasraie, B.; O'Donnell, W.J.; Porowski, J.S.; Selz, A.

1983-01-01

Conditions for expansion of tubes in tubesheets are often determined by the test. The tightness of the joint and pull out force are used as criteria for evaluation of the results. For closely spaced tubes, it is also necessary to control development of the plastic regions in the ligaments surrounding the tube being expanded. High local strains may occur and excessive distortion may result if the expansion of the tube is continued beyond the admissible limits. Elastic-plastic finite element analyses are performed herein in order to establish conditions for rolling of the tubes in tubesheets of low ligament efficiency. Such penetration patterns are often required in the design of tubular reactors for catalytic processes. The model considered includes individual tube expansion in tubesheets with triangular penetration patterns. The effect of prior expansion of the neighboring tubes is also evaluated. Gap elements are used to model the initial clearance of the tube in the hole. Development of the plastic zones and distortion of the ligaments is monitored during radial expansion of the tube diameter. The residual stresses between the tube and the hole surface and the history of gap closing after removal of the expansion tool are determined. The effect of axial extension of the tube on the tube thinning is determined. Tube thinning is often used as a measure of tube expansion in manufacturing processes. For the analyzed ligament efficiency, reliable joints are obtained for a thinning range within 2% to 3%

Instability of a planar expansion wave.

Science.gov (United States)

Velikovich, A L; Zalesak, S T; Metzler, N; Wouchuk, J G

2005-10-01

An expansion wave is produced when an incident shock wave interacts with a surface separating a fluid from a vacuum. Such an interaction starts the feedout process that transfers perturbations from the rippled inner (rear) to the outer (front) surface of a target in inertial confinement fusion. Being essentially a standing sonic wave superimposed on a centered expansion wave, a rippled expansion wave in an ideal gas, like a rippled shock wave, typically produces decaying oscillations of all fluid variables. Its behavior, however, is different at large and small values of the adiabatic exponent gamma. At gamma > 3, the mass modulation amplitude delta(m) in a rippled expansion wave exhibits a power-law growth with time alpha(t)beta, where beta = (gamma - 3)/(gamma - 1). This is the only example of a hydrodynamic instability whose law of growth, dependent on the equation of state, is expressed in a closed analytical form. The growth is shown to be driven by a physical mechanism similar to that of a classical Richtmyer-Meshkov instability. In the opposite extreme gamma - 1 gas with low . Exact analytical expressions for the growth rates are derived for both cases and favorably compared to hydrodynamic simulation results.

Thermal expansion absorbing structure for pipeline

International Nuclear Information System (INIS)

Nagata, Takashi; Yamashita, Takuya.

1995-01-01

A thermal expansion absorbing structure for a pipeline is disposed to the end of pipelines to form a U-shaped cross section connecting a semi-circular torus shell and a short double-walled cylindrical tube. The U-shaped longitudinal cross-section is deformed in accordance with the shrinking deformation of the pipeline and absorbs thermal expansion. Namely, since the central lines of the outer and inner tubes of the double-walled cylindrical tube deform so as to incline, when the pipeline is deformed by thermal expansion, thermal expansion can be absorbed by a simple configuration thereby enabling to contribute to ensure the safety. Then, the entire length of the pipeline can greatly be shortened by applying it to the pipeline disposed in a high temperature state compared with a method of laying around a pipeline using only elbows, which has been conducted so far. Especially, when it is applied to a pipeline for an FBR-type reactor, the cost for the construction of a facility of a primary systems can greater be reduced. In addition, it can be applied to a pipeline for usual chemical plants and any other structures requiring absorption of deformation. (N.H.)

Videojuego con Realidad Virtual

OpenAIRE

González Mora, César

2017-01-01

El objetivo del proyecto es el desarrollo de un videojuego deportivo que utilice realidad mixta. El videojuego se podrá utilizar con dispositivos de tipo cardboard, y utilizará realidad aumentada para la interacción del jugador con el videojuego. En el desarrollo se utilizará el motor Unity para conseguir una aplicación multiplataforma, y la librería Vuforia para implementar realidad mixta.

Factores psicosociales relacionados con la rehospitalización de pacientes con psicosis orgánica

Directory of Open Access Journals (Sweden)

Cortés-Padilla María Teresa

2001-01-01

Full Text Available Objetivo. Conocer los factores psicosociales relacionados con la frecuente rehospitalización de pacientes con psicosis orgánica. Material y métodos. Estudio de tipo observacional descriptivo, de corte transversal. La muestra estuvo formada por 33 pacientes del Hospital Psiquiátrico Guillermo Dávila, con Unidad de Medicina Familiar Número 10 del Instituto Mexicano del Seguro Social de la Ciudad de México, con psicosis orgánica y quienes durante los años de 1993-1994 presentaron más de dos rehospitalizaciones. Instrumentos: Entrevista grabada, o muestra de conversación de cinco minutos, para la emoción expresada (EE, cuestionarios mixtos para la Concepción de Enfermedad y la Relación médico-paciente. La validez y confiabilidad de los datos se establecieron con las pruebas de Kappa y Alpha de Cronbach y se efectuó análisis estadístico descriptivo e inferencial. Resultados. El 60.9% de los familiares presentan alto nivel de EE, es decir, expresan crítica, hostilidad o sobreinvolucramiento emocional; el 64.3% de los sujetos de la muestra conviven más de 35 horas a la semana con familiares que presentan Alta EE. Conclusiones. Altos niveles de EE estuvieron asociados con los frecuentes reingresos a hospitalización. Existe mayor conocimiento de las características de la enfermedad por parte del familiar que del paciente. La relación médico-paciente es satisfactoria pero no forma conciencia de enfermedad ni propicia apego al tratamiento terapeútico. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

The {β}-expansion formalism in perturbative QCD and its extension

Energy Technology Data Exchange (ETDEWEB)

Kataev, A.L. [Institute for Nuclear Research of the Academy of Sciences of Russia,60th October Anniversary Prospect 7a, 117312, Moscow (Russian Federation); Moscow Institute of Physics and Technology,Institutskii per. 9, 141700, Dolgoprudny, Moscow Region (Russian Federation); Mikhailov, S.V. [Bogoliubov Laboratory of Theoretical Physics, JINR,Joliot-Curie 6, 141980 Dubna (Russian Federation)

2016-11-11

We discuss the {β}-expansion for renormalization group invariant quantities tracing this expansion to the different contractions of the corresponding incomplete BPHZ R-operation. All of the coupling renormalizations, which follow from these contractions, should be taken into account for the {β}-expansion. We illustrate this feature considering the nonsinglet Adler function D{sup NS} in the third order of perturbation. We propose a generalization of the {β}-expansion for the renormalization group covariant quantities — the {β,γ}-expansion.

Temperature expansions for magnetic systems

International Nuclear Information System (INIS)

Cangemi, D.; Dunne, G.

1996-01-01

We derive finite temperature expansions for relativistic fermion systems in the presence of background magnetic fields, and with nonzero chemical potential. We use the imaginary-time formalism for the finite temperature effects, the proper-time method for the background field effects, and zeta function regularization for developing the expansions. We emphasize the essential difference between even and odd dimensions, focusing on 2+1 and 3+1 dimensions. We concentrate on the high temperature limit, but we also discuss the T=0 limit with nonzero chemical potential. Copyright copyright 1996 Academic Press, Inc

Análisis probabilista con caminata al azar del número de personas viviendo con VIH mundialmente

Directory of Open Access Journals (Sweden)

Javier Oswaldo Rodríguez-Velásquez

2018-01-01

Full Text Available Introducción: El estudio de la dinámica anual de la epidemia de VIH a partir de la caminata al azar ha mostrado ser de utilidad para llevar este fenómeno altamente variable a un comportamiento predecible Objetivo: Predecir el comportamiento de la dinámica del número de personas viviendo con VIH mediante la caminata al azar probabilista. Metodología: Se analizaron los valores anuales de personas que a nivel global viven con VIH desde el año 1990 hasta el 2009, a partir de los espacios de probabilidad generados con la caminata al azar probabilista, para posteriormente desarrollar la predicción del valor anual de personas viviendo con VIH para los años 2010, 2011 y 2012. Resultados: Se predijeron los valores anuales de personas viviendo con VIH con un porcentaje de acierto de 98,95% para el año 2010, de 98,82% para el año 2011 y de 98,99% para la predicción realizada para el año 2012. Conclusiones: Se establecieron órdenes matemáticos a partir de la caminata al azar probabilista, estableciendo predicciones prácticamente deterministas del número de personas viviendo con VIH, lo que podría ser útil para las decisiones en Salud Pública y para la evaluación de intervenciones.

Thermal expansion data of (Th,U)O2 fuels

International Nuclear Information System (INIS)

Sengupta, A.K.; Banerjee, J.; Bhagat, R.K.; Ramachandran, R.; Majumdar, S.; Purushotham, D.S.C.

2000-04-01

Thermal expansion data for sintered ThO 2 and ThO 2 containing 2, 4, 6, 10 and 20% UO 2 pellets were measured using a high temperature dilatometer in the temperature range from ambient to 1773 K. The dilatometer was first calibrated using a standard graphite sample as reference material. The reproducibility of the dilatometer was tested by measuring the coefficient of expansion of tungsten (NBS SRM 737) and comparing the data with that recommended by National Bureau of Standard. It was observed that there is close agreement between the experimental and reported data. The coefficient of expansion data of (Th,U)O 2 fuel indicate that out of all the six compositions, ThO 2 +2%UO 2 showed the maximum expansion of around 1.75% at 1773 K. However, the expansion data for all the compositions were very close to each other. Empirical equation correlating thermal expansion and temperature for all six compositions have been generated and reported. (author)

Ring-Expansion/Contraction Radical Crossover Reactions of Cyclic Alkoxyamines: A Mechanism for Ring Expansion-Controlled Radical Polymerization

Directory of Open Access Journals (Sweden)

Atsushi Narumi

2018-06-01

Full Text Available Macrocyclic polymers present an important class of macromolecules, displaying the reduced radius of gyration or impossibility to entangle. A rare approach for their synthesis is the ring expansion-controlled radical “vinyl” polymerization, starting from a cyclic alkoxyamine. We here describe ring-expansion radical crossover reactions of cyclic alkoxyamines which run in parallel to chain-propagation reactions in the polymerization system. The radical crossover reactions extensively occurred at 105–125 °C, eventually producing high molecular weight polymers with multiple inherent dynamic covalent bonds (NOC bonds. A subsequent ring-contraction radical crossover reaction and the second ring-expansion radical crossover reaction are also described. The major products for the respective three stages were shown to possess cyclic morphologies by the molecular weight profiles and the residual ratios for the NOC bonds (φ in %. In particular, the high φ values ranging from ca. 80% to 98% were achieved for this cyclic alkoxyamine system. This result verifies the high availability of this system as a tool demonstrating the ring-expansion “vinyl” polymerization that allows them to produce macrocyclic polymers via a one-step vinyl polymerization.

Supersonic expansion of argon into vacuum

Energy Technology Data Exchange (ETDEWEB)

Habets, A H.M.

1977-01-21

A theoretical description of a free supersonic expansion process is given. Three distinct regions in the expansion are discussed, namely the continuum region, the gradual transition to the collisionless regime, and the free-molecular-flow stage. Important topics are the peaking-factor formalism, the thermal-conduction model, and the virtual-source formalism. The formation of the molecular beam from the expansion and condensation phenomena occurring in the expanding gas are discussed. The molecular beam machine used in the measurements is described and special attention is given to the cryopumps used in the supersonic sources as well as to the time-of-flight analysis of the molecular beam velocity distributions. Finally, the processing of experimental data is discussed, particularly the least-squares determination of best-fit representations of the measurements.

Radial expansion for spinning conformal blocks

CERN Document Server

Costa, Miguel S.; Penedones, João; Trevisani, Emilio

2016-07-12

This paper develops a method to compute any bosonic conformal block as a series expansion in the optimal radial coordinate introduced by Hogervorst and Rychkov. The method reduces to the known result when the external operators are all the same scalar operator, but it allows to compute conformal blocks for external operators with spin. Moreover, we explain how to write closed form recursion relations for the coefficients of the expansions. We study three examples of four point functions in detail: one vector and three scalars; two vectors and two scalars; two spin 2 tensors and two scalars. Finally, for the case of two external vectors, we also provide a more efficient way to generate the series expansion using the analytic structure of the blocks as a function of the scaling dimension of the exchanged operator.

Supersonic expansion of argon into vacuum

International Nuclear Information System (INIS)

Habets, A.H.M.

1977-01-01

A theoretical description of a free supersonic expansion process is given. Three distinct regions in the expansion are discussed, namely the continuum region, the gradual transition to the collisionless regime, and the free-molecular-flow stage. Important topics are the peaking-factor formalism, the thermal-conduction model, and the virtual-source formalism. The formation of the molecular beam from the expansion and condensation phenomena occurring in the expanding gas are discussed. The molecular beam machine used in the measurements is described and special attention is given to the cryopumps used in the supersonic sources as well as to the time-of-flight analysis of the molecular beam velocity distributions. Finally, the processing of experimental data is discussed, particularly the least-squares determination of best-fit representations of the measurements

The relevance of grid expansion under zonal markets

Energy Technology Data Exchange (ETDEWEB)

Bertsch, Joachim; Hagspiel, Simeon; Just, Lisa [ewi Energy Research and Scenarios gGmbH, Cologne (Germany); Cologne Univ. (Germany). Dept. of Economics; Brown, Tom [Frankfurt Institute of Advanced Studies (Germany)

2015-12-15

The European electricity market design is based on zonal markets with uniform prices. Locational price signals within these zones - necessary to ensure long-term efficiency - are not provided. Specifically, if intra-zonal congestion occurs due to missing grid expansion, the market design is revealed as inherently incomplete. This might lead to severe, unwanted distortions of the electricity market, both in the short- and in the long-term. In this paper, we study these distortions with a specific focus on the impact of restricted grid expansion under zonal markets. For this, we use a long term fundamental dispatch and investment model of the European electricity system and gradually restrict the allowed expansion of the transmission grid per decade. We find that the combination of an incomplete market design and restricted grid expansion leads to a misallocation of generation capacities and the inability to transport electricity to where it is needed. Consequences are severe and lead to load curtailment of up to 2-3 %. Moreover, missing grid expansion makes it difficult and costly to reach envisaged energy targets in the power sector. Hence, we argue that in the likely event of restricted grid expansion, either administrative measures or - presumably more efficient - an adaptation of the current market design to include locational signals will become necessary.

The relevance of grid expansion under zonal markets

International Nuclear Information System (INIS)

Bertsch, Joachim; Hagspiel, Simeon; Just, Lisa

2015-01-01

The European electricity market design is based on zonal markets with uniform prices. Locational price signals within these zones - necessary to ensure long-term efficiency - are not provided. Specifically, if intra-zonal congestion occurs due to missing grid expansion, the market design is revealed as inherently incomplete. This might lead to severe, unwanted distortions of the electricity market, both in the short- and in the long-term. In this paper, we study these distortions with a specific focus on the impact of restricted grid expansion under zonal markets. For this, we use a long term fundamental dispatch and investment model of the European electricity system and gradually restrict the allowed expansion of the transmission grid per decade. We find that the combination of an incomplete market design and restricted grid expansion leads to a misallocation of generation capacities and the inability to transport electricity to where it is needed. Consequences are severe and lead to load curtailment of up to 2-3 %. Moreover, missing grid expansion makes it difficult and costly to reach envisaged energy targets in the power sector. Hence, we argue that in the likely event of restricted grid expansion, either administrative measures or - presumably more efficient - an adaptation of the current market design to include locational signals will become necessary.

Fuerza manual de adultos con discapacidad intelectual

Directory of Open Access Journals (Sweden)

Ruth Cabeza Ruiz

2017-09-01

Full Text Available Objetivo. Presentar una descripción de la fuerza de prensión manual de hombres y mujeres con discapacidad intelectual (DI y comparar los resultados con valores de referencia de otras personas con y sin discapacidad intelectual. Método. El presente trabajo es un estudio transversal observacional, financiado por la Fundación SAMU, en el que se evaluaron a 122 personas con DI (86 hombres y 36 mujeres durante el desarrollo de unas jornadas de carácter recreativo en las que participaron varias asociaciones de atención a este colectivo. La batería de test utilizada fue el Alpaha-Fit Test Battery for Adults. Resultados. Se presentan los resultados relacionados con las variables de fuerza del miembro superior (Hand Grip Strength por grupos de edad (20-24, 25- 29, 30-34, 35-39, 40-44, 45-49, 50-54, 55-59 años. Los datos muestran valores que oscilan desde los 31 kg en los hombres más jóvenes con DI hasta los 13.3 kg del grupo más maduro de mujeres. Estos hallazgos son similares a los valores de referencia de población con DI española. Sin embargo, son muy inferiores a los obtenidos por la población sin discapacidad de la misma edad. Conclusión. Los resultados evidencian el menor rendimiento de las personas con DI en pruebas de fuerza de prensión manual por lo que se hace evidente la necesidad de llevar a cabo programas de ejercicio físico o deporte con las personas con DI.

Controlled Thermal Expansion Alloys

Data.gov (United States)

National Aeronautics and Space Administration — There has always been a need for controlled thermal expansion alloys suitable for mounting optics and detectors in spacecraft applications.  These alloys help...

Sistemas integrados con Arduino

OpenAIRE

EL YAKOUTI, MOHAMMED

2017-01-01

Design of a robot prototype remotely controllable from Bluetooth using Arduino. Control and testing of sensors and events interacting with Arduino and Bluetooth. Diseño de un prototipo de robot controlable remotamente con Bluetooth utilizando Arduino. Control y verificación de los sensores y eventos que interactúan mediante el Arduino y el Bluetooth. El Yakouti, M. (2017). Sistemas integrados con Arduino. http://hdl.handle.net/10251/89274. TFGM

Controlling Thermal Expansion: A Metal?Organic Frameworks Route

OpenAIRE

Balestra, Salvador R. G.; Bueno-Perez, Rocio; Hamad, Said; Dubbeldam, David; Ruiz-Salvador, A. Rabdel; Calero, Sofia

2016-01-01

Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal?organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model m...

Surgically assisted rapid maxillary expansion in adults.

Science.gov (United States)

Pogrel, M A; Kaban, L B; Vargervik, K; Baumrind, S

1992-01-01

Twelve adults with maxillary width discrepancy of greater than 5 mm were treated by surgically assisted rapid maxillary expansion. The procedure consisted of bilateral zygomatic buttress and midpalatal osteotomies combined with the use of a tooth-borne orthopedic device postoperatively. Mean palatal expansion of 7.5 mm (range of 6 to 13 mm), measured in the first molar region, was achieved within 3 weeks in all patients. Expansion remained stable during the 12-month study period, with a mean relapse for the entire group of 0.88 +/- 0.48 mm. Morbidity was limited to mild postoperative discomfort. The results of this preliminary study indicated that surgically assisted rapid maxillary expansion is a safe, simple, and reliable procedure for achieving a permanent increase in skeletal maxillary width in adults. Further study is necessary to document the three-dimensional movements of the maxillary segments and long-term stability of the skeletal and dental changes.

Perturbation Expansion in Dynamical Nuclear Field Theory and Its Relation with Boson Expansion Theory : Nuclear Physics

OpenAIRE

Teruo, KISHIMOTO; Tetsuo, KAMMURI; Institute of Physics, University of Tsukuba; Department of Physics, Osaka University

1990-01-01

With the Dynamical Nuclear Field Theory (DNFT) in the Tamm-Dancoff representation we examine higher order corrections in the vibrational mode of a spherical nuclear system. Due to the effects of bubble diagrams, the perturbation expansion in terms of the unrenormalized coupling strength and boson energy fails at full self-consistency. On the other hand, it becomes applicable in the form of linked-cluster expansion when we use thses constants renormalized by the effect of bubble diagrams, in t...

Eta-Expansion Does The Trick

DEFF Research Database (Denmark)

Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens

1995-01-01

Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta-expansion, and a p......Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta...... across dynamic case expressions. This requirement precisely accounts for the nonstandard use of continuation-passing style encountered in partial evaluation. Eta-expansion thus acts as a uniform binding-time coercion between values and contexts, be they of function type, product type, or disjoint......-expansion, and a popular transformation called “The Trick.” We provide a unified view of these binding-time improvements, from a typing perspective. Just as a proper treatment of product values in partial evaluation requires partially static values, a proper treatment of disjoint sums requires moving static contexts...

Cluster expansion for vacuum confining fields

International Nuclear Information System (INIS)

Simonov, Yu.A.

1987-01-01

Colored particle Green functions in vacuum background random fields are written as path integrals. Averaging over random fields is done using the cluster (cumulant) expansion. The existence of a finite correlation length for vacuum background fields is shown to produce the linear confinement, in agreement with the results, obtained with the help of averaged Hamiltonians. A modified form of cluster expansion for nonabelian fields is introduced using the path-ordered cumulants

Stochastic quantization and 1/N expansion

International Nuclear Information System (INIS)

Brunelli, J.C.; Mendes, R.S.

1992-10-01

We study the 1/N expansion of field theories in the stochastic quantization method of Parisi and Wu using the supersymmetric functional approach. This formulation provides a systematic procedure to implement the 1/N expansion which resembles the ones used in the equilibrium. The 1/N perturbation theory for the non linear sigma model in two dimensions is worked out as an example. (author). 19 refs., 5 figs

Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR

Science.gov (United States)

Takegoshi, K.; Miyazawa, Norihiro; Sharma, Kshama; Madhu, P. K.

2015-04-01

We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes with the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order.

Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR

International Nuclear Information System (INIS)

Takegoshi, K.; Miyazawa, Norihiro; Sharma, Kshama; Madhu, P. K.

2015-01-01

We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes with the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order

Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR

Energy Technology Data Exchange (ETDEWEB)

Takegoshi, K., E-mail: takeyan@kuchem.kyoto-u.ac.jp; Miyazawa, Norihiro [Division of Chemistry, Graduate School of Science, Kyoto University, 606-8502 Kyoto (Japan); Sharma, Kshama [TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsingi, Hyderabad 500 075 (India); Madhu, P. K. [TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsingi, Hyderabad 500 075 (India); Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India)

2015-04-07

We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes with the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order.

fertilizada con diferentes abonos

Directory of Open Access Journals (Sweden)

Jorge Alberto Elizondo-Salazar

2007-01-01

Full Text Available Producción y calidad de la biomasa de morera (Morus alba fertilizada con diferentes abonos. Se llevó a cabo un experimento en la Estación Experimental “Alfredo Volio Mata” de la Universidad de Costa Rica con el fi n de evaluar la aplicación de 150 kg de N/ha/año proveniente de dos abonos orgánicos: lombriabono y compostaje; y de un fertilizante químico, sobre la producción y calidad de la biomasa de morera. El periodo experimental comprendió un ciclo de 12 meses, iniciando en julio del 2003 y fi nalizando en julio del 2004. Se utilizó una plantación de morera de 12 años de establecida con una densidad de siembra de 27.777 plantas/ ha. Se empleó un diseño de bloques completos al azar con cuatro tratamientos: dos abonos orgánicos, nitrato de amonio (33,5% N y un control. Las plantas se podaron a 0,6 m sobre el nivel del suelo al inicio del ensayo. Durante el periodo experimental, las plantas fueron podadas consecutivamente cada 90 días. Las hojas y los tallos fueron separados y analizados para determinar el contenido de materia seca y proteína cruda. La producción de materia seca fue 23% superior y el contenido de proteína cruda fue signifi cativamente mayor con el nitrógeno químico, mientras que el contenido de materia seca fue menor. No se encontraron diferencias signifi cativas entre el tratamiento control y los tratamientos orgánicos.

Estudio observacional prospectivo con insulina detemir en pacientes con diabetes mellitus tipo 2 mal controlados que inician por primer vez tratamiento con insulina (estudio SOLVE

Directory of Open Access Journals (Sweden)

Domingo Orozco-Beltrán

2016-02-01

Conclusiones: En esta cohorte de pacientes con diabetes mellitus tipo 2 recientemente insulinizados, la insulina detemir (una vez al día mejoró el control glucémico, con baja incidencia de hipoglucemia y una reducción significativa del peso.

Eficacia del tratamiento tópico con Vimang® en pacientes con estomatitis subprótesis

Directory of Open Access Journals (Sweden)

Laritza Coureaux Rojas

2013-10-01

Full Text Available Se efectuó un ensayo clínico terapéutico controlado de fase III en 120 pacientes con estomatitis subprótesis, atendidos en la Clínica Estomatológica Provincial Docente "Mártires del Moncada" de Santiago de Cuba, desde junio de 2010 hasta mayo de 2011, con vistas a evaluar la eficacia del tratamiento tópico con té de Vimang® en dichos pacientes. Se conformaron 2 grupos de 60 integrantes cada uno (de estudio y de control. Los primeros fueron tratados con enjuagatorios fríos de dicho té 4 veces al día y los segundos con el mismo tratamiento más vitaminas. Se utilizaron el porcentaje para variables cualitativas, así como la media aritmética y la desviación estándar para variables cuantitativas. Todos los integrantes del grupo de estudio se curaron y disminuyó el gasto de material, pero el costo-efectividad fue mayor por ser menor el tiempo de curación. El té de Vimang® resultó eficaz para eliminar las manifestaciones clínicas de esa lesión y no hubo reacciones adversas, de manera que se logró la curación de los afectados con ahorro de tiempo y recursos.

Trastornos temporomandibulares en pacientes con maloclusiones

Directory of Open Access Journals (Sweden)

Luis Soto Cantero

Full Text Available Introducción: existe una prevalencia de trastornos oclusales en gran medida relacionados con la presencia de disfunción temporomandibular. Objetivo: determinar el grado de disfunción temporomandibular según el Índice de Maglione en correspondencia con la prevalencia de maloclusiones en el área de salud del policlínico "Turcios Lima". Métodos: se realizó un estudio observacional descriptivo, de corte transversal, en la consulta de ortodoncia, de junio del 2008 a junio del 2009. De un universo constituido por los 280 pacientes que acudieron al servicio de ortodoncia en el período señalado con presencia de maloclusiones, se seleccionó una muestra de 84 pacientes por muestreo aleatorio simple, teniendo en cuenta los criterios de inclusión y exclusión realizados por criterios de expertos. Resultados: presentaban disfunción temporomandibular 74 pacientes y dentro de ellos 44 (52,4 % tenían disfunción grado II (Moderada. El 97 % de los pacientes con relación molar de clase II, presentaban disfunción temporomandibular. El 42,9 % de los pacientes con una maloclusión, presentaban disfunción grado I. El 60 % de los pacientes con dos maloclusiones presentaban disfunción grado II y el 66,7 % de los pacientes con tres maloclusiones, presentaban disfunción grado III. La mayor cantidad de pacientes tuvieron disfunción grado II (Moderada. Conclusiones: el mayor por ciento de los pacientes con disfunciones presentó una clase II molar y a medida que aumentó el número de maloclusiones aumentó también la severidad de la disfunción.

A summation procedure for expansions in orthogonal polynomials

International Nuclear Information System (INIS)

Garibotti, C.R.; Grinstein, F.F.

1977-01-01

Approximants to functions defined by formal series expansions in orthogonal polynomials are introduced. They are shown to be convergent even out of the elliptical domain where the original expansion converges

Future urban land expansion and implications for global croplands.

Science.gov (United States)

Bren d'Amour, Christopher; Reitsma, Femke; Baiocchi, Giovanni; Barthel, Stephan; Güneralp, Burak; Erb, Karl-Heinz; Haberl, Helmut; Creutzig, Felix; Seto, Karen C

2017-08-22

Urban expansion often occurs on croplands. However, there is little scientific understanding of how global patterns of future urban expansion will affect the world's cultivated areas. Here, we combine spatially explicit projections of urban expansion with datasets on global croplands and crop yields. Our results show that urban expansion will result in a 1.8-2.4% loss of global croplands by 2030, with substantial regional disparities. About 80% of global cropland loss from urban expansion will take place in Asia and Africa. In both Asia and Africa, much of the cropland that will be lost is more than twice as productive as national averages. Asia will experience the highest absolute loss in cropland, whereas African countries will experience the highest percentage loss of cropland. Globally, the croplands that are likely to be lost were responsible for 3-4% of worldwide crop production in 2000. Urban expansion is expected to take place on cropland that is 1.77 times more productive than the global average. The loss of cropland is likely to be accompanied by other sustainability risks and threatens livelihoods, with diverging characteristics for different megaurban regions. Governance of urban area expansion thus emerges as a key area for securing livelihoods in the agrarian economies of the Global South.

Evolution of density-dependent movement during experimental range expansions.

Science.gov (United States)

Fronhofer, E A; Gut, S; Altermatt, F

2017-12-01

Range expansions and biological invasions are prime examples of transient processes that are likely impacted by rapid evolutionary changes. As a spatial process, range expansions are driven by dispersal and movement behaviour. Although it is widely accepted that dispersal and movement may be context-dependent, for instance density-dependent, and best represented by reaction norms, the evolution of density-dependent movement during range expansions has received little experimental attention. We therefore tested current theory predicting the evolution of increased movement at low densities at range margins using highly replicated and controlled range expansion experiments across multiple genotypes of the protist model system Tetrahymena thermophila. Although rare, we found evolutionary changes during range expansions even in the absence of initial standing genetic variation. Range expansions led to the evolution of negatively density-dependent movement at range margins. In addition, we report the evolution of increased intrastrain competitive ability and concurrently decreased population growth rates in range cores. Our findings highlight the importance of understanding movement and dispersal as evolving reaction norms and plastic life-history traits of central relevance for range expansions, biological invasions and the dynamics of spatially structured systems in general. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Edgeworth Expansion Based Model for the Convolutional Noise pdf

Directory of Open Access Journals (Sweden)

Yonatan Rivlin

2014-01-01

Full Text Available Recently, the Edgeworth expansion up to order 4 was used to represent the convolutional noise probability density function (pdf in the conditional expectation calculations where the source pdf was modeled with the maximum entropy density approximation technique. However, the applied Lagrange multipliers were not the appropriate ones for the chosen model for the convolutional noise pdf. In this paper we use the Edgeworth expansion up to order 4 and up to order 6 to model the convolutional noise pdf. We derive the appropriate Lagrange multipliers, thus obtaining new closed-form approximated expressions for the conditional expectation and mean square error (MSE as a byproduct. Simulation results indicate hardly any equalization improvement with Edgeworth expansion up to order 4 when using optimal Lagrange multipliers over a nonoptimal set. In addition, there is no justification for using the Edgeworth expansion up to order 6 over the Edgeworth expansion up to order 4 for the 16QAM and easy channel case. However, Edgeworth expansion up to order 6 leads to improved equalization performance compared to the Edgeworth expansion up to order 4 for the 16QAM and hard channel case as well as for the case where the 64QAM is sent via an easy channel.

