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.
Andre Ampuero, Margarita; Baldoquin de la Pena, Maria Gulnara; Acuna Castillo, Silvia Teresita
2009-01-01
.... En este trabajo se describen los principales resultados del proceso de gestion de conocimientos realizado para obtener los elementos considerados en un modelo formal para la asignacion de personal...
Alba-Gomez, L; Tovar-Hernandez, J. H; Gutierrez-Alcaraz, G [Instituto Tecnologico de Morelia, Michoacan (Mexico)]. E-mail: horaciotovar@mexico.com; ggutier@itmorelia.edu.mx
2007-04-15
Use of network allocation costs by shift factors and MW-Mile method is reported in this paper. Conventional shift factors are computed based on DC power flow. DC power flow requires to selecting a slack bus in order to avoid matrix singularity. Therefore, shift factors are slack bus dependent. In order to evade slack bus dependency, two approaches are considered. [Spanish] Este trabajo presenta la asignacion de costos por uso de red mediante la aplicacion de Factores de Participacion (FP) y el metodo de MW-Milla. Los FP clasicos son calculados a partir del modelo lineal de flujos de potencia para lo que se requiere de establecer un nodo de referencia a fin de eliminar la singularidad de la matriz de coeficientes. Por lo tanto, los FP son dependientes de la asignacion del nodo de referencia. Dos metodos alternativos para evitar la dependencia del nodo compensador en la obtencion de los factores de participacion son presentados.
Expansion plan of the electrical sector; Plan de expansion del sector electrico
Cristerna Ocampo, Rafael [Comision Federal de Electricidad (Mexico)
1996-07-01
An analysis of the Mexican electrical market in the year 1994 as far as sales of electrical energy and types of users who utilized that energy, is presented. In addition, an analysis is made of the options for the future supply, where the installed electrical capacity in Mexico in 1994 is described. Also the requirements of additional capacity of power generation, from year 1995 to year 2004 are analyzed. In the internal supply of primary energy in Mexico, the hydrocarbons represent 83%, the diversified sources (nuclear, geothermal, hydro and coal) represent 7% and the biomass as well as complementary coal, the 10% balance of the primary energy. Finally an expansion plan of the transmission network of the Mexican electrical system is described. [Spanish] Se presenta un analisis del mercado electrico mexicano en el ano de 1994 en cuanto a ventas de energia electrica y los tipos de usuarios que utilizaron esa energia. Se hace un analisis ademas, de las opciones para la oferta futura, donde se describe la capacidad electrica instalada de Mexico en 1994. Tambien se analizan los requerimientos de capacidad adicional de generacion de 1995 al 2004. En la oferta interna de energia primaria en Mexico, los hidrocarburos representan el 83%, las fuentes diversificadas (nuclear, geotermia, hidro y carboelectrica) representan el 7% y la biomasa asi como el carbon complementario, el 10% restante de la energia primaria. Finalmente se describe un plan de expansion de la red de transmision del sistema electrico mexicano.
Guillen Moya, Isaias
1987-08-01
mathematics with dynamic programming to accelerate the search of a solution and (2) the development of an alternating method to solve the economic dispatch problem without restrictions. This method does not have to form the curve of incremental equivalent cost, with which a great deal of memory storage and execution time are saved. [Spanish] Se presenta un metodo para resolver el problema de asignacion de unidades termoelectricas en sistemas electricos de potencia de gran escala. El problema consiste en determinar cuales unidades generadoras deberan ser programadas para entrar o salir de operacion durante los intervalos de horizonte de planeacion, de tal forma que se satisfagan a minimo costo, y en forma confiable la demanda pronosticada de potencia electrica y las restricciones fisicas y operativas de los componentes del sistema de potencia. El metodo esta compuesto por dos etapas: la primera etapa encuentra una solucion inicial factible de unidades termo por medio de metodos heuristicos. La segunda etapa produce una solucion a partir de un estado de asignacion inicial factible. El costo de operacion se reduce aplicando programacion dinamica en aproximaciones sucesivas, de tal forma que el producto de cada interaccion constituye el estado de asignacion de menor costo encontrado hasta esa etapa. El rango de busqueda para la solucion optima es reducido aplicando tecnicas de relajacion lagrangeana para seleccionar unicamente las unidades que tienen el mayor potencial de reducir el costo de operacion. El algoritmo es validado utilizando un sistema representativo del sistema interconectado nacional que consta de 108 unidades termoelectricas agrupadas en 7 grupos de generacion, para un horizonte de planeacion de una semana dividido en intervalos horarios, conteniendo 18,144 variables discretas, 18,144 variables continuas y 39,024 restricciones. En una computadora VAX 11/780 el problema es resuelto en 55 minutos de CPU con una estimacion del 1.02% de suboptimalidad que indica que
IMPLICACIONES SANITARIAS DEL ESTABLECIMIENTOY EXPANSION EN ESPAÑA DEL MOSQUITO AEDES ALBOPICTUS
Rubén Bueno Marí
2012-01-01
Full Text Available La expansión de Aedes albopictus por el Levante español no ha cesado desde su primigenia detección en nuestro país en el año 2004, habiéndose constatado ya su presencia en las provincias de Girona, Barcelona, Tarragona, Castellón, Alicante y Murcia. La elevada sinantropía de la especie, unida al alto grado de antropofília y extensa capacidad vectorial para transmitir diversas arbovirosis, han propiciado el retorno al sur de Europa de ciclos de transmisión activa de enfermedades frecuentes en el pasado como el Dengue o la aparición de virosis tropicales inéditas hasta entonces como Chikungunya. El presente manuscrito analiza de forma pormenorizada las implicaciones para la salud pública de la previsible expansión de Ae. albopictus por gran parte del territorio peninsular, en el contexto climático y sociodemográfico actual. Adicionalmente, también se discuten diversas cuestiones relativas al control poblacional de la especie en ambientes urbanos y periurbanos, así como los datos preliminares existentes acerca de otros aedinos invasores de reciente hallazgo en el continente europeo.
Aplicación de los métodos mecanocuánticos al espectro de emisión del Ca I
C. Blume
2009-07-01
Full Text Available Hemos reestudiado las asignaciones del espectro de emisióndel Ca I mediante el cálculo de los valores de las integrales radialesF(k, G(k y f(n, 1 a partir de los valores experimentales paratodas las series con un número suficiente de términos. En general,las asignaciones de Moore están en mejor acuerdo que las de Risbergcon las previsiones teóricas.
Estrada S, G. J.; Martin del Campo M, C., E-mail: gestradas@yahoo.co [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)
2009-10-15
In this work the results of four studies appear that were realized to analyze plans of long term expansion of Mexican electrical system of generation for the study period 2005-2025. The objective is to identify between the two third generation reactors with greater maturity at present which is it is that it can be integrated better in the expansion of the Mexican electrical system of generation. It was analyzed which of the four cases represents the best expansion plan in terms of two only parameters that are: 1) total cost of generation and, 2) the diversity of generated energy in all the period. In all studies candidates three different units of combined cycle were considered (802, 583 and 291 MW), a turbo gas unit of 267 MW, units of 700 MW with coal base and integrated de sulphur, geo thermo electrical units of 26.95 MW and two different types of nuclear units. In both first studies the Advanced Boiling Water Reactor (A BWR) for the nuclear units is considered, considering that is technology with more maturity of all the third generation reactors. In the following two studies were considered the European Pressurized Reactor (EPR), also of third generation, that uses in essence technology more spread to world-wide level. For this task was used the uni nodal planning model WASP-IV, developed by the IAEA to find the expansion configuration with less generation cost for each study. Considering the present situation of the generation system, the capacity additions begin starting from the year 2012 for the four studies. It is not considered the installation of nuclear plants before 2016 considering that its planning period takes 3 years, and the construction period requires at least of 5 years. In order to evaluate the diversity of each study it was used the Stirling Index or of Shannon-Weiner. In order to classify the studies in cost terms and diversity it was used like decision tool the Savage criterion, called also of minimal repentance. With this data, taking
Garza-Cantu Chavez, Mariano
2004-01-01
... tecnicas suban a nivel de norma para que compremos conforme a Norma Oficial Mexicana. ?Que porcentaje de sus compras es por Licitacion, Asignacion Directa o Invitacion? El presupuesto anual de la Coordinacion de Abastecimiento y Equipamiento de la Direccion de Administracion y Calidad del IMSS es de alrededor de 7 mil millones de pesos, que se ut...
Rivera Vazquez, Juan C.
2012-01-01
Cyber crime is a term used to describe the abuse and misuse of a computer system where it is at a loss for someone across the world. It also refers to crimes committed by, or with computers via the Internet or only accessing a computer, is to steal or manipulate information of a company or a person and to use as a means for traditional such as…
Rivera Vazquez, Juan C.
2012-01-01
Cyber crime is a term used to describe the abuse and misuse of a computer system where it is at a loss for someone across the world. It also refers to crimes committed by, or with computers via the Internet or only accessing a computer, is to steal or manipulate information of a company or a person and to use as a means for traditional such as…
1970-10-01
sale: is disributici is unlimited = F’)RIWRD Seior Ignacio Soto, Rrecutive President, Instituto Mexicano del Cementc y Concreto , invited Mr. Bryant... Concreto , a.c., Kwidco, D. F., Mexico. Based on info.mation largely obtained from ACT Committee 223, Expansive ’ement. Concretes, ACI Journal, August 1Q70
García García, José Marino
2010-01-01
La asignación eficiente de los recursos escasos se produce a través del mercado mediante la información que transmiten los precios. En el caso de la asignación de frecuencias del espectro radioeléctrico la existencia de interferencias plantea un problema en la asignación de los derechos de propiedad y junto con la presencia de externalidades motiva la intervención estatal en la determinación del uso y precio de las frecuencias. La introducción de criterios de mercado en las asignaciones de es...
Ruiz Casillas, Manuel Eduardo
1986-05-01
A method is presented to find an approximated solution to the allocation problem of hydroelectric units. The problem consists in determining, for each one of the intervals the planned period, which hydroelectric units will be in operation and how much they will generate, so that the production cost of thermoelectric energy is minimum. The solution must satisfy certain operation policies, and restrictions of physical origin and safety. The modeling of the system elements is very detailed, for example, are considered: the not-linear dependency of the generating units with respect to the cost and the net height, the effects of the discharge level and the losses in conducts, and the relation volume storage against level in the dams. Mathematically, the problem is of non-linear programming, with continuous and discreet variables; in addition, if it is of large scale: in a real case, as de one that appears here, the problem has 16600 continuous variables, 8400 binary variables, and 51000 restrictions. The method exploits the problem structure and the modeled elements characteristics. It obtains a solution in reasonable computing time, and provides a lower elevation to the value of the optimal solution, which allows to judge the quality of the obtained solution. The algorithm was programmed for a VAX 11/780. Problems with a size as the one described are solved in 30 CPU minutes. The value of the obtained solutions, when 35% of the produced energy is hydroelectric, is typically 4% away from its respective inferior elevations. [Spanish] Se presenta un metodo para encontrar una solucion aproximada al problema de asignacion de unidades hidroelectricas. El problema consiste en determinar, para cada uno de los intervalos del periodo de planeacion, cuales unidades hidroelectricas estaran en operacion y cuanto generaran, para que el costo de produccion de energia termoelectrica sea minimo. La solucion debe satisfacer ciertas politicas de operacion y restricciones de origen fisico
Las asignaciones para el culto en el presupuesto de la provincia de Tucumán, Argentina (1852-1897
Esteban Abalo
2014-01-01
Full Text Available El presente trabajo tiene como finalidad analizar los montos destinados por el estado provincial de Tucumán, Argentina, al ítem de Culto, dentro del presupuesto de la provincia entre los años 1852 y 1897. Durante este período fueron constantes los aportes del gobierno para contribuir a los gastos originados por el ejercicio del culto católico en la provincia. El trabajo apunta a enmarcar estos aportes dentro de los estudios sobre la reconstrucción de la Iglesia Católica y sobre la edificación del aparato administrativo estatal en la provincia durante la segunda mitad del siglo xix.
Hernandez Galicia, Julio Alberto; Nieva Gomez, Rolando [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)
2009-07-01
The general characteristics of a planning model for the electrical generation system expansion with risk demarcation criteria, as well as the main results of a representative study case of the Mexican Electrical System is presented. The model is based on a methodology of multiannual optimization for the generation expansion plans determination. In this context, every expansion plan defines the technology type to be installed, as well as the installation year, unit size and its location within a regional electric network. For this purpose, the model considers an interregional representation of the system identifying the necessary reinforcements to the capacity of the interregional connections. It also incorporates a Demarcation of Risk module that considers the uncertainty of the future scenarios of fuels prices to generate a set of expansion plans, among which includes the following: a) For every future of the fuel prices: the plan that diminishes the present value of the total cost (investment plus production). b) The plan that diminishes the economic risk derived from the uncertainty in the future of the fuel prices. c) A subgroup of expansion plans that are located in the efficient borders of decision, under the context of three criteria of interest: the economic risk, the investment cost of and the total cost in the future considered of greater relevance. [Spanish] Se presentan las caracteristicas generales de un modelo de planificacion de la expansion del sistema electrico de generacion con criterios de acotamiento de riesgo, asi como los principales resultados de un caso de estudio representativo del Sistema Electrico Mexicano. El modelo se basa en una metodologia de optimacion multi-anual para la determinacion de planes de expansion de la generacion. En este contexto, cada plan de expansion define el tipo de tecnologia que debera instalarse, asi como el ano de instalacion, el tamano de la unidad y su localizacion dentro de una red electrica regional. Para
Chinthaka-Ganepola, G.A.; Mohammed, A. S.; Ordaz Hernandez, A.; Estevez Cruz, E.; Hernandez Santana, J.R.
2016-07-01
Expansive soils can be categorized as one of the geohazards observed in the urban environment, representing a silent hazard to buildings and infrastructure. To evaluate this problematic soil it is necessary to know some of its geotechnical properties. Generally, the average values of soil properties are used in the methods which characterize the geological formation and the lithological group, which causes a great degree of uncertainty. To overcome this problem, this study proposes a procedure for estimating and modelling the principle soil properties that have an impact on expansive soils. The selected case study is located in the Hermanos Cruz neighbourhood in the city of Pinar del Rio in Cuba. The investigation was organized into the following stages: primary assessment of the potential expansiveness of the soils, modelling of the soil properties utilizing 3D geostatistical methods and finally the cartographic representation of the potential Expansiveness of soils on a Geographic Information System (GIS) platform at different depth zones which are of importance in the construction of shallow foundations of engineering works. The application of this methodology in the Hermanos Cruz neighbourhood revealed that its soils possess a potential expansiveness of low to medium, apart from some isolated zones which show a potential expansiveness of medium to high. (Author)
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.
Toupiol, S.; Martin del Campo M, C.; Ortega C, R. [Departamento de Sistemas Energeticos, Facultad de Ingenieria UNAM, Circuito Exterior s/n, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)]. e-mail: stoupiol@yahoo.fr
2007-07-01
In the last years, the planning of the National Interconnected System has been guided mainly to technologies of combined cycle, contributing to the establishment of a generation system little diversified and clerk of the readiness and volatility of the prices of natural gas. On the other hand, the electric system continues expanding without to consider the emissions of gases coming from the electric generation and the significant participation of the renewable and nuclear technologies in the production of electricity like decisive parameters for the long term planning, for what the developed plans are economically attractive but they don't contribute to the respect of the environment, to the sustainable development, neither to the diversification. With base to the above-mentioned intended in this work to develop viable outlines for the long term expansion of the National Interconnected System (period 2005-2024), appealing to the pattern of uni nodal planning that uses the Federal Commission of Electricity at the moment (CFE) that is to say the pattern WASP given by the International Atomic Energy Agency. This way, you fixed as objective to propose two expansion alternatives to the reference plan developed by the CFE in 2005 for the period 2005-2024, with the purpose of not only looking for the good plan of these three plans in terms of the total cost of generation, but also in terms of the risk associated to the price of natural gas, the emissions of dioxide of sulfur and nitrogen oxides generated by the plants of the system and the diversity of the generation park. To compare the three developed plans, you applies an analysis of decision of multiple approaches based on the approach of Savage. Finally, starting from this analysis, he/she intended to determine if the plan of minimum cost represents the long term better option or if it suits but to expand the system being based on a plan that represents the best commitment cost-risk-emission-diversity. (Author)
BOCANEGRA GARCÍA, CARLOS ALFREDO
2005-01-01
Se presenta resultados del “Impacto de la expansión urbana sobre la sustentabilidad ambiental del litoral de la Bahía de Huanchaco-Perú“; los cuales están referidos a mostrar los principales indicadores de deterioro ambiental generado por el crecimiento poblacional y la presión urbana. Los resultados evidencian crecimiento acelerado de la población humana principalmente urbana la que mayormente se instaló en el litoral en desmedro de las áreas adyacentes caracterizadas por condiciones precari...
Nieva Gomez, Rolando; Hernandez Galicia, Julio Alberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Portes Mascorro, Enrique; Alvarez Chavez, Jose Maria [Comision Nacional para el Ahorro de Energia (CONAE), Mexico, D. F. (Mexico)
1997-12-31
The Comision Nacional para el Ahorro de Energia (CONAE) carried out a study to determine the amount of electric energy available by cogeneration in the industrial sector of our country. This study is based in a survey among the enterprises with the largest fuel consumption belonging to the industrial and commercial sectors and to the petrochemical branch of Petroleos Mexicanos (PEMEX). The results of the study are presented, which show the location of the cogeneration potential by the following estimates: a) The scenario under a potential of 5770 MW to generate annually 4.55 x 107 MWh of electric energy. b) The scenario with a potential of 10819 MW to generate annually 9.47 x 107 Mwh of electric energy [Espanol] La Comision Nacional para el Ahorro de Energia (CONAE) llevo acabo un estudio para determinar la cantidad de energia electrica disponible por cogeneracion en el sector industrial de nuestro pais. El estudio se fundamenta en una encuesta entre las empresas con mayor consumo de combustibles pertenecientes a los sectores industrial y comercial y al ramo petroquimico de Petroleos Mexicanos (PEMEX). Se presentan los resultados del estudio, el cual muestra la ubicacion del potencial de cogeneracion por los siguientes estimados: a) El escenario bajo con un potencial de 5770 MW para producir anualmente 4.55 x 107 Mwh de energia electrica. b) El escenario alto con un potencial de 10819 MW para producir anualmente 9.47 x 107 MWh de energia electrica
Martin Alberto Rodriguez-Brindis
2015-06-01
Full Text Available Este trabajo analiza los efectos a largo plazo entre la demanda de transporte aéreo y el crecimiento económico en Chile. Utilizando datos trimestrales de 1986 (T1 a 2014 (T29, el estudio investiga la posible relación de causalidad entre el pib real y el número de pasajeros aéreos que llegan y salen de los aeropuertos chilenos. Por medio de la cointegración de Johansen, se muestra la existencia de un vector de cointegración en el que las correspondientes elasticidades son positivas. El estudio muestra que la relación de causalidad es positiva y bidireccional. A su vez, el análisis de impulso-respuesta, muestra que un incremento en la magnitud del movimiento de pasajeros produce un efecto positivo en el crecimiento económico en el país.
Vecinday, Laura
2013-01-01
Full Text Available Se analizan recientes iniciativas de tratamiento social la pobreza en Uruguay con el objetivo de demostrar que representan un avance de la lógica punitiva sobre el comportamiento de los pobres. Los dispositivos seleccionados son: las asignaciones familiares del Plan de Equidad - principal programa de transferencias de renta condicionadas -, el Plan de las 7 zonas - que articula programas asistenciales con medidas de seguridad- y la recientemente aprobada Ley de Faltas - que reedita, en algunos de sus contenidos, las leyes de pobres inglesas. El trabajo se propone analizar los aspectos que constituyen el denominador común de estas iniciativas aparentemente diversas
Ángel Sanint Enrique
2011-11-01
Full Text Available En la línea de la Evaluación Ambiental Estratégica, EAE, se desarrolló un método para la determinación de restricciones y posibilidades ambientales en proyectos de transporte de gas natural por ductos, basado en el uso de herramientas de análisis territorial aplicadas sobre la plataforma SIG (Sistema de Información Geográfica, incorporando criterios ambientales que a escala 1:500.000 apoyarán la toma de decisiones en el nivel de planeación y propiciarán la elaboración del plan de expansión para el transporte de gas natural en Colombia. Para esto, se definió el concepto de ambiente a partir de un Modelo Analítico preexistente; se delimitó un área con posibilidades para la expansión de la red de transporte de gas natural incorporando nuevos trazados; se seleccionaron las variables y factores que complementaban el Modelo Analítico; se definió la estructura de preferencias a partir de una encuesta a expertos; se determinaron las restricciones nacionales y se construyeron superficies numéricas síntesis de critici dad ambiental para cada dimensión. Como resultado, se obtuvieron 5 superficies síntesis, una por cada dimensión, y una superficie final para Colombia, con restricciones y posibilidades ambientales. Además se propusieron análisis complementarios para establecer prioridades en la gestión ambiental.