Thermal and Hygric Expansion of High Performance Concrete

OpenAIRE

J. Toman; R. Černý

2001-01-01

The linear thermal expansion coefficient of two types of high performance concrete was measured in the temperature range from 20 °C to 1000 °C, and the linear hygric expansion coefficient was determined in the moisture range from dry material to saturation water content. Comparative methods were applied for measurements of both coefficients. The experimental results show that both the effect of temperature on the values of linear thermal expansion coefficients and the effect of moisture on th...

Cycle expansions: From maps to turbulence

Science.gov (United States)

Lan, Y.

2010-03-01

We present a derivation, a physical explanation and applications of cycle expansions in different dynamical systems, ranging from simple one-dimensional maps to turbulence in fluids. Cycle expansion is a newly devised powerful tool for computing averages of physical observables in nonlinear chaotic systems which combines many innovative ideas developed in dynamical systems, such as hyperbolicity, invariant manifolds, symbolic dynamics, measure theory and thermodynamic formalism. The concept of cycle expansion has a deep root in theoretical physics, bearing a close analogy to cumulant expansion in statistical physics and effective action functional in quantum field theory, the essence of which is to represent a physical system in a hierarchical way by utilizing certain multiplicative structures such that the dominant parts of physical observables are captured by compact, maneuverable objects while minor detailed variations are described by objects with a larger space and time scale. The technique has been successfully applied to many low-dimensional dynamical systems and much effort has recently been made to extend its use to spatially extended systems. For one-dimensional systems such as the Kuramoto-Sivashinsky equation, the method turns out to be very effective while for more complex real-world systems including the Navier-Stokes equation, the method is only starting to yield its first fruits and much more work is needed to enable practical computations. However, the experience and knowledge accumulated so far is already very useful to a large set of research problems. Several such applications are briefly described in what follows. As more research effort is devoted to the study of complex dynamics of nonlinear systems, cycle expansion will undergo a fast development and find wide applications.

Lessons from Early Medicaid Expansions Under Health Reform..

Data.gov (United States)

U.S. Department of Health & Human Services — Lessons from Early Medicaid Expansions Under Health Reform, Interviews with Medicaid Officials In a new study entitled Lessons from Early Medicaid Expansions Under...

RadCon: A Radiological Consequences Model

International Nuclear Information System (INIS)

Crawford, J.; Domel, R.U.

2000-05-01

RadCon estimates the dose received by user selected groups in the population from an accidental release of radionuclides to the environment. The exposure pathways considered are external exposure from the cloud and ground and internal exposure from inhalation and ingestion of contaminated food. Atmospheric dispersion modelling is carried out externally to RadCon.Given a two dimensional time varying air and ground concentration of radioactive elements, RadCon allows the user to: view the air and ground concentration over the affected area, select optional parameters and calculate the dose to people,display the results to the user, and change the parameter values. RadCon offers two user interfaces: 1) the standard graphical user interface which is started using Java DoseApp at the command line, or by setting up a shortcut to this command (particularly when RadCon is installed on a PC) and 2) the text based interface used to generate information for the model inter-comparison exercise . This is initiated using Java BIOMASS at the command line, or an equivalent shortcut. The text based interface was developed for research purposes and is not generally available. Appendices A, B and C provide a summary of instructions on setting up RadCon. This will generally be carried out by the computer support personnel

Thermal expansion accompanying the glass-liquid transition and crystallization

Directory of Open Access Journals (Sweden)

M. Q. Jiang

2015-12-01

Full Text Available We report the linear thermal expansion behaviors of a Zr-based (Vitreloy 1 bulk metallic glass in its as-cast, annealed and crystallized states. Accompanying the glass-liquid transition, the as-cast Vitreloy 1 shows a continuous decrease in the thermal expansivity, whereas the annealed glass shows a sudden increase. The crystallized Vitreloy 1 exhibits an almost unchanged thermal expansivity prior to its melting. Furthermore, it is demonstrated that the nucleation of crystalline phases can induce a significant thermal shrinkage of the supercooled liquid, but with the growth of these nuclei, the thermal expansion again dominates. These results are explained in the framework of the potential energy landscape, advocating that the configurational and vibrational contributions to the thermal expansion of the glass depend on both, structure and temperature.

Thermal expansion model for multiphase electronic packaging materials

International Nuclear Information System (INIS)

Allred, B.E.; Warren, W.E.

1991-01-01

Control of thermal expansion is often necessary in the design and selection of electronic packages. In some instances, it is desirable to have a coefficient of thermal expansion intermediate between values readily attainable with single or two phase materials. The addition of a third phase in the form of fillers, whiskers, or fibers can be used to attain intermediate expansions. To help design the thermal expansion of multiphase materials for specific applications, a closed form model has been developed that accurately predicts the effective elastic properties of isotropic filled materials and transversely isotropic lamina. Properties of filled matrix materials are used as inputs to the lamina model to obtain the composite elastic properties as a function of the volume fraction of each phase. Hybrid composites with two or more fiber types are easily handled with this model. This paper reports that results for glass, quartz, and Kevlar fibers with beta-eucryptite filled polymer matrices show good agreement with experimental results for X, Y, and Z thermal expansion coefficients

Asymptotic expansions for high-contrast linear elasticity

KAUST Repository

Poveda, Leonardo A.; Huepo, Sebastian; Calo, Victor M.; Galvis, Juan

2015-01-01

We study linear elasticity problems with high contrast in the coefficients using asymptotic limits recently introduced. We derive an asymptotic expansion to solve heterogeneous elasticity problems in terms of the contrast in the coefficients. We study the convergence of the expansion in the H1 norm. © 2015 Elsevier B.V.

Asymptotic expansions for high-contrast linear elasticity

KAUST Repository

Poveda, Leonardo A.

2015-03-01

We study linear elasticity problems with high contrast in the coefficients using asymptotic limits recently introduced. We derive an asymptotic expansion to solve heterogeneous elasticity problems in terms of the contrast in the coefficients. We study the convergence of the expansion in the H1 norm. © 2015 Elsevier B.V.

The critical thermal expansion of gadolinium

International Nuclear Information System (INIS)

Robinson, K.; Lanchester, P.C.

1978-01-01

Measurements have been made of the critical thermal expansion of single crystals of gadolinium, prepared by solid state electrotransport processing. Although the expansion data can be fitted to a simple power law with exponents lambda + =-0.25, lambda - =-0.33, these values are not predicted by theory and a discontinuity remains at Tsub(c)=293.620 K. It is suggested that the results relate to a region of crossover to uniaxial dipolar behaviour. (Auth.)

Foundations on Expansive Soils; A Review

OpenAIRE

Behzad Kalantari

2012-01-01

This study describes various types of foundation designs to be considered for structural engineering projects when the subsoil foundation consists of expansive or swelling soils. Among civil and architectural engineers expansive soils are known to be difficult foundation materials and problematic. These type of soils swell when they are subjected to moistures and shrink due to moisture loss. Because of this different behaviour upon wetting and drying, they cause minor to major structural dama...

Preliminary thermal expansion screening data for tuffs

International Nuclear Information System (INIS)

Lappin, A.R.

1980-03-01

A major variable in evaluating the potential of silicic tuffs for use in geologic disposal of heat-producing nuclear wastes is thermal expansion. Results of ambient-pressure linear expansion measurements on a group of tuffs that vary treatly in porosity and mineralogy are presente here. Thermal expansion of devitrified welded tuffs is generally linear with increasing temperature and independent of both porosity and heating rate. Mineralogic factors affecting behavior of these tuffs are limited to the presence or absence of cristobalite and altered biotite. The presence of cristobalite results in markedly nonlinear expansion above 200 0 C. If biotite in biotite-hearing rocks alters even slightly to expandable clays, the behavior of these tuffs near the boiling point of water can be dominated by contraction of the expandable phase. Expansion of both high- and low-porosity tuffs containing hydrated silicic glass and/or expandable clays is complex. The behavior of these rocks appears to be completely dominated by dehydration of hydrous phases and, hence, should be critically dependent on fluid pressure. Valid extrapolation of the ambient-pressure results presented here to depths of interest for construction of a nuclear-waste repository will depend on a good understanding of the interaction of dehydration rates and fluid pressures, and of the effects of both micro- and macrofractures on the response of tuff masss

Electric Grid Expansion Planning with High Levels of Variable Generation

Energy Technology Data Exchange (ETDEWEB)

Hadley, Stanton W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); You, Shutang [Univ. of Tennessee, Knoxville, TN (United States); Shankar, Mallikarjun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Yilu [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-02-01

Renewables are taking a large proportion of generation capacity in U.S. power grids. As their randomness has increasing influence on power system operation, it is necessary to consider their impact on system expansion planning. To this end, this project studies the generation and transmission expansion co-optimization problem of the US Eastern Interconnection (EI) power grid with a high wind power penetration rate. In this project, the generation and transmission expansion problem for the EI system is modeled as a mixed-integer programming (MIP) problem. This study analyzed a time series creation method to capture the diversity of load and wind power across balancing regions in the EI system. The obtained time series can be easily introduced into the MIP co-optimization problem and then solved robustly through available MIP solvers. Simulation results show that the proposed time series generation method and the expansion co-optimization model and can improve the expansion result significantly after considering the diversity of wind and load across EI regions. The improved expansion plan that combines generation and transmission will aid system planners and policy makers to maximize the social welfare. This study shows that modelling load and wind variations and diversities across balancing regions will produce significantly different expansion result compared with former studies. For example, if wind is modeled in more details (by increasing the number of wind output levels) so that more wind blocks are considered in expansion planning, transmission expansion will be larger and the expansion timing will be earlier. Regarding generation expansion, more wind scenarios will slightly reduce wind generation expansion in the EI system and increase the expansion of other generation such as gas. Also, adopting detailed wind scenarios will reveal that it may be uneconomic to expand transmission networks for transmitting a large amount of wind power through a long distance

Dynamical effects in the Colomb expansion following nuclear fragmentation

International Nuclear Information System (INIS)

Chung, K.C.; Donangelo, R.J.; Schechter, H.

1987-01-01

The effects of the Colomb expansion on the fragment Kinetic energy spectrum for a fragmentating hot nuclear system is investigated. In particular, 12 C fragment spectra are calculated and compared with those predicted by the uniform expansion approximation. The results indicate that energy spectra of fragments are quite sensitive to the details of the Coulomb expansion treatment. (Author) [pt

Hadronic mass-relations from topological expansion and string model

International Nuclear Information System (INIS)

Kaidalov, A.B.

1980-01-01

Hadronic mass-relations from topological expansion and string model are derived. For this purpose the space- time picture of hadron interactions at high energies corresponding to planar diagrams of topological expansion is considered. Simple relations between intercepts and slopes of Regge trajectories based on the topological expansion and q anti q-string picture of hadrons are obtained [ru

Thermal expansion of Ti-substituted barium hexaferrite

NARCIS (Netherlands)

Hernandez-Gomez, P.; Francisco, de C.; Brabers, V.A.M.; Dalderop, J.H.J.

2000-01-01

Thermal expansion measurements in the range of 20–500 °C were carried out on both poly- and single crystalline samples of the hexagonal magnetoplumbite ferrite with composition BaTiFe11O19. The continuous scanning of the thermal expansion reveals the existence of a -type anomaly near the Curie

Estudio comparativo del efecto del cepillado con una crema dental con propóleos rojos y de un gel con clorofila

Directory of Open Access Journals (Sweden)

Estela Gispert Abreu

1998-12-01

Full Text Available Se analiza comparativamente el efecto de un gel dental de clorofila y de una crema dental con propóleos rojos sobre varios parámetros relacionados con la caries dental, en escolares que se cepillaron durante 21 días con dichos productos. Se obtuvieron resultados favorables principalmente en la disminución del grado de infección por Streptococcus mutans y la elevación de la capacidad individual de remineralización; salvo en este último no hubo diferencias estadísticamente significativas.Authors made a comparative analysis about effect of chlorophyl dental gel and toothpaste containing red propolis, on some parameters related to dental caries in a group of students that brushed their teeth during 21 days using such products. Favourable results were obtained, mainly in decrease of infection level from Streptococcus mutans, and in increase of individual capacity of remineralization; except for this latter, there weren´t statistically significant differences.

Tratamiento conservador en pacientes con retinoblastoma bilateral

Directory of Open Access Journals (Sweden)

Juan C. Suárez

2008-11-01

Full Text Available OBJETIVO: comparar el tratamiento convencional del retinoblastoma bilateral, usado hasta hace algunos años, consistente en radioterapia o enucleación bilateral, con el tratamiento conservador actual que incluye termoterapia transpupilar (TTT o TTT/quimioterapia al menos en un ojo, en niños con diagnóstico de retinoblastoma bilateral. DISEÑO: estudio retrospectivo descriptivo. MUESTRA: 20 pacientes con diagnóstico de retinoblastoma bilateral que consultaron al Hospital Universitario San Vicente de Paúl, de Medellín, Colombia, entre 1997 y 2007. MÉTODO: se hizo enucleación del ojo con el tumor de mayor tamaño. En el otro ojo se hizo tratamiento con TTT, con el láser diodo (810 nm, spot amplio, solo o combinado con otras terapias. RESULTADOS: se dividió a los pacientes en dos grupos: 16 pacientes (32 ojos en el grupo 1 tratados conservadoramente y 4 pacientes (8 ojos en el grupo 2 con tratamiento convencional. El rango de edad fue de 1-72 meses en el grupo 1 y de 1-12 meses en el grupo 2. El tiempo de seguimiento fue de 7-67 meses para el grupo 1 y de 13-73 meses para el grupo 2. En el grupo 1 se hizo enucleación de 16 ojos (50%, radioterapia externa de uno (3,1%, quimioterapia más termoterapia de 5 (15,6% y quimioterapia más termoterapia más crioterapia de 10 (31,3%. En todos los pacientes se logró preservar al menos un ojo. En el grupo 2, se enuclearon 7 ojos (87,5% y se hizo radioterapia externa más enucleación en un paciente (12.5%. Además, todos los pacientes recibieron quimioterapia. CONCLUSIÓN: la terapia conservadora actual consistente en tratamiento local (termoterapia, crioterapia o braquiterapia y quimiorreducción permite preservar al menos un ojo y en algunos casos de los dos, muchas veces con buena agudeza visual, en niños con retinoblastoma bilateral; se evitan así la enucleación bilateral y la radioterapia externa usada en el tratamiento convencional con todos sus efectos secundarios. La enucleación contin

Finnish Higher Education Expansion and Regional Policy

Science.gov (United States)

Saarivirta, Toni

2010-01-01

This paper concentrates on the expansion of Finnish higher education between the 1960s and 1970s, exposes its background in the light of the policy decisions that were made, compares the unique features of this expansion with those of certain other countries, discusses the impact of the controlled "top down" governance of higher…

Spherical-wave expansions of piston-radiator fields.

Science.gov (United States)

Wittmann, R C; Yaghjian, A D

1991-09-01

Simple spherical-wave expansions of the continuous-wave fields of a circular piston radiator in a rigid baffle are derived. These expansions are valid throughout the illuminated half-space and are useful for efficient numerical computation in the near-field region. Multipole coefficients are given by closed-form expressions which can be evaluated recursively.

Series expansion of the modified Einstein Procedure

Science.gov (United States)

Seema Chandrakant Shah-Fairbank

2009-01-01

This study examines calculating total sediment discharge based on the Modified Einstein Procedure (MEP). A new procedure based on the Series Expansion of the Modified Einstein Procedure (SEMEP) has been developed. This procedure contains four main modifications to MEP. First, SEMEP solves the Einstein integrals quickly and accurately based on a series expansion. Next,...

Variables socionutricionales de hogares mazahuas integrados por preescolares desnutridos con madres con obesidad y sin obesidad

OpenAIRE

Viridiana Vanessa Conzuelo-González

2009-01-01

El primer objetivo fue conocer cuántos menores de cinco años con diferentes grados de desnutrición tienen una madre con sobrepeso/obesidad/ en una comunidad indígena que vive en extrema pobreza y bajo condiciones de migración masculina internacional. El segundo fue comparar tres variables socionutricionales (ingreso familiar, educación de la madre y adecuación nutrimental de la dieta diaria) entre estos hogares y los hogares con desnutrición infantil y madres sin obesidad. Se realizó un estud...

Terapia asistida con perros en niños con autismo revisión sistemática

OpenAIRE

Isaza Narváez, Ana Milena; Muñoz Chilito, Doumer Adrian

2013-01-01

Introducción: El autismo es un trastorno temprano y masivo del desarrollo en el cual se afecta la interacción social, el desarrollo del lenguaje, se presentan rituales y estereotipias. Hay evidencia que la interacción con un perro está asociada con efectos positivos en la salud del niño, lo cual se extiende al terreno terapéutico donde la compañía del perro estimula habilidades comunicativas para conectarse con el mundo exterior y romper el aislamiento que lo hace refractario a formas convenc...

Variables socionutricionales de hogares mazahuas integrados por preescolares desnutridos con madres con obesidad y sin obesidad

OpenAIRE

Viridiana Vanessa Conzuelo-González; Ivonne Vizcarra-Bordi

2009-01-01

El primer objetivo fue conocer cuántos menores de cinco años con diferentes grados de desnutrición tienen una madre con sobrepeso/obesidad/ en una comunidad indígena que vive en extrema pobreza y bajo condiciones de migración masculina internacional. El segundo fue comparar tres variables socionutricionales (ingreso familiar, educación de la madre y adecuación nutrimental de la dieta diaria) entre estos hogares y los hogares con desnutrición infantil y madres sin obesidad. Se realizó un est...

Efectos del contacto piel con piel del recién nacido con su madre

Directory of Open Access Journals (Sweden)

Camila Lucchini Raies

Full Text Available Antecedentes: el contacto piel con piel ha sido una práctica ancestral en toda cultura, que debido a la institucionalización de la atención del parto, disminuyó en occidente. Se retomó en el marco de la atención humanizada del parto. Objetivo principal: determinar los efectos del contacto piel con piel del recién nacido con su madre. Metodología: revisión bibliográfica de 26 estudios. Límites de búsqueda: new borns, humans, clinical trials, de 10 años de publicación, en bases de datos: Pubmed, ProQuest, CINHAL, Lilacs. Resultados principales: Se observaron beneficios en las variables: duración de lactancia materna, comportamiento neurosensorial, regulación de temperatura, como alternativa al cuidado estándar, disminución en días hospitalización y niveles de cortisol, favorecedor de la interacción madre-hijo y desarrollo infantil. Conclusión principal: el contacto piel con piel brinda múltiples beneficios a recién nacidos. Se presenta como alternativa de cuidado segura, factible de implementar.

Rapid replacement of bridge deck expansion joints study - phase I.

Science.gov (United States)

2014-12-01

Bridge deck expansion joints are used to allow for movement of the bridge deck due to thermal expansion, dynamics loading, and : other factors. More recently, expansion joints have also been utilized to prevent the passage of winter de-icing chemical...

Global operator expansions in conformally invariant relativistic quantum field theory

International Nuclear Information System (INIS)

Schoer, B.; Swieca, J.A.; Voelkel, A.H.

1974-01-01

A global conformal operator expansions in the Minkowski region in several models and their formulation in the general theory is presented. Whereas the vacuum expansions are termwise manisfestly conformal invariant, the expansions away from the vacuum do not share this property

Expansion reduction of clayey soils through Surcharge application and Lime Treatment

Directory of Open Access Journals (Sweden)

T. López-Lara

2017-12-01

Full Text Available Expansive clayey soils produce heaving and cracking of floor slabs and walls. Expansive soils owe their characteristics to the presence of swelling clay minerals. This soil expands and contracts due to changes in the moisture content of the soil. In this study the surcharge required to counteract soil expansion was measured in natural expansive soils (untreated soils and lime treated soils starting at 19.61 kPa (2 Ton/m2 and continuing with increments of 19.61 kPa. Additionaly in lime treated soils the amount of lime was determined under different surcharges in order to reduce the expansion. The test results indicated that the surcharges applied to untreated soils were not proportional to the decrease of expansion which is probably due to the increase of soil density. In fact, only the initial surcharge of 19.61 kPa significantly decreased the expansion. According to the results, the soil expansion was considerably reduced (1.54% with the surcharge of 78.45 kPa, therefore this surcharge can be considered as the Swelling pressure. On the other hand the soil tested (high compressibility clay was stabilized with 6% of lime (without surcharges which was determined with the lowest value of liquid limit and plastic index as well as expansion test. After the application of surcharges and lime treatment to expansive soil, the surcharges of 39.22 kPa and 58.84 kPa decreased expansion and increased their resistance. This was concluded by similar low values of expansion (without settlements under both surcharges of each treated soil tested (2, 4 and 6% of lime. It can be concluded that the surcharge contributed to the decrease of soil expansion due to the decrease of the amount of lime required (6% without surcharge. So, 4% of lime was enough for the surcharge of 19.61 kPa and 2% of lime required the surcharge minimum of 39.22 kPa. This shows that the surcharge of a house on expansive soil reduces soil expansion and therefore reduces costs of any

Expansion patterns and parallaxes for planetary nebulae

Science.gov (United States)

Schönberner, D.; Balick, B.; Jacob, R.

2018-02-01

Aims: We aim to determine individual distances to a small number of rather round, quite regularly shaped planetary nebulae by combining their angular expansion in the plane of the sky with a spectroscopically measured expansion along the line of sight. Methods: We combined up to three epochs of Hubble Space Telescope imaging data and determined the angular proper motions of rim and shell edges and of other features. These results are combined with measured expansion speeds to determine individual distances by assuming that line of sight and sky-plane expansions are equal. We employed 1D radiation-hydrodynamics simulations of nebular evolution to correct for the difference between the spectroscopically measured expansion velocities of rim and shell and of their respective shock fronts. Results: Rim and shell are two independently expanding entities, driven by different physical mechanisms, although their model-based expansion timescales are quite similar. We derive good individual distances for 15 objects, and the main results are as follows: (i) distances derived from rim and shell agree well; (ii) comparison with the statistical distances in the literature gives reasonable agreement; (iii) our distances disagree with those derived by spectroscopic methods; (iv) central-star "plateau" luminosities range from about 2000 L⊙ to well below 10 000 L⊙, with a mean value at about 5000 L⊙, in excellent agreement with other samples of known distance (Galactic bulge, Magellanic Clouds, and K648 in the globular cluster M 15); (v) the central-star mass range is rather restricted: from about 0.53 to about 0.56 M⊙, with a mean value of 0.55 M⊙. Conclusions: The expansion measurements of nebular rim and shell edges confirm the predictions of radiation-hydrodynamics simulations and offer a reliable method for the evaluation of distances to suited objects. Results of this paper are based on observations made with the NASA/ESA Hubble Space Telescope in Cycle 16 (GO11122

On the comparsion of the Spherical Wave Expansion-to-Plane Wave Expansion and the Sources Reconstruction Method for Antenna Diagnostics

DEFF Research Database (Denmark)

Alvarez, Yuri; Cappellin, Cecilia; Las-Heras, Fernando

2008-01-01

A comparison between two recently developed methods for antenna diagnostics is presented. On one hand, the Spherical Wave Expansion-to-Plane Wave Expansion (SWE-PWE), based on the relationship between spherical and planar wave modes. On the other hand, the Sources Reconstruction Method (SRM), based...

A matched expansion approach to practical self-force calculations

International Nuclear Information System (INIS)

Anderson, Warren G; Wiseman, Alan G

2005-01-01

We discuss a practical method of computing the self-force on a particle moving through a curved spacetime. This method involves two expansions to calculate the self-force, one arising from the particle's immediate past and the other from the more distant past. The expansion in the immediate past is a covariant Taylor series and can be carried out for all geometries. The more distant expansion is a mode sum, and may be carried out in those cases where the wave equation for the field mediating the self-force admits a mode expansion of the solution. In particular, this method can be used to calculate the gravitational self-force for a particle of mass μ orbiting a black hole of mass M to order μ 2 , provided μ/M << 1. We discuss how to use these two expansions to construct a full self-force, and in particular investigate criteria for matching the two expansions. As with all methods of computing self-forces for particles moving in black hole spacetimes, one encounters considerable technical difficulty in applying this method; nevertheless, it appears that the convergence of each series is good enough that a practical implementation may be plausible

Instability of a planar expansion wave

International Nuclear Information System (INIS)

Velikovich, A.L.; Zalesak, S.T.; Metzler, N.; Wouchuk, J.G.

2005-01-01

An expansion wave is produced when an incident shock wave interacts with a surface separating a fluid from a vacuum. Such an interaction starts the feedout process that transfers perturbations from the rippled inner (rear) to the outer (front) surface of a target in inertial confinement fusion. Being essentially a standing sonic wave superimposed on a centered expansion wave, a rippled expansion wave in an ideal gas, like a rippled shock wave, typically produces decaying oscillations of all fluid variables. Its behavior, however, is different at large and small values of the adiabatic exponent γ. At γ>3, the mass modulation amplitude δm in a rippled expansion wave exhibits a power-law growth with time ∝t β , where β=(γ-3)/(γ-1). This is the only example of a hydrodynamic instability whose law of growth, dependent on the equation of state, is expressed in a closed analytical form. The growth is shown to be driven by a physical mechanism similar to that of a classical Richtmyer-Meshkov instability. In the opposite extreme γ-1 -1/2 , and then starts to decrease. The mechanism driving the growth is the same as that of Vishniac's instability of a blast wave in a gas with low γ. Exact analytical expressions for the growth rates are derived for both cases and favorably compared to hydrodynamic simulation results

Larvicultura de Rhamdia quelen (Pisces, Pimelodidae con proteína vegetal y animal, suplementadas con plancton

Directory of Open Access Journals (Sweden)

Germán Castañeda A.

2011-12-01

Full Text Available Objetivo. Determinar el efecto de dietas con diferentes proporciones de fuentes proteicas animales y vegetales suplementadas con plancton sobre el crecimiento y sobrevivencia en larvas de Rhamdia quelen. Materiales y métodos. Fueron formuladas dos dietas experimentales, dieta-1 con 70% de proteína de origen vegetal (torta de soya y dieta-2 con 70% de proteína proveniente de animales (corazón bovino yharina de pescado; se utilizaron cuatro protocolos de alimentación (cinco réplicas por tratamiento: dieta-1 + plancton filtrado en tamiz de 50-200 micras (T1, dieta-2 + plancton filtrado en tamiz de 50-200 micras (T2, dieta-1 (T3, dieta-2 (T4. Las larvas fueron manejadas a una densidad de 20 animales L-1 suministrando alimentohasta aparente saciedad diariamente a las 07:00, 11:00, 16:00 y 21:00 horas; la suplementación con plancton se realizó a las 11:00 y 21:00 horas. Resultados. Entre T1 y T2 no se observaron diferencias estadísticas (p>0.05 en peso final (21.89 ± 15.17mg vs 20.37 ± 10.37mg, longitud total (13.41±2.34mm vs 13.39±1.99 mm, factor de condición (K (0.80±0.13 vs 0.78±0.13 y sobrevivencia (46.6±2.68% vs36.0±7.41%; las diferencias entre T3 y T4 tampoco fueron significativas (3.35±1.40 mg vs 2.98±1.48 mg; 7.54±0.91mm vs 7.33±0.96mm; 0.75±0.13 vs 0.71±0.12; 33.6±9.07% vs 24.8±6.76%, respectivamente; hubo diferencias significativas (p<0.05 entre los grupos suplementados con plancton y los alimentados solo con ración. Conclusiones. La suplementación con plancton fue más efectiva que elofrecimiento solo de ración. La inclusión del 62.9% de torta de soya en la formulación (T1, aparentemente no afectó el crecimiento ni la sobrevivencia.

Ensayo clínico con intervención educativa en mujeres perimenopáusicas con un factor de riesgo cardiovascular

Directory of Open Access Journals (Sweden)

Anxela Soto-Rodríguez

2017-01-01

Conclusiones: Una sencilla intervención educativa en mujeres perimenopáusicas con un factor de riesgo cardiovascular mejora aspectos relacionados con la calidad de vida y con hábitos saludables como la actividad física.

Cosmological expansion and local physics

International Nuclear Information System (INIS)

Faraoni, Valerio; Jacques, Audrey

2007-01-01

The interplay between cosmological expansion and local attraction in a gravitationally bound system is revisited in various regimes. First, weakly gravitating Newtonian systems are considered, followed by various exact solutions describing a relativistic central object embedded in a Friedmann universe. It is shown that the 'all or nothing' behavior recently discovered (i.e., weakly coupled systems are comoving while strongly coupled ones resist the cosmic expansion) is limited to the de Sitter background. New exact solutions are presented which describe black holes perfectly comoving with a generic Friedmann universe. The possibility of violating cosmic censorship for a black hole approaching the big rip is also discussed

Soporte social con el uso de tic’s para cuidadores familiares de personas con enfermedad crónica

OpenAIRE

Carrillo, Gloria Mabel; Chaparro, Olivia Lorena; Barrera, Lucy; Sanchez, beatriz; Pinto, Raquel Natividad

2012-01-01

Objetivo Determinar la efectividad del soporte social dado con el uso de tecnologías de la información y la comunicación (TIC’S) a los cuidadores familiares de personas con enfermedad crónica.  Material y Métodos. Estudio descriptivo, exploratorio realizado en Bogotá en 2008 y 2009 con 144 cuidadores familiares de personas con enfermedad crónica  que constó de tres etapas para su desarrollo: 1. Planeación, diseño de la TIC’s,  aplicación de  prueba piloto y  selección de  población objeto;  ...

Expansion of all multitrace tree level EYM amplitudes

Science.gov (United States)

Du, Yi-Jian; Feng, Bo; Teng, Fei

2017-12-01

In this paper, we investigate the expansion of tree level multitrace Einstein-Yang-Mills (EYM) amplitudes. First, we propose two types of recursive expansions of tree level EYM amplitudes with an arbitrary number of gluons, gravitons and traces by those amplitudes with fewer traces or/and gravitons. Then we give many support evidence, including proofs using the Cachazo-He-Yuan (CHY) formula and Britto-Cachazo-Feng-Witten (BCFW) recursive relation. As a byproduct, two types of generalized BCJ relations for multitrace EYM are further proposed, which will be useful in the BCFW proof. After one applies the recursive expansions repeatedly, any multitrace EYM amplitudes can be given in the Kleiss-Kuijf (KK) basis of tree level color ordered Yang-Mills (YM) amplitudes. Thus the Bern-Carrasco-Johansson (BCJ) numerators, as the expansion coefficients, for all multitrace EYM amplitudes are naturally constructed.

Expansive cements for the manufacture of the concrete protective bandages

Science.gov (United States)

Yakymechko, Yaroslav; Voloshynets, Vladyslav

2017-12-01

One of the promising directions of the use of expansive cements is making the protective bandages for the maintenance of pipelines. Bandages expansive application of the compositions of the pipeline reinforce the damaged area and reduce stress due to compressive stress in the cylindrical area. Such requirements are best suited for expansive compositions obtained from portland cement and modified quicklime. The article presents the results of expansive cements based on quick lime in order to implement protective bandages pipelines.

Adolescente femenino con granulomatosis de Wegener fulminante

Directory of Open Access Journals (Sweden)

S C Scheffler-Mendoza

2017-01-01

Full Text Available Adolescente femenino de 13 años de edad, originaria de Guerrero, grupo étnico mixteco, padres analfabetos y con poco entendimiento del español. Sin otros antecedentes de importancia para el padecimiento. Inició un mes previo con la aparición de una pápula hipercrómica en párpado superior derecho que en los 10 días previos al ingreso aumentó de volumen generando proptosis. Al interrogatorio se negó dolor, lagrimeo, fiebre, o pérdida de peso. Ingresó con fiebre (39.0°C, palidez generalizada, proptosis derecha con exposición de córnea y conjuntiva, eritema periorbitario, movimientos oculares y agudeza visual disminuidos (i.e. contaba dedos a 1 m, pupila con tendencia a midriasis, hiperreactividad a la luz, y fondo de ojo con papila hiperémica edematosa y tortuosidad peripapilar. El resto de exploración no mostró datos relevantes. Se hospitalizó para iniciar tratamiento antimicrobiano parenteral de amplio espectro (i.e. ceftriaxona y vancomicina y abordar proptosis unilateral.

Off-diagonal series expansion for quantum partition functions

Science.gov (United States)

Hen, Itay

2018-05-01

We derive an integral-free thermodynamic perturbation series expansion for quantum partition functions which enables an analytical term-by-term calculation of the series. The expansion is carried out around the partition function of the classical component of the Hamiltonian with the expansion parameter being the strength of the off-diagonal, or quantum, portion. To demonstrate the usefulness of the technique we analytically compute to third order the partition functions of the 1D Ising model with longitudinal and transverse fields, and the quantum 1D Heisenberg model.

Síntomas depresivos en pacientes con Trastorno por déficit de atención con hiperactividad.

Directory of Open Access Journals (Sweden)

Diego Artemio Reátegui Villegas

2008-07-01

Full Text Available Objetivos: Determinar la frecuencia de síntomas depresivos en pacientes con Trastorno por déficit de atención con hiperactividad (TDAH, así como determinar su asociación con edad, sexo y comorbilidad psiquiátrica. Material y Método: Se realizó un estudio descriptivo de corte transversal. Se incluyeron pacientes con diagnóstico de TDAH del Instituto Nacional de Salud Mental Honorio Delgado Hideyo Noguchi, desde febrero del 2006 hasta completar el tamaño de la muestra. Se les aplicó a los pacientes el Children´s depression inventory (CDI. Se consideró un punto de corte de 15 para definir presencia de trastorno depresivo. Se analizaron las siguientes variables: edad, sexo, comorbilidad psiquiátrica y sintomatología depresiva. Resultados: Sesenta y cuatro (85,3% fueron varones, en 35/75 (46,7% se encontró CDI ³ 15. No se encontró asociación estadísticamente significativa entre síntomas depresivos y sexo o edad. El síntoma depresivo más frecuente fue el problema del rendimiento escolar (65,3%. Se encontraron 6 pacientes con otra comorbilidad. Conclusión: Existe una alta frecuencia de sintomatología depresiva en niños y adolescentes con diagnóstico de TDAH. (Rev Med Hered 2008;19:96-101 .

Expansion at Olympic Dam

International Nuclear Information System (INIS)

Lewis, C.

1997-01-01

The Olympic Dam orebody is the 6th largest copper and the single largest uranium orebody in the world. Mine production commenced in June 1988, at an annual production rate of around 45,000 tonnes of copper and 1,000 tonnes of uranium. Western Mining Corporation announced in 1996 a proposed $1.25 billion expansion of the Olympic Dam operation to raise the annual production capacity of the mine to 200,000 tonnes of copper, approximately 3,700 tonnes of uranium, 75,000 ounces of gold and 950,000 ounces of silver by 2001. Further optimisation work has identified a faster track expansion route, with an increase in the capital cost to $1.487 billion but improved investment outcome, a new target completion date of end 1999, and a new uranium output of 4,600 tonnes per annum from that date

Caracterización de pacientes con lesiones pigmentarias de piel con riesgo de transformación maligna

Directory of Open Access Journals (Sweden)

María Elena Izquierdo Izquierdo

2015-06-01

Full Text Available Fundamento: el melanoma es el más terrible y mortífero de los cánceres de piel. Se origina frecuentemente a partir de un nevo melanocítico con riesgo de transformación maligna. Estas lesiones pigmentadas se diagnostican cada vez más en edades tan tempranas como la adolescencia. Objetivo: caracterizar los pacientes en edades pediátricas con signos de lesiones pigmentarias de la piel con riesgo de transformación maligna. Métodos: se realizó un estudio prospectivo de corte transversal en un grupo de 50 pacientes en edades entre 5 y 19 años, que asistieron a la consulta de dermatología del Hospital Pediátrico de Centro Habana en el año 2010, con signos de lesiones pigmentarias de la piel con riesgo de transformación maligna. Se aplicó un instrumento de recogida de datos, con previo consentimiento informado. Se utilizó la estadística descriptiva para el procesamiento de los datos. Resultados: en la población de estudio predominó la adolescencia temprana, el grupo de riesgo con daño actínico crónico y el fototipo III. Estuvo presente el antecedente familiar de cáncer de piel no-melanoma. La lesión más frecuente fue la de nevo melanocítico displásico. Además, se reportó un caso de carcinoma basal en paciente de fototipo II, perteneciente al grupo de riesgo de xeroderma pigmentoso. Conclusiones: se evidenció la transformación maligna de lesiones pigmentarias en piel de pacientes de grupos de riesgo.

STABILIZATION OF EXPANSIVE SOIL USING BAGASSE ASH & LIME

African Journals Online (AJOL)

tekimerry

expansive soils which depends on the stress and ... been employed to curb or reduce the severity of the damages caused by ... work is collected from Addis Ababa, Bole Sub. City at 8º 59' ..... Construction of flexible Pavements in Expansive ...

On the stress-free lattice expansion of porous cordierite

International Nuclear Information System (INIS)

Bruno, Giovanni; Efremov, Alexander M.; Clausen, Bjorn; Balagurov, Anatoly M.; Simkin, Valeriy N.; Wheaton, Bryan R.; Webb, James E.; Brown, Donald W.

2010-01-01

An extensive investigation of the lattice expansion (up to 1200 deg. C) of porous synthetic cordierite (obtained by firing a mixture of talc, clay, alumina and silica) was carried out using time-of-flight neutron diffraction at LANSCE, Los Alamos, NM, USA and FNLP, Dubna, Russia. An extruded rod and several powders, with different particle size (dispersity), were studied, with the aim of monitoring the variation of the (lattice) micro-strain as a function of temperature and its influence on the microscopic and macroscopic thermal expansion. Results show a different expansion of the a- and b-axes of the orthorhombic cell (in the rod above 800 deg. C). While the finest powder seems to contract more along the c-axis, thus hinting at the presence of smaller stress, the integral peak width increases as a function of temperature in the intermediate range (300-700 deg. C). This could be explained by the integrity factor modeling in terms of micro-cracking. In polycrystalline cordierite, the model implies tension along the a- and b-axes (positive thermal expansion) accompanied by compression along the c-axis (negative thermal expansion) and a stress release upon cooling, via a thermal micro-cracking mechanism. The calculations of the cordierite macroscopic thermal expansion having as input crystal axial expansions assumed to be stress-free allowed us to conclude that even a fine powder (5 μm particle size) cannot be considered completely stress-free. This conclusion is supported by microstructural observations.

Investigation of Thermal Expansion of a Glass Ceramic Material with an Extra-Low Thermal Linear Expansion Coefficient

Science.gov (United States)

Kompan, T. A.; Korenev, A. S.; Lukin, A. Ya.

2008-10-01

The artificial material sitall CO-115M was developed purposely as a material with an extra-low thermal expansion. The controlled crystallization of an aluminosilicate glass melt leads to the formation of a mixture of β-spodumen, β-eucryptite, and β-silica anisotropic microcrystals in a matrix of residual glass. Due to the small size of the microcrystals, the material is homogeneous and transparent. Specific lattice anharmonism of these microcrystal materials results in close to zero average thermal linear expansion coefficient (TLEC) of the sitall material. The thermal expansion coefficient of this material was measured using an interferometric method in line with the classical approach of Fizeau. To obtain the highest accuracy, the registration of light intensity of the total interference field was used. Then, the parameters of the interference pattern were calculated. Due to the large amount of information in the interference pattern, the error of the calculated fringe position was less than the size of a pixel of the optical registration system. The thermal expansion coefficient of the sitall CO-115M and its temperature dependence were measured. The TLEC value of about 3 × 10-8 K-1 to 5 × 10-8 K-1 in the temperature interval from -20 °C to +60 °C was obtained. A special investigation was carried out to show the homogeneity of the material.

disegnare con ... Alberto Pratelli

Directory of Open Access Journals (Sweden)

Roberto Mingucci

2017-12-01

Full Text Available Con questa breve intervista ad Alberto Pratelli, (non a caso scelto per aprire questa nuova rubrica intendia-mo inaugurare un dialogo con personalità significati-ve del Disegno di Architettura, che consenta riflessioni dedicate alle sue varie dimensioni, oggi più che mai da approfondire. La suggestione a farlo, viene da un’idea di Pablo Rodri-guez Navarro ed abbiamo quindi pensato di avviarla proprio in questo numero, che Pablo ha accettato di curare su un tema a lui particolarmente caro.

Toward convergence of the variational mass expansion in asymptotically free theories

CERN Document Server

Kneur, J L

2001-01-01

We re-examine a modification of perturbative expansions, valid for asymptotically free theories, producing "variationally improved" expansions of physical quantities relevant to dynamical (chiral) symmetry breaking. The large order behaviour of this expansion is shown to be drastically improved, for reasons analogous to the convergence properties of the delta-expansion of the anharmonic oscillator.

Trace expansions for mixed boundary problems

Energy Technology Data Exchange (ETDEWEB)

Seeley, Robert T

2002-01-01

We discuss the heat trace expansion for a mixed boundary problem for the Laplace operator acting on sections of some bundle V over a manifold M of dimension d. The boundary is divided in two parts N{sub D} and N{sub N}, intersecting in a smooth submanifold {sigma}. Dirichlet conditions are imposed on N{sub D} - {sigma}, and Neumann conditions on N{sub N} - {sigma}. It turns out that it is also necessary to impose a condition along {sigma}. We then obtain an expansion of the trace of the heat operator with these boundary conditions, containing integrals of the usual terms over the interior and the two parts of the boundary, together with integrals over {sigma} of terms that are 'global' in certain operators on a semicircle. The first nonzero such term is computed; it involves the zeta function of an operator on the semicircle, and depends on the boundary condition along {sigma}. We find that no logarithmic terms occur in the expansion.

Depresion en pacientes con alteraciones del tiroides

OpenAIRE

Radanovic-Grguric´, Ljiljana; Filakovic´, Pavo; Barkic´, Jelena; Mandic´, Nikola; Karner, Ivan; Smoje, Juraj

2003-01-01

Nuestro estudio fue realizado en un grupo de 53 mujeres con disfunción tiroidea y 28 mujeres con depresión mayor. Empleamos la Escala de la Depresión de Hamilton, la Escala de Autoevaluación de la Depresión de Zung y la Escala sobre la Impresión Clínica Global. Los resultados del estudio demuestran que la mayoría de los pacientes con disfunción tiroidea se mostraron clínicamente significativos en cuanto al trastorno depresivo. Los episodios depresivos son más frecuentes en pacientes con hipot...

Genetic evidence for a Paleolithic human population expansion in Africa

Science.gov (United States)

Reich, David E.; Goldstein, David B.

1998-01-01

Human populations have undergone dramatic expansions in size, but other than the growth associated with agriculture, the dates and magnitudes of those expansions have never been resolved. Here, we introduce two new statistical tests for population expansion, which use variation at a number of unlinked genetic markers to study the demographic histories of natural populations. By analyzing genetic variation in various aboriginal populations from throughout the world, we show highly significant evidence for a major human population expansion in Africa, but no evidence of expansion outside of Africa. The inferred African expansion is estimated to have occurred between 49,000 and 640,000 years ago, certainly before the Neolithic expansions, and probably before the splitting of African and non-African populations. In showing a significant difference between African and non-African populations, our analysis supports the unique role of Africa in human evolutionary history, as has been suggested by most other genetic work. In addition, the missing signal in non-African populations may be the result of a population bottleneck associated with the emergence of these populations from Africa, as postulated in the “Out of Africa” model of modern human origins. PMID:9653150

Thermal expansion of epoxy-fiberglass composite specimens

International Nuclear Information System (INIS)

McElroy, D.L.; Weaver, F.J.; Bridgman, C.

1986-01-01

The thermal expansion behavior of three epoxy-fiberglass composite specimens was measured from 20 to 120 0 C (70 to 250 0 F) using a fused quartz push-rod dilatometer. Billets produced by vacuum impregnating layers of two types of fiberglass cloth with an epoxy resin were core-drilled to produce cylindrical specimens. These were used to study expansion perpendicular and parallel to the fiberglass layers. The dilatometer is held at a preselected temperature until steady-state is indicated by stable length and temperature data. Before testing the composite specimens, a reliability check of the dilatometer was performed using a copper secondary standard. This indicated thermal expansion coefficient (α) values within +-2% of expected values from 20 to 200 0 C

Enfermedad coronaria en pacientes con psoriasis

Directory of Open Access Journals (Sweden)

Walter Masson

2013-10-01

Full Text Available Comunicaciones previas asociaron la psoriasis con la enfermedad coronaria. Desconocemos si en nuestro país o región existe dicha asociación. Se realizó un estudio transversal analizando los datos de la historia clínica electrónica de un sistema de salud de Buenos Aires. Analizamos todos los pacientes mayores de 18 años con diagnóstico de psoriasis entre el 1 de enero de 2003 y el 31 de julio de 2011 y los comparamos con un grupo control, en una relación 2:1, obtenido en forma aleatoria del mismo sistema de salud, apareados por edad y sexo. Determinamos la prevalencia de los factores de riesgo cardiovascular y de enfermedad coronaria. Analizamos la asociación entre la enfermedad coronaria y la psoriasis mediante análisis uni y multivariado. Se incluyeron 3 833 sujetos (1 286 pacientes con psoriasis y 2 547 controles. La prevalencia de hipertensión arterial (50% vs. 38%, p < 0.001, tabaquismo (25% vs. 17%, p < 0.001, diabetes (12% vs. 8%, p < 0.001 y enfermedad coronaria (4.98% vs. 3.06%, p = 0.003 fue mayor en los sujetos con psoriasis en comparación con el grupo control. Independientemente de la edad, la presencia de diabetes, hipertensión arterial o tabaquismo, hubo una asociación significativa entre la enfermedad coronaria y la psoriasis (OR 1.48, IC95% 1.04-2.11, p = 0.03. En conclusión, en esta población de Buenos Aires, los pacientes con psoriasis tuvieron una mayor prevalencia de diabetes, hipertensión arterial, tabaquismo y enfermedad coronaria. La asociación entre la psoriasis y la enfermedad coronaria fue independiente de los factores de riesgo explorados.

Mincle Signaling Promotes Con-A Hepatitis

Science.gov (United States)

Greco, Stephanie H.; Torres-Hernandez, Alejandro; Kalabin, Aleksandr; Whiteman, Clint; Rokosh, Rae; Ravirala, Sushma; Ochi, Atsuo; Gutierrez, Johana; Salyana, Muhammad Atif; Mani, Vishnu R.; Nagaraj, Savitha V.; Deutsch, Michael; Seifert, Lena; Daley, Donnele; Barilla, Rocky; Hundeyin, Mautin; Nikifrov, Yuriy; Tejada, Karla; Gelb, Bruce E.; Katz, Steven C.; Miller, George

2016-01-01

Concanavalin-A (Con-A) hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor (CLR) that is critical in the immune response to mycobacteria and fungi, but does not have a well-defined role in pre-clinical models of non-pathogen mediated inflammation. Since Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con-A hepatitis. Acute liver injury was assessed in the murine Con-A hepatitis model using C57BL/6, Mincle−/−, and Dectin-1−/− mice. The role of C/EBPβ and HIF-1α signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con-A hepatitis. Most significantly, Mincle deletion or blockade protected against Con-A hepatitis whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other CLRs did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κβ related signaling intermediates, C/EBPβ and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con-A hepatitis and inhibition of both C/EBPβ and HIF1-α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con-A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation. PMID:27559045

Mincle Signaling Promotes Con A Hepatitis.

Science.gov (United States)

Greco, Stephanie H; Torres-Hernandez, Alejandro; Kalabin, Aleksandr; Whiteman, Clint; Rokosh, Rae; Ravirala, Sushma; Ochi, Atsuo; Gutierrez, Johana; Salyana, Muhammad Atif; Mani, Vishnu R; Nagaraj, Savitha V; Deutsch, Michael; Seifert, Lena; Daley, Donnele; Barilla, Rocky; Hundeyin, Mautin; Nikifrov, Yuriy; Tejada, Karla; Gelb, Bruce E; Katz, Steven C; Miller, George

2016-10-01

Con A hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor that is critical in the immune response to mycobacteria and fungi but does not have a well-defined role in preclinical models of non-pathogen-mediated inflammation. Because Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con A hepatitis. Acute liver injury was assessed in the murine Con A hepatitis model using C57BL/6, Mincle(-/-), and Dectin-1(-/-) mice. The role of C/EBPβ and hypoxia-inducible factor-1α (HIF-1α) signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con A hepatitis. Most significantly, Mincle deletion or blockade protected against Con A hepatitis, whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other C-type lectin receptors did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κβ-related signaling intermediates C/EBPβ and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con A hepatitis and inhibition of both C/EBPβ and HIF-1α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation. Copyright © 2016 by The American Association of Immunologists, Inc.

A topological expansion for high energy hadronic collisions. I

International Nuclear Information System (INIS)

Ciafaloni, M.; Marchesini, G.; Veneziano, G.

1975-01-01

In this and in a companion paper a 'topological expansion' for high-energy hadronic processes is proposed and discussed. In the first paper the general properties of the expansion and its connection with Gribov's reggeon calculus are presented. The topological expansion is first defined mathematically for a large class of theories and is shown to be equivalent to a 'large N expansion' in some theories which include planar dual models and non-Abelaian gauge theories. Next, the definition of the bare parameters is given in terms of graphs on a sphere. The bare pomeron pole and its couplings are thus introduced. The (inclusive) form of s-channel unitarity and its consequences for the above couplings are recalled. It is then shown how the expansion in the number of 'handles' of the graph can be related to Gribov's reggeon calculus and how, with the aid of discontinuity equations in the J-plane, scaling solutions can be obtained and critical indices can be computed to yield known results. (Auth.)

Modeling of Viscosity and Thermal Expansion of Bioactive Glasses

OpenAIRE

Farid, Saad B. H.

2012-01-01

The behaviors of viscosity and thermal expansion for different compositions of bioactive glasses have been studied. The effect of phosphorous pentoxide as a second glass former in addition to silica was investigated. Consequently, the nonlinear behaviors of viscosity and thermal expansion with respect to the oxide composition have been modeled. The modeling uses published data on bioactive glass compositions with viscosity and thermal expansion. -regression optimization technique has been uti...

Efecto de un tratamiento intensivo con insulina sobre la reactividad plaquetaria en pacientes con hiperglucemia que ingresan con un síndrome coronario agudo

OpenAIRE

Vivas Balcones, Luis David

2011-01-01

El objetivo primario de este trabajo ha sido la valoración del efecto que produce el control estricto de la glucemia mediante un tratamiento intensivo y precoz con insulina sobre la reactividad plaquetaria durante la fase hospitalaria en pacientes que ingresan en una unidad de cuidados intensivos cardiológicos con un síndrome coronario agudo e hiperglucemia, respecto a un tratamiento convencional.

Colossal negative thermal expansion in reduced layered ruthenate.

Science.gov (United States)

Takenaka, Koshi; Okamoto, Yoshihiko; Shinoda, Tsubasa; Katayama, Naoyuki; Sakai, Yuki

2017-01-10

Large negative thermal expansion (NTE) has been discovered during the last decade in materials of various kinds, particularly materials associated with a magnetic, ferroelectric or charge-transfer phase transition. Such NTE materials have attracted considerable attention for use as thermal-expansion compensators. Here, we report the discovery of giant NTE for reduced layered ruthenate. The total volume change related to NTE reaches 6.7% in dilatometry, a value twice as large as the largest volume change reported to date. We observed a giant negative coefficient of linear thermal expansion α=-115 × 10 -6  K -1 over 200 K interval below 345 K. This dilatometric NTE is too large to be attributable to the crystallographic unit-cell volume variation with temperature. The highly anisotropic thermal expansion of the crystal grains might underlie giant bulk NTE via microstructural effects consuming open spaces in the sintered body on heating.

Ergodic model for the expansion of spherical nanoplasmas.

Science.gov (United States)

Peano, F; Coppa, G; Peinetti, F; Mulas, R; Silva, L O

2007-06-01

Recently, the collisionless expansion of spherical nanoplasmas has been analyzed with a new ergodic model, clarifying the transition from hydrodynamiclike to Coulomb-explosion regimes, and providing accurate laws for the relevant features of the phenomenon. A complete derivation of the model is presented here. The important issue of the self-consistent initial conditions is addressed by analyzing the initial charging transient due to the electron expansion, in the approximation of immobile ions. A comparison among different kinetic models for the expansion is presented, showing that the ergodic model provides a simplified description, which retains the essential information on the electron distribution, in particular, the energy spectrum. Results are presented for a wide range of initial conditions (determined from a single dimensionless parameter), in excellent agreement with calculations from the exact Vlasov-Poisson theory, thus providing a complete and detailed characterization of all the stages of the expansion.

Photographic assessment of nasal morphology following rapid maxillary expansion in children

Science.gov (United States)

da SILVA FILHO, Omar Gabriel; LARA, Tulio Silva; AYUB, Priscila Vaz; OHASHI, Amanda Sayuri Cardoso; BERTOZ, Francisco Antônio

2011-01-01

Objective The aim of the present study was to use facial analysis to determine the effects of rapid maxillary expansion (RME) on nasal morphology in children in the stages of primary and mixed dentition, with posterior cross-bite. Material and Methods Facial photographs (front view and profile) of 60 patients in the pre-expansion period, immediate post-expansion period and one year following rapid maxillary expansion with a Haas appliance were evaluated on 2 occasions by 3 experienced orthodontists independently, with a 2-week interval between evaluations. The examiners were instructed to assess nasal morphology and had no knowledge regarding the content of the study. Intraexaminer and interexaminer agreement (assessed using the Kappa statistic) was acceptable. Results From the analysis of the mode of the examiners' findings, no alterations in nasal morphology occurred regarding the following aspects: dorsum of nose, alar base, nasal width of middle third and nasal base. Alterations were only detected in the nasolabial angle in 1.64% of the patients between the pre-expansion and immediate post-expansion photographs. In 4.92% of the patients between the immediate post-expansion period and 1 year following expansion; and in 6.56% of the patients between the pre-expansion period and one year following expansion. Conclusion RME performed on children in stages of primary and mixed dentition did not have any impact on nasal morphology, as assessed using facial analysis. PMID:21986660

Hiperalgesia asociada al tratamiento con opioides

OpenAIRE

A. Gil Martín; M. Moreno García; J. Sánchez-Rubio Ferrández; T. Molina García

2014-01-01

La hiperalgesia inducida por opioides es una reacción paradójica caracterizada por una percepción intensificada de dolor relacionada con el uso de estos medicamentos en ausencia de progresión de la enfermedad o de síndrome de retirada. A diferencia de los casos de tolerancia, definida como pérdida de potencia analgésica durante el uso prolongado de opioides, no se produce mejoría con el escalado de dosis. La hiperalgesia inducida por opioides se ha manifestado en pacientes con dosis de manten...

Paciente con tumor de cuerpo carotideo

Directory of Open Access Journals (Sweden)

Mariuska Forteza Sáez

Full Text Available Los tumores de cuerpo carotideo (paragangliomas son neoplasias altamente vascularizadas, muy poco frecuentes y generalmente benignas, originadas en los quimiorreceptores del cuerpo carotideo. Se presenta el caso de un paciente de 54 años, con aumento de volumen cervical derecho, asintomático, con estudio preoperatorio y angiografía realizados por tomografía axial computarizada, que resultan compatibles con tumor de cuerpo carotideo. Se realiza disección subadventicial, informando la biopsia paraganglioma. El tumor fue completamente resecado, sin evidencia de recurrencia y sin complicaciones.

A simulation environment for dry-expansion evaporators with application to the design of autotuning control algorithms for electronic expansion valves

Energy Technology Data Exchange (ETDEWEB)

Beghi, Alessandro [Dipartimento di Ingegneria dell' Informazione, Universita di Padova, via Gradenigo 6/B, I-35131 Padova (Italy); Cecchinato, Luca [Dipartimento di Fisica Tecnica, Universita di Padova, via Venezia 1, I-35131 Padova (Italy)

2009-11-15

In this paper some results of a research project aimed at deriving high-performance, adaptive control algorithms for electronic expansion valves (EEVs) to be used in finned-coiled, dry-expansion evaporators for refrigeration systems are reported. With the aim of developing a software environment that can be used for controller design, rapid prototyping, optimization of data collection and test design, virtual prototyping approach to design was adopted. The development of a distributed dynamic simulation model of the evaporator coupled with an electronic expansion valve, and its use for deriving autotuning PID control algorithms is described. Experimental results confirm the effectiveness of this kind of approach. (author)

Spherical harmonic expansion of short-range screened Coulomb interactions

Energy Technology Data Exchange (ETDEWEB)

Angyan, Janos G [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Gerber, Iann [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Marsman, Martijn [Institut fuer Materialphysik and Center for Computational Materials Science, Universitaet Wien, Sensengasse 8, A-1090, Vienna (Austria)

2006-07-07

Spherical harmonic expansions of the screened Coulomb interaction kernel involving the complementary error function are required in various problems in atomic, molecular and solid state physics, like for the evaluation of Ewald-type lattice sums or for range-separated hybrid density functionals. A general analytical expression is derived for the kernel, which is non-separable in the radial variables. With the help of series expansions a separable approximate form is proposed, which is in close analogy with the conventional multipole expansion of the Coulomb kernel in spherical harmonics. The convergence behaviour of these expansions is studied and illustrated by the electrostatic potential of an elementary charge distribution formed by products of Slater-type atomic orbitals.

Radial expansion and multifragmentation

International Nuclear Information System (INIS)

Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Kerambrun, A.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Meslin, C.; Nakagawa, T.; Patry, J.P.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Yuasa-Nakagawa, K.; Wieloch, A.

1998-01-01

The light systems 36 Ar + 27 Al and 64 Zn + nat Ti were measured at several bombarding energies between ∼ 35 and 95 MeV/nucleon. It was found that the predominant part of the cross section is due to binary collisions. In this paper the focus is placed on the properties of the quasi-projectile nuclei. In the central collisions the excitation energies of the quasi-projectile reach values exceeding largely 10 MeV/nucleon. The slope of the high energy part of the distribution can give only an upper limit of the apparent temperature (the average temperature along the decay chain). The highly excited quasi-projectile may get rapidly fragmented rather than sequentially. The heavy fragments are excited and can emit light particles (n, p, d, t, 3 He, α,...) what perturbs additionally the spectrum of these particles. Concerning the expansion energy, one can determine the average kinetic energies of the product (in the quasi-projectile-framework) and compare with simulation values. To fit the experimental data an additional radial expansion energy is to be considered. The average expansion energy depends slightly on the impact parameter but it increases with E * / A, ranging from 0.4 to 1,2 MeV/nucleon for an excitation energy increasing from 7 to 10.5 MeV/nucleon. This collective radial energy seems to be independent of the fragment mass, what is possibly valid for the case of larger quasi-projectile masses. The origin of the expansion is to be determined. It may be due to a compression in the interaction zone at the initial stage of the collision, which propagates in the quasi-projectile and quasi-target, or else, may be due, simply, to the increase of thermal energy leading to a rapid fragment emission. The sequential de-excitation calculation overestimates light particle emission and consequently heavy residues, particularly, at higher excitation energies. This disagreement indicates that a sequential process can not account for the di-excitation of very hot nuclei

Expansion of a function about a displaced centre

International Nuclear Information System (INIS)

Rashid, M.A.

1981-07-01

We review the progress recently made in obtaining closed form expressions for the expansion of general orbitals about a displaced centre and establish the equivalence between different expansions. We also examine how these expressions do have the desired limit as the displacement approaches zero. (author)

Simplified Technique for Predicting Offshore Pipeline Expansion

Science.gov (United States)

Seo, J. H.; Kim, D. K.; Choi, H. S.; Yu, S. Y.; Park, K. S.

2018-06-01

In this study, we propose a method for estimating the amount of expansion that occurs in subsea pipelines, which could be applied in the design of robust structures that transport oil and gas from offshore wells. We begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea pipelines. Due to the effects of high pressure and high temperature, the production of fluid from offshore wells is typically caused by physical deformation of subsea structures, e.g., expansion and contraction during the transportation process. In severe cases, vertical and lateral buckling occurs, which causes a significant negative impact on structural safety, and which is related to on-bottom stability, free-span, structural collapse, and many other factors. In addition, these factors may affect the production rate with respect to flow assurance, wax, and hydration, to name a few. In this study, we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage, which can lead to savings in both cost and computation time. As such, in this paper, we propose an applicable diagram, which we call the standard dimensionless ratio (SDR) versus virtual anchor length (L A ) diagram, that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable scenarios. With this user guideline, offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation, design, and maintenance of the subsea pipeline.