La reforma tributaria pendiente en Costa Rica: consideraciones para el diseno del sistema tributario
Loria, Luis
2009-01-01
PALABRAS CLAVES: REFORMA FISCAL, ECONOMIA POLITICA, FILOSOFIA POLITICA, ESTUDIOS LATINOAMERICANOS, PROCESOS DE ASIGNACION DE RECURSOS, ECONOMIA DE LA INFORMACION, INSTITUCIONES ECONOMICAS, INVERSION EXTRANJERA...
Vázquez-Moreno, T.
1981-06-01
Full Text Available Not available
En los núms. 175, 177 y 179 de esta Revista "Materiales de Construcción" se ha publicado un trabajo con el título "Aplicaciones prácticas de la espectroscopia de absorción infrarroja en el estudio de los crudos, del clinker y del cemento portland anhidro"; en él se decía textualmente que... "se dará, en forma de tablas las frecuencias y asignaciones correspondientes a los espectros IR tanto de los compuestos que se van estudiando como otros muchos que se consideran de interés. Asimismo se incluirán los respectivos espectros IR".
A causa de la extensión y de las propias características del anexo, se consideró oportuno el publicarlo separadamente, incluso bajo un título más explicativo.
Jorge Arturo Mojica Cáceres
2013-07-01
Full Text Available Uno de los medios de transmisión de alta velocidad más utilizados en nuestro entorno es la fibra óptica especificada en el estándar ITU-T G.625; sin embargo, su despliegue y utilización plantea en la actualidad varios desafíos a resolver debido a su característica de no linealidad, dentro de los cuales se encuentra el relacionado con la disminución del nivel de interferencia. Con el ánimo de brindar un aporte en la solución de esta problemática se propone modelar el comportamiento no lineal de FWM cuando se implementan sistemas de multiplexación de longitudes de onda por un único hilo de fibra óptica a fin de poder estimar las características fundamentales que rige esta tecnología y poder plantear un algoritmo que sea capaz de reducir la interferencia no lineal de cuarta onda (FWM. Como conclusión principal se encontró que el modelo propuesto reduce la interferencia no lineal FWM, lo que permite un aumento en la asignación de canales DWDM aumentando el ancho de banda establecido en cada enlace óptico.
Silvia Ratto
2011-01-01
Full Text Available El objetivo de este trabajo es analizar la coyuntura del período 1869-1872, cuando se intentó llevar a adelante la conquista militar del territorio indígena del sur prevista en la Ley 215 promulgada en 1867. El análisis propone una visión de conjunto sobre las discusiones que se llevaron a cabo en torno a su realización y la respuesta que provocó en los principales líderes étnicos. Integra dos sectores fronterizos sobre los que se proyectaba avanzar -la frontera sur de Córdoba, Mendoza y San Luis y la frontera bonaerense- y las agrupaciones nativas más cercanas a esos espacios: los ranqueles y los salineros dirigidos por el cacique Calfucurá.The aim of this paper is to analyze the context during 1869-1872 when the central government attempted to carry out the military conquest of the Southern Indian Territory established by Law 215, issued in 1867. An overview of the discussions taken place around war conduct and the resistance of ethnic leaders are presented. It integrates two main border areas on which the conquest was expected: the southern border of Córdoba, Mendoza and San Luis and Buenos Aires and the strategies of the indigenous groups closer to these spaces: the ranqueles and the salineros.
Marisol Cuicas Avila
2007-01-01
Full Text Available La investigación tuvo como propósito el desarrollo de habilidades del pensamiento y el mejoramiento del aprendizaje en alumnos y alumnas de la asignatura Matemática II, del Decanato de Ingeniería Civil de la Universidad Centroccidental Lisandro Alvarado (UCLA, mediante el empleo de estrategias instruccionales basadas en el uso del software matemático. La investigación, de diseño cuasi-experimental, usó para el contraste de hipótesis la prueba t para muestras relacionadas. Además se aplicaron dos pruebas, tres asignaciones, una lista de cotejo y una entrevista semiestructurada. Los datos recogidos se analizaron utilizando estadística descriptiva. Los hallazgos del estudio fueron: (a los conocimientos de los discentes mejoraron; y (b estos pusieron en práctica sus procedimientos (sus habilidades cognoscitivas y metacognitivas. Por lo tanto, el estudio aportó evidencias para usar el software matemático bajo una metodología constructivista.
Marien Béguelin
2011-07-01
Full Text Available El objetivo de este trabajo es desarrollar funciones discriminantes para estimar el sexo en poblaciones cazadoras recolectoras sudamericanas a partir de variables métricas del húmero. Se seleccionaron tres muestras de poblaciones del Holoceno tardío procedentes de: a Sur de Patagonia (n= 64, b Noreste de Patagonia (n= 47, y c Noreste de Pampa y Entre Ríos (n= 35. Para obtener una estimación confiable del sexo se incluyeron individuos con estructuras diagnósticas presentes de la pelvis o el cráneo. Se analizaron seis variables del húmero que fueron empleadas para generar funciones discriminantes a través del método stepwise forward. El sexo estimado fue contrastado con el sexo basado en la pelvis a fin de establecer su exactitud. Las asignaciones correctas calculadas mediante el método de validación cruzada fueron relevadas en las tres muestras, que variaron entre el 82% y el 100%. A su vez, se estimó el sexo con funciones provenientes de otras poblaciones del mundo, que arrojaron porcentajes menores de asignaciones correctas. Por lo tanto, la técnica desarrollada proporciona estándares específicos para las poblaciones del cono sur de América y constituye una herramienta confiable para la estimación del sexo en muestras procedentes de las áreas analizadas.The purpose of this study is to develop discriminant functions for sex estimation in hunter-gatherer South American populations, using humerus metric variables. Three Late Holocene aboriginal population samples were selected from: a South Patagonia (n= 64, b Northeastern Patagonia (n= 47 and c Northeastern Pampa and Entre Ríos (n= 35. Only those individuals showing pelvic or cranial diagnostic structures were included, in order to obtain reliable and independent sex estimation. Six humeral variables were measured (Maximum Length, Epicondylar Breadth, Vertical Diameter of Head, Maximum and Minimum Diameter at Midshaft and Minimum Diaphyseal Circumference and discriminant
De la Torre Vega, Eli
1997-04-01
of some potential improvements that the proposed method has. [Espanol] En el primer capitulo se presenta la deduccion de los cortes de Benders partiendo de las propiedades de la dualidad. Tambien se presentan las propiedades de los cortes de Benders asi como el algoritmo inicial de Benders para resolver cualquier problema de programacion lineal entera-mixta. En el segundo capitulo, se presenta el problema de la planeacion de la expansion de los medios de generacion y transmision en un sistema electrico de potencia, las distintas estructuras de la programacion matematica a que da lugar y como se puede adaptar el metodo de Benders a estas. En el tercer capitulo se presentan las aportaciones teoricas de este trabajo: a) Como inicializar el problema maestro para aprovechar la experiencia adquirida despues de haber resuelto un problema similar, de modo que se pueda resolver mas eficientemente, la sucesion de problemas de programacion lineal entero-mixtos que surgen al resolver el problema de la planeacion de la expansion de los medios de generacion y transmision en un sistema electrico de potencia. b) Como generar un problema maestro cuya solucion optima continua corresponda al optimo continuo del problema entero-mixto, de modo que la busqueda de soluciones enteras se realice en la vecindad del optimo continuo. c) Como generar una solucion entera, cercana al optimo continuo del problema entero-mixto, que tenga mucha probabilidad de ser factible, y que quizas sea la solucion optima entera, en un tiempo menor al que se requiere para resolverlo en forma exacta. Ademas, se presentan otras ideas que se le pueden incorporar al metodo de Benders. A fin de mostrar la efectividad de las ideas propuestas, en el capitulo 4 se presentan los resultados obtenidos al resolver varios problemas usando: 1. El metodo de Benders in actualizacion, 2. El metodo de Ramificacion y Acotamiento, 3. La actualizacion de Benders al agregar restricciones y 4. La actualizacion de Benders al considerar
Carla Bellomo
2009-12-01
Full Text Available Desde 1995 se han informado más de 1000 casos de síndrome pulmonar por hantavirus (SPH en la Argentina, enfermedad grave y muchas veces fatal para los humanos. La mayoría de los casos fueron asociados al virus Andes (AND único hantavirus que ha sido informado como causante de transmisión persona a persona. Se han descrito varios linajes patogénicos del virus AND, de los cuales AND Sur, cuyo reservorio es el roedor Oligoryzomys longicaudatus, afecta a la región patagónica de Argentina y Chile. En el presente estudio se informan las manifestaciones clínicas y las características epidemiológicas de un caso de SPH. El objetivo fue describir la presentación clínica del caso, su entorno epidemiológico, el sitio probable de contagio, la variante viral implicada y su relación con los casos más cercanos notificados. Se realizó el seguimiento clínico, el diagnóstico serológico y molecular y la investigación epidemiológica, incluyendo un estudio de la población de roedores reservorios en las áreas involucradas. Se trató de una presentación clásica de SPH moderada, causada por el linaje viral AND sur y su secuencia nucleotídica se comparó con casos del sur argentino y chileno. El caso de hantavirus investigado resultó ser el más austral (48° 46´ 1.2´´ S; 70° 15´ 0´´ O notificado hasta el momento e involucró a una nueva provincia argentina.Since 1995 more than 1000 cases of hantavirus pulmonary syndrome (HPS were reported in Argentina, a severe disease and often fatal to humans. Most cases were associated with Andes virus (AND that caused few events of person-to-person transmission. Several lineages of pathogenic AND viruses have been described, including AND South, hosted by the rodent Oligoryzomys longicaudatus which affects the Patagonian region of Argentina and Chile. We studied the clinical and epidemiological characteristics of a HPS case. The objective was to describe the clinical presentation of the case, its
Béguelin, Marien
2008-01-01
Full Text Available El objetivo de este trabajo es desarrollar funciones discriminantes para estimar el sexo en poblaciones sudamericanas a partir de variables métricas del fémur. Con este fin se seleccionaron tres muestras de poblaciones aborígenes procedentes de: a Sur de Patagonia (n=61, b Norte de Patagonia y Sur de Pampa (n=94 y c NE Pampa y Entre Ríos (n=51. Sólo se incluyeron los individuos que presentaban estructuras diagnósticas de la pelvis que fueron utilizadas para obtener una estimación confiable del sexo. Posteriormente, se relevaron nueve variables del fémur, cinco de las cuales (diámetro de la cabeza, longitud fisiológica, ancho epicondilar y diámetros antero-posterior y medio-lateral del centro de la diáfisis fueron empleadas para generar funciones discriminantes a través del método stepwise forward. Estas funciones incorporaron diferentes combinaciones de las variables en las tres muestras. El sexo estimado con las funciones fue contrastado con su correspondiente, a partir de variables de la pelvis a fin de establecer la exactitud de las mismas. Los porcentajes de asignaciones correctas calculados mediante el método de validación cruzada fueron elevados en las tres muestras, variando en promedio entre el 80% y el 94%. Por lo tanto, los resultados obtenidos indican que la técnica desarrollada proporciona un estándar específico para las poblaciones del sur de Sudamérica y constituye una herramienta confiable para la estimación del sexo en muestras procedentes de las áreas analizadas.
Vaquer Caballeria, Marcos
2012-01-01
... ambientales y la interdependencia entre municipios y entre estos y las areas rurales han marcado un progresivo desplazamiento de la asignacion competencial de la orbita municipal a la supralocal...
Pamplona, Djenane C; Velloso, Raquel Q; Radwanski, Henrique N
2014-01-01
This article discusses skin expansion without considering cellular growth of the skin. An in vivo analysis was carried out that involved expansion at three different sites on one patient, allowing for the observation of the relaxation process. Those measurements were used to characterize the human skin of the thorax during the surgical process of skin expansion. A comparison between the in vivo results and the numerical finite elements model of the expansion was used to identify the material elastic parameters of the skin of the thorax of that patient. Delfino's constitutive equation was chosen to model the in vivo results. The skin is considered to be an isotropic, homogeneous, hyperelastic, and incompressible membrane. When the skin is extended, such as with expanders, the collagen fibers are also extended and cause stiffening in the skin, which results in increasing resistance to expansion or further stretching. We observed this phenomenon as an increase in the parameters as subsequent expansions continued. The number and shape of the skin expanders used in expansions were also studied, both mathematically and experimentally. The choice of the site where the expansion should be performed is discussed to enlighten problems that can lead to frustrated skin expansions. These results are very encouraging and provide insight into our understanding of the behavior of stretched skin by expansion. To our knowledge, this study has provided results that considerably improve our understanding of the behavior of human skin under expansion.
Alvarez Vargas, Zulma
2007-08-01
Full Text Available Resumen: La investigación tuvo como propósito el desarrollo de habilidades del pensamiento y el mejoramiento del aprendizaje en alumnos y alumnas de la asignatura Matemática II, del Decanato de Ingeniería Civil de la Universidad Centroccidental “Lisandro Alvarado” (UCLA, mediante el empleo de estrategias instruccionales basadas en el uso del software matemático. La investigación, de diseño cuasi-experimental, usó para el contraste de hipótesis la prueba t para muestras relacionadas. Además se aplicaron dos pruebas, tres asignaciones, una lista de cotejo y una entrevista semiestructurada. Los datos recogidos se analizaron utilizando estadística descriptiva. Los hallazgos del estudio fueron: (a los conocimientos de los discentes mejoraron; y (b estos pusieron en práctica sus procedimientos (sus habilidades cognoscitivas y metacognitivas. Por lo tanto, el estudio aportó evidencias para usar el software matemático bajo una metodología constructivista.ABSTRACT: The purpose of this research project was to develop thinking skills and improve learning abilities of university students attending Math II, at the School of Civil Engineering at the University Centroccidental “Lisandro Alvarado” (UCLA, by utilizing instructional strategies, based on the use of mathematical software. The quasi experimental design of the study performed, to contrast the hypothesis, utilized test t for related samples. Additionally, the following instruments were applied: two exams, three assignments, a checking list and a semi structured interview. The information collected was analyzed using descriptive statistics. The research findings were: (a the students’ knowledge improved; and (b the students put into practice their procedures, that is to say, their cognitive and metacognitive skills. Hence, the study contributed to evidence the utilization of the mathematical software using a constructivist instructional methodology.
Claudia Danani
2010-01-01
Full Text Available El trabajo analiza la capacidad de protección social del sistema de seguridad social argentino en inicios del siglo XXI (esto es en el alcance cuanti y cualitativo de satisfacción de necesidades de prestaciones y servicios definidas en un cierto sector de políticas, en este caso la seguridad social. Se abordan los contenidos político-culturales producidos en el curso de estos procesos, y los significados asignados a términos como "derechos", "solidaridad" o "papel del Estado, privilegiándose el sistema previsional las asignaciones familiares. Se rastrean los elementos más significativos de lo que se considera una "transición" en las políticas sociales en la primera década del siglo, sosteniendo que se registra en la Argentina una reorientación de algunas de las políticas de Estado, que constituye una contrarreforma de las características de la década de 1990.
Victor Gameiro Drummond
2016-06-01
Full Text Available Los sistemas de derecho de autor surgidos en Inglaterra y Francia son los herederos históricos de las concesiones monárquicas otorgadas a editores, que, en aquel entonces, también eran libreros o impresores. El sistema (o la práctica de asignación de monopolios no se podría sostener después del reconocimiento que se debe aplicar (a los autores y / o editores la exclusividad universal para la impresión. Este trabajo tiene como objetivo describir el desarrollo de asignaciones de privilegios de impresión, extrayendo de estas descripciones una evaluación crítica sobre el efecto histórico de tales elementos en el entorno de los derechos de autor que en, aquel entonces todavía estaba en su primer infancia. Cabe señalar, por último, la comprensión de que el desarrollo de privilegios no ha conducido a una justificación filosófica de los derechos de autor desde su surgimiento, pero, por otro lado, a una falsa idea que indica una justificación filosófica disfrazada para atingir intereses claramente económicos, dando lugar a lo que llamo “déficit filosófico del derecho de autor.
Economía y sistemas de asentamiento aborigen en la cuenca del río Limay
Mabel M. Fernández
2006-12-01
Full Text Available El presente trabajo es un aporte para el conocimiento, a través del análisis de fuentes escritas, de la diversidad espacio-temporal de los sistemas de asentamiento y subsistencia aborígenes de la cuenca superior y media del río Limay, noroeste patagónico, durante los siglos XVII y XIX. Caracterizamos los sistemas económicos y establecemos su correspondencia con las distintas etnías que, según las fuentes, se hallaban presentes en la zona durante el período en estudio. Además, discutimos algunos problemas relacionados con las asignaciones étnicas y los criterios utilizados para su identificación.The spatial and temporal diversity of the native settlement and subsistence systems in the upper and medium Limay river basin, northwestern Patagonia, is examined through written sources from the 17th and 19th centuries. Whenever possible, the connection between each system and the corresponding ethnic group (identified by its chieftain is stated, and the nomenclature employed in the sources is mentioned and discussed.
Barrera, G D [Departamento de QuImica, Universidad Nacional de la Patagonia SJB, Ciudad Universitaria, 9000 Comodoro Rivadavia (Argentina); Bruno, J A O [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de QuImica Inorganica, AnalItica y QuImica FIsica, Pabellon 2, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Barron, T H K [School of Chemistry, University of Bristol, Cantock' s Close, Bristol BS8 1TS (United Kingdom); Allan, N L [School of Chemistry, University of Bristol, Cantock' s Close, Bristol BS8 1TS (United Kingdom)
2005-02-02
There has been substantial renewed interest in negative thermal expansion following the discovery that cubic ZrW{sub 2}O{sub 8} contracts over a temperature range in excess of 1000 K. Substances of many different kinds show negative thermal expansion, especially at low temperatures. In this article we review the underlying thermodynamics, emphasizing the roles of thermal stress and elasticity. We also discuss vibrational and non-vibrational mechanisms operating on the atomic scale that are responsible for negative expansion, both isotropic and anisotropic, in a wide range of materials. (topical review)
Lorena B. Rodríguez
2004-12-01
Full Text Available La memoria social no es un mero reflejo de los hechos del pasado, sino una compleja construcción en la que tanto recuerdos individuales como colectivos, experiencias pasadas y situaciones presentes se intrincan inexorablemente. La memoria, entendida en esos términos, se constituye en un campo ideal para preguntar acerca de los diferentes sentidos que se le asignan al pasado desde o para el presente y analizar, por ende, las tensiones y disputas que tales asignaciones conllevan. En esta línea de trabajo, el objetivo del artículo es abordar el complejo proceso de atribuciones de sentido acerca del pasado que diferentes sectores y actores de la población del Dto. de Santa María (Pcia. de Catamarca realizan en la actualidad y, a la vez, reflexionar sobre algunas cuestiones teóricas que se desprenden del caso expuesto, en particular en torno a la idea del pasado como un recurso ilimitado pasible de ser usado por cualquier persona en cualquier momento.The social memory is not a mere reflection of the past events but a complex construction in which individual and colective memories, past experiences and current situations are inexorably mixed up. Memory, in that sense, became an ideal field to ask about the different meanings assigned to the past, from or for the present; thus allowing us to analize the tensions and disputes generated in this attributions. The aim of this paper is to approach the complex process by which different sectors and actors of Santa María district (Catamarca's province assign meanings to the past and, at the same time, to think about some theoretical subjects extracted of this case, particularly around the idea of the past as an unscared resource capable of being used by anyone at any moment.
Fakhruddin, Hasan
1993-01-01
Describes a paradox in the equation for thermal expansion. If the calculations for heating a rod and subsequently cooling a rod are determined, the new length of the cool rod is shorter than expected. (PR)
Barboza, María Carolina
2003-01-01
Full Text Available En este trabajo se presentan los resultados obtenidos al aplicar un conjunto de técnicas basadas en el uso de marcadores biológicos (morfológicos y métricos del sexo en los individuos adultos de una colección osteológica correspondiente al Período Formativo (AMS Calibrado de 2 Sigma, Prob. 95%, Cal AD 545 a 660; Cal BP 1405 -1290 de la Quebrada de Humahuaca (Mendonça et al., 2002. Los restos óseos fueron recuperados en el transcurso de excavaciones sistemáticas en el así denominado "Sitio Mulqui" (SJ Til. 20, de la ciudad de Tilcara (Pcia. de Jujuy y constituyen una colección de 16 individuos, única de estas características para el período considerado (Bordach et al., 1999. El objetivo de este trabajo ha sido estudiar el comportamiento del patrón general de variabilidad sexual en los individuos adultos del Sitio Mulqui. Para ello se realizó un estudio comparativo en el que se confronta la información proporcionada por los distintos marcadores óseos para determinación sexual. Nuestros resultados permiten comprobar la existencia de concordancias y discordancias en las asignaciones sexuales de índole osteológica, según el complejo o estructura anatómica considerada, las cuales son discutidas e interpretadas a la luz de la información tanto biológica como cultural disponible. Se presentan los marcadores osteológicos considerados más efectivos para esta muestra en particular.