216-B-3 expansion ponds closure plan

International Nuclear Information System (INIS)

1994-10-01

This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA

216-B-3 expansion ponds closure plan

Energy Technology Data Exchange (ETDEWEB)

1994-10-01

This document describes the activities for clean closure under the Resource Conservation and Recovery Act of 1976 (RCRA) of the 216-B-3 Expansion Ponds. The 216-B-3 Expansion Ponds are operated by the US Department of Energy, Richland Operations Office (DOE-RL) and co-operated by Westinghouse Hanford Company (Westinghouse Hanford). The 216-B-3 Expansion Ponds consists of a series of three earthen, unlined, interconnected ponds that receive waste water from various 200 East Area operating facilities. The 3A, 3B, and 3C ponds are referred to as Expansion Ponds because they expanded the capability of the B Pond System. Waste water (primarily cooling water, steam condensate, and sanitary water) from various 200 East Area facilities is discharged to the Bypass pipe (Project X-009). Water discharged to the Bypass pipe flows directly into the 216-B-3C Pond. The ponds were operated in a cascade mode, where the Main Pond overflowed into the 3A Pond and the 3A Pond overflowed into the 3C Pond. The 3B Pond has not received waste water since May 1985; however, when in operation, the 3B Pond received overflow from the 3A Pond. In the past, waste water discharges to the Expansion Ponds had the potential to have contained mixed waste (radioactive waste and dangerous waste). The radioactive portion of mixed waste has been interpreted by the US Department of Energy (DOE) to be regulated under the Atomic Energy Act of 1954; the dangerous waste portion of mixed waste is regulated under RCRA.

Local behaviour of negative thermal expansion materials

International Nuclear Information System (INIS)

Fornasini, P.; Dalba, G.; Grisenti, R.; Purans, J.; Vaccari, M.; Rocca, F.; Sanson, A.

2006-01-01

EXAFS can represent a powerful probe of the local behaviour of negative thermal expansion (NTE) materials, thanks to the possibility of measuring the expansion of selected inter-atomic bonds and the perpendicular relative atomic displacements. The effectiveness of EXAFS for NTE studies is illustrated by a comparison of results recently obtained on germanium, CuCl and the cuprites Cu 2 O and Ag 2 O

Medicaid expansion and access to care among cancer survivors: a baseline overview.

Science.gov (United States)

Tarazi, Wafa W; Bradley, Cathy J; Harless, David W; Bear, Harry D; Sabik, Lindsay M

2016-06-01

Medicaid expansion under the Affordable Care Act facilitates access to care among vulnerable populations, but 21 states have not yet expanded the program. Medicaid expansions may provide increased access to care for cancer survivors, a growing population with chronic conditions. We compare access to health care services among cancer survivors living in non-expansion states to those living in expansion states, prior to Medicaid expansion under the Affordable Care Act. We use the 2012 and 2013 Behavioral Risk Factor Surveillance System to estimate multiple logistic regression models to compare inability to see a doctor because of cost, having a personal doctor, and receiving an annual checkup in the past year between cancer survivors who lived in non-expansion states and survivors who lived in expansion states. Cancer survivors in non-expansion states had statistically significantly lower odds of having a personal doctor (adjusted odds ratio [AOR] 0.76, 95 % confidence interval [CI] 0.63-0.92, p Medicaid could potentially leave many cancer survivors with limited access to routine care. Existing disparities in access to care are likely to widen between cancer survivors in Medicaid non-expansion and expansion states.

Beneficios de la terapia con resistómetro inspiratorio en los pacientes con esclerosis multiple frente a terapias respiratorias convencionales

OpenAIRE

Martín Sánchez, Carlos

2016-01-01

[ES] La Universidad de Salamanca (USAL) a través del programa de Doctorado en Oncología Clínica realiza un estudio con ASPRODES, la Asociación Salmantina de Esclerosis Múltiple (ASDEM) y la Asociación Zamorana de Esclerosis Múltiple (AZDEM) para llevar a cabo un estudio experimental con el fin de analizar las ventajas que la terapia respiratoria con resistómetro inspiratorio puede aportar a los pacientes con Esclerosis Múltiple frente a las técnicas de fisioterapia respiratoria convencional. ...

Los adolescentes españoles y sus familias: Calidad en la comunicación con el padre y con la madre y conductas de riesgo relacionadas con el consumo de sustancias adictivas

OpenAIRE

Moreno Rodríguez, María del Carmen; Muñoz Tinoco, María Victoria; Pérez Moreno, Pedro Juan; Sánchez Queija, María Inmaculada

2006-01-01

Se presenta una reflexión acerca de cómo transcurren los años de la adolescencia en el contexto de la familia, analizando las transformaciones que se producen en las relaciones con los progenitores. El trabajo empírico se centra en una de las dimensiones que definen la calidad de las relaciones en el contexto familiar -la facilidad en la comunicación entre el adolescente y sus padres- y en su relación con algunas conductas de los adolescentes relacionadas con la salud, como es el caso del con...

Generalized approach to the non-backtracking lace expansion

NARCIS (Netherlands)

Fitzner, R.; van der Hofstad, R.W.

2017-01-01

The lace expansion is a powerful perturbative technique to analyze the critical behavior of random spatial processes such as the self-avoiding walk, percolation and lattice trees and animals. The non-backtracking lace expansion (NoBLE) is a modification that allows us to improve its applicability in

14 CFR 27.969 - Fuel tank expansion space.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 27.969 Section 27.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.969 Fuel tank expansion space...

14 CFR 25.969 - Fuel tank expansion space.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 25.969 Section 25.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.969 Fuel tank expansion space...

14 CFR 29.969 - Fuel tank expansion space.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank expansion space. 29.969 Section 29.969 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.969 Fuel tank expansion space...

Sensibilidad paramétrica de un automóvil con polinomios de caos

Directory of Open Access Journals (Sweden)

Eduardo Haro

2015-07-01

Full Text Available Resumen: Es de gran interés analizar la sensibilidad de los parámetros de modelos matemáticos que describen sistemas físicos, y merece una atención particular estudiar esta sensibilidad en modelos con incertidumbre en el valor de sus parámetros. La llamada sensibilidad global considera todo el intervalo de incertidumbre de los parámetros al considerarlos variables aleatorias. Este trabajo presenta el análisis de sensibilidad global en frecuencia del modelo matemático paramétrico de la dinámica lateral de un modelo de automóvil, con un enfoque basado en la expansión de la respuesta del modelo con polinomios de caos. Esta técnica permite representar fácilmente el sistema como un modelo estocástico, donde los parámetros pasan a ser variables aleatorias que varían de acuerdo a su incertidumbre. El modelo estocástico debe ser una aproximación muy cercana del modelo original. Abstract: It is interesting to analyze the parameter sensitivity of mathematical models that describe physical systems, and it deserves particular attention the sensitivity study of models with uncertainty in the parameter values. Global sensitivity takes into account the entire range of parameter uncertainty because it considers the parameters as random variables. This paper presents the global sensitivity analysis in frequency of a parametric mathematical model of lateral dynamics of a vehicle model, with an approach based on the polynomial chaos expansion of the model response. This technique allows to easily represent the system as a stochastic model, where the parameters become random variables that vary according to their uncertainty. The stochastic model should be a very close approximation of the original model. Palabras clave: sensibilidad, sistemas dinámicos inciertos, polinomios de caos, dinámica de vehículo, Keywords: sensitivity uncertain dynamic systems polynomial chaos vehicle dynamics

Santiago, una ciudad con temor

Directory of Open Access Journals (Sweden)

Enrique Oviedo S.

1999-04-01

Full Text Available El objetivo general de este artículo es evaluar los efectos de la inseguridad ciudadana en el uso del espacio público. Dicha evaluación exige analizar dos relaciones que se establecen en el ámbito de la violencia: la relación entre victimización y percepción de inseguridad; y la que se establece entre actitudes sociales y resolución pacífica de conflictos nacionales. Para ello, se analizaron las variables victimización, percepción de inseguridad, uso del espacio físico, actitudes hacia el sistema institucional político y social y hacia la resolución de conflictos nacionales, y las posibles relaciones entre ellas. Los datos para realizar el estudio se obtuvieron por medio de una encuesta que se llevó a cabo con 1 200 personas de 18 y 70 años de edad residentes en la ciudad de Santiago. Los resultados indican que Santiago es una ciudad de habitantes con temor y que el aumento de la percepción de inseguridad de sus habitantes contrasta con el hecho de que las tasas de victimización se hayan mantenido, más o menos, constantes en los años que precedieron a la encuesta. El temor se relaciona con el abandono del espacio público físico y sociopolítico, así como con el refugio en los espacios y la vida privados. La actitud de resolver los conflictos por medios no pacíficos es frecuente y se asocia en mayor medida con la inseguridad, la actitud negativa hacia la democracia y la falta de expectativas sobre el futuro del país. Los resultados de este estudio respaldan la idea de que para superar el temor la gente tiende a adaptarse a la realidad adoptando una postura conformista, homogeneizando las creencias y los comportamientos, y sobreestimando la fuerza como medio para resolver las diferencias.

Santiago, una ciudad con temor

Directory of Open Access Journals (Sweden)

Oviedo S. Enrique

1999-01-01

Full Text Available El objetivo general de este artículo es evaluar los efectos de la inseguridad ciudadana en el uso del espacio público. Dicha evaluación exige analizar dos relaciones que se establecen en el ámbito de la violencia: la relación entre victimización y percepción de inseguridad; y la que se establece entre actitudes sociales y resolución pacífica de conflictos nacionales. Para ello, se analizaron las variables victimización, percepción de inseguridad, uso del espacio físico, actitudes hacia el sistema institucional político y social y hacia la resolución de conflictos nacionales, y las posibles relaciones entre ellas. Los datos para realizar el estudio se obtuvieron por medio de una encuesta que se llevó a cabo con 1 200 personas de 18 y 70 años de edad residentes en la ciudad de Santiago. Los resultados indican que Santiago es una ciudad de habitantes con temor y que el aumento de la percepción de inseguridad de sus habitantes contrasta con el hecho de que las tasas de victimización se hayan mantenido, más o menos, constantes en los años que precedieron a la encuesta. El temor se relaciona con el abandono del espacio público físico y sociopolítico, así como con el refugio en los espacios y la vida privados. La actitud de resolver los conflictos por medios no pacíficos es frecuente y se asocia en mayor medida con la inseguridad, la actitud negativa hacia la democracia y la falta de expectativas sobre el futuro del país. Los resultados de este estudio respaldan la idea de que para superar el temor la gente tiende a adaptarse a la realidad adoptando una postura conformista, homogeneizando las creencias y los comportamientos, y sobreestimando la fuerza como medio para resolver las diferencias.

Back Reaction And Local Cosmological Expansion Rate

CERN Document Server

Geshnizjani, G; Geshnizjani, Ghazal; Brandenberger, Robert

2002-01-01

We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single field. We analyze back reaction both in a matter dominated Universe and in a phase of scalar field-driven chaotic inflation. In both cases, we find that the leading infrared terms contributing to the back reaction vanish when the local expansion rate is measured at a fixed value of the matter field which is used as a clock, whereas they do not appear to vanish if the expansion rate is evaluated at a fixed value of the background time. We discuss possible implications for more realistic models with a more complicated matter sector.

Effects of emergency department expansion on emergency department patient flow.

Science.gov (United States)

Mumma, Bryn E; McCue, James Y; Li, Chin-Shang; Holmes, James F

2014-05-01

Emergency department (ED) crowding is an increasing problem associated with adverse patient outcomes. ED expansion is one method advocated to reduce ED crowding. The objective of this analysis was to determine the effect of ED expansion on measures of ED crowding. This was a retrospective study using administrative data from two 11-month periods before and after the expansion of an ED from 33 to 53 adult beds in an academic medical center. ED volume, staffing, and hospital admission and occupancy data were obtained either from the electronic health record (EHR) or from administrative records. The primary outcome was the rate of patients who left without being treated (LWBT), and the secondary outcome was total ED boarding time for admitted patients. A multivariable robust linear regression model was used to determine whether ED expansion was associated with the outcome measures. The mean (±SD) daily adult volume was 128 (±14) patients before expansion and 145 (±17) patients after. The percentage of patients who LWBT was unchanged: 9.0% before expansion versus 8.3% after expansion (difference = 0.6%, 95% confidence interval [CI] = -0.16% to 1.4%). Total ED boarding time increased from 160 to 180 hours/day (difference = 20 hours, 95% CI = 8 to 32 hours). After daily ED volume, low-acuity area volume, daily wait time, daily boarding hours, and nurse staffing were adjusted for, the percentage of patients who LWBT was not independently associated with ED expansion (p = 0.053). After ED admissions, ED intensive care unit (ICU) admissions, elective surgical admissions, hospital occupancy rate, ICU occupancy rate, and number of operational ICU beds were adjusted for, the increase in ED boarding hours was independently associated with the ED expansion (p = 0.005). An increase in ED bed capacity was associated with no significant change in the percentage of patients who LWBT, but had an unintended consequence of an increase in ED boarding hours. ED expansion alone does

Thermal expansion and phase transitions of α-AlF{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Morelock, Cody R.; Hancock, Justin C. [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States); Wilkinson, Angus P., E-mail: angus.wilkinson@chemistry.gatech.edu [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)

2014-11-15

ReO{sub 3}-type materials are of interest for their potential low or negative thermal expansion. Many metal trifluorides MF{sub 3} adopt the cubic form of this structure at elevated temperatures, which rhombohedrally distorts upon cooling. The rhombohedral form displays strong positive volume thermal expansion, but cubic MF{sub 3} display much lower and sometimes negative thermal expansion. The expansion behavior of α-AlF{sub 3} was characterized via synchrotron powder diffraction between 323 and 1177 K. α-AlF{sub 3} is rhombohedral at ambient conditions and displays strongly anisotropic thermal expansion. The volume coefficient of thermal expansion (CTE), α{sub V}, at 500 K is ∼86 ppm K{sup −1}, but the linear CTE along the c-axis, α{sub c}, is close to zero. α-AlF{sub 3} becomes cubic on heating to ∼713 K and continues to show positive thermal expansion above the phase transition (α{sub V}(900 K) ∼25 ppm K{sup −1}). - Graphical abstract: α-AlF{sub 3} has a rhombohedrally distorted ReO{sub 3}-type structure at ambient conditions and displays strongly positive volume thermal expansion that is highly anisotropic; the material becomes cubic on heating above ∼713 K and continues to show positive thermal expansion. - Highlights: • ReO{sub 3}-type α-AlF{sub 3} displays strongly anisotropic thermal expansion below 713 K. • α-AlF{sub 3} is cubic above 713 K and maintains positive (isotropic) thermal expansion. • The volume CTE changes from ∼86 to ∼25 ppm K{sup −1} on heating from 500 to 900 K. • The PTE of cubic α-AlF{sub 3} may be due to the presence of local octahedral tilts.

Síndrome disejecutivo en personas con dependencia alcohólica con/sin recidivas

OpenAIRE

Fidalgo Martínez, Eva

2015-01-01

[ES]En la mayoría de las culturas el alcohol es el depresor del SNC utilizado con más frecuencia y el responsable de una morbilidad y una mortalidad considerables. En la actualidad, el consumo de bebidas alcohólicas constituye un importante problema de salud pública, especialmente en España, que es uno de los países con mayor consumo de alcohol por habitante y año. El objetivo general del estudio es determinar la existencia de diferencias significativas entre dos grupos clínicos de sujetos...

FORTIFICACIÓN DE PULPA DE UCHUVA CON CALCIO, OLIGOFRUCTOSA Y VITAMINA C, ESTABILIZADA CON HIDROCOLOIDE

Directory of Open Access Journals (Sweden)

ALBA LUCIA DUQUE

2014-06-01

Full Text Available La pulpa de uchuva fortificada con calcio, oligofructosa y vitamina C es un alimento funcional con grandes beneficios para la salud. Para ello se le adicionó componentes biológicamente activos, como ácidos grasos, fibra alimentaria y antioxidantes. En este trabajo se estudió la estabilidad de la pulpa enriquecida en diferentes formulaciones, teniendo en cuenta los criterios de incorporación de calcio y vitamina C (20% del valor diario recomendado VDR y para la oligofructosa (fibra dietaría en relación 1:1 con el calcio. Los resultados obtenidos mostraron que la pulpa de uchuva fortificada con CMC, ologofructosa, calcio y vitamina C presentó en promedio una estabilidad de 87,7±10,0; una viscosidad de 22,8±7,9; una aw de 0,9863±0; pH de 3,3±0,1; acidez de 1,6±0,1; grados Brix de 13,3±0,7; una densidad de 1,32±0 g/mL y las mejores respuestas sensoriales en cuanto a color, aroma, fluidez y sabor.

The 1/ N Expansion of Tensor Models Beyond Perturbation Theory

Science.gov (United States)

Gurau, Razvan

2014-09-01

We analyze in full mathematical rigor the most general quartically perturbed invariant probability measure for a random tensor. Using a version of the Loop Vertex Expansion (which we call the mixed expansion) we show that the cumulants write as explicit series in 1/ N plus bounded rest terms. The mixed expansion recasts the problem of determining the subleading corrections in 1/ N into a simple combinatorial problem of counting trees decorated by a finite number of loop edges. As an aside, we use the mixed expansion to show that the (divergent) perturbative expansion of the tensor models is Borel summable and to prove that the cumulants respect an uniform scaling bound. In particular the quartically perturbed measures fall, in the N→ ∞ limit, in the universality class of Gaussian tensor models.

Surgical Splint Design Influences Transverse Expansion in Segmental Maxillary Osteotomies

DEFF Research Database (Denmark)

Stokbro, Kasper; Aagaard, Esben; Torkov, Peter

2017-01-01

splint designs on achieving the planned transverse expansion in bimaxillary surgery with segmental maxillary procedures. Materials and Methods: Forty-two participants were included in a retrospective observational study. All participants had completed virtually planned bimaxillary surgery with 3-piece......Purpose: In segmental maxillary procedures, it is imperative to obtain as much of the planned expansion as possible. Lack of obtained expansion, in addition to late relapse after splint removal, can result in relapse of the posterior crossbite. This study investigated the influence of 2 surgical...... maxillary segmentation. The primary outcome variable was the transverse expansion obtained, measured as the expansion between the maxillary first molars on preoperative and postoperative cone-beam computed tomograms. The postoperative scan was performed 1 week after surgery with the splint still in place...

A two-parameter family of double-power-law biorthonormal potential-density expansions

Science.gov (United States)

Lilley, Edward J.; Sanders, Jason L.; Evans, N. Wyn

2018-05-01

We present a two-parameter family of biorthonormal double-power-law potential-density expansions. Both the potential and density are given in closed analytic form and may be rapidly computed via recurrence relations. We show that this family encompasses all the known analytic biorthonormal expansions: the Zhao expansions (themselves generalizations of ones found earlier by Hernquist & Ostriker and by Clutton-Brock) and the recently discovered Lilley et al. (2017a) expansion. Our new two-parameter family includes expansions based around many familiar spherical density profiles as zeroth-order models, including the γ models and the Jaffe model. It also contains a basis expansion that reproduces the famous Navarro-Frenk-White (NFW) profile at zeroth order. The new basis expansions have been found via a systematic methodology which has wide applications in finding other new expansions. In the process, we also uncovered a novel integral transform solution to Poisson's equation.

Evaluating expansion strategies for startup European Union dairy farm businesses.

Science.gov (United States)

McDonald, R; Shalloo, L; Pierce, K M; Horan, B

2013-06-01

A stochastic whole-farm simulation model was used to examine alternative strategies for new entrant dairy farmers to grow and develop dairy farm businesses in the context of European Union (EU) milk quota abolition in 2015. Six alternative strategies were compared: remain static, natural growth expansion, waiting until after EU milk quota abolition to expand, a full-scale expansion strategy without milk quotas and not incurring super levy penalties, a full-scale expansion strategy with milk quotas and incurring super levy penalties, and once-a-day milking until EU milk quota abolition, followed by full-scale expansion. Each discrete whole farm investment strategy was evaluated over a 15-yr period (2013-2027) using multiple financial stability and risk indicators, including overall discounted farm business profitability, net worth change, return on investment, and financial risk. The results of this study indicate that, although associated with increased risk, dairy farm expansion will ensure the future profitability of the farm business. Within the context of EU milk quotas until 2015, the most attractive expansion strategy is to increase cow numbers while avoiding super levy fines using once-a-day milking techniques, increasing to the full capacity of the dairy farm once milk quotas are removed. In contrast, the results also indicate that dairy farms that remain static will experience a significant reduction in farm profitability in the coming year due to production cost inflation. Cash flow deficits were observed during the initial year of expansion and, therefore, rapidly expanding dairy farm businesses require a significant cash reserve to alleviate business risk during the initial year of expansion. The results of this analysis also indicate that dairy farm businesses that expand using lower cost capital investments and avoid milk quota super levy fines significantly reduce the financial risks associated with expansion. Copyright © 2013 American Dairy Science

Genetic traces of east-to-west human expansion waves in Eurasia.

Science.gov (United States)

Chaix, Raphaëlle; Austerlitz, Frédéric; Hegay, Tatyana; Quintana-Murci, Lluís; Heyer, Evelyne

2008-07-01

In this study, we describe the landscape of human demographic expansions in Eurasia using a large continental Y chromosome and mitochondrial DNA dataset. Variation at these two uniparentally-inherited genetic systems retraces expansions that occurred in the past 60 ky, and shows a clear decrease of expansion ages from east to west Eurasia. To investigate the demographic events at the origin of this westward decrease of expansion ages, the estimated divergence ages between Eurasian populations are compared with the estimated expansion ages within each population. Both markers suggest that the demographic expansion diffused from east to west in Eurasia in a demic way, i.e., through migrations of individuals (and not just through diffusion of new technologies), highlighting the prominent role of eastern regions within Eurasia during Palaeolithic times. (c) 2008 Wiley-Liss, Inc.

Intervención psicomotriz en niños con trastorno por déficit de atención con hiperactividad

OpenAIRE

Herguedas Esteban, María del Carmen

2016-01-01

El trastorno por déficit de atención con hiperactividad (TDAH) es una de las principales causas de fracaso escolar. Los niños con este trastorno deben ser atendidos en una escuela inclusiva que permita responder a las necesidades de todos los alumnos. Se ha desarrollado un trabajo de investigación cuyos objetivos eran: evaluar las alteraciones psicomotoras de los niños con TDAH; elaborar un programa educativo de intervención psicomotriz para niños con TDAH; aplicar dicho programa en un gru...

Enfermedad periodontal en pacientes con discapacidad en custodia versus pacientes con discapacidad independientes

Directory of Open Access Journals (Sweden)

Fermín-Guerrero-Del Ángel

2012-01-01

Full Text Available Objetivo: Identificar el estado de salud periodontal en pacientes con discapacidad en custodia versus pacientes independientes en su higiene oral. Material y métodos: Se examinaron pacientes con discapacidad, ambos sexos, 3 a 19 años que acuden al Servicio de Odontopediatría del Centro de Rehabilitación Infantil Teletón (CRIT Tamaulipas mediante revisión de cavidad oral y aplicación del Índice de Higiene Oral Simplificado (IHOS, Índice Periodontal Comunitario de la Necesidad de Tratamiento (IPCNT y entrevista con su cuidador primario. Se agruparon en dos categorías: Independientes y de Custodia. Resultados: En el total de la muestra la Media y Desviación estándar (D.E. de IPCNT fue de 0.89±0.54, así como el IHOS de 1.88±0.77. El IPCNT en pacientes con discapacidad de Custodia fue 0.91±0.57 e Independientes de 0.86±0.49 (p=0.70, IHOS en pacientes de Custodia 1.89±0.78 e Independientes 1.87±.0.74 (p=.93. IPCNT en géneros masculino 1.03±0.54 y femenino 0.75±0.51 (p=.009. IHOS en pacientes que habitan área rural 2.41±1.25 y área urbana 1.83±0.68 (p=.02. Relación entre la edad y la necesidad de tratamiento periodontal (p=0.001. Frecuencia del cepillado del grupo Independientes 2.03±0.56 y de Custodia 2.00±0.75 (p=.84. Conclusiones: No existe diferencia en el estado de salud periodontal y el grado de higiene oral entre pacientes con discapacidad Independientes y de Custodia. La mayoría de los pacientes Independientes y de Custodia tienen una necesidad de tratamiento de Instrucción de Higiene Oral (TN1 y tienen Higiene Oral Regular.

Demodicidosis en pacientes con rosácea

Directory of Open Access Journals (Sweden)

Edhizon Trejo Mucha

2007-01-01

Full Text Available Objetivo: Determinar la frecuencia de demodicidosis y sus características clínicas en pacientes con rosácea. Materiales y métodos: Estudio de casos y controles en 42 pacientes con rosácea y 42 controles para describir la presencia y densidad de D. folliculorum. El estudio se realizó en el Hospital Nacional Cayetano Heredia entre marzo y setiembre del 2004, utilizándose la técnica de Tello. Resultados: Demodex folliculorum fue encontrado en los 42 pacientes con rosácea (100% y en 13 (31,0% del grupo control, (p= 0,000. La exposición a gatos, la crianza de roedores y cerdos, la seborrea y el uso de corticoides tópicos fueron mas frecuentes en los pacientes con rosácea. Conclusiones: La presencia de Demodex folliculorum fue más frecuente en los pacientes con rosácea. (Rev Med Hered 2007;18:15-21.

Materiales nanocumpuestos basados en LDPE relleno con nanotubos de carbono con potenciales propiedades bactericidas

OpenAIRE

Benigno Escribano, Erika

2015-01-01

En este trabajo, se ha seleccionado como material de estudio polietileno de baja densidad, LDPE, ya que es un polímero con múltiples aplicaciones en diversos campos. Se busca como objetivo principal, preparar y caracterizar nuevos materiales basados en LDPE con potenciales propiedades antibacterianas. Para ello, se van a estudiar dos posibles maneras de conseguirlo: La primera de ellas, consiste en realizar un procesado mecánico sobre el polietileno, concretamente, una molienda del alta en...

Setting time and thermal expansion of two endodontic cements.

Science.gov (United States)

Santos, Alailson D; Araújo, Eudes B; Yukimitu, Keizo; Barbosa, José C; Moraes, João C S

2008-09-01

The purpose of this study was to evaluate the setting time and the thermal expansion coefficient of 2 endodontic cements, MTA-Angelus and a novel cement called CER. The setting time was determined in accordance to ANSI/ADA specifications no. 57. Three samples of 10 mm diameter and 2 mm thickness were prepared for each cement. The thermal expansion measurements were performed by strain gauge technique. Four samples of each cement were prepared using silicone rings of 5 mm diameter and 2 mm thickness. The data were analyzed statistically using the Student t test. The setting time obtained for the MTA-Angelus and CER cements was 15 (SD 1) min and 7 (SD 1) min, respectively. The linear coefficient of thermal expansion was 8.86 (SD 0.28) microstrain/ degrees C for MTA-Angelus and 11.76 (SD 1.20) microstrain/ degrees C for CER. The statistical analysis showed significant difference (P linear coefficient of thermal expansion between the 2 cements. The CER cement has a coefficient of expansion similar to dentin, which could contribute to a decrease of microleakage degree.

Advanced methodology for generation expansion planning including interconnected systems

Energy Technology Data Exchange (ETDEWEB)

Zhao, M; Yokoyama, R; Yasuda, K [Tokyo Metropolitan Univ. (Japan); Sasaki, H [Hiroshima Univ. (Japan); Ogimoto, K [Electric Power Development Co. Ltd., Tokyo (Japan)

1994-12-31

This paper reviews advanced methodology for generation expansion planning including interconnected systems developed in Japan, putting focus on flexibility and efficiency in a practical application. First, criteria for evaluating flexibility of generation planning considering uncertainties are introduced. Secondly, the flexible generation mix problem is formulated as a multi-objective optimization with more than two objective functions. The multi-objective optimization problem is then transformed into a single objective problem by using the weighting method, to obtain the Pareto optimal solution, and solved by a dynamics programming technique. Thirdly, a new approach for electric generation expansion planning of interconnected systems is presented, based on the Benders Decomposition technique. That is, large scale generation problem constituted by the general economic load dispatch problem, and several sub problems which are composed of smaller scale isolated system generation expansion plans. Finally, the generation expansion plan solved by an artificial neural network is presented. In conclusion, the advantages and disadvantages of this method from the viewpoint of flexibility and applicability to practical generation expansion planning are presented. (author) 29 refs., 10 figs., 4 tabs.

Urban Land Expansion and Spatial Dynamics in Globalizing Shanghai

Directory of Open Access Journals (Sweden)

Han Li

2014-12-01

Full Text Available Urban land expansion in China has attracted considerable scholarly attention. However, more work is needed to apply spatial modeling to understanding the mechanisms of urban growth from both institutional and physical perspectives. This paper analyzes urban expansion in Shanghai and its development zones (DZs. We find that, as nodes of global-local interface, the DZs are the most significant components of urban growth in Shanghai, and major spatial patterns of urban expansion in Shanghai are infilling and edge expansion. We apply logistic regression, geographically weighted logistic regression (GWLR and spatial regime regression to investigate the determinants of urban land expansion including physical conditions, state policy and land development. Regressions reveal that, though the market has been an important driving force in urban growth, the state has played a predominant role through the implementation of urban planning and the establishment of DZs to fully capitalize on globalization. We also find that differences in urban growth dynamics exist between the areas inside and outside of the DZs. Finally, this paper discusses policies to promote sustainable development in Shanghai.

Separable pole expansions in four-nucleon bound state calculations

International Nuclear Information System (INIS)

Sofianos, S.A.; Fiedeldey, H.; Haberzettl, H.; Sandhas, W.

1982-04-01

We compare the utility of the Generalized Unitary Pole Expansion (GUPE) and the Energy-Dependent Pole Expansion (EDPE) for the three-body subsystem amplitudes in four-body state calculations for a variety of separable and local nucleon-nucleon interactions. It is found that, with the EDPE, the four-body binding energy is well reproduced with only two terms each for the (2+2)- and the (3+1)-subsystem, respectively, while the GUPE requires three terms for the (3+1)-channel and four terms for the (2+2)-channel. We thus conclude that pole dominance is of greater importance for the GUPE than for EDPE, which works equally well for both types of subsystems. It is found that both methods, in particular the EDPE, converge more rapidly with increasing repulsion in the two-body interaction, i.e. the more realistic the interaction becomes. Both expansions require similar computing times for a converged calculation and are about 15-20 times faster than the widely used Hilbert-Schmidt Expansion (HSE). The respective merits of the two pole expansions are discussed and compared with the HSE. (orig.)

A pedagogical approach to the Magnus expansion

International Nuclear Information System (INIS)

Blanes, S; Casas, F; Oteo, J A; Ros, J

2010-01-01

Time-dependent perturbation theory as a tool to compute approximate solutions of the Schroedinger equation does not preserve unitarity. Here we present, in a simple way, how the Magnus expansion (also known as exponential perturbation theory) provides such unitary approximate solutions. The purpose is to illustrate the importance and consequences of such a property. We suggest that the Magnus expansion may be introduced to students in advanced courses of quantum mechanics.

BIOMASA Y RENDIMIENTO DE FRIJOL CON POTENCIAL EJOTERO EN UNICULTIVO Y ASOCIADO CON GIRASOL

Directory of Open Access Journals (Sweden)

J. Garduño-González

2009-01-01

Full Text Available El objetivo del presente estudio fue estimar la producción de biomasa, rendimiento y algunos de sus componentes de dos cultivares de frijol (Phaseolus vulgaris L. con potencial ejotero ('Acerado' y 'Criollo', en unicultivo y asociado con dos cultivares de girasol (Helianthus annuus L. ('Sunbright' y 'Victoria'. El estudio se realizó durante el ciclo primavera verano 2006 bajo condiciones de temporal en Tenancingo, Méx. Las variables evaluadas fueron: índice de área foliar (IAF, tasa de asimilación neta (TAN, biomasa total (BT, diámetro de vaina (DV, longitud de vaina (LV, número de vainas·m-2 (NV y rendimiento de vaina·m-2 (RV; las cuales fueron analizadas en arreglo factorial, bajo un diseño de bloques completos al azar con cuatro repeticiones. Para estimar el grado de asociación, entre las variables estudiadas y el rendimiento de vainas, se realizó un análisis de correlación lineal simple. En el factor cultivares se detectaron diferencias estadísticas significativas para la TAN y DV; para el factor sistemas de siembra hubo diferencias significativas para BT, DV, NV y RV. La interacción cultivares * sistema de siembra fue significativa en todas las variables, excepto en la TAN. En ese sentido, las asociaciones 'Criollo' + 'Sunbright', 'Acerado' + 'Victoria' y 'Acerado' en unicultivo, presentaron el mayor RV. Las variables IAF, BT y NV se correlacionaron positiva y significativamente con el rendimiento de vaina. Los resultados indican que 'Criollo' y 'Acerado', asociados con 'Sunbright' y 'Victoria', respectivamente, responden positivamente a la asociación, constituyendo una buena opción para los productores de la región de Tenancingo, México.

Tratamiento con trióxido de arsénico en pacientes con leucemia promielocítica aguda

Directory of Open Access Journals (Sweden)

Lidia Clara Suárez Beyríes

2014-01-01

Full Text Available Se realizó un estudio observacional, descriptivo y transversal de 17 adultos con leucemia promielocítica aguda, atendidos en el Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba durante un quinquenio, con vistas a evaluar la eficacia del tratamiento de inducción con trióxido de arsénico. En la casuística, la remisión hematológica completa se obtuvo en 82,4 % de sus integrantes a los 42,2 días como promedio. Predominaron la hepatotoxicidad y los dolores óseos como reacciones adversas más comunes, así como también las hemorragias severas como causa principal de muerte. Con este tratamiento se logró la incorporación laboral de quienes mejoraron totalmente y la sobrevida global hasta la fecha es de 76,4 %

Tratamiento de la tiroiditis de Riedel con triamcinolona

Directory of Open Access Journals (Sweden)

Germán Brito Sosa

Full Text Available Se presenta el primer paciente con una tiroiditis de Riedel que se le aplica un tratamiento alternativo con triamcinolona creado por el profesor Juan Gualberto Vivó Núñez. Es el caso de una mujer de 48 años de edad, que acude al cuerpo de guardia por aumento de volumen de la región anterior del cuello y referir ligera disfagia. Tiene antecedente inicialmente de hipertiroidismo, a los 9 años comenzó con hipotiroidismo y hace aproximadamente un año se le diagnosticó una tiroiditis de Hashimoto, con seguimiento por endocrinología. La ecografía del tiroides muestra un aumento marcado de la glándula tiroidea y las imágenes de la biopsia por aspiración con aguja fina (BAAF son compatibles con una tiroiditis de Hashimoto. Con estos resultados se decide intervenirla quirúrgicamente eliminando así los signos compresivos. La biopsia postoperatoria describe una tiroiditis de Riedel. Por el gran tamaño de los lóbulos tiroideos, se le infiltra triamcinolona 1/2 cc en cada lóbulo, una vez al mes durante cuatro meses; logrando reducir aproximadamente el 50 % de los lóbulos tiroideos. Por lo que se puede apreciar los resultados obtenidos con el uso de la triamcinolona.

Outreach Opportunities for Early Career Scientists at the Phoenix ComiCon

Science.gov (United States)

Horodyskyj, L.; Walker, S. I.; Forrester, J. H.

2014-12-01

The Phoenix ComiCon (PCC) is a rapidly growing annual four-day pop culture event, featuring guests, costuming, exhibits, and discussion panels for popular sci-fi, fantasy, horror, and anime franchises. In 2013, PCC began experimenting with science discussion panels. The popularity of the science programming resulted in an expansion of the track for 2014, which Horodyskyj was responsible for coordinating. Thirty hours of programming were scheduled, including 25 discussion panels, NASA's FameLab, and a Mars room. Panelists included industry specialists, established scientists, STEM outreach enthusiasts, and early career scientists. The majority of the panelists were early career scientists recruited from planetary sciences and biology departments at ASU and UA. Panel topics included cosmology, biotechnology, artificial intelligence, space exploration, astrobiology, and the cross-linkages of each with pop culture. Formats consisted of Q&A, presentations, and interactive game shows. Although most panels were aimed at the general audience, some panels were more specialized. PCC 2014 attracted 77,818 attendees. The science programming received rave reviews from the audience, the PCC management, and the panelists themselves. Many panel rooms were filled to capacity and required crowd control to limit attendance. We observed the formation of science "groupies" who sought out the science panels exclusively and requested more information on other science public events in the Phoenix area. We distributed surveys to several select sessions to evaluate audience reasons for attending the science panels and their opinion of the scientists they observed. We will present the results of these surveys. As the PCC continues to grow at an exponential rate, the science programming will continue to expand. We will discuss ideas for continued expansion of the PCC science programming both to serve the public and as a unique public outreach opportunity for early career scientists.

Anisotropic thermal expansion behaviors of copper matrix in β-eucryptite/copper composite

International Nuclear Information System (INIS)

Wang Lidong; Xue Zongwei; Qiao Yingjie; Fei, W.D.

2012-01-01

Highlights: ► The thermal expansion behaviors of Cu matrix were studied by in situ XRD. ► The expansion of Cu{1 1 1} plane is linear, that of Cu{2 0 0} is nonlinear. ► The anisotropic thermal expansion of Cu is related to the twinning of Cu matrix. ► The twinning of Cu matrix makes the CTE of the composite increasing. - Abstract: A β-eucryptite/copper composite was fabricated by spark plasma sintering process. The thermal expansion behaviors of Cu matrix of the composite were studied by in situ X-ray diffraction during heating process. The results show that Cu matrix exhibits anisotropic thermal expansion behaviors for different crystallographic directions, the expansion of Cu{1 1 1} plane is linear in the temperature range from 20 °C to 300 °C and the expansion of Cu{2 0 0} is nonlinear with a inflection at about 180 °C. The microstructures of Cu matrix before and after thermal expansion testing were investigated using transmission electronic microscope. The anisotropic thermal expansion behavior is related to the deformation twinning formed in the matrix during heating process. At the same time, the deformation twinning of Cu matrix makes the average coefficient of thermal expansion of the composite increase.

pacientes con falla cardiaca

Directory of Open Access Journals (Sweden)

Diana Marcela Achury Saldaña

2007-01-01

Full Text Available Objetivo: determinar la adherencia al tratamiento de pacientes con falla cardiaca hospitalizados, al aplicar un plan educativo quefomenta el autocuidado.Método: estudio cuasiexperimental (entrevistas enfermera-paciente realizado entre diciembre de 2004 y mayo de 2006, con unamuestra de 50 pacientes seleccionados por conveniencia. Se diseñó un instrumento para evaluar los comportamientos de los pacientes,con base en algunos resultados de la adherencia y sus respectivos indicadores de la taxonomía NOC (Nursing out comes classification. Laadherencia al tratamiento fue medida en dos momentos: el primero durante la hospitalización, seguido de la aplicación del plan educativoantes del alta, que proporcionaba información en el manejo de su enfermedad desde una dimensión física, psicológica y social quepromueve el autocuidado; y el segundo un mes después del alta en su domicilio.Resultados: diferencias estadísticamente significativas (P=0,0001 que demuestran cómo mediante la capacitación al paciente enel manejo de su tratamiento farmacológico y no farmacológico, el establecimiento de una sana relación entre el profesional de enfermeríay el paciente, y la participación de la familia, se logra una total adherencia al tratamiento.Conclusiones: para lograr una adherencia total del paciente con falla cardiaca al tratamiento es necesario un proceso educativo y unseguimiento continuo y personalizado que motive permanentemente al paciente y se le reconozca el papel protagónico en su cuidado y manejo de la enfermedad.

Fission gas retention and axial expansion of irradiated metallic fuel

International Nuclear Information System (INIS)

Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.

1986-05-01

Out-of-reactor experiments utilizing direct electrical heating and infrared heating techniques were performed on irradiated metallic fuel. The results indicate accelerated expansion can occur during thermal transients and that the accelerated expansion is driven by retained fission gases. The results also demonstrate gas retention and, hence, expansion behavior is a function of axial position within the pin

Negative thermal expansion induced by intermetallic charge transfer.

Science.gov (United States)

Azuma, Masaki; Oka, Kengo; Nabetani, Koichiro

2015-06-01

Suppression of thermal expansion is of great importance for industry. Negative thermal expansion (NTE) materials which shrink on heating and expand on cooling are therefore attracting keen attention. Here we provide a brief overview of NTE induced by intermetallic charge transfer in A-site ordered double perovskites SaCu 3 Fe 4 O 12 and LaCu 3 Fe 4- x Mn x O 12 , as well as in Bi or Ni substituted BiNiO 3 . The last compound shows a colossal dilatometric linear thermal expansion coefficient exceeding -70 × 10 -6 K -1 near room temperature, in the temperature range which can be controlled by substitution.

Cryogenic expansion joint for large superconducting magnet structures

Science.gov (United States)

Brown, Robert L.

1978-01-01

An expansion joint is provided that accommodates dimensional changes occurring during the cooldown and warm-up of large cryogenic devices such as superconducting magnet coils. Flattened tubes containing a refrigerant such as gaseous nitrogen (N.sub.2) are inserted into expansion spaces in the structure. The gaseous N.sub.2 is circulated under pressure and aids in the cooldown process while providing its primary function of accommodating differential thermal contraction and expansion in the structure. After lower temperatures are reached and the greater part of the contraction has occured, the N.sub.2 liquefies then solidifies to provide a completely rigid structure at the cryogenic operating temperatures of the device.

Topological charges and convergence of the cluster expansion

International Nuclear Information System (INIS)

Simonov, Yu.A.

1989-01-01

Cluster expansion of Wilson loops is shown to diverge for the QCD vacuum populated by topological objects (instantons, magnetic monopoles). Using simple models the total sum of the cluster expansion for the string tension is calculated and found to be zero for instantons and nonzero for magnetic monopoles. 14 refs

Coriocarcinoma con metástasis pulmonar

Directory of Open Access Journals (Sweden)

Vicia Sánchez Abalos

2014-05-01

Full Text Available Se presenta el caso clínico de una fémina de 44 años de edad, con 32 semanas de embarazo, la cual fuera ingresada en la Unidad de Cuidados Intensivos del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, por presentar insuficiencia respiratoria aguda como consecuencia de una sepsis. La paciente fue tratada con cefalosporina de tercera generación y ventilación mecánica no invasiva, pero se mantuvieron las características gasométricas de hipoxemia y una mala reacción terapéutica, por lo que se requirió instrumentación de las vías respiratorias y soporte hemodinámico, sin lograr regresión del cuadro clínico, lo cual condujo a un paro cardiorrespiratorio y, con ello, a la muerte. La necropsia mostró un coriocarcinoma del endometrio con metástasis pulmonar

Bigravity from gradient expansion

International Nuclear Information System (INIS)

Yamashita, Yasuho; Tanaka, Takahiro

2016-01-01

We discuss how the ghost-free bigravity coupled with a single scalar field can be derived from a braneworld setup. We consider DGP two-brane model without radion stabilization. The bulk configuration is solved for given boundary metrics, and it is substituted back into the action to obtain the effective four-dimensional action. In order to obtain the ghost-free bigravity, we consider the gradient expansion in which the brane separation is supposed to be sufficiently small so that two boundary metrics are almost identical. The obtained effective theory is shown to be ghost free as expected, however, the interaction between two gravitons takes the Fierz-Pauli form at the leading order of the gradient expansion, even though we do not use the approximation of linear perturbation. We also find that the radion remains as a scalar field in the four-dimensional effective theory, but its coupling to the metrics is non-trivial.

Expansion of magnetic clouds

International Nuclear Information System (INIS)

Suess, S.T.

1987-01-01

Magnetic clouds are a carefully defined subclass of all interplanetary signatures of coronal mass ejections whose geometry is thought to be that of a cylinder embedded in a plane. It has been found that the total magnetic pressure inside the clouds is higher than the ion pressure outside, and that the clouds are expanding at 1 AU at about half the local Alfven speed. The geometry of the clouds is such that even though the magnetic pressure inside is larger than the total pressure outside, expansion will not occur because the pressure is balanced by magnetic tension - the pinch effect. The evidence for expansion of clouds at 1 AU is nevertheless quite strong so another reason for its existence must be found. It is demonstrated that the observations can be reproduced by taking into account the effects of geometrical distortion of the low plasma beta clouds as they move away from the Sun

Giochiamo con i robot

Directory of Open Access Journals (Sweden)

Andrea Bonarini

2009-01-01

Full Text Available "Giochiamo con i robot" e' un laboratorio interattivo per grandi e piccini realizzato per l'edizione 2007 del Festival della Scienza di Genova. Lungo un percorso che va dalla telerobotica alla robotica evolutiva, il laboratorio sviluppa il tema di dare intelligenza ai robot. Questo percorso, le cui tappe sono le varie installazioni, si conclude nella "bottega" dove e' possibile costruire e programmare i propri robot o smontare e modificare quelli esposti durante il percorso didattico. I visitatori sono coinvolti in attivita' ludiche grazie alle quali possonoentrare in contatto con alcune delle idee potenti della robotica,

Thermal Expansion of Vacuum Plasma Sprayed Coatings

Science.gov (United States)

Raj, S V.; Palczer, A. R.

2010-01-01

Metallic Cu-8%Cr, Cu-26%Cr, Cu-8%Cr-1%Al, NiAl and NiCrAlY monolithic coatings were fabricated by vacuum plasma spray deposition processes for thermal expansion property measurements between 293 and 1223 K. The corrected thermal expansion, (DL/L(sub 0) varies with the absolute temperature, T, as (DL/L(sub 0) = A(T - 293)(sup 3) + BIT - 293)(sup 2) + C(T - 293) + D, where, A, B, C and D are thermal, regression constants. Excellent reproducibility was observed for all of the coatings except for data obtained on the Cu-8%Cr and Cu-26%Cr coatings in the first heat-up cycle, which deviated from those determined in the subsequent cycles. This deviation is attributed to the presence of residual stresses developed during the spraying of the coatings, which are relieved after the first heat-up cycle. In the cases of Cu-8%Cr and NiAl, the thermal expansion data were observed to be reproducible for three specimens. The linear expansion data for Cu-8% Cr and Cu-26%Cr agree extremely well with rule of mixture (ROM) predictions. Comparison of the data for the Cu-8%Cr coating with literature data for Cr and Cu revealed that the thermal expansion behavior of this alloy is determined by the Cu-rich matrix. The data for NiAl and NiCrAlY are in excellent agreement with published results irrespective of composition and the methods used for processing the materials. The implications of these results on coating GRCop-84 copper alloy combustor liners for reusable launch vehicles are discussed.

Production expansion continues to accelerate

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that Saudi Arabian Oil Co. (Saudi Aramco) is continuing its accelerated Crude Oil Expansion Program initiated in 1989 that aims at achieving a 10 million bpd productive capacity by 1995. In addition to major engineering, construction and renovation work related to production expansion, Saudi Aramco drilling and workover operations have been markedly expanded. Since January 1991, rig activity has doubled. As an indication of aging of Saudi production, projects include modernizing current injection water treatment facilities, installing a new seawater injection plant on the Persian Gulf, installing dewatering facilities in a number of locations and installing a pilot gas lift project. In addition, equipment orders indicate the new discoveries south of Riyadh may also need the assistance of water injection from inception of production

Intubación de paciente despierto con fibroscopio rígido bajo sedación con remifentanil

OpenAIRE

Bocanegra, Juan Carlos; Ríos Medina, Ángela María; Aguirre Ospina, Óscar David

2010-01-01

Introducción. Al elegir el manejo de un paciente con vía aérea difícil, conocida o sospechada, es importante plantearse alternativas de intervención. Varios algoritmos de manejo, recomiendan la intubación con paciente despierto, con laringoscopia directa o instrumentos ópticos. Los estiletes rígidos y semirrígidos son dispositivos ópticos desarrollados para el manejo de la vía aérea difícil, que han mostrado ser rápidos, atraumáti-cos y confiables. Objetivos. Describir el uso de diferentes es...

Tumor germinal mixto con componentes de disgerminoma y coriocarcinoma de ovario en mujer adolescente con ataxiatelangiectasia

Directory of Open Access Journals (Sweden)

Eduardo Augusto Gálvez-Cuitiva

2015-11-01

días. Se suspendió la quimioterapia porque desarrolló choque séptico que puso en riesgo su vida. Por su enfermedad de base permaneció bajo vigilancia. Actualmente, 17 meses después, la paciente vive sin actividad tumoral.  Conclusión: existe asociación entre ataxia-telangiectasia, leucemia y linfomas. Se describe el caso clínico de una paciente con ataxia-telangiectasia y tumor germinal mixto con componente de disgerminoma y coriocarcinoma de ovario. Se propone establecer un tratamiento especial para estos pacientes inmunocomprometidos, con alto riesgo de cáncer pero, a la vez, de no tolerar los esquemas habituales.

Dolomite addition effects on the thermal expansion of ceramic tiles

International Nuclear Information System (INIS)

Marino, Luis Fernando Bruno; Boschi, Anselmo Ortega

1997-01-01

The thermal expansion of ceramic tiles is of greater importance in engineering applications because the ceramics are relatively brittle and cannot tolerate large internal strain imposed by thermal expansion. When ceramic bodies are produced for glazed ties the compatibility of this property of the components should be considered to avoid damage in the final products. Carbonates are an important constituent of ceramic wall-title bodies and its presence in formulations and the reactions that occur between them and other components modify body properties. The influence in expansivity by additions of calcium magnesium carbonate in a composition of wall tile bodies has been investigated. The relative content of mineralogical components was determined by X-ray diffraction and thermal expansion by dilatometric measurements. The results was indicated that with the effect of calcium-magnesium phases and porosity on thermal expansion of wall tile bodies. (author)

Cropland expansion in Brazil, 2000 to 2014

Science.gov (United States)

Zalles, V.; Hansen, M.; Potapov, P.; Stehman, S. V.; Tyukavina, A.; Pickens, A. H.; Okpa, C.; Aguilar, R.; John, N.; Chavez, S.

2017-12-01

Brazil has become a global leader in the production of commodity row crops such as soybean, sugarcane, cotton, and corn. Here, we employ 30m spatial resolution Landsat data to estimate cropland extent in the year 2000 and its subsequent expansion through 2014. A probability-based sample of reference data allows us to report unbiased estimates of national, biome, and state-scale area of crop expansion with associated uncertainties. We find an increase in Brazilian cropland extent from 26.0 Mha in 2000 to 46.1 Mha in 2014. The cropland frontier states of Maranhao, Tocantins, Piaui, Bahia (MATOPIBA), Mato Grosso, Mato Grosso do Sul, and Para all more than doubled in cropland extent. The states of Goias, Minas Gerais and Sao Paulo experienced >50% increases. The vast majority of expansion, 79%, occurred on repurposed pasture lands, and 20% from the conversion of natural vegetation. Area of converted Cerrado savannas was nearly 2.5 times that of Amazon forests, and accounted for over half of new cropland in MATOPIBA. Spatio-temporal dynamics of cropland expansion are reflected in market conditions, land use policies, and other factors. Continued extensification of cropland is a viable option across Brazil with attendant benefits for and challenges to development.

Evaluations of the criterion for lateral expansion of steels for nuclear components

International Nuclear Information System (INIS)

Susukida, H.; Satoh, M.; Fukuhara, A.

1980-01-01

The Charpy V notch impact tests were performed on Japanese made ferritic steels for nuclear components and their lateral expansions were investigated. The correlations of lateral expansion and absorbed energy with yield strength, and the correlation between lateral expansion and fracture toughness were also studied. The correlation at each lateral expansion level between absorbed energy and yield strength almost agreed with that published by the US PVRC. It was confirmed that lateral expansion could be used as a criterion for the toughness of the steels corresponding to changes in their yield strength, and that the lateral expansion criterion adopted in the ASME Code Section III was appropriate. Further, the correlation between fracture toughness and lateral expansion and that between fracture toughness and absorbed energy, were evaluated, and respective equations of correlation were proposed. (author)

Síndrome coronario agudo con supradesnivel del ST asociado al feocromocitoma con las catecolaminas inicialmente normales

Directory of Open Access Journals (Sweden)

Jorge M. Pacheco

2016-01-01

Full Text Available Los feocromocitomas son tumores secretores de catecolaminas que cursan con paroxismos de hipertensión o hipotensión arterial y palpitaciones. Son una causa rara del síndrome coronario agudo. Presentamos el caso de una paciente con síndrome coronario agudo secundario a feocromocitoma que inicialmente tenía valores normales de catecolaminas.

Síndrome coronario agudo con supradesnivel del ST asociado al feocromocitoma con las catecolaminas inicialmente normales

OpenAIRE

Pacheco, Jorge M.; Pérez Baztarrica, Gabriel; Díaz Bozio, Fernando; Jiménez, Andrés; Porcile, Rafael

2016-01-01

Los feocromocitomas son tumores secretores de catecolaminas que cursan con paroxismos de hipertensión o hipotensión arterial y palpitaciones. Son una causa rara del síndrome coronario agudo. Presentamos el caso de una paciente con síndrome coronario agudo secundario a feocromocitoma que inicialmente tenía valores normales de catecolaminas.

O-PRECISION: UNA ALTERNATIVA METODOLÓGICA DE TRABAJO CON PERSONAS CON DISCAPACIDAD FÍSICA E INTELECTUAL

Directory of Open Access Journals (Sweden)

Victoria Rey Niño

2015-04-01

Full Text Available La Clasificación Internacional del Funcionamiento, de la Discapacidad y de la Salud (CIF define la discapacidad como un término genérico que abarca deficiencias, limitaciones de la actividad y restricciones a la participación. En este caso hablamos de personas con discapacidad física e intelectual por parálisis cerebral, lo que significa que su acceso al mundo de la actividad física se encuentra en la mayoría de los casos muy restringido. Pero existe una modalidad de la orientación llamada Orientación de Precisión u O-Trail que, según la Federación Deportiva de Orientación (FEDO, ha sido adaptada para ofrecer a todos, independientemente de su sexo, edad, capacidad o discapacidad física, la oportunidad de participar en igualdad de condiciones en una típica competición de orientación. Como sugiere Arribas y Sánchez (1998: “En la actividad física podemos encontrar recursos y herramientas de intervención adecuadas a cada contexto y etapa de ciclo vital además, a través de su práctica pueden verse satisfechas determinadas necesidades e intereses personales y grupales, que pueden ser tratados desde un planteamiento educativo” . Este proyecto tiene la intención de ir más allá y pretende utilizar la Orientación de precisión como una herramienta para implementar una alternativa metodológica de trabajo a las actividades que se llevan a cabo con un colectivo de personas con discapacidad física e intelectual en la Asociación Cultural y rehabilitadora de Discapacitados Físicos de Palencia, desarrollando y estimulando sus aspectos intelectuales y sociales mediante una disciplina deportiva desconocida para ellos, con la intención de que aumente su motivación por participar.Objetivo: Implementar la O-Precisión como alternativa metodológica de trabajo con personas con discapacidad física e intelectual con el fin de desarrollar sus capacidades cognitivas y aumentar su autoestima.

Hubble expansion in a Euclidean framework

International Nuclear Information System (INIS)

Alfven, H.

1979-01-01

There now seems to be strong evidence for a non-cosmological interpretation of the QSO redshift - in any case, so strong that it is of interest to investigate the consequences. The purpose of this paper is to construct a model of the Hubble expansion which is as far as possible from the conventional Big Bang model without coming in conflict with any well-established observational results (while introducing no new laws of physics). This leads to an essentially Euclidean metagalactic model (see Table I) with very little mass outside one-third or half of the Hubble radius. The total kinetic energy of the Hubble expansion need only to be about 5% of the rest mass energy. Present observations support backwards in time extrapolation of the Hubble expansion to a 'minimum size galaxy' Rsub(m), which may have any value in 0 26 cm. Other arguments speak in favor of a size close to the upper value, say Rsub(m) = 10 26 cm (Table II). As this size is probably about 100 times the Schwarzschild limit, an essentially Euclidean description is allowed. The kinetic energy of the Hubble expansion may derive from an intense QSO-like activity in the minimum size metagalaxy, with an energy release corresponding to the annihilation of a few solar masses per galaxy per year. Some of the conclusions based on the Big Bang hypothesis are criticized and in several cases alternative interpretations are suggested. A comparison between the Euclidean and the conventional models is given in Table III. (orig.)

34 CFR 361.35 - Innovation and expansion activities.

Science.gov (United States)

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Innovation and expansion activities. 361.35 Section 361... Innovation and expansion activities. (a) The State plan must assure that the State will reserve and use a...) To support the funding of— (i) The State Rehabilitation Council, if the State has a Council...

Rocket nozzle expansion ratio analysis for dual-fuel earth-to-orbit vehicles

Science.gov (United States)

Martin, James A.

1989-01-01

Results are reported from a recent study of the effects of Space Shuttle Main Engine expansion ratio modifications, in the cases of both single-stage and two-stage systems. Two-position nozzles were employed; after varying the lower expansion ratio while the higher was held constant at 120, the lower expansion ratio was held constant at 40 or 60 while the higher expansion ratio was varied. The expansion ratios for minimum vehicle dry mass are different for single-stage and two-stage systems. For two-stage systems, a single expansion ratio of 77.5 provides a lower dry mass than any two-position nozzle.

Operator expansion at short distance in QCD

Energy Technology Data Exchange (ETDEWEB)

Hubschmid, W [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik; Mallik, S [Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Theoretische Kernphysik

1982-11-01

We present a method of calculating coefficients of gluon operators in the operator product expansion of two-point functions at short distance. It is based on a short-distance expansion of the singular part of the quark propagator in the gluon field, the latter being treated as external. We verify in full generality that the spin zero, gluon operator of dimension six does not contribute to the two-point functions of quark bilinears.

Resolution of hydrodynamical equations for transverse expansions

International Nuclear Information System (INIS)

Hama, Y.; Pottag, F.W.

1984-01-01

The three-dimensional hydrodynamical expansion is treated with a method similar to that of Milekhin, but more explicit. Although in the final stage one have to appeal to numerical calculation, the partial differential equations governing the transverse expansions are treated without transforming them into ordinary equations with an introduction of averaged quantities. It is only concerned with the formalism and the numerical results will be given in the next paper. (Author) [pt

Resolution of hydrodynamical equations for transverse expansions

International Nuclear Information System (INIS)

Hama, Y.; Pottag, F.W.

1985-01-01

The three-dimensional hydrodynamical expansion is treated with a method similar to that of Milekhin, but more explicit. Although in the final stage we have to appeal to numerical calculation, the partial differential equations governing the transverse expansions are treated without transforming them into ordinary equations with an introduction of averaged quantities. The present paper is concerned with the formalism and the numerical results will be reported in another paper. (Author) [pt

Sistema constructivo «Quincha Prefabricada»

Directory of Open Access Journals (Sweden)

Díaz Gutiérrez, Aníbal

1984-06-01

Full Text Available «Prefabricated cane lathing» basically involves the use of frames of sawn timber, filled with round wattle, cane and strips of bamboo, all plaited together so that they can be placed and fixed in the frame without nails being required. Once these panels have been assembled and fixed in place to provide walls, they are covered with a mixture of mud and straw forming a primary layer, and finally, they are given a top layer using such material as mud, cement, plaster and other substances, depending on preferences, costs and climatic or other conditions to which the wall is to be exposed, or on the preferences of the user. A light roof is used for roofing, based on a wooden support structure and a covering made of cane and a mud cast packed with straw. For regions of high rainfall, planks of asbestos and cement, zinc or other materials are fixed over the mud cast.La «Quincha Prefabricada» consiste básicamente en el empleo de bastidores de madera aserrada, rellenados con cañizo redondo, caña brava, tiras de bambú, todos ellos colocados en el bastidor en forma trenzada para su auto fijación sin necesidad de usar clavos; estos paneles, después de ser montados y fijados en sitio constituyendo paredes, son revocados con barro mezclado con paja, formando una primera capa; y, finalmente, reciben una última capa de revoque utilizándose materiales como el barro, cemento, yeso u otros, dependiendo de las preferencias, costos, de las condiciones climatológicas u otras a las que estará expuesta la pared o de las preferencias del usuario. Como techado se emplea un techo liviano a base de una estructura portante de madera y cobertura de caña y torta de barro con paja. Para zonas de alta precipitación pluvial se fija, sobre la torta de barro, planchas de asbesto-cemento, planchas de zinc u otras.

Retinitis por citomegalovirus en un paciente con VIH

Directory of Open Access Journals (Sweden)

Alena de los Ángeles Vejerano Duany

Full Text Available La retinitis por citomegalovirus es la infección ocular más frecuente en pacientes con un recuento de linfocitos CD4 inferior a 200 por µL. El aspecto oftalmoscópico de las lesiones se caracteriza, en la mayoría de los casos, por infiltrados retinianos resultados de la necrosis retiniana producida por citomegalovirus y el edema en asociación con hemorragias. Estas lesiones se disponen, por lo general, siguiendo las arcadas vasculares temporales con invasión hacia la mácula. Se presentó una paciente de 24 años de edad, femenina, blanca, ama de casa, con antecedentes patológicos personales oculares sin datos de interés, y antecedentes patológicos personales generales de ser diagnosticadas con VIH. Hace cuatro años que comenzó con tratamiento antirretroviral, y tuvo cambios de tratamiento en dos ocasiones. El último fue impuesto en mayo del año 2011, con el cual presentó mala adherencia terapéutica, y comenzó desde entonces a presentar disminución de su peso corporal de forma marcada en breve período de tiempo. Refiere que desde hace unos meses comenzó a presentar una disminución progresiva de la agudeza visual en el ojo derecho, acompañado de visión borrosa. Adquiere gran importancia este caso, ya que ante la supervivencia de los pacientes con sida, va a ser cada vez más frecuente la aparición de las afecciones oculares relacionadas con esta enfermedad. Dentro de ellas se encuentran las infecciones oportunistas mayores como la retinitis por citomegalovirus.