Composite asymptotic expansions
Fruchard, Augustin
2013-01-01
The purpose of these lecture notes is to develop a theory of asymptotic expansions for functions involving two variables, while at the same time using functions involving one variable and functions of the quotient of these two variables. Such composite asymptotic expansions (CAsEs) are particularly well-suited to describing solutions of singularly perturbed ordinary differential equations near turning points. CAsEs imply inner and outer expansions near turning points. Thus our approach is closely related to the method of matched asymptotic expansions. CAsEs offer two unique advantages, however. First, they provide uniform expansions near a turning point and away from it. Second, a Gevrey version of CAsEs is available and detailed in the lecture notes. Three problems are presented in which CAsEs are useful. The first application concerns canard solutions near a multiple turning point. The second application concerns so-called non-smooth or angular canard solutions. Finally an Ackerberg-O’Malley resonance pro...
Novel Foraminal Expansion Technique
Senturk, Salim; Ciplak, Mert; Oktenoglu, Tunc; Sasani, Mehdi; Egemen, Emrah; Yaman, Onur; Suzer, Tuncer
2016-01-01
The technique we describe was developed for cervical foraminal stenosis for cases in which a keyhole foraminotomy would not be effective. Many cervical stenosis cases are so severe that keyhole foraminotomy is not successful. However, the technique outlined in this study provides adequate enlargement of an entire cervical foraminal diameter. This study reports on a novel foraminal expansion technique. Linear drilling was performed in the middle of the facet joint. A small bone graft was placed between the divided lateral masses after distraction. A lateral mass stabilization was performed with screws and rods following the expansion procedure. A cervical foramen was linearly drilled medially to laterally, then expanded with small bone grafts, and a lateral mass instrumentation was added with surgery. The patient was well after the surgery. The novel foraminal expansion is an effective surgical method for severe foraminal stenosis. PMID:27559460
Minjares-Lugo, Jose Luis; Salmon-Castelo, Roberto Fernando; Oroz-Ramos, Lucas Antonio [Comision Nacional del Agua (Mexico); Cruz-Medina, Isidro Roberto [Instituto Tecnologico de Sonora (Mexico)
2008-07-15
The objective of this study is to develop an integrated hydrologic-agronomic-economic annual model for the optimal operation of the Yaqui River reservoir system to support irrigation and urban water supply in the watershed. The model solves for each year's water allocations by crop, maximizing annual agricultural income for a specified risk of reservoir shortages and spills. It accounts for adjustments in water supply arising from changes in precipitation and runoff uncertainty and from changes in water demand arising from variations in crop prices and production costs. Model predictions for the agricultural year 2000-2001 are compared with observed results to test the model's predictive ability. Results demonstrate that the model can be used to optimize and analyze reservoir system operation and for water resources management in the Irrigation District No. 041, providing a framework for improving the operation of a reservoir system, selecting an optimal cropping pattern according to its maximum economic benefits, and in the optimal monthly water releases from the reservoir system. The model considers the simultaneous operation of three dams and it is applied to the Irrigation District No. 041, Rio Yaqui. [Spanish] El objetivo de este estudio es desarrollar un modelo integral de optimizacion anual para definir la operacion del sistema de presas del rio Yaqui y la asignacion del volumen mensual de agua para la irrigacion de diferentes cultivos, asi como para satisfacer los requerimientos de uso urbano basado en las condiciones hidrologicas, agronomicas y economicas en la cuenca. El modelo maximiza los beneficios anuales netos del sector agricola, minimizando el riesgo de deficit o derrames en el sistema de presas; incluye cambios en el suministro de agua debido a la incertidumbre de las precipitaciones y del escurrimiento del rio y cambios en la demanda de agua provocados por la incertidumbre de los precios y costos de los cultivos. Se utilizaron datos del
Steppe expansion in Patagonia?
Veblen, Thomas T.; Markgraf, Vera
1988-11-01
Westward expansion of the Patagonian steppe and retrocession of Andean forests due to increasing aridity over the past one or two millennia has been a persistent theme in the ecological and paleoecological literature for at least half a century. New evidence from pollen profiles, tree-ring analysis, vegetation structure, and photographic and documentary historical sources does not show the expansion of the steppe. Instead, over the past century trees have invaded the steppe as a consequence mainly of human-induced changes in the fire regime, and trees have regenerated in forest areas that were heavily burnt at the onset of European colonization.
Massimo Giovannini
2015-06-01
Full Text Available 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.
Giovannini, Massimo, E-mail: massimo.giovannini@cern.ch [Department of Physics, Theory Division, CERN, 1211 Geneva 23 (Switzerland); INFN, Section of Milan-Bicocca, 20126 Milan (Italy)
2015-06-30
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.
For the Long Island, New Jersey, and southern New England region, one facet of marsh drowning as a result of accelerated sea level rise is the expansion of salt marsh ponds and pannes. Over the past century, marsh ponds and pannes have formed and expanded in areas of poor drainag...
Kowalski, Emmanuel
2010-01-01
This is a survey report for the Bourbaki Seminar (Exp. no. 1028, November 2010) concerning sieve and expanders, in particular the recent works of Bourgain, Gamburd and Sarnak introducing "sieve in orbits", and the related developments concerning expansion properties of Cayley graphs of finite linear groups.
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...
Barboza, María Carolina
2001-01-01
Full Text Available Se presentan los resultados de una experiencia con marcadores osteológicos de edad sobre una muestra correspondiente al Período Hispano-Indígena, con notorio grado de integridad y asociación contextual. La misma se compone de un total de treinta y un individuos entre maduros e inmaduros, los cuales son considerados a su vez en subrangos de edad. Los complejos anatómicos considerados comprenden pelvis, cráneo, dentición, fusión epifisiaria, y aspectos métricos. Se observan concordancias y discrepancias en las asignaciones; se discuten los resultados para cada método por individuo y para el conjunto analizado; y se realizan recomendaciones instrumentales para la aplicación técnica. Los resultados, son interpretados en función de los referentes teóricos disponibles para la biología del crecimiento y desarrollo, señalándose la necesidad de focalizar los aspectos vinculados con la biología de la senescencia del sistema esqueletal humano.
Giubergia, J.H.; Coppari, N.R. [Comision Nacional de Energia Atomica, Centro Atomico Constituyentes, Unidad de Actividad Reactores y Centrales Nucleares, Avda. Gral. Paz 1499 (1650) San Martin, Provincia de Buenos Aires (Argentina); Rey, F.C. [Comision Nacional de Energia Atomica, Centro Atomico Ezeiza, Presbitero Juan Gonzalez y Aragon 15, (B1802AYA) Ezeiza, Provincia de Buenos Aires (Argentina)]. E-mail: giuberg@cnea.gov.ar
2004-07-01
In this work one simulates, using the program MESSAGE, the generation park electric of the Argentine Republic and their possible expansion, with restrictions in the readiness of fossil fuels. This, as other models of planning energetics promoted by IAEA, optimizes the expansion of the net having as function objective the smallest cost in the system. 25 years they were simulated, adopting like base the anus 2000 and considering different scenarios of internal and external demands. It was analysed the increase of the demand with restrictions in the readiness of the natural gas in the winter periods, since the Argentinean electric system has a great dependence of this fuel. To cover the increase of the electric demand, were selected the machines and fuels, at the moment available, with more technical and economic possibilities. In the scenarios without restrictions to the use of natural gas the program selects to the nuclear power station of Atucha II, to the increase of bench mark of the hydraulic power station of Yacireta and combined cycles that burn natural gas. In those in that the supply of natural gas is limited, it selects previously besides the signal ones, other nuclear power stations, other hydroelectric projects and turbines of gas operating with gas oil to cover the top requirements. (Author)
Barboza, María Carolina
2001-01-01
Full Text Available Se presentan los resultados de una experiencia basada en la utilización de un conjunto de técnicas consideradas convencionales las cuales se basan en el tratamiento y la consideración de marcadores morfoosteológicos de edad sobre una muestra correspondiente al Período Hispano-Indígena, caracterizada por su notorio grado de integridad y asociación contextual. La misma se compone de un total de treinta y un individuos entre maduros e inmaduros. En este caso se consideran exclusivamente los resultados correspondientes a los individuos adultos que componen el conjunto, los cuales a su vez son subdivididos en subrangos de edad. Los complejos anatómicos considerados en este caso comprenden pelvis y cráneo. Los resultados permiten observar la existencia dentro y entre procedimientos de concordancias y discrepancias en las asignaciones de edad. Mediante la estructuración de un diseño basado en el análisis de la varianza, se discuten los resultados obtenidos por cada procedimiento para el conjunto analizado; y se realizan recomendaciones instrumentales para la aplicación no indiscriminada de las distintas técnicas de estimación, particularmente cuando se trata de materiales con valor bioarqueológico. Los resultados, son interpretados en función de los referentes teóricos disponibles para la biología del crecimiento y desarrollo, señalándose la necesidad de focalizar los aspectos vinculados con la biología de la senescencia del sistema esqueletal humano.
Xiberta, B. J.; Juarez, A. J.
2004-07-01
The purpose of this article is to analyze the feasibility of the expansion of the Pico Gallo Wind Farm (Tineo-Asturias) from the point of view of the existing wind resource in this location. With this in mind, the weather data of the pre-existing Wind Farm have been compiled in the period between July 2002-November 2003. In the same way a temporary extrapolation has been made with the MCP Method (Measure-Correlate-Predict) from the data of another wind measurement tower located in the proximities. The obtained results show the viability of the Wind Farm extension so much for its wind resource potential as for terrain features from the studied location. (Author)
Bigravity from gradient expansion
Yamashita, Yasuho [Yukawa Institute for Theoretical Physics, Kyoto University,606-8502, Kyoto (Japan); Tanaka, Takahiro [Yukawa Institute for Theoretical Physics, Kyoto University,606-8502, Kyoto (Japan); Department of Physics, Kyoto University,606-8502, Kyoto (Japan)
2016-05-04
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.
Operator product expansion algebra
Holland, Jan [CPHT, Ecole Polytechnique, Paris-Palaiseau (France)
2014-07-01
The Operator Product Expansion (OPE) is a theoretical tool for studying the short distance behaviour of products of local quantum fields. Over the past 40 years, the OPE has not only found widespread computational application in high-energy physics, but, on a more conceptual level, it also encodes fundamental information on algebraic structures underlying quantum field theories. I review new insights into the status and properties of the OPE within Euclidean perturbation theory, addressing in particular the topics of convergence and ''factorisation'' of the expansion. Further, I present a formula for the ''deformation'' of the OPE algebra caused by a quartic interaction. This formula can be used to set up a novel iterative scheme for the perturbative computation of OPE coefficients, based solely on the zeroth order coefficients (and renormalisation conditions) as initial input.
Thermal expansion of glassy polymers.
Davy, K W; Braden, M
1992-01-01
The thermal expansion of a number of glassy polymers of interest in dentistry has been studied using a quartz dilatometer. In some cases, the expansion was linear and therefore the coefficient of thermal expansion readily determined. Other polymers exhibited non-linear behaviour and values appropriate to different temperature ranges are quoted. The linear coefficient of thermal expansion was, to a first approximation, a function of both the molar volume and van der Waal's volume of the repeating unit.
Operator product expansion algebra
Holland, Jan [School of Mathematics, Cardiff University, Senghennydd Rd, Cardiff CF24 4AG (United Kingdom); Hollands, Stefan [School of Mathematics, Cardiff University, Senghennydd Rd, Cardiff CF24 4AG (United Kingdom); Institut für Theoretische Physik, Universität Leipzig, Brüderstr. 16, Leipzig, D-04103 (Germany)
2013-07-15
We establish conceptually important properties of the operator product expansion (OPE) in the context of perturbative, Euclidean φ{sup 4}-quantum field theory. First, we demonstrate, generalizing earlier results and techniques of hep-th/1105.3375, that the 3-point OPE,
Testing Machine for Expansive Mortar
Silva, Romulo Augusto Ventura
2011-01-01
The correct evaluation of a material property is fundamental to, on their application; they met all expectations that were designed for. In development of an expansive cement for ornamental rocks purpose, was denoted the absence of methodologies and equipments to evaluate the expansive pressure and temperature of expansive cement during their expansive process, having that data collected in a static state of the specimen. In that paper, is described equipment designed for evaluation of pressure and temperature of expansive cements applied to ornamental rocks.
Engineering Properties of Expansive Soil
DAI Shaobin; SONG Minghai; HUANG Jun
2005-01-01
The components of expansive soil were analyzed with EDAX, and it is shown that the main contents of expansive soil in the northern Hubei have some significant effects on engineering properties of expansive soil. Furthermore, the soil modified by lime has an obvious increase of Ca2+ and an improvement of connections between granules so as to reduce the expansibility and contractility of soil. And it also has a better effect on the modified expansive soil than the one modified by pulverized fuel ash.
Milagros GUTIÉRREZ FERNÁNDEZ
2012-01-01
Full Text Available La actual crisis financiera internacional está actuando como catalizador de un profundo proceso de cambio en el sector bancario español que está afectando también a las entidades de crédito de la Economía Social: cajas de ahorros y cooperativas de crédito. Su modelo de banca “minorista”, centrada en la cercanía al cliente, se ha visto acompañado en los últimos años de un fuerte proceso de expansión geográfica que ha supuesto un sobredimensionamiento de su red de sucursales. Sin embargo, como consecuencia de las actuales circunstancias de la economía española en general, y del sistema bancario en particular, dicha estrategia de desarrollo interno no parece sostenible, siendo necesario que se produzca un redimensionamiento del sector, para ver recuperada la confianza en el sistema y para que éste vuelva a ser considerado como uno de los más solventes del mundo. Bajo este enfoque, el objetivo de este trabajo es analizar las distintas estrategias de expansión territorial desarrolladas por dichas entidades con el objetivo de plasmar su situación actual y comprender por qué es necesaria la reestructuración del sector. Para ello se ha empleado tanto el análisis descriptivo como el econométrico, utilizando en todo momento los datos que presentan la Confederación Española de Cajas de Ahorros (CECA y la Unión Nacional de Cooperativas de Crédito (UNACC en sus anuarios estadísticos. / The current financial international crisis is acting as catalyst of a deep process of change in the Spanish banking sector which is affecting also the credit institutions of the Social Economy: saving banks and credit cooperatives. These entities share a model of "retail" banking, centered on the nearness to the client, that has been accompanied in the last years of a strong process of geographical expansion which has supposed an oversizing of its network of branches. Nevertheless, as a consequence of the current circumstances of the Spanish
Conformal expansions and renormalons
Gardi, E; Gardi, Einan; Grunberg, Georges
2001-01-01
The large-order behaviour of QCD is dominated by renormalons. On the other hand renormalons do not occur in conformal theories, such as the one describing the infrared fixed-point of QCD at small beta_0 (the Banks--Zaks limit). Since the fixed-point has a perturbative realization, all-order perturbative relations exist between the conformal coefficients, which are renormalon-free, and the standard perturbative coefficients, which contain renormalons. Therefore, an explicit cancellation of renormalons should occur in these relations. The absence of renormalons in the conformal limit can thus be seen as a constraint on the structure of the QCD perturbative expansion. We show that the conformal constraint is non-trivial: a generic model for the large-order behaviour violates it. We also analyse a specific example, based on a renormalon-type integral over the two-loop running-coupling, where the required cancellation does occur.
Optical imaging. Expansion microscopy.
Chen, Fei; Tillberg, Paul W; Boyden, Edward S
2015-01-30
In optical microscopy, fine structural details are resolved by using refraction to magnify images of a specimen. We discovered that by synthesizing a swellable polymer network within a specimen, it can be physically expanded, resulting in physical magnification. By covalently anchoring specific labels located within the specimen directly to the polymer network, labels spaced closer than the optical diffraction limit can be isotropically separated and optically resolved, a process we call expansion microscopy (ExM). Thus, this process can be used to perform scalable superresolution microscopy with diffraction-limited microscopes. We demonstrate ExM with apparent ~70-nanometer lateral resolution in both cultured cells and brain tissue, performing three-color superresolution imaging of ~10(7) cubic micrometers of the mouse hippocampus with a conventional confocal microscope.
Lara Covarrubias, Hector
2004-05-15
This thesis work shows the development of a classification model that allows the user to assess the operative condition of power transformers. The proposed model includes the following steps: Relative weights assignation for each IEEE-62-1995 required test. Those relative weights are obtained from test results and standardized and experience based limits obtained by Comision Federal de Electricidad (CFE). Once the relative weights have been assigned, three states, green, yellow and red were defined. Each state was then ranked with a weight number (1, 2 or 3). Specific weights were assigned for each test included in the model. Test score assignation takes into account the product of the relative value and the specific weight of each test. Transformer risk assessment uses the total score obtained from the sum of the tests partial scores. Transformer risk assessment was then classified in three categories. Total score causes the system to issue maintenance or substitution recommendations. The described model will improve maintenance scheduling according the transformer risk assessment and it is fully applicable to the complete CFE power transformer population. Further, smart investment and substitution plans, can be easily obtained from the model, preventing catastrophic failures that may cause logistic and economical problems to the Mexican Power System operation. As an example, the results obtained from the model application to two transformer banks installed in a CFE hydroelectric power plant were discussed and analyzed. [Spanish] El trabajo que se muestra en esta tesis, es el desarrollo de un modelo para la clasificacion del estado operativo de los transformadores de potencia. El modelo propuesto incluye los siguientes pasos: Asignacion de pesos relativos para cada una de las pruebas establecidas en la norma IEEE-62-1995 en funcion de sus resultados, limites establecidos en la normatividad y limites propuestos con base en la experiencia de la Comision Federal de
Burial Ground Expansion Hydrogeologic Characterization
Gaughan , T.F.
1999-02-26
Sirrine Environmental Consultants provided technical oversight of the installation of eighteen groundwater monitoring wells and six exploratory borings around the location of the Burial Ground Expansion.
Ackerman, Margareta; Lopez-Ortiz, Alejandro
2011-01-01
Over the last fifteen years, web searching has seen tremendous improvements. Starting from a nearly random collection of matching pages in 1995, today, search engines tend to satisfy the user's informational need on well-formulated queries. One of the main remaining challenges is to satisfy the users' needs when they provide a poorly formulated query. When the pages matching the user's original keywords are judged to be unsatisfactory, query expansion techniques are used to alter the result set. These techniques find keywords that are similar to the keywords given by the user, which are then appended to the original query leading to a perturbation of the result set. However, when the original query is sufficiently ill-posed, the user's informational need is best met using entirely different keywords, and a small perturbation of the original result set is bound to fail. We propose a novel approach that is not based on the keywords of the original query. We intentionally seek out orthogonal queries, which are r...
Lattice harmonics expansion revisited
Kontrym-Sznajd, G.; Holas, A.
2017-04-01
The main subject of the work is to provide the most effective way of determining the expansion of some quantities into orthogonal polynomials, when these quantities are known only along some limited number of sampling directions. By comparing the commonly used Houston method with the method based on the orthogonality relation, some relationships, which define the applicability and correctness of these methods, are demonstrated. They are verified for various sets of sampling directions applicable for expanding quantities having the full symmetry of the Brillouin zone of cubic and non-cubic lattices. All results clearly show that the Houston method is always better than the orthogonality-relation one. For the cubic symmetry we present a few sets of special directions (SDs) showing how their construction and, next, a proper application depend on the choice of various sets of lattice harmonics. SDs are important mainly for experimentalists who want to reconstruct anisotropic quantities from their measurements, performed at a limited number of sampling directions.
Isotropic Negative Thermal Expansion Metamaterials.
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.
On genus expansion of superpolynomials
Mironov, A; Sleptsov, A; Smirnov, A
2013-01-01
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 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 letter 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 beta-deformed to Hamiltonians of the Calogero-Moser-Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is rather straightforward only for the thin knots. Beyond this family additional algebraically independent terms appear in the Vassiliev and genus expansions. This can suggest that the superpol...
Cortes, F.; Cuevas, G.; Tenorio, J.; Rochin, A.L. [Universidad Nacional Autonoma de Mexico, Instituto de Quimica, A.P. 70213, 04510 Mexico D.F. (Mexico)
2000-07-01
Ab initio calculations, within the frame of Density Functional Theory were carried out on camphene and {alpha}-pinene. The {sup 1} H and {sup 13} C shifts were estimated according to the recently developed Sum-Over-States Density Functional Perturbation Theory (SOS-DFPT) as implemented in a modified deMon-KS program. The calculations not only reproduced the observed NMR chemical shifts, quantitatively in the case of {sup 1} H nuclei and qualitatively in the case of {sup 13} C nuclei, but also allow assigning unambiguously the signal on these spectra. (Author)
Agregación de para-H2 en chorros supersónicos: del dímero al sólido
María Fernández, José
En este trabajo se mostrarán los estudios de expansiones supersónicas de para-H2 desde toberas criogénicas, realizados en el laboratorio de Fluidodinámica Molecular del IEM. Hemos registrado los espectros Raman de dichas expansiones en el intervalo de frecuencias de 4145 a 4162 cm-1, próximo a la línea Q(0) del monómero no rotante H2, a 4161.18 cm-1. En el espectro Raman, además de la línea Q(0) del monómero, se observan unos picos débiles, que, por su comportamiento con la temperatura de la tobera y la distancia a la misma, asignamos a la transición homóloga en agregados de p-H2. Dependiendo de las condiciones, se observan agregados pequeños (de 2 a 13 moléculas de p-H2), agregados medios y masivos, y se llega incluso al líquido y al sólido. Las asignaciones se apoyan en un modelo sencillo, basado en la perturbación, debida al potencial intermolecular, de los estados vibracionales v=0 y v=1 en los agregados de p-H2. Se mostrarán detalles de la instalación experimental, ejemplos de los espectros obtenidos en diversas condiciones, y detalles de la interpretación cuantitativa.