Lace expansion for dummies

NARCIS (Netherlands)

Bolthausen, Erwin; Van Der Hofstad, Remco; Kozma, Gady

2018-01-01

We show Green's function asymptotic upper bound for the two-point function of weakly self-Avoiding walk in d >4, revisiting a classic problem. Our proof relies on Banach algebras to analyse the lace-expansion fixed point equation and is simpler than previous approaches in that it avoids Fourier

On Fourier re-expansions

OpenAIRE

Liflyand, E.

2012-01-01

We study an extension to Fourier transforms of the old problem on absolute convergence of the re-expansion in the sine (cosine) Fourier series of an absolutely convergent cosine (sine) Fourier series. The results are obtained by revealing certain relations between the Fourier transforms and their Hilbert transforms.

Near threshold expansion of Feynman diagrams

International Nuclear Information System (INIS)

Mendels, E.

2005-01-01

The near threshold expansion of Feynman diagrams is derived from their configuration space representation, by performing all x integrations. The general scalar Feynman diagram is considered, with an arbitrary number of external momenta, an arbitrary number of internal lines and an arbitrary number of loops, in n dimensions and all masses may be different. The expansions are considered both below and above threshold. Rules, giving real and imaginary part, are derived. Unitarity of a sunset diagram with I internal lines is checked in a direct way by showing that its imaginary part is equal to the phase space integral of I particles

Eigenfunction expansion for fractional Brownian motions

International Nuclear Information System (INIS)

Maccone, C.

1981-01-01

The fractional Brownian motions, a class of nonstationary stochastic processes defined as the Riemann-Liouville fractional integral/derivative of the Brownian motion, are studied. It is shown that these processes can be regarded as the output of a suitable linear system of which the input is the white noise. Their autocorrelation is then derived with a study of their standard-deviation curves. Their power spectra are found by resorting to the nonstationary spectral theory. And finally their eigenfunction expansion (Karhunen-Loeve expansion) is obtained: the eigenfunctions are proved to be suitable Bessel functions and the eigenvalues zeros of the Bessel functions. (author)

Strategic Expansion Models in Academic Radiology.

Science.gov (United States)

Natesan, Rajni; Yang, Wei T; Tannir, Habib; Parikh, Jay

2016-03-01

In response to economic pressures, academic institutions in the United States and their radiology practices, are expanding into the community to build a larger network, thereby driving growth and achieving economies of scale. These economies of scale are being achieved variously via brick-and-mortar construction, community practice acquisition, and partnership-based network expansion. We describe and compare these three expansion models within a 4-part framework of: (1) upfront investment; (2) profitability impact; (3) brand impact; and (4) risk of execution. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Expansions for model-independent analyses of inelastic electron scattering

International Nuclear Information System (INIS)

Jackson, D.F.; Hilton, J.M.; Roberts, A.C.M.

1977-01-01

It is noted that the commonly-used Fourier-Bessel expansion for the transition density for inelastic electron scattering depends sensitively on an arbitrary parameter and is not realistic at large distances. Alternative expansions are suggested. (author)

Strain expansion-reduction approach

Science.gov (United States)

Baqersad, Javad; Bharadwaj, Kedar

2018-02-01

Validating numerical models are one of the main aspects of engineering design. However, correlating million degrees of freedom of numerical models to the few degrees of freedom of test models is challenging. Reduction/expansion approaches have been traditionally used to match these degrees of freedom. However, the conventional reduction/expansion approaches are only limited to displacement, velocity or acceleration data. While in many cases only strain data are accessible (e.g. when a structure is monitored using strain-gages), the conventional approaches are not capable of expanding strain data. To bridge this gap, the current paper outlines a reduction/expansion technique to reduce/expand strain data. In the proposed approach, strain mode shapes of a structure are extracted using the finite element method or the digital image correlation technique. The strain mode shapes are used to generate a transformation matrix that can expand the limited set of measurement data. The proposed approach can be used to correlate experimental and analytical strain data. Furthermore, the proposed technique can be used to expand real-time operating data for structural health monitoring (SHM). In order to verify the accuracy of the approach, the proposed technique was used to expand the limited set of real-time operating data in a numerical model of a cantilever beam subjected to various types of excitations. The proposed technique was also applied to expand real-time operating data measured using a few strain gages mounted to an aluminum beam. It was shown that the proposed approach can effectively expand the strain data at limited locations to accurately predict the strain at locations where no sensors were placed.

Eugenol: propiedades farmacológicas y toxicológicas. Ventajas y desventajas de su uso

Directory of Open Access Journals (Sweden)

Raimara González Escobar

2002-08-01

Full Text Available El Eugenol es un derivado fenólico conocido comúnmente como esencia de clavo, que es utilizado desde hace varios siglos en la práctica odontológica. Por sus propiedades farmacológicas tiene diferentes usos. Sus efectos farmacológicos son complejos y dependen de la concentración del Eugenol libre a la cual el tejido se expone. En este trabajo se presentan sus características farmacológicas y toxicológicas; se mencionan algunos de los mecanismos de acción propuestos para ambos efectos, y se exponen algunos de los nuevos materiales que se utilizan actualmente en estomatología; se presentan sus usos y sus ventajas sobre las formulaciones de Eugenol ya existentes.Eugenol is a phenolic derivative, commonly known as "esencia de clavo", which has been used in dental practice for centuries. Its pharmacological properties determined different uses. Its pharmacological effects are complex and depend on the concentration of free Eugenol to which the tissue is exposed. This paper presents the pharmacological and toxicological characteristics of Eugenol; it mentions some of the mechanisms of action proposed for both effects and also presents some of the new materials used in dentistry nowadays. Their uses and advantages over already existing Eugenol formulations are set forth.

Equinoterapia en niños con autismo

OpenAIRE

Martinez Alvernia, Carlos Francisco

2015-01-01

Introducción: Autismo es un trastorno del desarrollo caracterizado por compromiso en interacción social, habilidades de lenguaje, presentando rituales con estereotipias. Sin tratamientos curativos, actualmente se buscan terapias alternativas. Un incremento de la literatura científica de terapias asistidas con animales se ha evidenciado, demostrando mejoría en pacientes autistas con la equinoterapia. Objetivo: Realizar una revisión sistemática de la literatura para evaluar efectividad de la eq...

Dimensional expansion for the Ising limit of quantum field theory

International Nuclear Information System (INIS)

Bender, C.M.; Boettcher, S.

1993-01-01

A recently proposed technique, called dimensional expansion, uses the space-time dimension D as an expansion parameter to extract nonperturbative results in quantum field theory. Here we apply dimensional-expansion methods to examine the Ising limit of a self-interacting scalar field theory. We compute the first few coefficients in the dimensional expansion of γ 2n , the renormalized 2n-point Green's function at zero momentum, for n=2, 3, 4, and 5. Because the exact results for γ 2n are known at D=1 we can compare the predictions of the dimensional expansion at this value of D. We find typical accuracies of less than 5%. The radius of convergence of the dimensional expansion for γ 2n appears to be 2n/(n-1). As a function of the space-time dimension D, γ 2n appears to rise monotonically with increasing D and we conjecture that it becomes infinite at D=2n/(n-1). We presume that for values of D greater than this critical value γ 2n vanishes identically because the corresponding φ 2n scalar quantum field theory is free for D>2n/(n-1)

Plasma rico en plaquetas en pacientes con gonartrosis

OpenAIRE

Álvarez López, Alejandro; Ortega González, Carlos; García Lorenzo, Yenima; Arias Sifontes, Joanka; Ruiz de Villa Suárez, Abel

2013-01-01

Fundamento: la aplicación del plasma rico en plaquetas se ha convertido en una modalidad de tratamiento para pacientes con gonartrosis, tanto de forma aislada como en combinación con otros procedimientos. Objetivo: actualizar al personal médico sobre aspectos esenciales relacionados con la aplicación del plasma rico en plaquetas en pacientes con gonartrosis. Método: se realizó una revisión bibliográfica de un total de 300 artículos originales publicados en Pubmed, Hinari y Medline, mediante e...

Decenal plan of electric energy expansion - 2006-2015

International Nuclear Information System (INIS)

2005-01-01

This report is divided into seven chapters and presents: 1) Introduction - a brief description of the institutional context of the study and the decenal planning role in this context; 2) electric power market - the evolution of market and economy conjuncture of electric power and the basic premises for the market projections, including the considered macroeconomic scenery description; 3) electric power generation - considered premises, methodology and criteria for the formulation and adjustment of generation expansion alternatives of electric power; 4) electric power transmission - main aspects which guided the evolution of the interlinked system reference configuration in the decenal period and a description of the main result of transmission system expansion analysis, consolidated by SIN geoelectric region and by each state of these regions; 5) socioenvironmental analysis - adopted methodology and the results of the socioenvironmental analysis for the foreseen business in the decenal horizon; 6) expansion indicators of the electric system - synthesizes the main indicators referring to the decenal period as far the market evolution, generation expansion and transmission is concerned; 7)bibliographic references

Decenal plan of electric energy expansion - 2006-2015

International Nuclear Information System (INIS)

2006-01-01

This report is divided into seven chapters and presents: 1) Introduction - a brief description of the institutional context of the study and the decenal planning role in this context; 2) electric power market - the evolution of market and economy conjuncture of electric power and the basic premises for the market projections, including the considered macroeconomic scenery description; 3) electric power generation - considered premises, methodology and criteria for the formulation and adjustment of generation expansion alternatives of electric power; 4) electric power transmission - main aspects which guided the evolution of the interlinked system reference configuration in the decenal period and a description of the main result of transmission system expansion analysis, consolidated by SIN geoelectric region and by each state of these regions; 5) socioenvironmental analysis - adopted methodology and the results of the socioenvironmental analysis for the foreseen business in the decenal horizon; 6) expansion indicators of the electric system - synthesizes the main indicators referring to the decenal period as far the market evolution, generation expansion and transmission is concerned; 7)bibliographic references

A Model for the Expansion of the Universe

Directory of Open Access Journals (Sweden)

Silva N. P.

2014-04-01

Full Text Available One introduces an ansatz for the expansion factor a ( t = e ( H ( t t or our Universe in the spirit of the FLRW model; is a constant to be determined. Considering that the ingredients acting on the Universe expansion ( t > 4 10 12 s 1 : 3 10 are mainly matter (baryons plus dark matter and dark energy, one uses the current mea- sured values of Hubble constant H 0 , the Universe current age T 0 , matter density param- eter Ω m ( T 0 and dark energy parameter Ω ( T 0 together with the Friedmann equations to find = 0 : 5804 and that our Universe may have had a negative expansion accelera- tion up to the age T ⋆ = 3 : 214 G y r ( matter era and positive after that ( dark energy era , leading to an eternal expansion. An interaction between matter and dark energy is found to exist. The deceleration q ( t has been found to be q ( T ⋆ = 0 and q ( T 0 = -0.570.

Transmission pricing and expansion methodology: lessons from Argentina

International Nuclear Information System (INIS)

Anderson, K.P.; McCarthy, A.

1999-01-01

This paper focuses on the pricing of electric transmission service in Argentina and on the mechanisms for expanding the transmission system as of late 1998. We also discuss the pricing of energy and generating capacity, since locational differences in their prices constitute charges for transmission service. We find that the methods in place for pricing transmission service are, in the main, consistent with the principles of efficient pricing but that the incentives and mechanisms established for expanding transmission are deficient in some respects. Most notable is the failure to provide for transmission rights, given the system's heavy reliance on user-driven expansion. We find that Argentina can improve upon its pioneering effort to implement user-driven expansion and indeed is exploring ways to do so. The most important tasks are to investigate (a) whether a system of financial transmission rights can be made to work as part of the process of user-driven expansion and (b) whether a backstop role for centrally planned expansion can be preserved without inhibiting or preempting the user-driven process. (author)

Low temperature thermal expansion of liquid Helium-4

International Nuclear Information System (INIS)

Berthold, J.E.

1976-01-01

Results of a measurement of the thermal expansion of liquid He-4 are presented along the saturated vapor pressure curve at low temperatures (0.1 - 0.6 0 K). The thermal expansion is related to the low momentum region of the He-4 excitation spectrum, and the results of this measurement are analyzed to gain information concerning deviations from linearity in the phonon region of the spectrum. The data is also compared with theoretical predictions of Alrich and Bhatt and McMillan and with the thermal expansion measurement of Van Degrift. In addition a discussion of previous experimental evidence on the shape of the low momentum region of the dispersion relation is presented

Thermal expansion of coexistence of ferromagnetism and superconductivity

International Nuclear Information System (INIS)

Hatayama, Nobukuni; Konno, Rikio

2010-01-01

The temperature dependence of thermal expansion of coexistence of ferromag-netism and superconductivity below the superconducting transition temperature T cu of a majority spin conduction band is investigated. Majority spin and minority spin superconducting gaps exist in the coexistent state. We assume that the Curie temperature is much larger than the superconducting transition temperatures. The free energy that Linder et al. [Phys. Rev. B76, 054511 (2007)] derived is used. The thermal expansion of coexistence of ferromagnetism and superconductivity is derived by the application of the method of Takahashi and Nakano [J. Phys.: Condens. Matter 18, 521 (2006)]. We find that we have the anomalies of the thermal expansion in the vicinity of the superconducting transition temperatures.

Three-dimensional static and dynamic reactor calculations by the nodal expansion method

International Nuclear Information System (INIS)

Christensen, B.

1985-05-01

This report reviews various method for the calculation of the neutron-flux- and power distribution in an nuclear reactor. The nodal expansion method (NEM) is especially described in much detail. The nodal expansion method solves the diffusion equation. In this method the reactor core is divided into nodes, typically 10 to 20 cm in each direction, and the average flux in each node is calculated. To obtain the coupling between the nodes the local flux inside each node is expressed by use of a polynomial expansion. The expansion is one-dimensional, so inside each node such three expansions occur. To calculate the expansion coefficients it is necessary that the polynomial expansion is a solution to the one-dimensional diffusion equation. When the one-dimensional diffusion equation is established a term with the transversal leakage occur, and this term is expanded after the same polynomials. The resulting equation system with the expansion coefficients as the unknowns is solved with weigthed residual technique. The nodal expansion method is built into a computer program (also called NEM), which is divided into two parts, one part for steady-state calculations and one part for dynamic calculations. It is possible to take advantage of symmetry properties of the reactor core. The program is very flexible with regard to the number of energy groups, the node size, the flux expansion order and the transverse leakage expansion order. The boundary of the core is described by albedos. The program and input to it are described. The program is tested on a number of examples extending from small theoretical one up to realistic reactor cores. Many calculations are done on the wellknown IAEA benchmark case. The calculations have tested the accuracy and the computing time for various node sizes and polynomial expansions. In the dynamic examples various strategies for variation of the time step-length have been tested. (author)

Modelling The Effects of Aggregate Size on Alkali Aggregate Reaction Expansion

Directory of Open Access Journals (Sweden)

N. Z. Sekrane

2014-06-01

Full Text Available This work aims at developing models to predict the potential expansion of concrete containing alkali-reactive aggregates. The paper gives measurements in order to provide experimental data concerning the effect of particle size of an alkali-reactive siliceous limestone on mortar expansion. Results show that no expansion was measured on the mortars using small particles (0.5-1.0 mm while the particles (1.0–2.0 mm gave the largest expansions (0.217%. Two models are proposed, the first one studies the correlations between the measured expansions and the size of aggregates, the second one calculates the thickness of the porous zone necessary to take again all the volume of the gel created.

Estudio de viabilidad de cajones marítimos con hormigón con fibras

OpenAIRE

Ramos Marquès, Òscar Gonçal

2017-01-01

En este TFM se estudia la viabilidad de sustituir la armadura pasiva por fibras metálicas o plásticas en cajones para obras portuarias. Para ello, en primer lugar, se estudia el procedimiento constructivo de un cajón y las propiedades de los hormigones con fibras. Una vez analizado el estado del conocimiento se procede a escoger un cajón representativo, ya construido con armadura pasiva. El cajón escogido es el cajón tipo 3 del dique est...

An Arabidopsis kinase cascade influences auxin-responsive cell expansion.

Science.gov (United States)

Enders, Tara A; Frick, Elizabeth M; Strader, Lucia C

2017-10-01

Mitogen-activated protein kinase (MPK) cascades are conserved mechanisms of signal transduction across eukaryotes. Despite the importance of MPK proteins in signaling events, specific roles for many Arabidopsis MPK proteins remain unknown. Multiple studies have suggested roles for MPK signaling in a variety of auxin-related processes. To identify MPK proteins with roles in auxin response, we screened mpk insertional alleles and identified mpk1-1 as a mutant that displays hypersensitivity in auxin-responsive cell expansion assays. Further, mutants defective in the upstream MAP kinase kinase MKK3 also display hypersensitivity in auxin-responsive cell expansion assays, suggesting that this MPK cascade affects auxin-influenced cell expansion. We found that MPK1 interacts with and phosphorylates ROP BINDING PROTEIN KINASE 1 (RBK1), a protein kinase that interacts with members of the Rho-like GTPases from Plants (ROP) small GTPase family. Similar to mpk1-1 and mkk3-1 mutants, rbk1 insertional mutants display auxin hypersensitivity, consistent with a possible role for RBK1 downstream of MPK1 in influencing auxin-responsive cell expansion. We found that RBK1 directly phosphorylates ROP4 and ROP6, supporting the possibility that RBK1 effects on auxin-responsive cell expansion are mediated through phosphorylation-dependent modulation of ROP activity. Our data suggest a MKK3 • MPK1 • RBK1 phosphorylation cascade that may provide a dynamic module for altering cell expansion. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Glass ceramics for sealing to high-thermal-expansion metals

International Nuclear Information System (INIS)

Wilder, J.A. Jr.

1980-10-01

Glass ceramics were studied, formulated in the Na 2 O CaO.P 2 O 5 , Na 2 O.BaOP 2 O 5 , Na 2 O.Al 2 O 3 .P 2 O 5 , and Li 2 O.BaO.P 2 O 5 systems to establish their suitability for sealing to high thermal expansion metals, e.g. aluminum, copper, and 300 series stainless steels. Glass ceramics in Na 2 O.CaO.P 2 O 5 and Na 2 O.BaO.P 2 O 5 systems have coefficients of thermal expansion in the range 140 x 10 -1 per 0 C less than or equal to α less than or equal to 225 x 10 -7 per 0 C and fracture toughness values generally greater than those of phosphate glasses; they are suitable for fabricating seals to high thermal expansion metals. Crystal phases include NaPo 3 , (NaPO 3 ) 3 , NaBa(PO 3 ) 3 , and NaCa(PO 3 ) 3 . Glass ceramics formed in the Na 2 O.Al 2 O 3 .P 2 O 5 systems have coefficients of thermal expansion greater than 240 x 10 -7 per 0 C, but they have extensive microcracking. Due to their low thermal expansion values (α less than or equal to 120 x 10 -7 per 0 C), glass ceramics in the Li 2 O.BaO.P 2 O 5 system are unsuitable for sealing to high thermal expansion metals

Thermal expansion of two-dimensional itinerant nearly ferromagnetic metal

International Nuclear Information System (INIS)

Konno, R; Hatayama, N; Takahashi, Y; Nakano, H

2009-01-01

Thermal expansion of two-dimensional itinerant nearly ferromagnetic metal is investigated according to the recent theoretical development of magneto-volume effect for the three-dimensional weak ferromagnets. We particularly focus on the T 2 -linear thermal expansion of magnetic origin at low temperatures, so far disregarded by conventional theories. As the effect of thermal spin fluctuations we have found that the T-linear thermal expansion coefficient shows strong enhancement by assuming the double Lorentzian form of the non-interacting dynamical susceptibility justified in the small wave-number and low frequency region. It grows faster in proportional to y -1/2 as we approach the magnetic instability point than two-dimensional nearly antiferromagnetic metals with ln(1/y s ) dependence, where y and y s are the inverses of the reduced uniform and staggered magnetic susceptibilities, respectively. Our result is consistent with the Grueneisen's relation between the thermal expansion coefficient and the specific heat at low temperatures. In 2-dimensional electron gas we find that the thermal expansion coefficient is divergent with a finite y when the higher order term of non-interacting dynamical susceptibility is taken into account.

Cost of Incremental Expansion of an Existing Family Medicine Residency Program.

Science.gov (United States)

Ashkin, Evan A; Newton, Warren P; Toomey, Brian; Lingley, Ronald; Page, Cristen P

2017-07-01

Expanding residency training programs to address shortages in the primary care workforce is challenged by the present graduate medical education (GME) environment. The Medicare funding cap on new GME positions and reductions in the Health Resources and Services Administration (HRSA) Teaching Health Center (THC) GME program require innovative solutions to support primary care residency expansion. Sparse literature exists to assist in predicting the actual cost of incremental expansion of a family medicine residency program without federal or state GME support. In 2011 a collaboration to develop a community health center (CHC) academic medical partnership (CHAMP), was formed and created a THC as a training site for expansion of an existing family medicine residency program. The cost of expansion was a critical factor as no Federal GME funding or HRSA THC GME program support was available. Initial start-up costs were supported by a federal grant and local foundations. Careful financial analysis of the expansion has provided actual costs per resident of the incremental expansion of the residencyRESULTS: The CHAMP created a new THC and expanded the residency from eight to ten residents per year. The cost of expansion was approximately $72,000 per resident per year. The cost of incremental expansion of our residency program in the CHAMP model was more than 50% less than that of the recently reported cost of training in the HRSA THC GME program.

External Volume Expansion in Irradiated Tissue: Effects on the Recipient Site.

Science.gov (United States)

Chin, Michael S; Lujan-Hernandez, Jorge; Babchenko, Oksana; Bannon, Elizabeth; Perry, Dylan J; Chappell, Ava G; Lo, Yuan-Chyuan; Fitzgerald, Thomas J; Lalikos, Janice F

2016-05-01

External volume expansion prepares recipient sites to improve outcomes of fat grafting. For patients receiving radiotherapy after mastectomy, results with external volume expansion vary, and the relationship between radiotherapy and expansion remains unexplored. Thus, the authors developed a new translational model to investigate the effects in chronic skin fibrosis after radiation exposure. Twenty-four SKH1-E mice received 50 Gy of β-radiation to each flank and were monitored until fibrosis developed (8 weeks). External volume expansion was then applied at -25 mmHg to one side for 6 hours for 5 days. The opposite side served as the control. Perfusion changes were assessed with hyperspectral imaging. Mice were euthanized at 5 (n = 12) and 15 days (n = 12) after the last expansion application. Tissue samples were analyzed with immunohistochemistry for CD31 and Ki67, Masson trichrome for skin thickness, and picrosirius red to analyze collagen composition. All animals developed skin fibrosis 8 weeks after radiotherapy and became hypoperfused based on hyperspectral imaging. Expansion induced edema on treated sides after stimulation. Perfusion was decreased by 13 percent on the expansion side (p External volume expansion temporarily reduces perfusion, likely because of transient ischemia or edema. Together with mechanotransduction, these effects encourage a proangiogenic and proliferative environment in fibrotic tissue after radiotherapy in the authors' mouse model. Further studies are needed to assess these changes in fat graft retention.

Provincial hydro expansions

Energy Technology Data Exchange (ETDEWEB)

Froschauer, K J

1993-01-01

A study of the development of five provincial hydroelectric utilities in Canada indicates that power companies and the state invited manufacturers to use hydroelectricity and natural resources in order to diversify provincial economies. These hydro expansions also show that utilities and government designed hydro projects to serve continental requirements; serving both objectives became problematic. It is argued that when the Canadian state and firms such as utilities use hydro expansions to serve both continentalism and industrialization, then at best they foster dependent industrialization and staple processing. At worst, they overbuild the infrastructure to generate provincial surplus energy for continental, rather than national, integration. Hydro developments became subject to state intervention in Canada mainly through the failures of private utilities to provide power for the less-lucrative industrial markets within provincial subregions. Although the state and utilities invited foreign firms to manufacture hydro equipment within the provinces and others to use electricity to diversify production beyond resource processing, such a diversification did not occur. Since 1962, ca 80% of industrial energy was used to semi-process wood-derived products, chemicals, and metals. The idea for a national power network became undermined by interprovincial political-economic factors and since 1963, the federal national/continential power policy prevailed. 187 refs., 6 figs., 52 tabs.

Bases tratadas con cemento, en California

Directory of Open Access Journals (Sweden)

Chinchilla, M.

1962-05-01

Full Text Available El uso de bases tratadas con cemento para autopistas se inició en el Estado de California en 1938, empleándose para carreteras con determinadas condiciones de tráfico. Inicialmente, se especificó el uso obligatorio de plantas mezcladoras para asegurar el debido control de las proporciones adecuadas.

Prediction of shrinkage cracking age of concrete with and without expansive additive

Directory of Open Access Journals (Sweden)

Dung Tien Nguyen

2010-10-01

Full Text Available The aim of this research is to propose a model for predicting cracking age of concrete due to restrained shrinkage. Thisstudy focuses on analyzing shrinkage and expansion mechanisms in the expansive concrete to formulate a model that can beemployed to predict whether shrinkage cracking occurs or not. In case of conventional (non-expansive concrete, this modelcan be applied by neglecting the early expansion due to expansive additive. Parameters considered in this model are restrainedexpansion, free shrinkage, cracking strain that can be experimentally measured by experiment and tensile creep which isderived by back calculation. The model was verified by test results of expansive concrete mixtures as well as normal concretemixtures both with and without fly ash.

Multiple pathways of commodity crop expansion in tropical forest landscapes

Science.gov (United States)

Meyfroidt, Patrick; Carlson, Kimberly M.; Fagan, Matthew E.; Gutiérrez-Vélez, Victor H.; Macedo, Marcia N.; Curran, Lisa M.; DeFries, Ruth S.; Dyer, George A.; Gibbs, Holly K.; Lambin, Eric F.; Morton, Douglas C.; Robiglio, Valentina

2014-07-01

Commodity crop expansion, for both global and domestic urban markets, follows multiple land change pathways entailing direct and indirect deforestation, and results in various social and environmental impacts. Here we compare six published case studies of rapid commodity crop expansion within forested tropical regions. Across cases, between 1.7% and 89.5% of new commodity cropland was sourced from forestlands. Four main factors controlled pathways of commodity crop expansion: (i) the availability of suitable forestland, which is determined by forest area, agroecological or accessibility constraints, and land use policies, (ii) economic and technical characteristics of agricultural systems, (iii) differences in constraints and strategies between small-scale and large-scale actors, and (iv) variable costs and benefits of forest clearing. When remaining forests were unsuitable for agriculture and/or policies restricted forest encroachment, a larger share of commodity crop expansion occurred by conversion of existing agricultural lands, and land use displacement was smaller. Expansion strategies of large-scale actors emerge from context-specific balances between the search for suitable lands; transaction costs or conflicts associated with expanding into forests or other state-owned lands versus smallholder lands; net benefits of forest clearing; and greater access to infrastructure in already-cleared lands. We propose five hypotheses to be tested in further studies: (i) land availability mediates expansion pathways and the likelihood that land use is displaced to distant, rather than to local places; (ii) use of already-cleared lands is favored when commodity crops require access to infrastructure; (iii) in proportion to total agricultural expansion, large-scale actors generate more clearing of mature forests than smallholders; (iv) property rights and land tenure security influence the actors participating in commodity crop expansion, the form of land use displacement

Multiple pathways of commodity crop expansion in tropical forest landscapes

International Nuclear Information System (INIS)

Meyfroidt, Patrick; Lambin, Eric F; Carlson, Kimberly M; Fagan, Matthew E; DeFries, Ruth S; Gutiérrez-Vélez, Victor H; Macedo, Marcia N; Curran, Lisa M; Dyer, George A; Gibbs, Holly K; Morton, Douglas C; Robiglio, Valentina

2014-01-01

Commodity crop expansion, for both global and domestic urban markets, follows multiple land change pathways entailing direct and indirect deforestation, and results in various social and environmental impacts. Here we compare six published case studies of rapid commodity crop expansion within forested tropical regions. Across cases, between 1.7% and 89.5% of new commodity cropland was sourced from forestlands. Four main factors controlled pathways of commodity crop expansion: (i) the availability of suitable forestland, which is determined by forest area, agroecological or accessibility constraints, and land use policies, (ii) economic and technical characteristics of agricultural systems, (iii) differences in constraints and strategies between small-scale and large-scale actors, and (iv) variable costs and benefits of forest clearing. When remaining forests were unsuitable for agriculture and/or policies restricted forest encroachment, a larger share of commodity crop expansion occurred by conversion of existing agricultural lands, and land use displacement was smaller. Expansion strategies of large-scale actors emerge from context-specific balances between the search for suitable lands; transaction costs or conflicts associated with expanding into forests or other state-owned lands versus smallholder lands; net benefits of forest clearing; and greater access to infrastructure in already-cleared lands. We propose five hypotheses to be tested in further studies: (i) land availability mediates expansion pathways and the likelihood that land use is displaced to distant, rather than to local places; (ii) use of already-cleared lands is favored when commodity crops require access to infrastructure; (iii) in proportion to total agricultural expansion, large-scale actors generate more clearing of mature forests than smallholders; (iv) property rights and land tenure security influence the actors participating in commodity crop expansion, the form of land use displacement

Composite asymptotic expansions and scaling wall turbulence.

Science.gov (United States)

Panton, Ronald L

2007-03-15

In this article, the assumptions and reasoning that yield composite asymptotic expansions for wall turbulence are discussed. Particular attention is paid to the scaling quantities that are used to render the variables non-dimensional and of order one. An asymptotic expansion is proposed for the streamwise Reynolds stress that accounts for the active and inactive turbulence by using different scalings. The idea is tested with the data from the channel flows and appears to have merit.

Loop vertex expansion for higher-order interactions

Science.gov (United States)

Rivasseau, Vincent

2018-05-01

This note provides an extension of the constructive loop vertex expansion to stable interactions of arbitrarily high order, opening the way to many applications. We treat in detail the example of the (\\bar{φ } φ )^p field theory in zero dimension. We find that the important feature to extend the loop vertex expansion is not to use an intermediate field representation, but rather to force integration of exactly one particular field per vertex of the initial action.

Did the Higgs boson drive the universe's expansion?