Albores, Marta E.; Maldonado, Luis A. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)
1999-08-01
The construction of the chromone, thiochromone and 4-quinolone ring systems by ring expansion of appropriate 5-membered heterocyclic enol acetates, with dibromocarbene generated by Seyferth's method, is described. The use of the method for the synthesis of 2-bromo-1-naphthyl acetate and an attempted synthesis of the flavone ring are also reported. [Spanish] Se describe la construccion de los sistemas anulares de cromona, tiocromona y 4-quinolona por la expansion de acetatos de enol heterociclicos apropiados, con dibromocarbeno generado por el metodo de Seyferth. Tambien se informa del uso de este metodo para la sintesis del acetato de 2-bromo-1-naftilo y del intento de sintesis del anillo de flavona.
Thermal Expansion of Polyurethane Foam
Lerch, Bradley A.; Sullivan, Roy M.
2006-01-01
Closed cell foams are often used for thermal insulation. In the case of the Space Shuttle, the External Tank uses several thermal protection systems to maintain the temperature of the cryogenic fuels. A few of these systems are polyurethane, closed cell foams. In an attempt to better understand the foam behavior on the tank, we are in the process of developing and improving thermal-mechanical models for the foams. These models will start at the microstructural level and progress to the overall structural behavior of the foams on the tank. One of the key properties for model characterization and verification is thermal expansion. Since the foam is not a material, but a structure, the modeling of the expansion is complex. It is also exacerbated by the anisoptropy of the material. During the spraying and foaming process, the cells become elongated in the rise direction and this imparts different properties in the rise direction than in the transverse directions. Our approach is to treat the foam as a two part structure consisting of the polymeric cell structure and the gas inside the cells. The polymeric skeleton has a thermal expansion of its own which is derived from the basic polymer chemistry. However, a major contributor to the thermal expansion is the volume change associated with the gas inside of the closed cells. As this gas expands it exerts pressure on the cell walls and changes the shape and size of the cells. The amount that this occurs depends on the elastic and viscoplastic properties of the polymer skeleton. The more compliant the polymeric skeleton, the more influence the gas pressure has on the expansion. An additional influence on the expansion process is that the polymeric skeleton begins to breakdown at elevated temperatures and releases additional gas species into the cell interiors, adding to the gas pressure. The fact that this is such a complex process makes thermal expansion ideal for testing the models. This report focuses on the thermal
Luis Fernando Botero Botero
2005-01-01
Full Text Available Lean construction es una nueva filosofía orientada hacia la administración de la producción en construcción, cuyo objetivo fundamental es la eliminación de las actividades que no agregan valor (pérdidas. Para contribuir a tal fin, Ballard y Howell diseñaron un nuevo sistema de planificación y control denominado Last planner, con cambios fundamentales en la manera como los proyectos de construcción se planifican y controlan. El objetivo de este artículo es divulgar los resultados de la aplicación del sistema Last planner en proyectos de construcción en Medellín durante 2003, como parte de la investigación Implementación de un programa de mejoramiento en gestión de la construcción. Los resultados obtenidos muestran una tendencia al mejoramiento cada vez que se aplica el sistema, de acuerdo con el indicador PAC (porcentaje de asignaciones completadas
Flávio Manoel Coelho Borges Cardoso
2013-01-01
Full Text Available This article discusses the factors that favored creation and expansion of the health organization cluster in the city of Ceres, Goiás. Despite the small population of some 19,000 inhabitants, Ceres is recognized as a center for health services. This article investigates the creation and expansion of the health cluster in Ceres from two perspectives. The first considers the existence of so-called economic factors such as demand, infrastructure, presence of specialized skills, government policies, invitation to specialized professionals by businessmen and location on an important access route. The second takes into account sociological factors, highlighting social networks, professional and family ties, trust, values, rules and traditions as responsible for the multiplication of companies in the same sector in this location. Through an exploratory study based on interviews with 20 of the 65 physicians in the city, it is concluded that in the case of Ceres, great demand for health services, government actions to populate Brazil’s Mid-West and the activities of pioneers incentivating the entrepreneurial spirit of physicians were determining factors in the creation and expansion of this health cluster.Este trabajo discute los factores que favorecieron la formación y la expansión de la aglomeración de organizaciones de salud en el municipio de Ceres, en el estado brasileño de Goiás. A pesar de su pequeña población, cerca de 19.000 habitantes, Ceres es reconocida como una ciudad modelo en lo que se refiere a la prestación de servicios de salud. En este trabajo, analizamos la formación y expansión del cluster de salud de Ceres bajo dos perspectivas. La primera considera la existencia de los llamados factores económicos, como la demanda, la infraestructura, la presencia de mano de obra especializada, las políticas gubernamentales, la invitación de empresarios a profesionales especializados y la dependencia de la
Gradient expansion for anisotropic hydrodynamics
Florkowski, Wojciech; Ryblewski, Radoslaw; Spaliński, Michał
2016-12-01
We compute the gradient expansion for anisotropic hydrodynamics. The results are compared with the corresponding expansion of the underlying kinetic-theory model with the collision term treated in the relaxation time approximation. We find that a recent formulation of anisotropic hydrodynamics based on an anisotropic matching principle yields the first three terms of the gradient expansion in agreement with those obtained for the kinetic theory. This gives further support for this particular hydrodynamic model as a good approximation of the kinetic-theory approach. We further find that the gradient expansion of anisotropic hydrodynamics is an asymptotic series, and the singularities of the analytic continuation of its Borel transform indicate the presence of nonhydrodynamic modes.
Gradient expansion for anisotropic hydrodynamics
Florkowski, Wojciech; Spaliński, Michał
2016-01-01
We compute the gradient expansion for anisotropic hydrodynamics. The results are compared with the corresponding expansion of the underlying kinetic-theory model with the collision term treated in the relaxation time approximation. We find that a recent formulation of anisotropic hydrodynamics based on an anisotropic matching principle yields the first three terms of the gradient expansion in agreement with those obtained for the kinetic theory. This gives further support for this particular hydrodynamic model as a good approximation of the kinetic-theory approach. We further find that the gradient expansion of anisotropic hydrodynamics is an asymptotic series, and the singularities of the analytic continuation of its Borel transform indicate the presence of non-hydrodynamic modes.
Strategic Complexity and Global Expansion
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....
Expansion Nets and Expansion Processes of Elementary Net Systems
曹存根
1995-01-01
Occurrence nets are insufficient to precisely describe executions of elementary net systems with contacts.Traditionally,S-complementation is used for removal of contacts from the systems.Although the main behavior and properties of the original elementary net systems are preserved during S-complementation,their topologies may be changed greatly.This paper introduces a new kind of nets-expansion nets-for representing behavior of elementary net systems.As shown in the paper,expansion nets are natural as well as sufficient for describing the precise behavior of elementary net systems with or without contactks.
Reed's Conjecture on hole expansions
Fouquet, Jean-Luc
2012-01-01
In 1998, Reed conjectured that for any graph $G$, $\\chi(G) \\leq \\lceil \\frac{\\omega(G) + \\Delta(G)+1}{2}\\rceil$, where $\\chi(G)$, $\\omega(G)$, and $\\Delta(G)$ respectively denote the chromatic number, the clique number and the maximum degree of $G$. In this paper, we study this conjecture for some {\\em expansions} of graphs, that is graphs obtained with the well known operation {\\em composition} of graphs. We prove that Reed's Conjecture holds for expansions of bipartite graphs, for expansions of odd holes where the minimum chromatic number of the components is even, when some component of the expansion has chromatic number 1 or when a component induces a bipartite graph. Moreover, Reed's Conjecture holds if all components have the same chromatic number, if the components have chromatic number at most 4 and when the odd hole has length 5. Finally, when $G$ is an odd hole expansion, we prove $\\chi(G)\\leq\\lceil\\frac{\\omega(G)+\\Delta(G)+1}{2}\\rceil+1$.
Barboza, María Carolina
2002-01-01
Full Text Available En la investigación arqueológica, el potencial para la interpretación de los restos óseos humanos está directamente vinculado con las condiciones de hallazgo, recuperación y asociación contextual. La excavación del Cementerio de La Falda (SJ Til. 43 Tilcara, Jujuy, proporcionó un conjunto de treinta y un individuos con alto grado de integridad y con asociaciones culturales que, entre otros aspectos, permiten la identificación de atributos propios de cada sexo. Desde el punto de vista bioantropológico, la manifestación de muchos rasgos anatómicos, tanto métricos como morfológicos puede resultar específica para cada población. Advertidos de que los patrones de dimorfismo sexual pueden variar entre grupos, el objetivo de este trabajo ha sido estudiar el comportamiento del patrón general de variabilidad sexual en los individuos adultos de La Falda. Para ello se realizó un estudio comparativo en el que se confronta la información cultural que permite identificar sexo, con aquella proporcionada por los marcadores óseos para determinación sexual. Nuestros resultados permiten comprobar la existencia de concordancias y discordancias en las asignaciones sexuales de índole osteológica, según el complejo o estructura anatómica considerada, las cuales son discutidas e interpretadas a la luz de la información tanto biológica como cultural disponible. Se presentan los marcadores osteológicos considerados más efectivos para esta muestra en particular.
Thermal Expansion of Hafnium Carbide
Grisaffe, Salvatore J.
1960-01-01
Since hafnium carbide (HfC) has a melting point of 7029 deg. F, it may have many high-temperature applications. A literature search uncovered very little information about the properties of HfC, and so a program was initiated at the Lewis Research Center to determine some of the physical properties of this material. This note presents the results of the thermal expansion investigation. The thermal-expansion measurements were made with a Gaertner dilatation interferometer calibrated to an accuracy of +/- 1 deg. F. This device indicates expansion by the movement of fringes produced by the cancellation and reinforcement of fixed wave-length light rays which are reflected from the surfaces of two parallel quartz glass disks. The test specimens which separate these disks are three small cones, each approximately 0.20 in. high.
Low thermal expansion glass ceramics
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...
Low Thermal Expansion Glass Ceramics
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...
Energy efficient perlite expansion process
Jenkins, K.L.
1982-08-31
A thermally efficient process for the expansion of perlite ore is described. The inlet port and burner of a perlite expansion chamber (Preferably a vertical expander) are enclosed such that no ambient air can enter the chamber. Air and fuel are metered to the burner with the amount of air being controlled such that the fuel/air premix contains at least enough air to start and maintain minimum combustion, but not enough to provide stoichiometric combustion. At a point immediately above the burner, additional air is metered into an insulated enclosure surrounding the expansion chamber where it is preheated by the heat passing through the chamber walls. This preheated additional air is then circulated back to the burner where it provides the remainder of the air needed for combustion, normally full combustion. Flow of the burner fuel/air premix and the preheated additional air is controlled so as to maintain a long luminous flame throughout a substantial portion of the expansion chamber and also to form a moving laminar layer of air on the inner surface of the expansion chamber. Preferably the burner is a delayed mixing gas burner which materially aids in the generation of the long luminous flame. The long luminous flame and the laminar layer of air at the chamber wall eliminate hot spots in the expansion chamber, result in relatively low and uniform temperature gradients across the chamber, significantly reduce the amount of fuel consumed per unit of perlite expanded, increase the yield of expanded perlite and prevent the formation of a layer of perlite sinter on the walls of the chamber.
Bearing-Mounting Concept Accommodates Thermal Expansion
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.
Properties of Ettringite Type Expansive Agent
无
2001-01-01
By employing different forms and amounts of materials,many kinds of ettringite type expansive agents had been prepared.The relationship between the compositions and properties of expansive agents was analyzed.The design methods of expansive agent have been put forward according to the property requirement of expansive concrete.
18 CFR 154.309 - Incremental expansions.
2010-04-01
... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Incremental expansions... Changes § 154.309 Incremental expansions. (a) For every expansion for which incremental rates are charged... incremental facilities to be rolled-in to the pipeline's rates. For every expansion that has an at-risk...
Caloric Curves and Nuclear Expansion
Natowitz, J B; Ma, Y; Murray, M; Qin, L; Shlomo, S; Wada, R; Wang, J
2002-01-01
Nuclear caloric curves have been analyzed using an expanding Fermi gas hypothesis to extract average nuclear densities. In this approach the observed flattening of the caloric curves reflects progressively increasing expansion with increasing excitation energy. This expansion results in a corresponding decrease in the density and Fermi energy of the excited system. For nuclei of medium to heavy mass apparent densities $~0.3\\rho_0$ are reached at the higher excitation energies. The average densities derived in this manner are in good agreement with those derived using other, more complicated, techniques.
Multipole Expansion in Generalized Electrodynamics
Bonin, C A; Ortega, P H
2016-01-01
In this article we study some classical aspects of Podolsky Electrodynamics in the static regime. We develop the multipole expansion for the theory in both the electrostatic and the magnetostatic cases. We also address the problem of consistently truncating the infinite series associated with the several kinds of multipoles, yielding approximations for the static Podolskian electromagnetic field to any degree of precision required. Moreover, we apply the general theory of multipole expansion to some specific physical problems. In those problems we identify the first terms of the series with the monopole, dipole and quadrupole terms in the generalized theory. We also propose a situation in which Podolsky theory can be experimentally tested.
Thermal Expansion of Irradiated Polytetrafluoroethylene
Subrahmanyam, HN; Subramanyam, SV
1987-01-01
The thermal expansion coefficient of gamma-irradiated Polytetrafluoroethylene (PTFE) has been measured in the temperature range 80-340 K by using a three-terminal capacitance technique. The samples are irradiated in air at room temperature with gamma rays from a $Co^{60}$ source at a dose rate of 0.26 Mrad/h. The change in crystallinity is measured by an x-ray technique. The expansion coefficient is found to increase with radiation dose below 140 K owing to the predominant effect of degradati...
Removable Type Expansion Bolt Innovative Design
Wang, Feng-Lan; Zhang, Bo; Gao, Bo; Liu, Yan-Xin; Gao, Bo
2016-05-01
Expansion bolt is a kind of the most common things in our daily life. Currently, there are many kinds of expansion bolts in the market. However, they have some shortcomings that mainly contain underuse and unremovement but our innovation of design makes up for these shortcomings very well. Principle of working follows this: expansion tube is fixed outside of bolt, steel balls and expansion covers are fixed inside. Meanwhile, the steel balls have 120° with each other. When using it ,expansion cover is moved in the direction of its internal part. So the front part of expansion bolt cover is increasingly becoming big and steel halls is moved outside. Only in this way can it be fixed that steel balls make expansion tube expand. When removing them, expansion bolt is moved outside. So the front part of expansion bolt cover is gradually becoming small and steel balls moves inside, after expansion tube shrinks, we can detach them.
The Thermal Expansion Of Feldspars
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
González, Cristina
2012-01-01
Full Text Available El presente trabajo está dirigido a reflexionar sobre algunos de los rasgos actuales de las políticas sociales en Argentina, que – como se sugiere en el título – están marcando nuevas tendencias en el sistema de seguridad social del país, que reteniendo elementos que lo caracterizaron desde su consolidación en la década de los 40 del siglo XX, recuperan la centralidad del Estado como proveedor de bienes y servicios y como garante de derechos. Dado que tales características sólo pueden comprenderse a la luz de las transformaciones efectuadas en el pasado reciente, la introducción y la primera sección están dedicadas a brindar una somera descripción y análisis de las políticas sociales neoliberales que se implantaron en el país en la década de 1990, así como los cambios de las recomendaciones de las agencias multilaterales de desarrollo, que han ido nutriendo normativamente estas políticas. En la sección final, se describirán las nuevas políticas de previsión social y asignaciones familiares, que sin agotar las acciones estatales en materia de intervención social, tienen un papel central en la nueva configuración. Por último, en las conclusiones se desarrollan algunas conjeturas acerca de la significación de estas nuevas tendencias
Histone deacetylase complexes promote trinucleotide repeat expansions.
Kim Debacker
2012-02-01
Full Text Available Expansions of DNA trinucleotide repeats cause at least 17 inherited neurodegenerative diseases, such as Huntington's disease. Expansions can occur at frequencies approaching 100% in affected families and in transgenic mice, suggesting that specific cellular proteins actively promote (favor expansions. The inference is that expansions arise due to the presence of these promoting proteins, not their absence, and that interfering with these proteins can suppress expansions. The goal of this study was to identify novel factors that promote expansions. We discovered that specific histone deacetylase complexes (HDACs promote CTG•CAG repeat expansions in budding yeast and human cells. Mutation or inhibition of yeast Rpd3L or Hda1 suppressed up to 90% of expansions. In cultured human astrocytes, expansions were suppressed by 75% upon inhibition or knockdown of HDAC3, whereas siRNA against the histone acetyltransferases CBP/p300 stimulated expansions. Genetic and molecular analysis both indicated that HDACs act at a distance from the triplet repeat to promote expansions. Expansion assays with nuclease mutants indicated that Sae2 is one of the relevant factors regulated by Rpd3L and Hda1. The causal relationship between HDACs and expansions indicates that HDACs can promote mutagenesis at some DNA sequences. This relationship further implies that HDAC3 inhibitors being tested for relief of expansion-associated gene silencing may also suppress somatic expansions that contribute to disease progression.
Regulation of gas infrastructure expansion
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 storag
On persistently positively expansive maps
Alexander Arbieto
2010-06-01
Full Text Available In this paper, we prove that any C¹-persistently positively expansive map is expanding. This improves a result due to Sakai (Sakai 2004.Neste artigo, mostramos que todo mapa C¹-persistentemente positivamente expansivo e expansor. Isto melhora um resultado devido a Sakai (Sakai 2004.
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.
Large N Expansion. Vector Models
Nissimov, E; Nissimov, Emil; Pacheva, Svetlana
2006-01-01
Preliminary version of a contribution to the "Quantum Field Theory. Non-Perturbative QFT" topical area of "Modern Encyclopedia of Mathematical Physics" (SELECTA), eds. Aref'eva I, and Sternheimer D, Springer (2007). Consists of two parts - "main article" (Large N Expansion. Vector Models) and a "brief article" (BPHZL Renormalization).
Effective Expansion: Balance between Shrinkage and Hygroscopic Expansion.
Suiter, E A; Watson, L E; Tantbirojn, D; Lou, J S B; Versluis, A
2016-05-01
The purpose of this study was to investigate the relationship between hygroscopic expansion and polymerization shrinkage for compensation of polymerization shrinkage stresses in a restored tooth. One resin-modified glass-ionomer (RMGI) (Ketac Nano, 3M ESPE), 2 compomers (Dyract, Dentsply; Compoglass, Ivoclar), and a universal resin-based composite (Esthet•X HD, Dentsply) were tested. Volumetric change after polymerization ("total shrinkage") and during 4 wk of water storage at 37°C was measured using an optical method (n= 10). Post-gel shrinkage was measured during polymerization using a strain gauge method (n= 10). Extracted human molars with large mesio-occluso-distal slot preparations were restored with the tested restorative materials. Tooth surfaces at baseline (preparation), after restoration, and during 4 wk of 37°C water storage were scanned with an optical scanner to determine cuspal flexure (n= 8). Occlusal interface integrity was measured using dye penetration. Data were analyzed using analysis of variance and post hoc tests (significance level 0.05). All tested materials shrunk after polymerization. RMGI had the highest total shrinkage (4.65%) but lowest post-gel shrinkage (0.35%). Shrinkage values dropped significantly during storage in water but had not completely compensated polymerization shrinkage after 4 wk. All restored teeth initially exhibited inward (negative) cuspal flexure due to polymerization shrinkage. Cuspal flexure with the RMGI restoration was significantly less (-6.4 µm) than with the other materials (-12.1 to -14.1 µm). After 1 d, cuspal flexure reversed to +5.0 µm cuspal expansion with the RMGI and increased to +9.3 µm at 4 wk. After 4 wk, hygroscopic expansion compensated cuspal flexure in a compomer (Compoglass) and reduced flexure with Dyract and resin-based composite. Marginal integrity (93.7% intact restoration wall) was best for the Compoglass restorations and lowest (73.1%) for the RMGI restorations. Hygroscopic
Exponential Expansion in Evolutionary Economics
Frederiksen, Peter; Jagtfelt, Tue
2013-01-01
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...... of Thomas Kuhn’s notion of scientific paradigms and criteria for a good theory (1977, 1996). The paper thus aims to augment and assimilate the fragmented and scattered body of concepts presently residing within the field of evolutionary economics, by presenting an intuitive framework, applicable within...... 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...