CERN Multimedia

2008-01-01

The Higgs boson has been moonlighting. Not content with its day job of giving other particles their mass, it may also have driven the expansion of the early universe, given a little tinkering, according to two separate studies. Soon after the big bang the early universe is believed to have undergone a period of rapid expansion, known as inflation.

Acoustic waves in shock tunnels and expansion tubes

Science.gov (United States)

Paull, A.; Stalker, R. J.

1992-01-01

It is shown that disturbances in shock and expansion tubes can be modelled as lateral acoustic waves. The ratio of sound speed across the driver-test gas interface is shown to govern the quantity of noise in the test gas. Frequency 'focusing' which is fundamental to centered unsteady expansions is discussed and displayed in centerline pitot pressure measurements.

Isotropic cosmic expansion and the Rubin-Ford effect

International Nuclear Information System (INIS)

Fall, S.M.; Jones, B.J.T.

1976-01-01

It is shown that the Rubin-Ford data (Astrophys. J. Lett. 183:L111 (1973)), often taken as evidence for large scale anisotropic cosmic expansion, probably only reflect the inhomogeneous distribution of galaxies in the region of the sample. The data presented are consistent with isotropic expansion, an unperturbed galaxy velocity field, and hence a low density Universe. (author)

Semiclassical expansions of the nuclear relativistic Hartree-Fock theory

International Nuclear Information System (INIS)

Weigel, M.K.; Haddad, S.

1991-01-01

Semiclassical expansions for Green functions, self-energy, phase-space density and density are given and discussed. The many-body problem was treated in the relativistic Hartree-Fock approximation with a Lagrangian with a standard OBE potential structure including the possibility of space-dependent couplings. The expansions are obtained by formulating the many-body problem in the mixed position-momentum (Wigner) representation and application of the (h/2π)-Wigner-Kirkwood expansion scheme. The resulting self-consistency problems for the zeroth and second order are formulated in three versions. (author)

Cumulants in perturbation expansions for non-equilibrium field theory

International Nuclear Information System (INIS)

Fauser, R.

1995-11-01

The formulation of perturbation expansions for a quantum field theory of strongly interacting systems in a general non-equilibrium state is discussed. Non-vanishing initial correlations are included in the formulation of the perturbation expansion in terms of cumulants. The cumulants are shown to be the suitable candidate for summing up the perturbation expansion. Also a linked-cluster theorem for the perturbation series with cumulants is presented. Finally a generating functional of the perturbation series with initial correlations is studied. We apply the methods to a simple model of a fermion-boson system. (orig.)

Critical experiment tests of bowing and expansion reactivity calculations for LMRS

International Nuclear Information System (INIS)

Schaefer, R.W.

1988-01-01

Experiments done in several LMR-type critical assemblies simulated core axial expansion, core radial expansion and bowing, coolant expansion, and control driveline expansion. For the most part new experimental techniques were developed to do these experiments. Calculations of the experiments basically used design-level methods, except when it was necessary to investigate complexities peculiar to the experiments. It was found that these feedback reactivities generally are overpredicted, but the predictions are within 30% of the experimental values. 14 refs., 2 figs., 4 tabs

Thermal expansion studies on europium titanate (Eu2TiO5)

International Nuclear Information System (INIS)

Panneerselvam, G.; Subramanian, G.G.S.; Antony, M.P.

2008-01-01

The lattice thermal expansion characteristics of europium titanate (Eu 2 TiO 5 ) have been studied by measuring the lattice parameter by high temperature X-ray diffraction technique (HT-XRD) in the temperature range 298-1573K. Percentage linear thermal expansion and mean linear thermal expansion coefficients were computed from the lattice parameter data. The percentage linear thermal expansion in the temperature range 298-1573 K along a, b and c axes are 1.05, 1.15 and 0.95 respectively. (author)

Eta-expansion does The Trick

DEFF Research Database (Denmark)

Danvy, Olivier; Malmkjær, Karoline; Palsberg, Jens

1996-01-01

Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta-expansion, and a p......Partial-evaluation folklore has it that massaging one's source programs can make them specialize better. In Jones, Gomard, and Sestoft's recent textbook, a whole chapter is dedicated to listing such “binding-time improvements”: nonstandard use of continuation-passing style, eta...... across dynamic case expressions. This requirement precisely accounts for the nonstandard use of continuation-passing style encountered in partial evaluation. Eta-expansion thus acts as a uniform binding-time coercion between values and contexts, be they of function type, product type, or disjoint...

DR Con o:

African Journals Online (AJOL)

which could fall under the Ugandan influence. The con-. flict in the ..... The Congolese people and international community within SADC, the AU ..... ments and make peace among themselves. However, one ... friends overnight.There is a great ...

Effect of rolling motion on the expansion and contraction loss coefficients

International Nuclear Information System (INIS)

Yan, B.H.; Gu, H.Y.

2013-01-01

Highlights: ► The expansion and contraction loss coefficients in rolling motion are analyzed. ► Effects of rolling motion on the expansion and contraction loss coefficients are different. ► The spanwise and transverse additional forces contribute slightly to the local loss. ► The oscillations of loss coefficients increase as the strengthening of rolling motion. - Abstract: The sudden expansion and sudden contraction loss coefficients in rolling motion are investigated with CFD code FLUENT. The calculation results are validated with experimental and theoretical results in steady state. The effects of rolling motion on the expansion and contraction loss coefficients are different. The effects of spanwise and transverse additional forces on the expansion and contraction loss coefficients are weak. The effect of velocity oscillation on the contraction loss coefficient is more significant than that on the expansion loss coefficient. The oscillation of local loss coefficient also becomes more and more irregular as the strengthening of rolling motion

Graph approach to the gradient expansion of density functionals

International Nuclear Information System (INIS)

Kozlowski, P.M.; Nalewajski, R.F.

1986-01-01

A graph representation of terms in the gradient expansion of the kinetic energy density functional is presented. They briefly discuss the implications of the virial theorem for the graph structure and relations between possible graphs at a given order of expansion

A Revisit of Query Expansion with Different Semantic Levels

DEFF Research Database (Denmark)

Zhang, Ce; Cui, Bin; Cong, Gao

2009-01-01

Query expansion has received extensive attention in information retrieval community. Although semantic based query expansion appears to be promising in improving retrieval performance, previous research has shown that it cannot consistently improve retrieval performance. It is a tricky problem to...

IKEA's International Expansion

OpenAIRE

Harapiak, Clayton

2013-01-01

This case concerns a global retailing firm that is dealing with strategic management and marketing issues. Applying a scenario of international expansion, this case provides a thorough analysis of the current business environment for IKEA. Utilizing a variety of methods (e.g. SWOT, PESTLE, McKinsey Matrix) the overall objective is to provide students with the opportunity to apply their research skills and knowledge regarding a highly competitive industry to develop strategic marketing strateg...

Experiencia con Nexobrid® para el desbridamiento enzimático de quemaduras faciales seguido de tratamiento conservador con Medihoney®

Directory of Open Access Journals (Sweden)

José-Manuel Sampietro-De-Luis

Full Text Available Introducción y Objetivos. El desbridamiento enzimático de las quemaduras ha sido objeto de estudio durante décadas; en este terreno, NexoBrid® (MediWound Ltd., Israel se postula como una prometedora alternativa al desbridamiento quirúrgico clásico. Por otra parte, las propiedades antibacterianas y promotoras de la cicatrización de la miel también se han evaluado recientemente con buenos resultados clínicos. Describimos nuestra experiencia preliminar con el empleo de NexoBrid® para el tratamiento de quemaduras faciales, seguido de curas tópicas con Medihoney® Wound Gel (Derma Sciences Ltd., EE.UU.. Material y Método. Incluimos en el estudio todos los pacientes atendidos en nuestra Unidad de Quemados con quemaduras faciales dérmicas o subdérmicas que afectaban a 2 o más subunidades estéticas. Realizamos desbridamiento enzimático con NexoBrid® en las primeras 24 horas. Posteriormente, llevamos a cabo tratamiento conservador con curas tópicas con Medihoney® Wound Gel. Recogimos todos los datos de calidad del desbridamiento, necesidad de desbridamiento quirúrgico, tiempo hasta epitelización completa, presencia de infección y necesidad de cirugía correctora de secuelas. Resultados. Tratamos 10 pacientes con quemaduras faciales de etiología diversa (llama, flash eléctrico, deflagración, escaldadura y química. El desbridamiento inicial fue completo en todos los pacientes. Se alcanzó la epitelización completa en una media de 13.88 días (10-20 días. Ningún paciente presentó infección clínicamente manifiesta ni precisó desbridamiento quirúrgico, cobertura mediante autoinjertos o cirugía de secuelas. Conclusiones. Nuestra experiencia preliminar indica que parece factible la aplicación de NexoBrid® y su combinación con Medihoney® para el tratamiento conservador de las quemaduras faciales.

Conversazioni autobiografiche con Albino Sacco-Casamassima

Directory of Open Access Journals (Sweden)

Orazio Maria Valastro

2004-03-01

Full Text Available Nel 1948 venne Olivetti a Matera. Olivetti venne a Matera con un certo ambasciatore americano che praticamente aveva preparato o stava dando una mano per il piano Marschall, venne a Matera e mi vollero incontrare. Io sono stato chiamato dalla piazza, stavo nella piazza, era il mese di luglio, una cosa di questo genere, e andai in un bar, un bar ad angolo mi ricordo in Via Don Minzioni, dove questo Olivetti mi disse 'ma lei che cosa fa coi sassi?' 'Che cos'è questa storia?' Gli raccontai un po' che cosa facevo io con questi amici, avevamo fatto questo, insomma tutto quello che avevamo fatto nei sassi e che volevamo preparare ancora per presentare a qualcuno un piano di revisionamento dei sassi. Mi ricordo, era la prima volta che avevo visto Adriano Olivetti, ne avevo sentito parlare però non avevo mai visto quest'uomo con gli occhi celesti, minuto, coi capelli bianchi, riccioluto, con una cravatta bianca, cosa che mi fece impressione, una specie di angelo.

Peso y talla en niños con retinoblastoma

Directory of Open Access Journals (Sweden)

Cecilia Ridaura-Sanz

2015-03-01

Full Text Available Introducción: la talla baja se ha descrito como característica clínica de niños con retinoblastoma. Esta particularidad puede estar relacionada directamente con la enfermedad de base o con factores externos.  Objetivo: el propósito de esta investigación fue conocer la frecuencia de talla y peso bajos en niños mexicanos con retinoblastoma y correlacionar los valores antropométricos con variables de la enfermedad y ambientales. Materiales y métodos: se analizaron expedientes clínicos de 346 pacientes con retinoblastoma. Se obtuvieron los datos de peso y talla referidos al ingreso; antes del tratamiento. Se comparó el valor de Z con las referencias de la distribución normal de la población mexicana. La asociación de las medidas antropométricas con las variables clínicas, sociales y genéticas se estableció con la prueba de c2. Resultados: la talla y el peso promedio de los niños con retinoblastoma fueron significativamente más bajos que los de la población general (p < 0.001 y p = 0.013, respectivamente. La talla y peso bajos fueron más frecuentes en niños con enfermedad avanzada, provenientes de medio rural y de bajo nivel socioeconómico. Conclusiones: los déficits en peso y talla en niños con retinoblastoma se deben a factores relacionados con enfermedad avanzada al momento del diagnóstico, lo cual a su vez es consecuencia de la situación de marginación de la población rural mexicana. Dado que la mayoría de las variables sociales y ambientales están muy relacionadas y que no podemos descartar posibles factores genéticos, las conclusiones de este estudio deben verificarse analizando las medidas de los padres y hermanos y establecer grupos comparativos para controlar las variables confusas.

Hole expansion test of third generation steels

Science.gov (United States)

Agirre, Julen; Mendiguren, Joseba; Galdos, Lander; de Argandoña, Eneko Sáenz

2017-10-01

The trend towards the implementation of new materials in the chassis of the automobiles is considerably making more complex the manufacturing of the components that built it up. In this scenario materials with higher strengths and lower formabilities are daily faced by tool makers and component producers what reduces the process windows and makes the forming processes to be in the limits of the materials. One of the concerns that tool makers must face during the definition of the tools is the expansion ratios that the holes in the sheet may reach before producing a breakage due to the stretching of the material (also known as edge cracks). For the characterization of such limits, a standard test, the hole expansion test, can be applied so that the limits of the material are known. At the present study, hole expansion tests of a third generation steel, Fortiform1050 with a thickness of 1.2 millimeters have been carried out and compared them to a mild steel, DX54D with a thickness of 0.6 millimeters. A comparison for each material in terms of technology used to punch the hole, mechanical punching vs laser cutting has also been conducted. In addition, the measurement technique (online measurement vs offline measurement) followed in the Hole Expansion Ratio (HER) identification has also been analyzed. Finally, differences between both materials and techniques are presented.

Specific heat of Ginzburg-Landau fields in the n-1 expansion

International Nuclear Information System (INIS)

Bray, A.J.

1975-01-01

The n -1 expansion for the specific heat C/subv/ of the n-component Ginzburg-Landau model is discussed in terms of an n -1 expansion for the irreducible polarization. In the low-temperature limit, each successive term of the latter expansion diverges more strongly than the last, invalidating a truncation of this series at any finite order in 1/n. The most divergent terms in each order are identified and summed. The results provide justification for the usual truncated expansions for C/subv/

Incidencia y factores asociados con las reacciones adversas del tratamiento antirretroviral inicial en pacientes con VIH

Directory of Open Access Journals (Sweden)

Juan Astuvilca

2007-07-01

Full Text Available La alta incidencia de reacciones adversas medicamentosas (RAMA al tratamiento antirretroviral de gran actividad (TARGA en pacientes con VIH/SIDA puede afectar la calidad de vida y adherencia al tratamiento. Objetivos: Determinar la incidencia de RAMA del TARGA inicial e identificar los factores asociados con la ocurrencia de RAMA al recibir dicha terapia. Materiales y métodos: Se realizó un estudio de cohorte histórica con todos los pacientes VIH (+ mayores de 18 años que recibieron TARGA por primera vez en el Hospital Nacional Arzobispo Loayza, con un seguimiento de 360 días desde la primera prescripción. Se recabó las RAMA de las historias clínicas y tarjetas de control. Resultados: Se incluyeron 353 pacientes, se encontró una incidencia acumulada de 66,7% de efectos adversos al TARGA inicial y una densidad de incidencia de 9,1 eventos de RAMA por 10 personas año de seguimiento (IC95%: 8,1-10,1. Anemia (23,4%, náuseas (20,6% y rash (17,2% fueron las RAMA más frecuentes. El uso de drogas (OR 2,40; IC95% 1,01-5,67; consumo de alcohol (OR 0.32; IC95%: 0,19-0,55 y estadio SIDA (OR 0,20; IC95%: 0,04-0,95 estuvieron asociadas con la presencia de RAMA. Conclusiones: Existe un alta incidencia de RAMA, siendo la anemia la más frecuente. El uso de drogas es un factor de riesgo para presentar RAMA.

Hausdorff dimension of unique beta expansions

International Nuclear Information System (INIS)

Kong, Derong; Li, Wenxia

2015-01-01

Given an integer N ⩾ 2 and a real number β > 1, let Γ β, N be the set of all x=∑ i=1 ∞ d i /β i with d i  ∈ {0, 1, ···, N − 1} for all i ⩾ 1. The infinite sequence (d i ) is called a β-expansion of x. Let U β,N be the set of all x's in Γ β,N which have unique β-expansions. We give explicit formula of the Hausdorff dimension of U β,N for β in any admissible interval [β L , β U ], where β L is a purely Parry number while β U is a transcendental number whose quasi-greedy expansion of 1 is related to the classical Thue–Morse sequence. This allows us to calculate the Hausdorff dimension of U β,N for almost every β > 1. In particular, this improves the main results of Gábor Kallós (1999, 2001). Moreover, we find that the dimension function f(β) = dim H U β,N fluctuates frequently for β ∈ (1, N). (paper)

Leptodermous expansion of finite-nucleus incompressibility

International Nuclear Information System (INIS)

Nayak, R.C.

1990-01-01

We consider the influence of higher-order terms in the leptodermous expansion used to extract the incompressibility K v of infinite nuclear matter from data on the breathing mode of finite nuclei. The terms we calculate are the curvature term K cv A -2/3 , the surface-symmetry term K ss I 2 A -1/3 , the quartic volume-symmetry term K 4 I 4 , and a Coulomb-exchange term. Working within the framework of the scaling model we derive expressions for their coefficients in terms of quantities that are defined for infinite and semi-infinite nuclear matter. We calculate these coefficients for four different Skyrme-type forces, using the extended Thomas-Fermi (ETF) approximation. With the same forces we also calculate the incompressibility K (A, I) for a number of finite nuclei, fit the results to the leptodermous expansion, and thereby extract new results for the same coefficients. The comparison of the two calculations shows that the leptodermous expansion is converging rapidly. Of the new terms, the term K 4 I 4 is quite negligible, the curvature term should be included, and we discuss to what extent the other higher-order terms are significant. (orig.)

2D XXZ model ground state properties using an analytic Lanczos expansion

International Nuclear Information System (INIS)

Witte, N.S.; Hollenberg, L.C.L.; Weihong Zheng

1997-01-01

A formalism was developed for calculating arbitrary expectation values for any extensive lattice Hamiltonian system using a new analytic Lanczos expansion, or plaquette expansion, and a recently proved exact theorem for ground state energies. The ground state energy, staggered magnetisation and the excited state gap of the 2D anisotropic antiferromagnetic Heisenberg Model are then calculated using this expansion for a range of anisotropy parameters and compared to other moment based techniques, such as the t-expansion, and spin-wave theory and series expansion methods. It was found that far from the isotropic point all moment methods give essentially very similar results, but near the isotopic point the plaquette expansion is generally better than the others. 20 refs., 6 tabs

Indicadores de enfermedades mentales en pacientes mexicanos con VIH/SIDA y su relación con la adherencia terapéutica

Directory of Open Access Journals (Sweden)

Ismael García-Cedillo

2011-01-01

Full Text Available Objetivo. Se analiza la relación entre algunos indicadores de enfermedades mentales y la adherencia terapéutica en pacientes con VIH/SIDA. Participantes. Muestra de 76 pacientes mexicanos infectados por VIH/SIDA. Procedimiento. Entrevista a profundidad a pacientes de un hospital público de la ciudad de San Luis Potosí, México. Resultados. 80% de los participantes presentó indicadores de enfermedades mentales correspondientes a: 28% conducta antisocial; 20% depresión clínica; 13% síndrome de estrés postraumático, 12% psicosis orgánica y 8% discapacidad intelectual. El porcentaje de pacientes infectados con VIH/SIDA con indicadores de enfermedad mental concuerda con los resultados de investigaciones realizadas en otros países. Solamente 7% de los participantes mostró un nivel de adherencia apropiado. La adherencia no guarda una relación lineal con la presencia de indicadores de enfermedad mental. La adherencia se relaciona con la escolaridad, la utilización de estrategias para recordar la toma del medicamento, confiar el estatus a los familiares y apoyo familiar.

Contribution of future urbanisation expansion to flood risk changes

Science.gov (United States)

Bruwier, Martin; Mustafa, Ahmed; Archambeau, Pierre; Erpicum, Sébastien; Pirotton, Michel; Teller, Jacques; Dewals, Benjamin

2016-04-01

The flood risk is expected to increase in the future due to climate change and urban development. Climate change modifies flood hazard and urban development influences exposure and vulnerability to floods. While the influence of climate change on flood risk has been studied widely, the impact of urban development also needs to be considered in a sustainable flood risk management approach. The main goal of this study is the determination of the sensitivity of future flood risk to different urban development scenarios at a relatively short-time horizon in the River Meuse basin in Wallonia (Belgium). From the different scenarios, the expected impact of urban development on flood risk is assessed. Three urban expansion scenarios are developed up to 2030 based on a coupled cellular automata (CA) and agent-based (AB) urban expansion model: (i) business-as-usual, (ii) restrictive and (iii) extreme expansion scenarios. The main factor controlling these scenarios is the future urban land demand. Each urban expansion scenario is developed by considering or not high and/or medium flood hazard zones as a constraint for urban development. To assess the model's performance, it is calibrated for the Meuse River valley (Belgium) to simulate urban expansion between 1990 and 2000. Calibration results are then assessed by comparing the 2000 simulated land-use map and the actual 2000 land-use map. The flood damage estimation for each urban expansion scenario is determined for five flood discharges by overlaying the inundation map resulting from a hydraulic computation and the urban expansion map and by using damage curves and specific prices. The hydraulic model Wolf2D has been extensively validated by comparisons between observations and computational results during flood event .This study focuses only on mobile and immobile prices for urban lands, which are associated to the most severe damages caused by floods along the River Meuse. These findings of this study offers tools to

INVESTIGATION OF HOLOCENE FAULTING PROPOSED C-746-U LANDFILL EXPANSION

Energy Technology Data Exchange (ETDEWEB)

Lettis, William [William Lettis & Associates, Inc.

2006-07-01

This report presents the findings of a fault hazard investigation for the C-746-U landfill's proposed expansion located at the Department of Energy's (DOE) Paducah Gaseous Diffusion Plant (PGDP), in Paducah, Kentucky. The planned expansion is located directly north of the present-day C-746-U landfill. Previous geophysical studies within the PGDP site vicinity interpret possible northeast-striking faults beneath the proposed landfill expansion, although prior to this investigation the existence, locations, and ages of these inferred faults have not been confirmed through independent subsurface exploration. The purpose of this investigation is to assess whether or not Holocene-active fault displacement is present beneath the footprint of the proposed landfill expansion.

The thermal expansion of austenitic manganese and manganese-chromium steels

International Nuclear Information System (INIS)

Richter, F.

1977-01-01

The linear coefficient of thermal expansion was determined by dilatometer for 5 Mn steels and 6 Mn-Cr steels between -196 and +500 0 C. Because of the antiferromagnetic properties, the thermal expansion of austenitic Mn and Mn-Cr steels is determined by the position of the magnetic changeover temperature (Neel temperature), which depends on the chemical composition of the steel. Below the Neel temperature, the thermal coefficient of expansion is greatly reduced by volumetric magnetostriction (Invar effect). For this reason, one can only give approximate values for thermal expansion for all Mn and Mn-Cr steels in the temperature range of -100 0 C to about +100 0 C. (GSC) [de

Testing the isotropy of the Hubble expansion

OpenAIRE

Migkas, K.; Plionis, M.

2016-01-01

Abstract: We have used the Union2.1 SNIa compilation to search for possible Hubble expansion anisotropies, dividing the sky in 9 solid angles containing roughly the same number of SNIa, as well as in two Galactic hemispheres. We identified only one sky region, containing 82 SNIa (~15% of total sample with z > 0.02), that indeed appears to share a Hubble expansion significantly different from the rest of the sample. However, this behaviour can be attributed to the joint "erratic" behaviour of ...

Expansion program is a challenging project

International Nuclear Information System (INIS)

Walker, G.L.

1992-01-01

This paper reports that construction is set to begin on the $1.5 billion PGT-PG and E Pipeline Expansion Project. It will consist of 691 miles of 42-in pipeline and 110 miles of 36-in. pipeline, to be built over 2 years. The project, which will transport additional supplies of natural gas to US West Coast markets, has its US regulatory approval in hand. On Oct. 16, 1991, the Federal Energy Regulatory Commission authorized Pacific Gas Transmission Co. to construct its Pacific Northwest segment of the expansion. Pacific Gas and Electric Co. received approval to build its California segment in late 1990 from the California Public Utilities Commission

Short interval expansion of Rényi entropy on torus

Energy Technology Data Exchange (ETDEWEB)

Chen, Bin [Department of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,5 Yiheyuan Rd, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter,5 Yiheyuan Rd, Beijing 100871 (China); Center for High Energy Physics, Peking University,5 Yiheyuan Rd, Beijing 100871 (China); Wu, Jun-Bao [Theoretical Physics Division, Institute of High Energy Physics, Chinese Academy of Sciences,19B Yuquan Rd, Beijing 100049 (China); Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences,19B Yuquan Rd, Beijing 100049 (China); Center for High Energy Physics, Peking University,5 Yiheyuan Rd, Beijing 100871 (China); Zhang, Jia-ju [Theoretical Physics Division, Institute of High Energy Physics, Chinese Academy of Sciences,19B Yuquan Rd, Beijing 100049 (China); Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences,19B Yuquan Rd, Beijing 100049 (China)

2016-08-23

We investigate the short interval expansion of the Rényi entropy for two-dimensional conformal field theory (CFT) on a torus. We require the length of the interval ℓ to be small with respect to the spatial and temporal sizes of the torus. The operator product expansion of the twist operators allows us to compute the short interval expansion of the Rényi entropy at any temperature. In particular, we pay special attention to the large c CFTs dual to the AdS{sub 3} gravity and its cousins. At both low and high temperature limits, we read the Rényi entropies to order ℓ{sup 6}, and find good agreements with holographic results. Moreover, the expansion allows us to read 1/c contribution, which is hard to get by expanding the thermal density matrix. We generalize the study to the case with the chemical potential as well.

The free-jet expansion from a capillary source

International Nuclear Information System (INIS)

Miller, D.R.; Fineman, M.A.; Murphy, H.

1985-01-01

This paper presents a comparison of the free-jet expansions originating from an orifice and a capillary by measuring the terminal gas properties. Time-of-flight and intensity data are reported for pure gases (He, Ar, CO 2 ) and mixtures of CO 2 /He, together with condensed dimer intensities for Ar and Co 2 . Pitot tube data are reported for N 2 . The results suggest that the free-jet expansions are nearly the same, provided the capillary is modeled as a non-isentropic Fanno flow process. The Fanno flow is slightly non-adiabatic, which complicates the analysis. Only the condensation kinetics appear strongly sensitive to the differences in the initial conditions for the supersonic expansion; any kinetic process relaxing near the capillary orifice exit would be affected

TDHF simulation of the expansion of abraded nuclei

International Nuclear Information System (INIS)

Lacroix, D.; Chomaz, Ph.

1998-03-01

A recent interpretation of the caloric curve based on the expansion of the abraded spectator nuclear is re-analysed in the framework of the Time Dependent Hartree Fock (TDHF) evolution. It is shown that the TDHF dynamics can not be reduced to a single monopolar collective motion at moderate energy. The inclusion of other important collective degrees of freedom may lead to the dynamical creation of hollow structure. Then, low density regions could be locally reached after a long time by the creation of these exotic density profiles. The TDHF simulations do not confirm conclusions made when using an monopolar isentropic expansion. In particular the systematic of the minimum density reached during the expansion (the so-called turning points) appears to be different. (author)

Magnetic susceptibilities and thermal expansion of artificial graphites

International Nuclear Information System (INIS)

Cornuault, P.; Herpin, A.; Hering, H.; Seguin, M.; Commissariat a l'Energie Atomique, Saclay

1960-01-01

Starting from measurements of the magnetic susceptibility made in the two principal directions of a graphite bar, the distribution function of the normals to the carbon planes in the crystallites has been evaluated. The effect of different variation in the manufacturing process on this crystalline anisotropy has been studied. From this crystalline anisotropy we have calculated the thermal expansion coefficient possessed by a compact mass of crystallites having exactly the same orientational anisotropy as the porous body consideration. The difference between this and the observed expansion coefficient leads to the determination of the expansion of the non-graphitic part of the mass which turns out to have a negative value and is also anisotropic. We have attempted to draw some conclusions from this result. (author) [fr

Cathode plasma expansion in diode with explosive emission

International Nuclear Information System (INIS)

Zuo Yinghong; Fan Ruyu; Wang Jianguo; Zhu Jinhui

2012-01-01

The evolution characteristics of the cathode plasma in a planar diode with explosive emission were analyzed. Be- sides the axial expansion which can reduce the effective anode-cathode gap, the radial expansion of the cathode plasma which can affect the effective emitting area was also taken into account. According to the Child-Langmuir law and the experimental data of current and voltage with a electron vacuum diode under four-pulse mode, the dynamics of the cathode plasma was investigated, on the assumption that the radial speeds of the cathode plasma was approximately equal to the axial speed. The results show that the radial and axial expansion speeds of the cathode plasma are 0.9-2.8 cm/μs. (authors)

CALIDAD DE VIDA RELACIONADA CON LA SALUD EN PACIENTES CON LUPUS ERITEMATOSO SISTÉMICO Y SU RELACIÓN CON DEPRESIÓN, ANSIEDAD Y OPTIMISMO DISPOSICIONAL.

Directory of Open Access Journals (Sweden)

Juan Manuel Anaya

2006-06-01

Full Text Available La siguiente investigación presenta los resultados de un estudio desarrollado en Colombia sobre la evaluación de la calidad de vida y sus relaciones con la depresión, ansiedad y optimismo disposicional en 32 pacientes con diagnóstico de lupus eritematoso sistémico de la Clínica Universitaria Bolivariana de la ciudad de Medellín, Colombia. Para evaluar la calidad de vida se utilizó el Cuestionario SF36, la ansiedaddepresión fue evaluada mediante el Cuestionario HAD, y se trabajó con el Cuestionario DIOP para medir optimismo. El estudio evidenció que los pacientes perciben una calidad de vida favorable en todas las dimensiones que conforman el cuestionario SF36, no se encontraron niveles clínicamente significativos de ansiedad-depresión, y por último se encontró alta predisposición hacia el optimismo.

On a generalized oscillator system: interbasis expansions

Energy Technology Data Exchange (ETDEWEB)

Kibler, M [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Mardoyan, L G; Pogosyan, G S [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Lab. of Theoretical Physics

1997-12-31

This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The Schroedinger equation for this generalized oscillator system is separable in spherical, cylindrical, and spheroidal (prolate and oblate) coordinates. The quantum mechanical spectrum of this system is worked out in some details. The problem of interbasis expansions of the wave functions is completely solved. The coefficients for the expansion of the cylindrical basis in terms of the spherical basis, and vice-versa, are found to be analytic continuations (to real values of their arguments) of Clebsch-Gordan coefficients for the group SU(2). The interbasis expansion coefficients for the prolate and oblate spheroidal bases in terms of the spherical or the cylindrical bases are shown to satisfy three-term recursion relations. Finally, a connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) are discussed. 41 refs.,.

On a generalized oscillator system: interbasis expansions

International Nuclear Information System (INIS)

Kibler, M.; Mardoyan, L.G.; Pogosyan, G.S.

1996-01-01

This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The Schroedinger equation for this generalized oscillator system is separable in spherical, cylindrical, and spheroidal (prolate and oblate) coordinates. The quantum mechanical spectrum of this system is worked out in some details. The problem of interbasis expansions of the wave functions is completely solved. The coefficients for the expansion of the cylindrical basis in terms of the spherical basis, and vice-versa, are found to be analytic continuations (to real values of their arguments) of Clebsch-Gordan coefficients for the group SU(2). The interbasis expansion coefficients for the prolate and oblate spheroidal bases in terms of the spherical or the cylindrical bases are shown to satisfy three-term recursion relations. Finally, a connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) are discussed. 41 refs.,

Thermal expansion of UO2 and simulated DUPIC fuel

International Nuclear Information System (INIS)

Ho Kang, Kweon; Jin Ryu, Ho; Chan Song, Kee; Seung Yang, Myung

2002-01-01

The lattice parameters of simulated DUPIC fuel and UO 2 were measured from room temperature to 1273 K using neutron diffraction to investigate the thermal expansion and density variation with temperature. The lattice parameter of simulated DUPIC fuel is lower than that of UO 2 , and the linear thermal expansion of simulated DUPIC fuel is higher than that of UO 2 . For the temperature range from 298 to 1273 K, the average linear thermal expansion coefficients for UO 2 and simulated DUPIC fuel are 10.471x10 -6 and 10.751x10 -6 K -1 , respectively

A new separable expansion for the two-body problem

International Nuclear Information System (INIS)

Haberzettl, H.

1988-07-01

We derive a new separable expansion of the two-body T matrix which represents the T matrix as a series of diagonal separable terms. The representation is exact half-on-shell at all energies even when truncated to one single term; moreover, the truncated expansion satisfies the full off-shell unitarity relation. The approach does not take recourse to some complete set of functions but rather uses properties of the Lippmann-Schwinger equation itself to arrive at the expansion. It is based on the W-matrix representation of the two-body T matrix introduced by Bartnik, Haberzettl, and Sandhas. That representation provides a splitting of the T matrix in one single separable term which contains all bound state poles and scatttering cuts and in a nonsingular, real remainder which vanishes half-on-shell. The method presented here yields a separable expansion of this remainder in which all its properties are preserved term by term. Any given n-term approximation can easily be refined to an (n+1)-term expansion by simply adding a new term. At each stage the amount of additional numerical work is constant. The method is applicable to any kind of short range potential, local, nonlocal or energy dependent. (orig.)

Symmetric eikonal expansion

International Nuclear Information System (INIS)

Matsuki, Takayuki

1976-01-01

Symmetric eikonal expansion for the scattering amplitude is formulated for nonrelativistic and relativistic potential scatterings and also for the quantum field theory. The first approximations coincide with those of Levy and Sucher. The obtained scattering amplitudes are time reversal invariant for all cases and are crossing symmetric for the quantum field theory in each order of approximation. The improved eikonal phase introduced by Levy and Sucher is also derived from the different approximation scheme from the above. (auth.)

Planificación Neuroquirúrgica con Software Osirix

Science.gov (United States)

Jaimovich, Sebastián Gastón; Guevara, Martin; Pampin, Sergio; Jaimovich, Roberto; Gardella, Javier Luis

2014-01-01

Introducción: La individualidad anatómica es clave para reducir el trauma quirúrgico y obtener un mejor resultado. Actualmente, el avance en las neuroimágenes ha permitido objetivar esa individualidad anatómica, permitiendo planificar la intervención quirúrgica. Con este objetivo, presentamos nuestra experiencia con el software Osirix. Descripción de la técnica: Se presentan 3 casos ejemplificadores de 40 realizados. Caso 1: Paciente con meningioma de la convexidad parasagital izquierda en área premotora; Caso 2: Paciente con macroadenoma hipofisario, operada previamente por vía transeptoesfenoidal en otra institución con una resección parcial; Caso 3: Paciente con lesiones en pedúnculo cerebeloso medio bilateral. Se realizó la planificación prequirúrgica con el software OsiriX, fusionando y reconstruyendo en 3D las imágenes de TC e IRM, para analizar relaciones anatómicas, medir distancias, coordenadas y trayectorias, entre otras funciones. Discusión: El software OsiriX de acceso libre y gratuito permite al cirujano, mediante la fusión y reconstrucción en 3D de imágenes, analizar la anatomía individual del paciente y planificar de forma rápida, simple, segura y económica cirugías de alta complejidad. En el Caso 1 se pudo analizar las relaciones del tumor con las estructuras adyacentes para minimizar el abordaje. En el Caso 2 permitió comprender la anatomía post-operatoria previa del paciente, para determinar la trayectoria del abordaje transnasal endoscópico y la necesidad de ampliar su exposición, logrando la resección tumoral completa. En el Caso 3 permitió obtener las coordenadas estereotáxicas y trayectoria de una lesión sin representación tomográfica. Conclusión: En casos de no contar con costosos sistemas de neuronavegación o estereotáxia el software OsiriX es una alternativa a la hora de planificar la cirugía, con el objetivo de disminuir el trauma y la morbilidad operatoria. PMID:25165617

A treatment of expansive soil using different additives

Directory of Open Access Journals (Sweden)

Bestun J. Nareeman

2010-11-01

Full Text Available There are many factors that govern the expansion behavior of soil. The primary factors are a change in water contentand the amount and type of clay size particles in the soil. Other important factors affecting the expansion behavior include the typeof soil (natural or fill, condition of the soil in terms of dry density and moisture content, magnitude of the surcharge pressure,and amount of no expansive material such as gravel or cobble size particles.In this paper, a swelling soil from the site Hamamuk earth dam, which is located in Koya town north of Iraq, is treated by fourtypes of additives; cement, steel fibers, gasoline fuel and injection by cement grout.The treatment of the expansive soil with 5 % of cement or steel fibers or the injection with cement grout revealed a betterimprovement while 4 % of gasoline oil is sufficient to reveal the optimum treatment by this material. The angle of internal friction is notaffected by the treatment while the cohesion between particles is slightly affected by these additives due to a change in the adhesionbetween the additive and soil particles.

El maltrato en las personas con discapacidad

OpenAIRE

Revuelta, Lucerga

2014-01-01

El maltrato no solo se realiza por acción sino también por omisión, la indiferencia hacia la persona con discapacidad es una forma de maltrato muy frecuente. Por ejemplo, ignorar y desatender las necesidades de la persona con discapacidad o, al contrario, la sobreprotección son maneras de maltrato. Cuando a un niño con discapacidad el padre o cuidador le hace todo, el niño se siente agredido pues le están incapacitando más de lo que su enfermedad ya lo hace.

Zero thermal expansion in NaZn13-type La(Fe,Si)13 compounds.

Science.gov (United States)

Wang, Wei; Huang, Rongjin; Li, Wen; Tan, Jie; Zhao, Yuqiang; Li, Shaopeng; Huang, Chuanjun; Li, Laifeng

2015-01-28

A zero thermal expansion material in a pure form of NaZn13-type La(Fe,Si)13 was fabricated. Through optimizing the chemical composition, an isotropic zero thermal expansion material is achieved. The obtained materials exhibit a low expansion of |α| linear thermal expansion) over a broad temperature range (15-150 K). The present study indicates that the thermal expansion behavior of the NaZn13-type La(Fe,Si)13 compounds depends mainly on the content of Si element. This new material is desirable in many fields of industry as a reliable and low-cost zero thermal expansion material.

Exponential Expansion in Evolutionary Economics

DEFF Research Database (Denmark)

Frederiksen, Peter; Jagtfelt, Tue

2013-01-01

This article attempts to solve current problems of conceptual fragmentation within the field of evolutionary economics. One of the problems, as noted by a number of observers, is that the field suffers from an assemblage of fragmented and scattered concepts (Boschma and Martin 2010). A solution...... to this problem is proposed in the form of a model of exponential expansion. The model outlines the overall structure and function of the economy as exponential expansion. The pictographic model describes four axiomatic concepts and their exponential nature. The interactive, directional, emerging and expanding...... concepts are described in detail. Taken together it provides the rudimentary aspects of an economic system within an analytical perspective. It is argued that the main dynamic processes of the evolutionary perspective can be reduced to these four concepts. The model and concepts are evaluated in the light...

Shrub expansion in SW Greenland

DEFF Research Database (Denmark)

Jørgensen, Rasmus Halfdan

Arctic regions have experienced higher temperatures in recent decades, and the warming trend is projected to continue in the coming years. Arctic ecosystems are considered to be particularly vulnerable to climate change. Expansion of shrubs has been observed widely in tundra areas across the Arctic......, and has a range of ecosystem effects where it occurs. Shrub expansion has to a large extend been attributed to increasing temperatures over the past century, while grazing and human disturbance have received less attention. Alnus viridis ssp. crispa is a common arctic species that contributes...... to increasing shrub cover. Despite this, there is only limited experimental evidence that growth of the species responds to warming. Plant populations in fragmented and isolated locations could face problems adapting to a warming climate due to limited genetic variation and restricted migration from southern...

Actitud de universitarios hacia las personas con discapacidad

Directory of Open Access Journals (Sweden)

Alexis Araya-Cortés

2014-08-01

Full Text Available El objetivo de este estudio fue describir y comparar la actitud hacia las personas con discapacidad de estudiantes de pedagogía, con estudiantes de otras profesiones y en distintos niveles de formación. Se utilizó un diseño descriptivo y correlacional en el que participaron 260 estudiantes de ambos sexos de una universidad privada de la cuidad de La Serena, Chile. Como instrumento se aplicó la Escala de Actitudes hacia las Personas con Discapacidad de Verdugo, Jenaro y Arias. Los resultados mostraron que la totalidad del alumnado presenta actitudes positivas. En relación con el tipo de carrera y nivel de estudio no se encontraron diferencias estadísticamente significativas. Se puede inferir que los estudiantes presentan una predisposición favorable a comportarse de manera efectiva frente a personas con discapacidad, valorando positivamente sus capacidades y reconociendo sus derechos fundamentales.

Insuficiencia renal aguda relacionada con medicamentos en pacientes hospitalizados

Directory of Open Access Journals (Sweden)

Lujan Iavecchia

2015-11-01

Conclusiones: La mitad de los episodios de IRA intrahospitalaria se relacionaron con medicamentos. Los pacientes con IRA relacionada con medicamentos presentaron más antecedentes patológicos cardiovasculares, pero menos factores de riesgo de IRA y una menor mortalidad.

Improved wave functions for large-N expansions

International Nuclear Information System (INIS)

Imbo, T.; Sukhatme, U.

1985-01-01

Existing large-N expansions of radial wave functions phi/sub n/,l(r) are only accurate near the minimum of the effective potential. Within the framework of the shifted 1/N expansion, we use known analytic results to motivate a simple modification so that the improved wave functions are accurate over a wide range of r and any choice of quantum numbers n and l. It is shown that these wave functions yield simple and accurate analytic expressions for certain quantities of interest in quarkonium physics

New dynamic system suggested for earth expansion

Energy Technology Data Exchange (ETDEWEB)

Fitzpatrick, J [Asuncion Nacional Univ. (Paraguay). Inst. de Ciencias

1972-01-01

It is here suggested that there may have been much more radioactive materials in the deep interior of the earth than bitherto supposed. Trapped heat being generated in the interior would provide a mechanism for earth expansion. An assumption of heat generation in the deep interior of the earth of the order of 0,5 X 10-13 calories per second, per cubic centimeter, would provide sufficient thermal expansion to account for approximately 0.1 mm. change in the radius of the earth per year.

ALMACÉN DE CARBONO EN SISTEMAS AGROFORESTALES CON CAFÉ

Directory of Open Access Journals (Sweden)

William Espinoza-Domínguez

2012-01-01

Full Text Available El presente estudio se realizó con el objetivo de estimar el almacén de carbono en sistemas agroforestales (SAF con base en café en la región de Huatusco, zona de mayor producción de café (Coffea arabiga L. en el estado de Veracruz, México, a fin de obtener información cuantitativa sobre el potencial de mitigación de carbono en los SAF de la región. Para ello, se estimaron los reservorios de carbono en biomasa vegetal y la materia orgánica edáfica existentes en sistemas agroforestales de café-plátano, café-macadamia, café-cedro rosado, café-ganado ovino y café-chalahuite, y como referencia de una condición no agroforestal se incluyeron un bosque primario y un potrero con pradera natural. La recolección de muestras se hizo en parcelas de 4 x 25 m (100 m2, donde se colectó biomasa de vegetación herbácea y mantillo, y para el suelo la profundidad de muestreo fue de 0 a 30 cm. El sistema agroforestal que presentó la mayor cantidad de carbono aéreo, estimado con modelos alelométricos, fue café-cedro rosado (Ca + Ce, con 114 Mg C·ha-1, seguido de los sistemas café - macadamia (Ca + Ma, con 34 Mg C·ha-1; café-chalahuite (Ca + Ch, con 29 Mg C·ha-1; café-plátano velillo (Ca + Pl, con 27 Mg C·ha-1; y por último el sistema silvopastoril (Sp, con 2 Mg C·ha-1. Para el caso del carbono orgánico del suelo, el tratamiento (Ca + Ce fue el que presentó mayor contenido de carbono fácilmente oxidable en el suelo, con 58 Mg C·ha-1, y el menor fue el tratamiento potrero (P, con 50 Mg C·ha-1. Del carbono orgánico total entre los SAF el tratamiento Ca + Ce fue el que tuvo el mayor valor, con 172 Mg C·ha-1, y el tratamiento silvopastoril (Sp presentó el menor, con 65 Mg C·ha-1. De los sistemas evaluados se concluye que, en promedio, los SAF almacenan 102 Mg C·ha-1, mientras que el potrero almacena 52 t C·ha-1, y el bosque primario es el sistema que más almacena carbono total, con un valor de 355 Mg C·ha-1.

On the meaning of perturbation expansions in quantum field theory

International Nuclear Information System (INIS)

Burdik, C.; Chyla, J.

1987-01-01

We reformulate perturbation expansions in renormalized quantum field theories in a way that allows straightforward handling of situations when in the conventional approach (i.e. in fixed renormalization scheme) these expansions are divergent. In our approach the results of perturbation calculations of physical quantities appear in the form of (under certain circumstances) convergent expansions in powers of a free parameter χ, characterising the procedure involved. This inherent ambiguity of perturbative calculations is conjectures to be an expression of the underlaying ambiguity in the separation of the full theory into its perturbative and nonperturbative parts. The close connection of our results with the Borel summation technique is demonstrated and their relation to conventional perturbation expansions in fixed renormalization scheme is clarified

Modified Hermitian treatment of Dyson boson expansion theory

International Nuclear Information System (INIS)

Kajiyama, Atsushi

2009-01-01

The Hermitian treatment of the Dyson-type boson expansion theory is reinvestigated with the aid of small-parameter expansion. A naive application of the Hermitization formula sometimes yields an unrealistic phase that spoils the conventional treatment. The complementary use of another formula having the form of the arithmetic mean can avoid that problem. This modification will improve the accuracy of the Hermitian treatment. (author)

Integrating agricultural expansion into conservation biogeography: conflicts and priorities

Directory of Open Access Journals (Sweden)

Ricardo Dobrovolski

2014-06-01

Full Text Available Increasing food production without compromising biodiversity is one of the great challenges for humanity. The aims of my thesis were to define spatial priorities for biodiversity conservation and to evaluate conservation conflicts considering agricultural expansion in the 21st century. I also tested the effect of globalizing conservation efforts on both food production and biodiversity conservation. I found spatial conflicts between biodiversity conservation and agricultural expansion. However, incorporating agricultural expansion data into the spatial prioritization process can significantly alleviate conservation conflicts, by reducing spatial correlation between the areas under high impact of agriculture and the priority areas for conservation. Moreover, developing conservation blueprints at the global scale, instead of the usual approach based on national boundaries, can benefit both food production and biodiversity. Based on these findings I conclude that the incorporation of agricultural expansion as a key component for defining global conservation strategies should be added to the list of solutions for our cultivated planet.

Negative thermal expansion near two structural quantum phase transitions

Energy Technology Data Exchange (ETDEWEB)

Occhialini, Connor A.; Handunkanda, Sahan U.; Said, Ayman; Trivedi, Sudhir; Guzmán-Verri, G. G.; Hancock, Jason N.

2017-12-01

Recent experimental work has revealed that the unusually strong, isotropic structural negative thermal expansion in cubic perovskite ionic insulator ScF3 occurs in excited states above a ground state tuned very near a structural quantum phase transition, posing a question of fundamental interest as to whether this special circumstance is related to the anomalous behavior. To test this hypothesis, we report an elastic and inelastic x-ray scattering study of a second system Hg2I2 also tuned near a structural quantum phase transition while retaining stoichiometric composition and high crystallinity. We find similar behavior and significant negative thermal expansion below 100 K for dimensions along the body-centered-tetragonal c axis, bolstering the connection between negative thermal expansion and zero-temperature structural transitions.We identify the common traits between these systems and propose a set of materials design principles that can guide discovery of newmaterials exhibiting negative thermal expansion

Negative thermal expansion in Sc2(WO4)3

International Nuclear Information System (INIS)

Evans, J.S.O.; Mary, T.A.; Sleight, A.W.

1998-01-01

Sc 2 (WO 4 ) 3 has been found to show the highly unusual property of negative thermal expansion over a temperature range of 10 to 1,073 K. Powder neutron diffraction data from 10 to 450 K shows an essentially linear decrease in cell volume as a function of temperature. The intrinsic linear coefficient of thermal expansion from this data is -2.2 x 10 -6 K -1 . The linear coefficient of thermal expansion measured on a ceramic bar of Sc 2 (WO 4 ) 3 can be as negative as -11 x 10 -6 K -1 due to microstructure changes as a function of temperature. Rietveld refinement as a function of temperature suggests that the intrinsic negative thermal expansion can be related to transverse vibrations of bridging oxygen atoms in the structure. The anharmonic nature of these vibrations leads to a coupled tilting of the quasi-rigid framework polyhedra. This tilting in turn causes the structure to become more dense with increasing temperature

Glass transition and thermal expansivity of polystyrene thin films

International Nuclear Information System (INIS)

Inoue, R.; Kanaya, T.; Miyazaki, T.; Nishida, K.; Tsukushi, I.; Shibata, K.

2006-01-01

We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T g and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements

Glass transition and thermal expansivity of polystyrene thin films

Energy Technology Data Exchange (ETDEWEB)

Inoue, R. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Kanaya, T. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan)]. E-mail: kanaya@scl.kyoto-u.ac.jp; Miyazaki, T. [Nitto Denko Corporation, 1-1-2 Shimohozumi, Ibaraki, Osaka-fu 567-8680 (Japan); Nishida, K. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Tsukushi, I. [Chiba Institute of Technology, Narashino, Chiba-ken 275-0023 (Japan); Shibata, K. [Japan Atomic Energy Research Institute, Tokai, Ibaraki-ken 319-1195 (Japan)

2006-12-20

We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T {sub g} and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements.

Influence of electron evaporative cooling on ultracold plasma expansion

International Nuclear Information System (INIS)

Wilson, Truman; Chen, Wei-Ting; Roberts, Jacob

2013-01-01

The expansion of ultracold neutral plasmas (UCP) is driven primarily by the thermal pressure of the electron component and is therefore sensitive to the electron temperature. For typical UCP spatial extents, evaporative cooling has a significant influence on the UCP expansion rate at lower densities (less than 10 8 /cm 3 ). We studied the effect of electron evaporation in this density range. Owing to the low density, the effects of three-body recombination were negligible. We modeled the expansion by taking into account the change in electron temperature owing to evaporation as well as adiabatic expansion and found good agreement with our data. We also developed a simple model for initial evaporation over a range of ultracold plasma densities, sizes, and electron temperatures to determine over what parameter range electron evaporation is expected to have a significant effect. We also report on a signal calibration technique, which relates the signal at our detector to the total number of ions and electrons in the ultracold plasma

Tube Expansion Under Various Down-Hole End Conditions

Directory of Open Access Journals (Sweden)

FJ Sanchez

2013-06-01

Full Text Available Fossil hydrocarbons are indispensables commodities that motorize the global economy, and oil and gas are two of those conventional fuels that have been extracted and processed for over a century. During last decade, operators face challenges discovering and developing reservoirs commonly found up to several kilometers underground, for which advanced technologies are developed through different research programs. In order to optimize the current processes to drill and construct oil/gas wells, a large number of mechanical technologies discovered centuries ago by diverse sectors are implemented by well engineers. In petroleum industry, the ancient tube forming manufacturing process founds an application once well engineers intend to produce from reservoirs that cannot be reached unless previous and shallower troublesome formations are isolated. Solid expandable tubular is, for instance, one of those technologies developed to mitigate drilling problems and optimize the well delivery process. It consists of in-situ expansion of a steel-based tube that is attained by pushing/pulling a solid mandrel, which permanently enlarge its diameters. This non-linear expansion process is strongly affected by the material properties of the tubular, its geometry, and the pipe/mandrel contact surface. The anticipated force required to deform long sections of the pipe in an uncontrollable expansion environment, might jeopardize mechanical properties of the pipe and the well structural integrity. Scientific-based solutions, that depend on sound theoretical formulation and are validated through experiments, will help to understand possible tubular failure mechanisms during its operational life. This work is aimed to study the effect of different loading/boundary conditions on mechanical/physical properties of the pipe after expansion. First, full-scale experiments were conducted to evaluate the geometrical and behavioral changes. Second, simulation of deformation

Negative thermal expansion of lithium aluminosilicate ceramics at cryogenic temperatures

International Nuclear Information System (INIS)

Garcia-Moreno, Olga; Fernandez, Adolfo; Khainakov, Sergei; Torrecillas, Ramon

2010-01-01

Five lithium aluminosilicate compositions of the LAS system have been synthesized and sintered. The coefficient of thermal expansion of the sintered samples has been studied down to cryogenic conditions. The data presented here under cryogenic conditions will be of value in the future design of new composite materials with very low thermal expansion values. The variation in thermal expansion properties with composition and sintering temperature was studied and is discussed in relation to composition and crystal structure.

TRACCIÓN DE EQUIPOS AGRÍCOLAS CON ECUACIONES MICKLETHWAITE, BEKKER, JANOSI-HANOMOTO Y BRIXIUS EVALUADOS CON VISUAL BASIC

Directory of Open Access Journals (Sweden)

Américo José Hossne García

2017-06-01

Full Text Available La determinación de la tracción de los tractores agrícolas acredita su empleo eficiente, por ejemplo en: disminución del tiempo oportuno de operación, reducción de daños físicos y terramecánicos, adecuadas característica ingenieriles, tipo y número de neumáticos tractivos y reducción de los costos. El objetivo de este trabajo fue la utilización de las ecuaciones de Micklethwaite, Bekker, Janosi-Hanomoto, y Brixius adaptadas al campo agrícola analizadas con el lenguaje de programación Visual Basic. En la metodología se utilizaron los procedimientos de aplicación de las ecuaciones, las relaciones algebraicas y procedimientos programáticos en Visual Basic 6, diagrama de flujo y el análisis en la tracción sencilla, doble, aperos de tiro y montados; todos, con transferencia de peso y análisis de inestabilidad. El programa desarrollado con sus códigos proporciona una interfaz de usuario intuitiva mediante la vinculación de bases de datos con especificaciones del equipo agrícola, características del neumático, datos del suelo, datos del apero y los coeficientes de las ecuaciones para predecir el rendimiento de un tractor y modelo seleccionados. El programa demostró ser accesible, con mecanismos de uso sin instalación, eficiente y versátil. Las ecuaciones se emplearon con un número de parámetros representativos del área, que pueden ser reemplazados o ampliados y aplicables al agro involucrando la humedad del suelo.

Prediction and observation of post-admission hematoma expansion in patients with intracerebral hemorrhage

DEFF Research Database (Denmark)

Ovesen, Christian; Havsteen, Inger; Rosenbaum, Sverre

2014-01-01

within the hematoma along with the hematoma-size is reported to be predictive of hematoma expansion and outcome. Because patients tend to arrive earlier to the hospital, a larger fraction of acute ICH-patients must be expected to undergo hematoma expansion. This renders observation and radiological......Post-admission hematoma expansion in patients with intracerebral hemorrhage (ICH) comprises a simultaneous major clinical problem and a possible target for medical intervention. In any case, the ability to predict and observe hematoma expansion is of great clinical importance. We review...... radiological concepts in predicting and observing post-admission hematoma expansion. Hematoma expansion can be observed within the first 24 h after symptom onset, but predominantly occurs in the early hours. Thus capturing markers of on-going bleeding on imaging techniques could predict hematoma expansion...

Bosonization of fermion operators as linked-cluster expansions

International Nuclear Information System (INIS)

Kishimoto, T.; Tamura, T.

1983-01-01

In order for a boson-expansion theory to be useful for practical purposes, it must satisfy at least two requirements: It must be in the form of a linked-cluster expansion, and the pure (ideal) boson states must be usable as basis states. Previously, we constructed such a boson theory and used it successfully for many realistic calculations. This construction, however, lacked mathematical rigor. In the present paper, we develop an entirely new approach, which results in the same boson expansions obtained earlier, but now in a mathematically rigorous fashion. The achievement of the new formalism goes beyond this. Its framework is much more general and flexible than was that of the earlier formalism, and it allows us to extend the calculations beyond what had been done in the past

Back reaction and the local cosmological expansion rate

CERN Document Server

Geshnizjani, G

2002-01-01

We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single field. We analyze back reaction both in a matter-dominated Universe and in a phase of scalar field-driven chaotic inflation. In both cases, we find that the leading infrared terms contributing to the back reaction vanish when the local expansion rate is measured at a fixed value of the matter field which is used as a clock, whereas they do not appear to vanish if the expansion rate is evaluated at a fixed value of the background time. We discuss possible implications for more realistic models with a more complicated matter sector.

en personas con el VIH/SIDA

Directory of Open Access Journals (Sweden)

Ximena Palacios Espinosa

2006-01-01

Full Text Available El objetivo de este estudio fue hallar la relación de la intención e ideación suicida con algunas variables sociodemográficas, las características de la enfermedad, el tratamiento antirretroviral y los aspectos piscoafectivos en personas con el VIH/SIDA que residen en Bogotá (Colombia y pertenecientes a una fundación. Para ello, se tomó una muestra de 75 pacientes con VIH positivo a quienes se evaluó a través de una entrevista semiestructurada y dos instrumentos: el inventario de depresión de Beck (IBD y la escala de Ideación Suicida (SSI. Los resultados mostraron que solo 29 personas tenían ideación suicida y 10 intención suicida: De los 10 solo 2 sujetos tenían intención después del diagnóstico. Se encontró una relación estadística significativa para ideación suicida e intención suicida con edad, estrato socioeconómico, estado civil, orientación sexual, las características de la enfermedad, el tratamiento antirretroviral y los aspectos piscoafectivos.

Investigation on the reliability of expansion joint for piping with probabilistic method

International Nuclear Information System (INIS)

Ishii, Y.; Kambe, M.

1980-01-01

The reduction of the plant size is necessitated as one of the major targets in LMFBR design. Usually, piping work system is extensively used to absorb thermal expansion between two components anywhere. Besides above, expansion joint for piping seems to be attractive lately for the same object. This paper describes the significance of expansion joint with multiple boundaries, breakdown probability of expansion joint assembly and partly the bellows by introducing several hypothetical conditions in connection with piping. Also, an importance of in-service inspection (ISI) for expansion joint was discussed using a comparative table and probabilities on reliability from partly broken to full penetration. In conclusion, the expansion joint with ISI should be manufactured with excellent reliability in order to cope with piping work system; several conditions of the practical application for piping systems are suggested. (author)

Investigation on the reliability of expansion joint for piping with probabilistic method

Energy Technology Data Exchange (ETDEWEB)

Ishii, Y; Kambe, M

1980-02-01

The reduction of the plant size is necessitated as one of the major targets in LMFBR design. Usually, piping work system is extensively used to absorb thermal expansion between two components anywhere. Besides above, expansion joint for piping seems to be attractive lately for the same object. This paper describes the significance of expansion joint with multiple boundaries, breakdown probability of expansion joint assembly and partly the bellows by introducing several hypothetical conditions in connection with piping. Also, an importance of in-service inspection (ISI) for expansion joint was discussed using a comparative table and probabilities on reliability from partly broken to full penetration. In conclusion, the expansion joint with ISI should be manufactured with excellent reliability in order to cope with piping work system; several conditions of the practical application for piping systems are suggested. (author)

Investigation on the reliability of expansion joint for piping with probabilistic method

International Nuclear Information System (INIS)

Ishii, Yoichiro; Kambe, Mitsuru.

1979-11-01

The reduction of the plant size if necessitated as one of the major target in LMFBR design. Usually, piping work system is extensively used to absorb thermal expansion between two components anywhere. Besides above, expansion joint for piping seems to be attractive lately for the same object. This paper describes about the significance of expansion joint with multiple boundaries, breakdown probability of expansion joint assembly and partly the bellows by introducing several hypothetical conditions in connection with piping. Also, an importance of inservice inspection (ISI) for expansion joint was discussed using by comparative table and probabilities on reliability from partly broken to full penetration. In the conclusion, the expansion joint with ISI should be manufactured with excellent reliability in order to cope with piping work system, and several conditions of the practical application for piping systems are suggested. (author)

Multipole expansion of acoustical Bessel beams with arbitrary order and location.

Science.gov (United States)

Gong, Zhixiong; Marston, Philip L; Li, Wei; Chai, Yingbin

2017-06-01

An exact solution of expansion coefficients for a T-matrix method interacting with acoustic scattering of arbitrary order Bessel beams from an obstacle of arbitrary location is derived analytically. Because of the failure of the addition theorem for spherical harmonics for expansion coefficients of helicoidal Bessel beams, an addition theorem for cylindrical Bessel functions is introduced. Meanwhile, an analytical expression for the integral of products including Bessel and associated Legendre functions is applied to eliminate the integration over the polar angle. Note that this multipole expansion may also benefit other scattering methods and expansions of incident waves, for instance, partial-wave series solutions.

Carcinoma tricofolicular con capacidad metastásica

Directory of Open Access Journals (Sweden)

C.B. Pinilla-Martínez

2015-03-01

Full Text Available El carcinoma folicular es un tumor maligno derivado del folículo piloso. La mayor parte de los tumores foliculares son benignos, pero en los últimos años se han publicado casos aislados de tumores anexiales con características de malignidad y con una gran agresividad local siendo en principio tumores que se consideraban benignos. Creemos que este tumor está siendo infradiagnosticado, y como consecuencia, infratratado al ser confundido con otros tumores malignos originados en la piel, como el carcinoma basocelular y sobre todo con el carcinoma epidermoide, en parte por poca documentación y por la dificultad para su diagnóstico anatomopatológico. Presentamos un caso de carcinoma tricofolicular en cuero cabelludo en una mujer de 51 años de edad que rápidamente invade sistema nervioso central y que en solo 3 meses metastatiza a pulmón.