Multiscale expansions in discrete world
Ömer Ünsal; Filiz Taşcan; Mehmet Naci Özer
2014-07-01
In this paper, we show the attainability of KdV equation from some types of nonlinear Schrödinger equation by using multiscale expansions discretely. The power of this manageable method is confirmed by applying it to two selected nonlinear Schrödinger evolution equations. This approach can also be applied to other nonlinear discrete evolution equations. All the computations have been made with Maple computer packet program.
College Expansion and Curriculum Choice
Kaganovich, Michael; Su, Xuejuan
2012-01-01
This paper analyzes the impact of college enrollment expansion on student academic achievements and labor market outcomes in the context of competition among colleges. When public policies promote “access” to college education, colleges adjust their curricula: Less selective public colleges adopt a less demanding curriculum in order to accommodate the influx of less able students. As we argue in the paper, this adjustment benefits low-ability college students at the expense of those of medium...
RELIABILITY OF LENTICULAR EXPANSION COMPENSATORS
Gabriel BURLACU,
2011-11-01
Full Text Available Axial lenticular compensators are made to take over the longitudinal heat expansion, shock , vibration and noise, made elastic connections for piping systems. In order to have a long life for installations it is necessary that all elements, including lenticular compensators, have a good reliability. This desire can be did by technology of manufactoring and assembly of compensators, the material for lenses and by maintenance.of compensator
Topological expansion and boundary conditions
Eynard, Bertrand
2008-01-01
In this article, we compute the topological expansion of all possible mixed-traces in a hermitian two matrix model. In other words we give a recipe to compute the number of discrete surfaces of given genus, carrying an Ising model, and with all possible given boundary conditions. The method is recursive, and amounts to recursively cutting surfaces along interfaces. The result is best represented in a diagrammatic way, and is thus rather simple to use.
Multiple scattering expansion with distortion
Tandy, P. C.; Thaler, R. M.
1980-12-01
A multiple scattering description of elastic scattering is formulated in terms of impulsive scatterings from single target nucleons and pairs of target nucleons. In this description, distortion effects on the projectile from the residual medium are also described by multiple scattering in terms of the same single and pair amplitudes. At the level of single scattering, this procedure yields the first order optical potential result of Kerman, McManus, and Thaler. When scattering from both single nucleons and pairs of nucleons is included, the method leads to a one-body integral equation which requires the physical projectile-nucleon and projectile-pair transition amplitudes as input. This input is similar, but not exactly equivalent to that required by the spectator expansion for the optical potential truncated at second order. A principal advantage of the present formulation is that there need be no explicit dependence upon the projection operator Q which projects off the target ground state. This feature introduces a scaling which appears to be a direct extension of the first order Kerman, McManus, and Thaler type of scaling. We follow up suggestions arising in the foregoing to show that the exact optical potential to second order in the spectator expansion can also be cast into a form having no explicit dependence upon Q, and requiring physical projectile-nucleon and projectile-pair transition amplitudes as input. NUCLEAR REACTIONS Multiple scattering from single nucleons, pairs of nucleons in nucleus. Distortion from residual medium. Optical potential. spectator expansion.
Urban underground network expansion planning
Bozic, Z. [Sinclair Knight Merz Pty Ltd., Perth (Australia); Hobson, E. [HI Consulting Services Pty Ltd., Adelaide (Australia)
1997-03-01
The authors describe a three step approach to expansion planning of high voltage (HV) urban underground distribution networks. Although the techniques are specifically oriented to underground systems, they are equally applicable to overhead system design. The fundamental engineering problem is how to connect individual high voltage to low voltage substations (HV/LV SS) and zone HV SS into a future urban underground network. The problem is to rearrange the HV network to minimise the cost of expansion subject to provision of an alternative supply, specified load transfer among the neighbouring zone SS, and other general planning constraints such as feeder capacity, voltage regulation, operational requirements and losses. A review of the current state of the art of distribution expansion planning is provided. The normal manual approach is discussed together with more recent research into computer methods. Three lines of computer research are identified and classified as radially constrained, security constrained and utilisation of travelling salesman/vehicle routing problem algorithms (TSP/VRP). The TSP/VRP line of research has been extended here to produce practical techniques for the assistance of network planners. (Author)
Yolanda Galindo Montiel
2012-02-01
; posteriormente se utiliza una técnica del consenso de la opinión, denominada Técnica Delphi, para determinar los pesos de contribución relativa de cada una de las variables definidas por los usuarios, con el objetivo de integrar por medio de la agregación de las valoraciones, hechas por el usuario, en un único valor denominado Indicador del Nivel de Servicio del Usuario de las Carreteras (INSUC. El INSUC podrá ser utilizado conjuntamente con otros criterios técnicos como el Índice Internacional de Rugosidad (IRI y el Tránsito Diario Promedio Anual (TDPA, con la finalidad de determinar las asignaciones presupuestarias para la conservación de las carreteras. Con esto quedaría considerada la opinión del usuario en las estrategias de conservación para mejorar el servicio que una red de carreteras presta. El producto de esta investigación es la metodología para determinar el Indicador del Nivel de Satisfacción del Usuario de las Carreteras y para su validación se hace el estudio de caso de la Red Estatal de Carreteras Pavimentadas de Guanajuato.
2013-06-17
... Federal Register (77 FR 43047, 07/23/12) and the application has been processed pursuant to the FTZ Act... Foreign-Trade Zones Board Reorganization/Expansion of Foreign-Trade Zone 104; (Expansion of Service Area and Expansion of Zone); Under Alternative Site Framework, Savannah, Georgia Pursuant to its...
Thermal expansion of ceramics around room temperature
橋本, 忍; 安達, 信泰; 太田, 敏孝; 宮崎, 英敏; ハシモト, シノブ; アダチ, ノブヤス; オオタ, トシタカ; Hashimoto, Shinobu; Adachi, Nobuyasu; Ota, Toshitaka
2010-01-01
Thermal expansion of some ceramics, polymers and metals was measured by dilatometer around room temperature (from -140℃to +200℃), and compared with thermal expansion in the high temperature region. The CTE (coefficient of thermal expansion)of almost ceramics changed drastically between room temperature and high temperature region. On the other hand, the CTE ofmetals did not change between room temperature and high temperature region. The difference on thermal expansion betweenceramics and met...
Bobev, Svilen; Williams, Darrick J.; Thompson, J.D.; Sarrao, J L
2004-01-01
Thermal expansion and magnetic susceptibility measurements as a function of temperature are reported for YbGaGe. Despite the fact that this material has been claimed to show zero thermal expansion over a wide temperature range, we observe thermal expansion typical of metals and Pauli paramagnetic behavior, which perhaps indicates strong sample dependence in this system.
Multiplier theorems for special Hermite expansions on
张震球; 郑维行
2000-01-01
The weak type (1,1) estimate for special Hermite expansions on Cn is proved by using the Calderon-Zygmund decomposition. Then the multiplier theorem in Lp(1 < p < ω ) is obtained. The special Hermite expansions in twisted Hardy space are also considered. As an application, the multipli-ers for a certain kind of Laguerre expansions are given in Lp space.
An All-Orders Derivative Expansion
Dunne, Gerald(Department of Physics, University of Connecticut, Storrs, CT, 06269, U.S.A.)
1996-01-01
We evaluate the exact $QED_{2+1}$ effective action for fermions in the presence of a family of static but spatially inhomogeneous magnetic field profiles. This exact result yields an all-orders derivative expansion of the effective action, and indicates that the derivative expansion is an asymptotic, rather than a convergent, expansion.
Quantum fields and "Big Rip" expansion singularities
Calderon, H; Calderon, Hector; Hiscock, William A.
2005-01-01
The effects of quantized conformally invariant massless fields on the evolution of cosmological models containing a ``Big Rip'' future expansion singularity are examined. Quantized scalar, spinor, and vector fields are found to strengthen the accelerating expansion of such models as they approach the expansion singularity.
Bayuelo, Ezequiel
Este estudio examino y comparo las actitudes de los candidatos a maestros de ciencias y los maestros de ciencias en servicio acerca de la utilizacion de las herramientas computadorizadas en las clases de ciencias. Tambien identifico y diferencio el uso que ellos dan a estas herramientas en las clases de ciencias. Este estudio presenta un diseno descriptivo exploratorio. Constituyeron la muestra trescientos diez sujetos que fueron candidatos a maestros de ciencias o maestros de ciencias en servicio. Para recoger los datos se construyo y valido un cuestionario de treinta y un itemes. Se utilizaron las pruebas estadisticas no parametricas Kruskal Wallis y Chi-cuadrado (test de homogeneidad) para establecer las diferencias entre las actitudes de los sujetos con relacion al uso de las herramientas computadorizadas en las clases de ciencias. Los hallazgos evidenciaron que son positivas y muy parecidas las actitudes de los candidatos a maestros y maestros en servicio hacia el uso de las herramientas computadorizadas. No hubo diferencias entre los candidatos y maestros en servicio en terminos de las actitudes de confianza y empatia hacia el uso de las herramientas computadorizadas en las clases de ciencias. En aspectos como el uso del banco de datos bibliografico Eric y el uso de las herramientas computadorizadas en actividades educativas como explorar conceptos, conceptuar, aplicar lo aprendido y hacer asignaciones hubo diferencias estadisticamente significativas entre los candidatos y los maestros en servicio. Al comparar las frecuencias observadas con las esperadas hubo mas maestros en servicio y menos candidatos que indicaron usar el anterior banco de datos y las herramientas computadorizadas en las mencionadas actividades educativas.
Expansion of protein domain repeats.
Asa K Björklund
2006-08-01
Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.
Gravitational entropy of cosmic expansion
Sussman, Roberto A
2014-01-01
We apply a recent proposal to define "gravitational entropy" to the expansion of cosmic voids within the framework of non-perturbative General Relativity. By considering CDM void configurations compatible with basic observational constraints, we show that this entropy grows from post-inflationary conditions towards a final asymptotic value in a late time fully non-linear regime described by the Lemaitre-Tolman-Bondi (LTB) dust models. A qualitatively analogous behavior occurs if we assume a positive cosmological constant consistent with a $\\Lambda$-CDM background model. However, the $\\Lambda$ term introduces a significant suppression of entropy growth with the terminal equilibrium value reached at a much faster rate.
Contribution of thermal expansion and
O.I.Pursky
2007-01-01
Full Text Available A theoretical model is developed to describe the experimental results obtained for the isobaric thermal conductivity of rare gas solids (RGS. The isobaric thermal conductivity of RGS has been analysed within Debye approximation with regard to the effect of thermal expansion. The suggested model takes into consideration the fact that thermal conductivity is determined by U-processes while above the phonon mobility edge it is determined by "diffusive" modes migrating randomly from site to site. The mobility edge ω0 is determined from the condition that the phonon mean-free path restricted by the U-processes cannot be smaller than half of the phonon wavelength.
Cosmic Growth and Expansion Conjoined
Linder, Eric V
2016-01-01
Cosmological measurements of both the expansion history and growth history have matured, and the two together provide an important test of general relativity. We consider their joint evolutionary track, showing that this has advantages in distinguishing cosmologies relative to considering them individually or at isolated redshifts. In particular, the joint comparison relaxes the shape degeneracy that makes $f\\sigma_8(z)$ curves difficult to separate from the overall growth amplitude. The conjoined method further helps visualization of which combinations of redshift ranges provide the clearest discrimination. We examine standard dark energy cosmologies, modified gravity, and "stuttering" growth, each showing distinct signatures.
Digital expansions with negative real bases
Steiner, Wolfgang
2011-01-01
Similarly to Parry's characterization of $\\beta$-expansions of real numbers in real bases $\\beta > 1$, Ito and Sadahiro characterized digital expansions in negative bases, by the expansions of the endpoints of the fundamental interval. Parry also described the possible expansions of 1 in base $\\beta > 1$. In the same vein, we characterize the sequences that occur as $(-\\beta)$-expansion of $\\frac{-\\beta}{\\beta+1}$ for some $\\beta > 1$. These sequences also describe the itineraries of 1 by linear mod one transformations with negative slope.
Bustamante Heliodoro
1986-12-01
Full Text Available La energía potencial del agua presenta diferencias de un punto del suelo a otro; esas diferencias son las que originan el movimiento del agua de acuerdo a la tendencia universal de la materia en el sentido de moverse de donde la energía potencial es mayor a donde dicha energía es menor. En el suelo el agua en consecuencia se mueve hacia donde su energía decrece hasta lograr su estado de equilibrio. Se desprende entonces que la cantidad de energía potencial absoluta contenida en el agua, no es importante por sí misma, sino por su relación con la energía en diferentes lugares dentro del suelo. El concepto Potencial de agua del suelo es un criterio para esta energía.
Gyrification from constrained cortical expansion
Tallinen, Tuomas; Biggins, John S; Mahadevan, L
2015-01-01
The exterior of the mammalian brain - the cerebral cortex - has a conserved layered structure whose thickness varies little across species. However, selection pressures over evolutionary time scales have led to cortices that have a large surface area to volume ratio in some organisms, with the result that the brain is strongly convoluted into sulci and gyri. Here we show that the gyrification can arise as a nonlinear consequence of a simple mechanical instability driven by tangential expansion of the gray matter constrained by the white matter. A physical mimic of the process using a layered swelling gel captures the essence of the mechanism, and numerical simulations of the brain treated as a soft solid lead to the formation of cusped sulci and smooth gyri similar to those in the brain. The resulting gyrification patterns are a function of relative cortical expansion and relative thickness (compared with brain size), and are consistent with observations of a wide range of brains, ranging from smooth to highl...
Primordial vorticity and gradient expansion
Giovannini, Massimo; Rezaei, Zahra
2012-02-01
The evolution equations of the vorticities of the electrons, ions and photons in a pre-decoupling plasma are derived, in a fully inhomogeneous geometry, by combining the general relativistic gradient expansion and the drift approximation within the Adler-Misner-Deser decomposition. The vorticity transfer between the different species is discussed in this novel framework and a set of general conservation laws, connecting the vorticities of the three-component plasma with the magnetic field intensity, is derived. After demonstrating that a source of large-scale vorticity resides in the spatial gradients of the geometry and of the electromagnetic sources, the total vorticity is estimated to lowest order in the spatial gradients and by enforcing the validity of the momentum constraint. By acknowledging the current bounds on the tensor to scalar ratio in the (minimal) tensor extension of the ΛCDM paradigm, the maximal comoving magnetic field induced by the total vorticity turns out to be, at most, of the order of 10-37 G over the typical comoving scales ranging between 1 and 10 Mpc. While the obtained results seem to be irrelevant for seeding a reasonable galactic dynamo action, they demonstrate how the proposed fully inhomogeneous treatment can be used for the systematic scrutiny of pre-decoupling plasmas beyond the conventional perturbative expansions.
Imagination as expansion of experience.
Zittoun, Tania; Cerchia, Frédéric
2013-09-01
This paper proposes a developmental view on imagination: from this perspective, imagination can be seen as triggered by some disrupting event, which generates a disjunction from the person's unfolding experience of the "real" world, and as unfolding as a loop, which eventually comes back to the actual experience. Examining recent and classical theorization of imagination in psychology, the paper opposes a deficitary view of imagination to an expansive notion of imagination. The paper explores Piaget, Vygotsky, Harris and Pelaprat & Cole consider: 1) What does provoke a "rupture" or disjunction? 2) What are the psychological processes involved in the imaginary loop? 3) What nourishes such processes? 4) What are the consequences of such imaginary loop, or what does it enable doing? The paper proposes to adopt an expansive view of imagination, as Vygotsky proposed-a perspective that has been under-explored empirically since his seminal work. To stimulate such sociocultural psychology of imagination, two empirical examples are provided, one showing how children make sense of metaphor in an experimental setting, the other showing a young person using a novel met at school as symbolic resource.
Evolutionary expansion of the Monogenea.
Kearn, G C
1994-12-01
The evolutionary expansion of the monogeneans has taken place in parallel with the diversification of the fish-like vertebrates. In this article the main trends in monogenean evolution are traced from a hypothetical skin-parasitic ancestor on early vertebrates. Special consideration is given to the following topics: early divergence between skin feeders and blood feeders; diversification and specialization of the haptor for attachment to skin; transfer from host to host, viviparity and the success of the gyrodactylids; predation on skin parasites and camouflage; colonization of the buccal and branchial cavities; diversification and specialization of the haptor for attachment to the gills; phoresy in gill parasites; the development of endoparasitism and the origin of the cestodes; the success of dactylogyroidean gill parasites; the uniqueness of the polyopisthocotyleans; ovoviviparity and the colonization of the tetrapods. Host specificity has been the guiding force of coevolution between monogeneans and their vertebrate hosts, but the establishment of monogeneans on unrelated hosts sharing the same environment (host-switching) may have been underestimated. Host-switching has provided significant opportunities for evolutionary change of direction and is probably responsible for the establishment of monogeneans on cephalopod molluscs, on the hippopotamus and possibly on chelonians. There are indications that host-switching may be more common in monogeneans that spread by direct transfer of adults/juveniles from host to host. A limitation on the further expansion of monogeneans is the need for water for the dispersal of the infective larva (oncomiracidium).
Fast algorithms for Quadrature by Expansion I: Globally valid expansions
Rachh, Manas; Klöckner, Andreas; O'Neil, Michael
2017-09-01
The use of integral equation methods for the efficient numerical solution of PDE boundary value problems requires two main tools: quadrature rules for the evaluation of layer potential integral operators with singular kernels, and fast algorithms for solving the resulting dense linear systems. Classically, these tools were developed separately. In this work, we present a unified numerical scheme based on coupling Quadrature by Expansion, a recent quadrature method, to a customized Fast Multipole Method (FMM) for the Helmholtz equation in two dimensions. The method allows the evaluation of layer potentials in linear-time complexity, anywhere in space, with a uniform, user-chosen level of accuracy as a black-box computational method. Providing this capability requires geometric and algorithmic considerations beyond the needs of standard FMMs as well as careful consideration of the accuracy of multipole translations. We illustrate the speed and accuracy of our method with various numerical examples.
LOUIS DE GRANGE C
2010-04-01
Full Text Available Las grandes ciudades del mundo que han resuelto su problema de transporte público lo han logrado principalmente a la luz de las siguientes dos políticas públicas: una expansión significativa de la red de Metro y trenes urbanos, y una firme regulación en el uso del automóvil. La evidencia empírica a nivel mundial ha permitido constatar que la expansión de redes de Metro genera una reducción mucho más efectiva en el uso del transporte privado que otras medidas como por ejemplo subsidiar la tarifa del transporte público. Adicionalmente, la existencia de una importante red de Metro o trenes urbanos permite aumentar notablemente la efectividad de políticas regulatorias al uso del automóvil, como tarificación vial y gravámenes específicos, entre otras, ya que los automovilistas habituales sí ven en el Metro una alternativa real de transporte, no así en los servicios de buses.Large cities around the world that have successfully addressed their public transport problems have made it mainly through the folio wing two public policies: a significant expansion of the Metro or urban train networks, and a tight regulation of the use of automobiles. Empirical evidence worldwide shows that the expansion of the Metro network produces a much more effective reduction in the use of private transport than alternative policies as for instance subsidizing the tariff of public transport. Besides, the existence of an important Metro or urban train network enlarges the effectiveness of other regulatory policies to the use of automobile, as road pricing and specific taxes, since the users of automobiles see in Metro a reasonable alternative of transport, which is not the case for buses.
Bustamante Heliodoro
2012-01-01
La energía potencial del agua presenta diferencias de un punto del suelo a otro; esas diferencias son las que originan el movimiento del agua de acuerdo a la tendencia universal de la materia en el sentido de moverse de donde la energía potencial es mayor a donde dicha energía es menor. En el suelo el agua en consecuencia se mueve hacia donde su energía decrece hasta lograr su estado de equilibrio. Se desprende entonces que la cantidad de energía potencial absoluta contenida en el agua, no es...
On the Equisummability of Hermite and Fourier Expansions
E K Narayanan; S Thangavelu
2001-02-01
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.
Shrub expansion in SW Greenland
Jørgensen, Rasmus Halfdan
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...... of firewood collection. A delayed reaction to the ending of the little ice age cannot be excluded, but seems rather unlikely considering other studies from Greenland. Effects of global warming in SW Greenland must be studied over even longer time periods than the 120 years of the current study. To answer......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...
Bilinear Expansion For Redistribution Functions
Harutyunian, Haik; Alecian, Georges; Khachatryan, Knarik; Vardanyan, Ani
2016-11-01
We suggest here a method for construction of a bilinear expansion for an angle-averaged redistribution function. This function describes the elementary act of a photon scattering by a model two-level atom with the upper level broadened due to radiation damping. An eigenvalue and eigenvector determination problem is formulated and the relevant matrices are found analytically. Numerical procedures for their computations are elaborated as well. A simple method for the numerical calculations accuracy evaluation is suggested. It is shown that a family of redistribution functions describing the light scattering process within the spectral line frequencies can be constructed if the eigenvalue problem for the considered function is solved. It becomes possible if the eigenvalues and eigenvectors with the appropriate basic functions are used. The Voigt function and its derivatives used as basic functions are studied in detail as well.
Accelerating Expansion of the Universe
Chakraborty, Writambhara
2011-01-01
This thesis concentrates on the accelerated expansion of the Universe recently explored by measurements of redshift and luminosity-distance relations of type Ia Supernovae. We have considered a model of the universe filled with modified Chaplygin gas and barotropic fluid. The role of dynamical cosmological constant has been explored with Modified Chaplygin Gas as the background fluid. Various phenomenological models for \\Lambda have been studied in presence of the gravitational constant G to be constant or time dependent. A new form of the well known Chaplygin gas model has been presented by introducing inhomogeneity in the EOS. This model explains w=-1 crossing. An interaction of this model with the scalar field has also been investigated through a phenomenological coupling function. Tachyonic field has been depicted as dark energy model to represent the present acceleration of the Universe. A mixture of the tachyonic fluid has been considered with Generalized Chaplygin Gas to show the role of the later as a...
Asymptotic expansions in nonlinear rotordynamics
Day, William B.
1987-01-01
This paper is an examination of special nonlinearities of the Jeffcott equations in rotordynamics. The immediate application of this analysis is directed toward understanding the excessive vibrations recorded in the LOX pump of the SSME during hot-firing ground testing. Deadband, side force, and rubbing are three possible sources of inducing nonlinearity in the Jeffcott equations. The present analysis initially reduces these problems to the same mathematical description. A special frequency, named the nonlinear natural frequency, is defined and used to develop the solutions of the nonlinear Jeffcott equations as singular asymptotic expansions. This nonlinear natural frequency, which is the ratio of the cross-stiffness and the damping, plays a major role in determining response frequencies.
Pressurized electrolysis stack with thermal expansion capability
Bourgeois, Richard Scott
2015-07-14
The present techniques provide systems and methods for mounting an electrolyzer stack in an outer shell so as to allow for differential thermal expansion of the electrolyzer stack and shell. Generally, an electrolyzer stack may be formed from a material with a high coefficient of thermal expansion, while the shell may be formed from a material having a lower coefficient of thermal expansion. The differences between the coefficients of thermal expansion may lead to damage to the electrolyzer stack as the shell may restrain the thermal expansion of the electrolyzer stack. To allow for the differences in thermal expansion, the electrolyzer stack may be mounted within the shell leaving a space between the electrolyzer stack and shell. The space between the electrolyzer stack and the shell may be filled with a non-conductive fluid to further equalize pressure inside and outside of the electrolyzer stack.
Novel thermal expansion of lead titanate
XING Xianran; DENG Jinxia; CHEN Jun; LIU Guirong
2003-01-01
Lattice parameters of lead titanate were precisely re-determined in the ternperature range of-150-950℃ by high precision XRPD measurements. It was clarified that there was no any evidence for a new phase transition at low temperatures. Tetragonal distortion strain decreases with temperature increasing. A novel thermal expansion was observed, positive thermal expansion from-150℃ to room temperature (RT) and above 490℃, and the negative thermal expansion in the temperature range of RT-490℃. A big jump of thermal expansion coefficient is attributed to the tetragonal-cubic phase transition. A rationalization for the negative thermal expansion of PbTiO3 is due to the decrease of anion-anion repulsion as polyhedra become more regular at heating. The mechanisms of positive and negative thermal expansions were elucidated as the same nature in the homogenous tetragonal phase at present case.
Anomalous thermal expansion in $\\alpha$-titanium
Souvatzis, P.; O. Eriksson; M. I. Katsnelson
2007-01-01
We provide a complete quantitative explanation for the anisotropic thermal expansion of hcp Ti at low temperature. The observed negative thermal expansion along the c-axis is reproduced theoretically by means of a parameter free theory which involves both the electron and phonon contributions to the free energy. The thermal expansion of titanium is calculated and found to be negative along the c-axis for temperatures below $\\sim$ 170 K, in good agreement with observations. We have identified ...
Hydration and Thermal Expansion in Anatase Nanoparticles.
Zhu, He; Li, Qiang; Ren, Yang; Fan, Longlong; Chen, Jun; Deng, Jinxia; Xing, Xianran
2016-08-01
A tunable thermal expansion is reported in nanosized anatase by taking advantage of surface hydration. The coefficient of thermal expansion of 4 nm TiO2 along a-axis is negative with a hydrated surface and is positive without a hydrated surface. High-energy synchrotron X-ray pair distribution function analysis combined with ab initio calculations on the specific hydrated surface are carried out to reveal the local structure distortion that is responsible for the unusual negative thermal expansion.
Hydration and Thermal Expansion in Anatase Nanoparticles
Zhu, He [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Li, Qiang [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Ren, Yang [Argonne National Laboratory, X-Ray Science Division, Argonne IL 60439 USA; Fan, Longlong [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Chen, Jun [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Deng, Jinxia [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China; Xing, Xianran [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 China
2016-06-06
A tunable thermal expansion is reported in nanosized anatase by taking advantage of surface hydration. The coefficient of thermal expansion of 4 nm TiO2 along a-axis is negative with a hydrated surface and is positive without a hydrated surface. High-energy synchrotron X-ray pair distribution function analysis combined with ab initio calculations on the specific hydrated surface are carried out to reveal the local structure distortion that is responsible for the unusual negative thermal expansion.
GAUSSIAN WHITE NOISE CALCULUS OF GENERALIZED EXPANSION
陈泽乾
2002-01-01
A new framework of Gaussian white noise calculus is established, in line with generalized expansion in [3, 4, 7]. A suitable frame of Fock expansion is presented on Gaussian generalized expansion functionals being introduced here, which provides the integral kernel operator decomposition of the second quantization of Koopman operators for chaotic dynamical systems, in terms of annihilation operators (e)t and its dual, creation operators (e)*t.
Rodrigo Arias Duque
2005-01-01
Full Text Available Desde el punto de vista farmacológico, es importante comprender qué es el alcohol y cómo actúa en el organismo. No existe una causa simple, sino una interacción complicada de factores neuroquímicos, fisiológicos, psicológicos y sociales que originan y desarrollan esta grave enfermedad fármaco-dependiente. La acción psicofisiológica y farmacodinámica del alcohol es fundamentalmente depresiva, por la reducción de la transmisión sináptica en el sistema nervioso humano. Es un hecho conocido que el consumo excesivo de alcohol causa una disfunción aguda y crónica del cerebro, produciendo trastornos en el sistema nervioso central, presentando alteraciones en la memoria y en las funciones intelectuales como cálculo, comprensión y aprendizaje. A nivel hepático tiene lugar, en su mayoría, el metabolismo del alcohol, produciéndose un hígado graso alcohólico, aumentando el tamaño, terminando en necrosis e inflamación grave del hígado; esto se llama hepatitis alcohólica, y si se sigue consumiendo alcohol se desarrollará la cirrosis. El alcohol también ha estado relacionado con alteraciones del miocardio; se ha constatado en animales de experimentación sanos que tanto la velocidad de contracción del músculo cardiaco y su máxima tensión disminuyen en presencia del alcohol, como consecuencia, la fuerza de cada contracción y el aumento de presión en el ventrículo izquierdo son menores, perdiendo eficacia el corazón como bomba.
Structure and thermal expansion of liquid bismuth
Mudry S.
2015-12-01
Full Text Available Experimental structural data for liquid Bi were used for estimation of the main structure parameters as well as the thermal expansion coefficient both in supercooled and superheated temperature ranges. It was shown that the equilibrium melt had a positive thermal expansion coefficient within a temperature range upon melting and a negative one at higher temperatures. The former was related to structure changes upon melting, whereas the latter with topologic disordering upon further heating. It was found that the superheated melt had a negative thermal expansion coefficient. The results obtained from structural data were compared with the thermal expansion coefficient calculated from the data of density for liquid Bi.
TAYLOR EXPANSION METHOD FOR NONLINEAR EVOLUTION EQUATIONS
HE Yin-nian
2005-01-01
A new numerical method of integrating the nonlinear evolution equations, namely the Taylor expansion method, was presented. The standard Galerkin method can be viewed as the 0-th order Taylor expansion method; while the nonlinear Galerkin method can be viewed as the 1-st order modified Taylor expansion method. Moreover, the existence of the numerical solution and its convergence rate were proven. Finally, a concrete example,namely, the two-dimensional Navier-Stokes equations with a non slip boundary condition,was provided. The result is that the higher order Taylor expansion method is of the higher convergence rate under some assumptions about the regularity of the solution.
Magnetic Clouds: Global and local expansion
Gulisano, Adriana; Demoulin, Pascal; Soledad Nakwacki, Ms Maria; Dasso, Sergio; Emilia Ruiz, Maria
Magnetic clouds (MCs) are magnetized objects forming flux ropes, which are expelled from the Sun and travel through the heliosphere, transporting important amounts of energy, mass, magnetic flux, and magnetic helicity from the Sun to the interplanetary medium. To know the detailed dynamical evolution of MCs is very useful to improve the knowledge of solar processes, for instance from linking a transient solar source with its interplanetary manifestation. During its travel, and mainly due to the decrease of the total (magnetic plus thermal) pressure in the surrounding solar wind, MCs are objects in expansion. However, the detailed magnetic structure and the dynamical evolution of MCs is still not fully known. Even the identification of their boundaries is an open question in some cases. In a previous work we have shown that from onepoint observations of the bulk velocity profile, it is possible to infer the 'local' expansion rate for a given MC, i.e., the expansion rate while the MC is observed by the spacecraft. By the another hand, and from the comparison of sizes for different MCs observed at different heliodistances, it is possible to quantify an 'average' expansion law (i.e., a global expansion). In this work, in order to study the variability of the 'local' expansion with respect to the 'average' expansion of MCs during their travel, we present results and a comparison between both approaches. We make a detailed study of one-point observations (magnetic and bulk velocity) using a set of MCs and we get the 'local' expansion rate for each studied event. We compare the obtained 'local' expansion rates with the 'average' expansion law, and also with the expansion rates for the stationary solar wind.
Primordial vorticity and gradient expansion
Giovannini, Massimo
2012-01-01
The evolution equations of the vorticities of the electrons, ions and photons in a pre-decoupling plasma are derived, in a fully inhomogeneous geometry, by combining the general relativistic gradient expansion and the drift approximation within the Adler-Misner-Deser decomposition. The vorticity transfer between the different species is discussed in this novel framework and a set of general conservation laws, connecting the vorticities of the three-component plasma with the magnetic field intensity, is derived. After demonstrating that a source of large-scale vorticity resides in the spatial gradients of the geometry and of the electromagnetic sources, the total vorticity is estimated to lowest order in the spatial gradients and by enforcing the validity of the momentum constraint. By acknowledging the current bounds on the tensor to scalar ratio in the (minimal) tensor extension of the $\\Lambda$CDM paradigm the maximal comoving magnetic field induced by the total vorticity turns out to be, at most, of the or...
Negative thermal expansion materials: technological key for control of thermal expansion
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...
The Expansion Postponement in Pure Type Systems
宋方敏
1997-01-01
The expansion postponement problem in Pure Type Systems is an open problem raised by R.Pollack in 1992.In this paper,the author presents a set of necessary and sufficient conditions for this problem and a set of sufficient conditions for it.The author also gives some properties for pure typ systems without the expansion rule.
Multipole expansion method for supernova neutrino oscillations
Duan, Huaiyu; Shalgar, Shashank, E-mail: duan@unm.edu, E-mail: shashankshalgar@unm.edu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)
2014-10-01
We demonstrate a multipole expansion method to calculate collective neutrino oscillations in supernovae using the neutrino bulb model. We show that it is much more efficient to solve multi-angle neutrino oscillations in multipole basis than in angle basis. The multipole expansion method also provides interesting insights into multi-angle calculations that were accomplished previously in angle basis.
Finnish Higher Education Expansion and Regional Policy
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…
Flash Expansion Threshold in Whirligig Swarms.
William L Romey
Full Text Available In the selfish herd hypothesis, prey animals move toward each other to avoid the likelihood of being selected by a predator. However, many grouped animals move away from each other the moment before a predator attacks. Very little is known about this phenomenon, called flash expansion, such as whether it is triggered by one individual or a threshold and how information is transferred between group members. We performed a controlled experiment with whirligig beetles in which the ratio of sighted to unsighted individuals was systematically varied and emergent flash expansion was measured. Specifically, we examined: the percentage of individuals in a group that startled, the resulting group area, and the longevity of the flash expansion. We found that one or two sighted beetles in a group of 24 was not enough to cause a flash expansion after a predator stimulus, but four sighted beetles usually initiated a flash expansion. Also, the more beetles that were sighted the larger the resulting group area and the longer duration of the flash expansion. We conclude that flash expansion is best described as a threshold event whose adaptive value is to prevent energetically costly false alarms while quickly mobilizing an emergent predator avoidance response. This is one of the first controlled experiments of flash expansion, an important emergent property that has applications to understanding collective motion in swarms, schools, flocks, and human crowds. Also, our study is a convincing demonstration of social contagion, how the actions of one individual can pass through a group.
A reduced volumetric expansion factor plot
Hendricks, R. C.
1979-01-01
A reduced volumetric expansion factor plot has been constructed for simple fluids which is suitable for engineering computations in heat transfer. Volumetric expansion factors have been found useful in correlating heat transfer data over a wide range of operating conditions including liquids, gases and the near critical region.
Earnings Returns to the British Education Expansion
Devereux, Paul J.; Fan, Wen
2011-01-01
We study the effects of the large expansion in British educational attainment that took place for cohorts born between 1970 and 1975. Using the Quarterly Labour Force Survey, we find that the expansion caused men to increase education by about a year on average and gain about 8% higher wages; women obtained a slightly greater increase in education…
The heavy quark expansion of QCD
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.
Expansion techniques for collisionless stellar dynamical simulations
Meiron, Yohai [Kavli Institute for Astronomy and Astrophysics at Peking University, Beijing 100871 (China); Li, Baile; Holley-Bockelmann, Kelly [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Spurzem, Rainer, E-mail: ymeiron@pku.edu.cn [National Astronomical Observatories of China, Chinese Academy of Sciences, Beijing 100012 (China)
2014-09-10
We present graphics processing unit (GPU) implementations of two fast force calculation methods based on series expansions of the Poisson equation. One method is the self-consistent field (SCF) method, which is a Fourier-like expansion of the density field in some basis set; the other method is the multipole expansion (MEX) method, which is a Taylor-like expansion of the Green's function. MEX, which has been advocated in the past, has not gained as much popularity as SCF. Both are particle-field methods and optimized for collisionless galactic dynamics, but while SCF is a 'pure' expansion, MEX is an expansion in just the angular part; thus, MEX is capable of capturing radial structure easily, while SCF needs a large number of radial terms. We show that despite the expansion bias, these methods are more accurate than direct techniques for the same number of particles. The performance of our GPU code, which we call ETICS, is profiled and compared to a CPU implementation. On the tested GPU hardware, a full force calculation for one million particles took ∼0.1 s (depending on expansion cutoff), making simulations with as many as 10{sup 8} particles fast for a comparatively small number of nodes.
CONCEPT OF TISSUE EXPANSION IN RECONSTRUCTIVE SURGERY
Sheeja Rajan
2015-01-01
Full Text Available BACKGROUND: Tissue expansion is a unique reconstructive option in the armamentarium of a reconstructive surgeon whereby skin and soft tissues of our body can be stretched to large dimensions for wound coverage. The basis for such stretch ability lies in the inherent viscoelastic properties of skin. AIMS: This paper explores the prospects of using tissue expanders to reconstruct defects arising due to a kaleidoscope of pathological conditions including burns scars, post traumatic scars, congenital anomalies like hairy nevus, involutional scars in haemangioma as well as in post mastectomy breast reconstruction . MATERIALS AND METHODS: Our experience with tissue expansion in 14 patients over 24 months is presented. Tissue expanders made of silicone in sizes from 100 - 250ml, of round, rectangular or croissant (crescent shapes have been used. Areas expanded include scalp, forehead, neck, abdomen and forearm. Multiple expanders have been used when possible. Average expansion time was 8 - 12 weeks and the expanded tissue was transferred as advancement flaps. RESULTS AND CONCLUSIONS: Tissue expansion was successfully completed in 13 patients. Expansion had to be aborted in 1 paediatric patient undergoing neck expansion due to infection. Implant failure occurred in 1 patient during serial expansion. Nevertheless, in our experience tissue expan sion is an invaluable reconstructive tool to give excellent donor tissue with colour and texture match in countless situations demanding aesthetic and functional reconstruction. KEYWORDS: Burns scars, Reconstruction, Tissue expansion .
Virial expansion coefficients in the harmonic approximation
R. Armstrong, J.; Zinner, Nikolaj Thomas; V. Fedorov, D.
2012-01-01
The virial expansion method is applied within a harmonic approximation to an interacting N-body system of identical fermions. We compute the canonical partition functions for two and three particles to get the two lowest orders in the expansion. The energy spectrum is carefully interpolated...
Perturbative expansion of Chern-Simons theory
SAWON, Justin
2005-01-01
An overview of the perturbative expansion of the Chern--Simons path integral is given. The main goal is to describe how trivalent graphs appear: as they already occur in the perturbative expansion of an analogous finite-dimensional integral, we discuss this case in detail.
Benwell, Ann Fenger; Costa, Alberto; Waehle, Espen
2006-01-01
’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39......’Culturas del mundo. Colecciones del Museo Nacional de Dinamarca’ with Ann Fenger Benwell in Culturas del Mundo. Colecciones del Museo Nacional de Dinamarca, ed. Silvia Sauquet, Fundación "la Caixa", Barcelona 2006, pp. 31-39...
Development of Soda Residue Concrete Expansion Agent
WANG Bao-min; WANG Li-jiu; M F Mohd Zain; F C Lai
2003-01-01
A new type of concrete expansion agent has been successfully developed for the first time in the world by utilizing an industrial waste residue-soda residue and an industrial wasteliquor.Adding 3%-6% of the agent into Portland cement enables a shrinkage-compensating concrete to be prepared.Mortar and concrete containing this expansion agent have better shrinkage-compensating and mechanical properties.The raw materials component,production process,technical properties,micro-analysis of mortar made with this expansion agent,mechanism of expansion and research results are described in this article.The experimental results show that the new type of concrete expansion agent accords with the standard and its main mineral component is xCaO-ySO3-zAl2O3.
Business information query expansion through semantic network
Gong, Zhiguo; Muyeba, Maybin; Guo, Jingzhi
2010-02-01
In this article, we propose a method for business information query expansions. In our approach, hypernym/hyponymy and synonym relations in WordNet are used as the basic expansion rules. Then we use WordNet Lexical Chains and WordNet semantic similarity to assign terms in the same query into different groups with respect to their semantic similarities. For each group, we expand the highest terms in the WordNet hierarchies with hypernym and synonym, the lowest terms with hyponym and synonym and all other terms with only synonym. In this way, the contradictory caused by full expansion can be well controlled. Furthermore, we use collection-related term semantic network to further improve the expansion performance. And our experiment reveals that our solution for query expansion can improve the query performance dramatically.
Maxwell superalgebras and Abelian semigroup expansion
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.
Maxwell superalgebras and Abelian semigroup expansion
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.
Shrinkage and Expansive Strain of Concrete with Fly Ash and Expansive Agent
GAO Peiwei; LU Xiaolin; TANG Mingshu
2009-01-01
The effects of fly ash and MgO-type expansive agent on the shrinkage and expan-sive strain of concrete with high magnesia cement were investigated. The results show that high volumes of fly ash may reduce the shrinkage strain of concrete and inhibit the expansive strain of concrete with MgO-type expansive agent, but can not eliminate the shrinkage of concrete. MgO-type expansive agent may produce expansive strain and compensate the shrinkage strain of concrete, re-lieve the cracking risk, but the hydration product of magnesia tends to get together in paste and pro-duce expansive cracking of concrete with high magnesia content according to SEM observation.
Expansion Techniques for Collisionless Stellar Dynamical Simulations
Meiron, Yohai; Holley-Bockelmann, Kelly; Spurzem, Rainer
2014-01-01
We present GPU implementations of two fast force calculation methods, based on series expansions of the Poisson equation. One is the Self-Consistent Field (SCF) method, which is a Fourier-like expansion of the density field in some basis set; the other is the Multipole Expansion (MEX) method, which is a Taylor-like expansion of the Green's function. MEX, which has been advocated in the past, has not gained as much popularity as SCF. Both are particle-field method and optimized for collisionless galactic dynamics, but while SCF is a "pure" expansion, MEX is an expansion in just the angular part; it is thus capable of capturing radial structure easily, where SCF needs a large number of radial terms. We show that despite the expansion bias, these methods are more accurate than direct techniques for the same number of particles. The performance of our GPU code, which we call ETICS, is profiled and compared to a CPU implementation. On the tested GPU hardware, a full force calculation for one million particles took...
Giant negative thermal expansion in magnetic nanocrystals.
Zheng, X G; Kubozono, H; Yamada, H; Kato, K; Ishiwata, Y; Xu, C N
2008-12-01
Most solids expand when they are heated, but a property known as negative thermal expansion has been observed in a number of materials, including the oxide ZrW2O8 (ref. 1) and the framework material ZnxCd1-x(CN)2 (refs 2,3). This unusual behaviour can be understood in terms of low-energy phonons, while the colossal values of both positive and negative thermal expansion recently observed in another framework material, Ag3[Co(CN)6], have been explained in terms of the geometric flexibility of its metal-cyanide-metal linkages. Thermal expansion can also be stopped in some magnetic transition metal alloys below their magnetic ordering temperature, a phenomenon known as the Invar effect, and the possibility of exploiting materials with tuneable positive or negative thermal expansion in industrial applications has led to intense interest in both the Invar effect and negative thermal expansion. Here we report the results of thermal expansion experiments on three magnetic nanocrystals-CuO, MnF2 and NiO-and find evidence for negative thermal expansion in both CuO and MnF2 below their magnetic ordering temperatures, but not in NiO. Larger particles of CuO and MnF2 also show prominent magnetostriction (that is, they change shape in response to an applied magnetic field), which results in significantly reduced thermal expansion below their magnetic ordering temperatures; this behaviour is not observed in NiO. We propose that the negative thermal expansion effect in CuO (which is four times larger than that observed in ZrW2O8) and MnF2 is a general property of nanoparticles in which there is strong coupling between magnetism and the crystal lattice.
Philip J. Purnell
2013-01-01
Full Text Available La expansión de contenido regional de la Web of Science de Thomson Reuters (anteriormente ISI indexó aproximadamente 1.600 revistas en la base de datos con un enfoque regional en contraposición al internacional. La cobertura de la Web of Science ha crecido para reflejar la naturaleza cambiante de las tendencias globales de las publicaciones de investigación y ofrecer mayor visibilidad a estudios locales con alta calidad, más allá de las barreras tradicionales, a través de la incorporación de revistas regionales. Las referencias indexadas que son citadas en las revistas regionales representan la influencia de las revistas en las comunidades científicas, tanto globales como locales. Este estudio analiza el impacto de la indexación de revistas regionales españolas en la Web of Science sobre la publicación y patrones de citación de la investigación española. Los hallazgos demuestran un incremento reciente en la producción investigadora de España, no solo debida a la indexación de revistas españolas, sino principalmente a una mayor producción científica del país; de hecho, esto se demuestra porque la mayoría de las investigaciones españolas no se publican en revistas de dicho país. El análisis de las citaciones de las revistas de España descubre una red de citación regional no detectada previamente y que proporciona una valiosa información para los evaluadores de revistas españolas.
Critical exponents from large mass expansion
Yamada, Hirofumi
2014-01-01
We perform estimation of critical exponents via large mass expansion under crucial help of delta-expansion. We address to the three dimensional Ising model at high temperature and estimate omega, the correction-to-scaling exponent, nu, eta and gamma in unbiased and self-contained manner. The results read at the highest 25th order expansion omega=0.8002, nu=0.6295, eta=0.0369 and gamma=1.2357. Estimation biased by omega=0.84(4) is also performed and proved to be in agreement with the summary of recent literatures.
ON CONVERGENCE OF WAVELET PACKET EXPANSIONS
Morten Nielsen
2002-01-01
It is well known that the-Walsh-Fourier expansion of a function from the block space ([0, 1 ) ), 1 ＜q≤∞, converges pointwise a.e. We prove that the same result is true for the expansion of a function from in certain periodixed smooth periodic non-stationary wavelet packets bases based on the Haar filters. We also consider wavelet packets based on the Shannon filters and show that the expansion of Lp-functions, 1＜p＜∞, converges in norm and pointwise almost everywhere.
Extrudate Expansion Modelling through Dimensional Analysis Method
A new model framework is proposed to correlate extrudate expansion and extrusion operation parameters for a food extrusion cooking process through dimensional analysis principle, i.e. Buckingham pi theorem. Three dimensionless groups, i.e. energy, water content and temperature, are suggested...... to describe the extrudates expansion. From the three dimensionless groups, an equation with three experimentally determined parameters is derived to express the extrudate expansion. The model is evaluated with whole wheat flour and aquatic feed extrusion experimental data. The average deviations...
Does cosmological expansion affect local physics?
Giulini, Domenico
2013-01-01
In this contribution I wish to address the question whether, and how, the global cosmological expansion influences local physics. I argue that a pseudo Newtonian picture can be quite accurate if ``expansion'' is taken to be an attribute of the inertial structure rather than of ``space'' in some substantivalist sense. This contradicts the often-heard suggestion to imagine cosmological expansion as that of ``space itself''. Regarding General Relativity, I emphasise the need for proper geometric characterisations in order to meaningfully compare localised systems in different spacetimes, like black holes in static and expanding environments. Examples of this sort are discussed in some detail to clearly map out the problems.
Some Improved Nonperturbative Bounds for Fermionic Expansions
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.
Hubble expansion is not a velocity
Ma, Yin-Zhe; Zhang, Shuang-Nan
2016-11-01
In this paper, we clarify the difference between the Hubble expansion and the Doppler shift pedagogically and illustrate both physically and mathematically why the Hubble expansion cannot be regarded as a velocity. Therefore, we suggest to replace the misleading word ‘recession velocity’ to be ‘Hubble recession’ to describe the cosmic expansion. We further derive how the peculiar velocity of a galaxy is related to its observed redshift and proper distance, which has practical use in the galaxy redshift and distance surveys.
Heydi Robles
2005-01-01
Full Text Available Este artículo muestra los resultados de una investigación sobre la ansiedad causada por el aprendizaje de idiomas. Está centrado en la ansiedad relacionada con la habilidad de producción oral. El objetivo del estudio era identificar los factores externos que producen ansiedad en el desarrollo de la competencia oral en un grupo de estudiantes de Psicología. Para lograr su objetivo, la investigación utilizó diarios, cuestionarios, grabaciones (opiniones personales, presentaciones orales breves y entrevistas. Con respecto de los factores externos que producen ansiedad en relación con las actividades, los resultados muestran que todas las actividades orales producen un alto grado de ansiedades en los estudiantes, especialmente las actividades no programadas. También muestran una falta de participación en clase con un fuerte rechazo a las actividades orales. Entre las posibles causas de reticencia puede estar el hecho de que los estudiantes no quieren ser objeto de burla. Además, la habilidad de producción oral no fue estimulada en los niveles anteriores del programa de inglés. Es vital mencionar que los alumnos son conscientes de sus carencias en algunos aspectos del idioma como vocabulario, gramática y fluidez.
Surgically assisted rapid maxillary expansion in adults.
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.
High Falls generation station expansion approvals process
Litschko, C. [Lakeland Holding, Bracebridge, ON (Canada)
2005-07-01
Lakeland Holding Ltd. is the parent company for Lakeland Power Distribution Ltd., Bracebridge Generation Ltd., and Lakeland Energy Ltd. This PowerPoint presentation highlighted the High Falls generation expansion process. During construction of the High Falls plant, a concrete foundation was built beside the plant for future expansion. The expansion process involves building a 1,500 kilowatt generator to supply electricity to as many as 1600 households. The presentation described the context and background for the expansion and presented information on the water power generation plants. It presented site specifications as well as the approvals process by which final approval was granted in 2004. Observations and lessons learned from the approval process were identified. figs.
Origami Metamaterials for Tunable Thermal Expansion.
Boatti, Elisa; Vasios, Nikolaos; Bertoldi, Katia
2017-07-01
Materials with engineered thermal expansion, capable of achieving targeted 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 engineered coefficient of thermal expansion consist of bi-material 2D or 3D lattices, here it is shown that origami metamaterials also provide a platform for the design of systems with a wide range of thermal expansion coefficients. Experiments and simulations are combined to demonstrate that by tuning the geometrical parameters of the origami structure and the arrangement of plates and creases, an extremely broad range of thermal expansion coefficients can be obtained. Differently from all previously reported systems, the proposed structure is tunable in situ and nonporous. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
An effective theory of accelerated expansion
Jimenez, Raul; Verde, Licia
2011-01-01
We work out an effective theory of accelerated expansion to describe general phenomena of inflation and acceleration (dark energy) in the Universe. Our aim is to determine from theoretical grounds, in a physically-motivated and model independent way, which and how many (free) parameters are needed to broadly capture the physics of a theory describing cosmic acceleration. Our goal is to make as much as possible transparent the physical interpretation of the parameters describing the expansion. We show that, at leading order, there are five independent parameters, of which one can be constrained via general relativity tests. The other four parameters need to be determined by observing and measuring the cosmic expansion rate only, H(z). Therefore we suggest that future cosmology surveys focus on obtaining an accurate as possible measurement of $H(z)$ to constrain the nature of accelerated expansion (dark energy and/or inflation).
Collisional and collisionless expansion of Yukawa balls.
Piel, Alexander; Goree, John A
2013-12-01
The expansion of Yukawa balls is studied by means of molecular dynamics simulations of collisionless and collisional situations. High computation speed was achieved by using the parallel computing power of graphics processing units. When the radius of the Yukawa ball is large compared to the shielding length, the expansion process starts with the blow-off of the outermost layer. A rarefactive wave subsequently propagates radially inward at the speed of longitudinal phonons. This mechanism is fundamentally different from Coulomb explosions, which employ a self-similar expansion of the entire system. In the collisionless limit, the outer layers carry away most of the available energy. The simulations are compared with analytical estimates. In the collisional case, the expansion process can be described by a nonlinear diffusion equation that is a special case of the porous medium equation.
On Learning Ring-Sum-Expansions
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 a 2-CNF and a 1-DNF. Finally the paper presents learning (on-line prediction) algorithms for k-RSE that are optimal with respect to the sample size (worst case mistake bound)...... 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...
Fuel Thermal Expansion (FTHEXP). [BWR; PWR
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/sub 2/ and PuO/sub 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/sub 2/, and the fraction of fuel which is molten.
Thermal expansion coefficient of binary semiconductors
Kumar, V.; Sastry, B.S.R. [Indian School of Mines, Dhanbad (India). Dept. of Electronics and Instrumentation
2001-07-01
The linear thermal expansion coefficient of tetrahedrally coordinated A{sup II}B{sup VI} and A{sup III}B{sup V} semiconductors has been calculated using plasmon energy data. A simple relation between the bond length and plasmon energy has been derived. The calculated values of thermal expansion coefficient and bond length have been compared with the experimental values and the values reported by different workers. An excellent experiment has been obtained between them. (orig.)
Cluster expansion in the canonical ensemble
Pulvirenti, Elena
2011-01-01
We consider a system of particles confined in a box $\\La\\subset\\R^d$ interacting via a tempered and stable pair potential. We prove the validity of the cluster expansion for the canonical partition function in the high temperature - low density regime. The convergence is uniform in the volume and in the thermodynamic limit it reproduces Mayer's virial expansion providing an alternative and more direct derivation which avoids the deep combinatorial issues present in the original proof.
Index calculation by means of harmonic expansion
Imamura, Yosuke
2015-01-01
We review derivation of superconformal indices by means of supersymmetric localization and spherical harmonic expansion for 3d N=2, 4d N=1, and 6d N=(1,0) supersymmetric gauge theories. We demonstrate calculation of indices for vector multiplets in each dimensions by analysing energy eigenmodes in S^pxR. For the 6d index we consider the perturbative contribution only. We put focus on technical details of harmonic expansion rather than physical applications.
Optimized $\\delta$ expansion for relativistic nuclear models
Krein, G I; Peres-Menezes, D; Nielsen, M; Pinto, M B
1998-01-01
The optimized $\\delta$-expansion is a nonperturbative approach for field theoretic models which combines the techniques of perturbation theory and the variational principle. This technique is discussed in the $\\lambda \\phi^4$ model and then implemented in the Walecka model for the equation of state of nuclear matter. The results obtained with the $\\delta$ expansion are compared with those obtained with the traditional mean field, relativistic Hartree and Hartree-Fock approximations.
On storm weakening during substorm expansion phase
G. L. Siscoe
Full Text Available Iyemori and Rao recently presented evidence that the strength of a magnetic storm, as measured by -Dst, weakens, or its rate of growth slows, during the substorm expansion phase. Yet the expansion phase is known to inject energetic particles into the ring current, which should strengthen the storm. We propose to reconcile these apparently contradictory results by combining the virial theorem and a principle of energy partitioning between energy storage elements in a system with dissipation. As applied to the unloading description of the substorm expansion phase, the virial theorem states that -Dst is proportional to the sum of the total magnetic energy and twice the total kinetic energy in the magnetosphere including the tail. Thus if expansion phase involves converting magnetic energy stored in the tail into kinetic energy stored in the ring current, a drop in -Dst during expansion phase requires that less than half the drop in magnetic energy goes into the ring current, the rest going into the ionosphere. Indeed Weiss et al., have estimated that the energy dissipated in the ionosphere during expansion phase is twice that injected into the ring current. This conclusion is also consistent with the mentioned energy partitioning principle, which requires that more energy be dissipated than transferred between storage elements. While Iyemori and Rao's observations seem to contradict the hypothesis that storms consist at least in part of a sum of substorms, this mode of description might nonetheless be preserved by including the substorm's growth-phase contribution. Then the change in storm strength measured from before the growth phase to after the expansion phase is positive, even though the expansion phase alone makes a negative contribution.
Expansion of Bubbles in Inflationary Universe
Mohazzab, M.; Jabbari, M. M. Sheikh; Salehi, H.
1995-01-01
We show that particle production during the expansion of bubbles of true vacuum in the sea of false vacuum is possible and calculate the resulting rate. As a result the nucleated bubbles cannot expand due to the transfer of false vacuum energy to the created particles inside the bubbles. Therefore all the inflationary models dealing with the nucleation and expansion of the bubbles (including extended inflation) may not be viable.
Expansion of bubbles in inflationary universe
Mohazzab, M
1995-01-01
We show that particle production during the expansion of bubbles of true vacuum in the sea of false vacuum is possible and calculate the resulting rate. As a result the nucleated bubbles cannot expand due to the transfer of false vacuum energy to the created particles inside the bubbles. Therefore all the inflationary models dealing with the nucleation and expansion of the bubbles (including extended inflation) may not be viable.
Thermal Expansion Coefficients of Thin Crystal Films
无
2005-01-01
The formulas for atomic displacements and Hamiltonian of a thin crystal film in phonon occupation number representation are obtained with the aid of Green's function theory. On the basis of these results, the formulas for thermal expansion coefficients of the thin crystal film are derived with the perturbation theory, and the numerical calculations are carried out. The results show that the thinner films have larger thermal expansion coefficients.
Fixed Point Theorems for Times Reasonable Expansive Mapping
Chen Chunfang
2008-01-01
Full Text Available Abstract Based on previous notions of expansive mapping, times reasonable expansive mapping is defined. The existence of fixed point for times reasonable expansive mapping is discussed and some new results are obtained.
Expansive Soil Crack Depth under Cumulative Damage
Bei-xiao Shi
2014-01-01
Full Text Available The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil.
Thermal expansion of doped lanthanum gallates
K T Jacob; S Jain; V S Saji; P V K Srikanth
2010-08-01
Thermal expansion of several compositions of Sr and Mg-doped LaGaO3 including an -site deficient composition (La0.9Sr0.1)0.98(Ga0.8Mg0.2)O2.821 were measured in the temperature range from 298 to 1273 K. The effect of doping on thermal expansion was studied by varying the composition at one site of the perovskite structure (either or ), while keeping the composition at the other site invariant. Thermal expansion varied nonlinearly with temperature and exhibited an inflexion between 550 and 620 K, probably related to the change in crystal structure from orthorhombic to rhombohedral. The dependence of average thermal expansion coefficient (av) on the dopant concentration on either or site of the perovskite structure was found to be linear, when the composition at the other site was kept constant. Mg doping on the -site had a greater effect on the average thermal expansion coefficient than Sr doping on the -site. Cation deficiency at the -site decreases thermal expansion when compositions at both sites are held constant.
Design of Airport Pavements for Expansive Soils.
1981-01-01
34 .’. . , . Vol. 57:437-444. Nunez, E., and Carrillo, A., (1977) " Suelos Especiales: Colapsibles, Expansivo , Preconsolidados por Desecacion...1975) "Las Arcillas Expansivas: Su Estudio y Trataniento," Laboratorio del Transporte y Mechanica del Suelo , i.,’. ". pp. 3-30. Russam, Kenneth
Negative thermal expansion materials: technological key for control of thermal expansion.
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.
Del Derecho laboral al Derecho del trabajo
Jaramillo Jassir, Ivan Daniel
2011-01-01
El Derecho Laboral hijo de la revolución industrial, calificado como el acontecimiento jurídico del siglo XX, reduce su ámbito de estudio al trabajo subordinado. Los cambios del sistema de producción superan la centralidad del contrato de trabajo subordinado a tiempo indeterminado, situación que demanda ampliación del ámbito de aplicación subjetivo y objetivo de la materia, dando paso al Derecho del Trabajo que se ocupa del trabajo en todas sus modalidades como fuente de ingreso para satisfac...
Preliminary thermal expansion screening data for tuffs
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{sup 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.
The $\\hbar$ Expansion in Quantum Field Theory
Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; Hoyer, Paul; /Southern Denmark U., CP3-Origins /Helsinki U. /Helsinki Inst. of Phys.
2010-10-27
We show how expansions in powers of Planck's constant {h_bar} = h = 2{pi} can give new insights into perturbative and nonperturbative properties of quantum field theories. Since {h_bar} is a fundamental parameter, exact Lorentz invariance and gauge invariance are maintained at each order of the expansion. The physics of the {h_bar} expansion depends on the scheme; i.e., different expansions are obtained depending on which quantities (momenta, couplings and masses) are assumed to be independent of {h_bar}. We show that if the coupling and mass parameters appearing in the Lagrangian density are taken to be independent of {h_bar}, then each loop in perturbation theory brings a factor of {h_bar}. In the case of quantum electrodynamics, this scheme implies that the classical charge e, as well as the fine structure constant are linear in {h_bar}. The connection between the number of loops and factors of {h_bar} is more subtle for bound states since the binding energies and bound-state momenta themselves scale with {h_bar}. The {h_bar} expansion allows one to identify equal-time relativistic bound states in QED and QCD which are of lowest order in {h_bar} and transform dynamically under Lorentz boosts. The possibility to use retarded propagators at the Born level gives valence-like wave-functions which implicitly describe the sea constituents of the bound states normally present in its Fock state representation.
Expansion Under Climate Change: The Genetic Consequences.
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.
[Forum on tissue expansion. Expansion of the scalp. Surgical techniques and clinical applications].
Foyatier, J L; Delay, E; Comparin, J P; Latarjet, J; Masson, C L
1993-02-01
Repair of all forms of alopecia is one of the principal applications of scalp expansion. The authors have inserted 400 expansion prostheses, including 20 in the scalp. The surgical technique, choice of material and various types of flaps are described and illustrated by clinical cases of extensive alopecia.
Influence of MgO-type Expansive Agent Hydration Behaviors on Expansive Properties of Concrete
LU Xiaolin; GENG Fei; ZHANG Hongbo; CHEN Xiong
2011-01-01
The hydration behaviors and expansive properties of MgO-type expansive agent curing at different temperatures and environment were investigated. When the curing temperatures changed from 25℃ to 50 ℃, the conductivities of MgO samples increased from 40 to 80 μ s/cm,and the hydrations of MgO were quickened up obviously. Through SEM observation, the hydration product of MgO cured at 50 ℃ for 28 day was about 2-3 μ m in length. The expansion of pastes with 5% of the MgO-type expansive agent was from 0.36% to 1.01% when the curing temperature changed from 25℃ to 50 ℃. When 8% of the MgO-type expansive agent was added, the early shrinkage of concrete was reduced. The expansion ratio increased with the curing temperature, and the expansive cracking of concrete with MgO-type expansive agent might be decreased by blending fly ash.
Thermal expansion in lead zirconate titanate
无
2002-01-01
The volume anomalies with temperature variations in tin-modified lead zirconate titanate ceramics are investigated. Experimental results show that the volume changes are related to the phase transitions induced with temperature. The magnitude and orientation of crystal volume changes are dependent on the particular phase transition. When antiferroelectrics is transformed to ferroelectrics or paraelectrics the volume expands. Oppositely when ferroelectrics is transformed to antiferroelectrics or paraelectrics the volume contracts. In the transition of antiferroelectric orthorhombic structure to tetragonal structure or ferroelectric low-temperature rhombohedral structure to high-tem- perature rhombohedral structure, there are also revealed apparent anomalies in the curves of thermal expansion. Among them, the volume strain caused by the transition between antiferroelectrics and ferroelectrics is the biggest in magnitude, and the linear expansion dL/L0 and the expansion coefficient (dL/L0)/dT can reach 2.810?3 and 7.5 × 10?4 K?1 respectively.
Spectator expansion in multiple scattering theory
Siciliano, E.R.; Thaler, R.M.
1977-10-01
A finite expansion for the scattering of a structureless projectile from a complex target of A particles is presented. This development is given as a spectator expansion, in the sense that the first term represents the scattering of the projectile from single target constitutent particles, with all other target particles playing a passive role (i.e., acting as spectators). Similarly, the second term represents the scattering from pairs of target particles with (A-2) spectators, and so on. It is demonstrated that such expansions, one of which has been obtained previously as a resummation of the multiple scattering series, are very general in nature and obtain under circumstances for which the standard multiple scattering treatment is not valid.
Radial expansion for spinning conformal blocks
Costa, Miguel; Hansen, Tobias; Penedones, João; Trevisani, Emilio
2016-01-01
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.
Does cosmological expansion affect local physics?
Giulini, Domenico
2014-05-01
In this contribution I wish to address the question whether, and how, the global cosmological expansion influences local physics, like particle orbits and black hole geometries. Regarding the former I argue that a pseudo Newtonian picture can be quite accurate if "expansion" is taken to be an attribute of the inertial structure rather than of "space" in some substantivalist sense. This contradicts the often-heard suggestion to imagine cosmological expansion as that of "space itself". Regarding isolated objects in full General Relativity, like black holes, I emphasise the need for proper geometric characterisations in order to meaningfully compare them in different spacetimes, like static and expanding ones. Examples are discussed in some detail to clearly map out the problems. A slightly extended version of this contribution may be found at philsci-archive.pitt.edu/10033.
A meaningful expansion around detailed balance
Colangeli, Matteo; Wynants, Bram
2011-01-01
We consider Markovian dynamics modeling open mesoscopic systems which are driven away from detailed balance by a nonconservative force. A systematic expansion is obtained of the stationary distribution around an equilibrium reference, in orders of the nonequilibrium forcing. The first order around equilibrium has been known since the work of McLennan (1959), and involves the transient irreversible entropy flux. The expansion generalizes the McLennan formula to higher orders, complementing the entropy flux with the dynamical activity. The latter is more kinetic than thermodynamic and is a possible realization of Landauer's insight (1975) that, for nonequilibrium, the relative occupation of states also depends on the noise along possible escape routes. In that way nonlinear response around equilibrium can be meaningfully discussed in terms of two main quantities only, the entropy flux and the dynamical activity. The expansion makes mathematical sense as shown in the simplest cases from exponential ergodicity.
Towards finite density QCD with Taylor expansions
Karsch, Frithjof; Wagner, Mathias; Wambach, Jochen
2011-01-01
We analyze general convergence properties of the Taylor expansion of observables to finite chemical potential in the framework of an effective 2+1 flavor Polyakov-quark-meson model. To compute the required higher order coefficients a novel technique based on algorithmic differentiation has been developed. Results for thermodynamic observables as well as the phase structure obtained through the series expansion up to 24th order are compared to the full model solution at finite chemical potential. The available higher order coefficients also allow for resummations, e.g. Pade series, which improve the convergence behavior. In view of our results we discuss the prospects for locating the QCD phase boundary and a possible critical endpoint with the Taylor expansion method.
Cosmological Constant, Quintessence and Expansive Nondecelerative Universe
Sima, J; Sima, Jozef; Sukenik, Miroslav
2001-01-01
Recent observations of the Universe have led to a conclusion suppressing an up-to-now supposed deceleration of the Universe caused by attractive gravitational forces. Contrary, there is a renaissance of the cosmological member lambda and introduction of enigmatic repulsive dark energy in attempts to rationalize a would-be acceleration of the Universe expansion. It is documented that the model of Expansive Nondecelerative Universe is capable to offer acceptable answers to the questions on the Universe expansion, state equations of the Universe, the parameter omega, the cosmological member lambda without any necessity to introduce new strange kinds of matter or energy being in accord with the fundamental conservation laws and generally accepted parameters of the Universe.
MODIFIED PERIODONTAL EXPLORER FOR EXPANSION SCREW ACTIVATION
Srinivasan
2012-08-01
Full Text Available INTRODUCTION: Accidents with expansion screw activation keys are r eported in the literature 1,2 . A simple method to prevent such accident is to use a modified periodontal explorer as a key for expansion screw activation. A no.17 per iodontal explorer (fig 1 is cut at its first terminal bend (fig 2. The second section is bent m ore vertically to the long axis of the shaft (fig 3. This part which is tapered and stiff enough to ac tivate the screw is tried extra orally into the screw. It is further trimmed in such a way that onl y a mm of instrument can project through the screw hole (fig 4. Now a safe key for activating t he maxillary expansion screw is ready to use (fig 5. Once the patient’s parent or guardian succes sfully repeat the activation procedure in office, the instrument can be given to them for hom e use
Graphite thermal expansion reference for high temperature
Gaal, P. S.
1974-01-01
The design requirements of the aerospace and high-temperature nuclear reactor industries necessitate reliable thermal expansion data for graphite and other carbonaceous materials. The feasibility of an acceptable reference for calibration of expansion measuring systems that operate in carbon-rich atmospheres at temperatures ranging to 2500 C is the prime subject of this work. Present-day graphite technology provides acceptable materials for stable, reproducible references, as reflected by some of the candidate materials. The repeatability for a single specimen in a given expansion measuring system was found to be plus or minus 1%, while the combined results of several tests made on a number of samples fell within a plus or minus 2.5% band.
Bond return predictability in expansions and recessions
Engsted, Tom; Møller, Stig Vinther; Jensen, Magnus David Sander
We document that over the period 1953-2011 US bond returns are predictable in expansionary periods but unpredictable during recessions. This result holds in both in-sample and out-of-sample analyses and using both univariate regressions and combination forecasting techniques. A simulation study...... shows that our tests have power to reject unpredictability in both expansions and recessions. To judge the economic significance of the results we compute utility gains for a meanvariance investor who takes the predictability patterns into account and show that utility gains are positive in expansions...... but negative in recessions. The results are also consistent with tests showing that the expectations hypothesis of the term structure holds in recessions but not in expansions. However, the results for bonds are in sharp contrast to results for stocks showing that stock returns are predictable in recessions...
From greedy to lazy expansions and their driving dynamics
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
Necessary and Sufficient Conditions for Expansions of Wilson Type
Kun Chuan WANG
2008-01-01
We consider expansions of the type arising from Wilson bases.We characterize such expansions for L2(R).As an application,we see that such an expansion must be orthonormal,in contrast to the case of wavelet expansions generated by translations and dilation.
Alejandro Canales
2006-01-01
Full Text Available El artículo analiza las propuestas y los compromisos en materia de cobertura y de financiamiento en el periodo 2000-2006. En particular, revisa las modificaciones y los ajustes de los tres principales documentos en los que se expresaron las iniciativas: el de la Asociación Nacional de Universidades e Instituciones de Educación Superior, el del equipo de la transición y el programa sectorial. Los resultados muestran que las cifras de atención a la demanda educativa e inversión quedaron lejos de las metas autoimpuestas por el gobierno federal y que será necesario realizar mayores esfuerzos para atender tales desafíos.
Expansive mortar-induced ocular injury.
Balasubramanya, Ramamurthy; Rani, Alka; Sangwan, Virender S
2006-12-01
We describe here a case of bilateral chemical injury (with an expansive mortar which is being used in recent times to cut the rocks). On examination limbal ischemia was more in the left eye (9 clock hours) than the right eye (2 clock hours). The case was managed by bilateral removal of foreign bodies, along with conjunctival resection and amniotic membrane transplantation in the left eye. At six-month follow-up, patient had best corrected visual acuity of 20/30 and 20/60 in the right and left eyes respectively. Since this being an occupational hazard, proper eye protection gear should be used by persons using this expansive mortar.
Expansion Coefficient on Oxides and Oxide Ceramics.
1986-05-01
Ferroelectrics )," Ph.D. thesis submitted to the Indian Institute of Science, Bangalore- 12, (1969). 29. B. Alefeld. "The Change of Lattice Parameters of...Kamenetskii. "Anomalous Thermal Expansion of ZrO2 and HfO2 Over the Range 20-1200 0 C," Soy. Phy.-Cryst., 14 (1970) pp. 696-99. 89. A. K. Sreedhar. "Thermal...D. Gac. "Axial and Linear Thermal Expansion of ZrO 2 and HfO2 ," Am. Ceram. Soc. RuZl. 60(4) (1981), pp. 504-506. 167. R. Ruh, G. W. Hollenberg, E
Experimental Tests of Local Cosmological Expansion Rates
Widom, A; Srivastava, Y
2015-01-01
Cosmological expansion on a local scale is usually neglected in part due to its smallness, and in part due to components of bound systems (especially those bound by non-gravitational forces such as atoms and nuclei) not following the geodesics of the cosmological metric. However, it is interesting to ask whether or not experimental tests of cosmological expansion on a local scale (well within our own galaxy) might be experimentally accessible in some manner. We point out, using the Pioneer satellites as an example, that current satellite technology allows for this possibility within time scales of less than one human lifetime.
The replication of expansive production knowledge
Wæhrens, Brian Vejrum; Yang, Cheng; Madsen, Erik Skov
2012-01-01
. Design/methodology/approach – Two case studies are introduced. Empirical data were collected over a period of two years based on interviews and participating observations. Findings – The findings show that (1) knowledge transfer within the replication of a production line is a stepwise expansive process......Purpose – With the aim to support offshore production line replication, this paper specifically aims to explore the use of templates and principles to transfer expansive productive knowledge embedded in a production line and understand the contingencies that influence the mix of these approaches...... and principles to transfer productive knowledge in a specific context, which, in this paper, is a production line....
Expansion of the whole wheat flour extrusion
Cheng, Hongyuan; Friis, Alan
2008-01-01
A new model framework is proposed to describe the expansion of extrudates with extruder operating conditions based on dimensional analysis principle. The Buckingham pi dimensional analysis method is applied to form the basic structure of the model from extrusion process operational parameters. Us....... Using the Central Composite Design (CCD) method, whole wheat flour was processed in a twin-screw extruder with 16 trials. The proposed model can well correlate the expansion of the 16 trials using 3 regression parameters. The average deviation of the correlation is 5.9%....
On the Expansions in Spin Foam Cosmology
Hellmann, Frank
2011-01-01
We discuss the expansions used in spin foam cosmology. We point out that already at the one vertex level arbitrarily complicated amplitudes contribute, and discuss the geometric asymptotics of the five simplest ones. We discuss what type of consistency conditions would be required to control the expan- sion. We show that the factorisation of the amplitude originally considered is best interpreted in topological terms. We then consider the next higher term in the graph expansion. We demonstrate the tension between the truncation to small graphs and going to the homogeneous sector, and conclude that it is necessary to truncate the dynamics as well.
Air expansion in the water rocket
Romanelli, Alejandro; Madina, Federico González
2012-01-01
We study the thermodynamics of the water rocket in the thrust phase, taking into account the expansion of the air with water vapor, vapor condensation and the energy taken from the environment. We set up a simple experimental device with a stationary bottle and verified that the gas expansion in the bottle is well approximated by a polytropic process $PV^\\beta$= constant, where the parameter $\\beta$ depends on the initial conditions. We find an analytical expression for $\\beta $ that only depends on the thermodynamic initial conditions and is in good agreement with the experimental results.
Geometrization of spin systems using cycle expansions
Mainieri, R
1995-01-01
It is shown that a spin system with long range interactions can be converted into a chaotic dynamical system that is differentiable and low-dimensional. The thermodynamic limit of the spin system is then equivalent to studying the long term behavior of the dynamical system. Cycle expansions of chaotic systems (expansion of the Fredholm determinant) are then used to study the thermodynamic limit. By considering the smooth dynamical system, it is possible to converge to the thermodynamic limit faster than with transfer matrices.
Strategic Expansion Models in Academic Radiology.
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.
The Monetary Policy – Restrictive or Expansive?
Adam Szafarczyk
2007-10-01
Full Text Available The monetary policy plays an important role in macroeconomic policy of government. There is a question concerning type of this policy expansive or restrictive (easy or tidy monetary policy. Unfortunately, we have a lot of criteria. Each of them gives us other answer. So due to equitation of Irving Fisher we have dominantly expansive monetary policy. This same situation exists when we use nominal value of rediscount interest rate of central bank. Opposite result appears when we use real value of this interest rate or level of obligatory reserve. Taking under consideration liquidity on money market we know, that level of interest rate is too high.
Expansion of the whole wheat flour extrusion
Cheng, Hongyuan; Friis, Alan
2008-01-01
A new model framework is proposed to describe the expansion of extrudates with extruder operating conditions based on dimensional analysis principle. The Buckingham pi dimensional analysis method is applied to form the basic structure of the model from extrusion process operational parameters....... Using the Central Composite Design (CCD) method, whole wheat flour was processed in a twin-screw extruder with 16 trials. The proposed model can well correlate the expansion of the 16 trials using 3 regression parameters. The average deviation of the correlation is 5.9%....
Asymptotic expansions for the Gaussian unitary ensemble
Haagerup, Uffe; Thorbjørnsen, Steen
2012-01-01
Let g : R ¿ C be a C8-function with all derivatives bounded and let trn denote the normalized trace on the n × n matrices. In Ref. 3 Ercolani and McLaughlin established asymptotic expansions of the mean value ¿{trn(g(Xn))} for a rather general class of random matrices Xn, including the Gaussian...... Unitary Ensemble (GUE). Using an analytical approach, we provide in the present paper an alternative proof of this asymptotic expansion in the GUE case. Specifically we derive for a random matrix Xn that where k is an arbitrary positive integer. Considered as mappings of g, we determine the coefficients...
Debbie E. Guerra M.
2010-12-01
Full Text Available Este estudio revisa el discurso de pensadores y pensadoras locales de territorios estuariales donde residen comunidades indígenas y chilenas enfrentadas a fuerte presiones externas. El contenido de estos discursos, influido por la ecología histórica que ha moldeado el paisaje, representa un soporte teórico para nuevas prácticas democráticas que resisten la fragmentación impuesta. La tarea de articular y enunciar estos contenidos recae en intelectuales que contribuyen a la creación de un sentido común que reclama soberanía local. En la construcción de esta subjetividad cabe un papel significativo a las mujeres fruto del vínculo de residencia que establece con el medio y del carácter transitivo que tienen en la comunidad. En este artículo se subraya: (a La autoría de un sentido común que se propaga en el territorio a través de las pr��cticas organizativas de sus habitantes, (b La importancia que la ecología histórica tiene en la determinación de los discursos locales, y (c El incipiente desarrollo de formas de soberanía local asociadas a la constitución y defensa de los paisajes que sirven de soporte a la vida social.The aim of the present study was to analyse and interpret the discourses of local thinkers of estuarine territories inhabited by indigenous and Chilean communities faced with strong external pressures. The contents of these discourses, influenced by the historical ecology that has shaped the landscape, represent a framework for new democratic practices that resist the fragmentation imposed by external agencies. The task of articulating and enunciating these contents rely on intellectuals, who contribute to the creation of a common sense that claims local sovereignty. Due to their relation to the land and to their intermediary position in the community, women have a meaningful role in the construction of that common sense. This article emphasizes: (a The authorship of a common sense that propagates in the
Principles of Thermal Expansion in Feldspars
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
LA POLITICA SOCIAL DEL "GOBIERNO DEL CAMBIO"
Laura Mota Díaz
2002-01-01
El artículo se centra en la política social del actual sexenio foxista , la cual se ha definido como incluyente y equitativa dentro del marco de un gobierno autodenominado del cambio, no sólo por lo que se refiere a la alternancia política del poder, sino porque además pretende ser un gobierno con una visión más amplia del desarrollo. Todo ello se traduce en nuevas estrategias para alcanzar la democracia, la equidad, la justicia social y el bienestar general de la población. El ob...
Reactivity and expansion of electric arc furnace slag in their application in construction
Vázquez Rafionich, E.
2001-12-01
Full Text Available EAF-slag have adequate technical properties for its use as aggregates. The MgO content is the main responsable of the expansions. The expansion produced affect in different way the new material depending of the rigidity of the matrices formed. EAF-slag shows hidraulicity and forms as reaction products CSH, calcium aluminiunsilicates and amorphous phases that can increase the strength of concretes containing slags. The Le Chatelier , autoclave expansion and volume expansion tests can not be used in detecting the potential expansion of slag when used as aggregate in rigid matrix (concrete. Two new methods of measuring the potential expansion of EAF-slag are proposed.
La escoria de acero de horno de arco eléctrico presenta propiedades técnicas adecuadas para su uso como árido. El contenido de MgO es el principal causante de expansiones que afectan de forma distinta en función de la rigidez del sistema en que están integradas. Muestran una hidraulicidad que se traduce en formación de CSH, un silico aluminato cálcico y materia amorfa que pueden actuar como aglomerante débil, aumentando la resistencia de hormigones que las contienen. Ni los ensayos de Le Chatelier y autoclave convencionales, ni el llamado "steam test" (UNE-EN 1744-1 sirven para medir el potencial expansivo de las escorias cuando se encuentra en una matriz rígida. Se proponen nuevos métodos de medir el potencial de expansión de las escorias.
Thermal expansion anomaly regulated by entropy.
Liu, Zi-Kui; Wang, Yi; Shang, ShunLi
2014-11-13
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.
Peruvian Higher Education: Expansions Amid Economic Crisis.
Post, David
1991-01-01
Development of the Peruvian university system is described, focusing on periods of rapid expansion. Enrollment declines in 1974-78 are analyzed in the context of the educational reform program of the military government. The 1983 new university law, following return to civilian government, and future prospects for higher education are discussed.…
Platform Expansion Design as Strategic Choice
Staykova, Kalina S.; Damsgaard, Jan
2016-01-01
the main characteristics of the two approaches and to identify the potential trade-offs associated with the selection of particular expansion mode. To this end, we construct the Platform Strategy Framework and apply it to two exemplary cases – WeChat, which functions as a feature bundling platform...
Effects of forest expansion on mountain grassland
Guidi, Claudia; Magid, Jakob; Rodeghiero, Mirco
2014-01-01
Background and aims. Grassland abandonment followed by forest succession is the dominant land-use change in the European Alps. We studied the impact of current forest expansion on mountain grassland on changes in physical soil organic carbon (SOC) fractions along a land-use and management gradient...
Transmission network expansion planning under deliberate outages
Alguacil, Natalia; Carrion, Miguel; Arroyo, Jose Manuel [E.T.S. de Ingenieros Industriales, Universidad de Castilla - La Mancha, Campus Universitario s/n, 13071 Ciudad Real (Spain)
2009-10-15
The reasons why the transmission network is a potentially attractive target for deliberate outages are twofold: (i) its crucial importance as a critical infrastructure for the society welfare, and (ii) its high level of vulnerability due to the current operation close to its static and dynamic limits. This new context where destructive agents come into play has been recognized by several agencies in Europe and North America, and various initiatives have been launched worldwide in order to assess and mitigate the vulnerability of transmission. Within this framework, this paper proposes the reinforcement and expansion of the transmission network as a way of mitigating the impact of increasingly plausible deliberate outages. The network planner selects the new lines to be built accounting not only for economic issues, as traditionally done, but also for the vulnerability of the transmission network against a set of credible intentional outages. The resulting vulnerability- and economic-constrained transmission expansion planning problem is formulated as a mixed-integer linear program. A number of case studies numerically illustrate the tradeoff between economic- and vulnerability-related issues and its impact on the expansion plans. In addition, we compare the results with those achieved by a traditional expansion planning model based on cost minimization. (author)
Climate Science: Tropical Expansion by Ocean Swing
Lu, Jian
2014-04-01
The tropical belt has become wider over the past decades, but climate models fall short of capturing the full rate of the expansion. The latest analysis of the climate simulations suggests that a long-term swing of the Pacific Decadal Oscillation is the main missing cause.
Accelerated dryland expansion under climate change
Huang, Jianping; Yu, Haipeng; Guan, Xiaodan; Wang, Guoyin; Guo, Ruixia
2016-02-01
Drylands are home to more than 38% of the total global population and are one of the most sensitive areas to climate change and human activities. Projecting the areal change in drylands is essential for taking early action to prevent the aggravation of global desertification. However, dryland expansion has been underestimated in the Fifth Coupled Model Intercomparison Project (CMIP5) simulations considering the past 58 years (1948-2005). Here, using historical data to bias-correct CMIP5 projections, we show an increase in dryland expansion rate resulting in the drylands covering half of the global land surface by the end of this century. Dryland area, projected under representative concentration pathways (RCPs) RCP8.5 and RCP4.5, will increase by 23% and 11%, respectively, relative to 1961-1990 baseline, equalling 56% and 50%, respectively, of total land surface. Such an expansion of drylands would lead to reduced carbon sequestration and enhanced regional warming, resulting in warming trends over the present drylands that are double those over humid regions. The increasing aridity, enhanced warming and rapidly growing human population will exacerbate the risk of land degradation and desertification in the near future in the drylands of developing countries, where 78% of dryland expansion and 50% of the population growth will occur under RCP8.5.
The worldwide expansion of the Argentine ant
Vogel, Valerie; Pedersen, Jes Søe; Giraud, Tatiana;
2010-01-01
) and secondary introductions (from sites with established invasive supercolonies) were important in the global expansion of the Argentine ant. In combination with the similar social organization of colonies in the native and introduced range, this indicates that invasiveness did not evolve recently as a unique...
Further Notes on the Gaussian Beam Expansion
DAI Yu-Rong; DING De-Sheng
2012-01-01
We provide alternatively a simple way of computing the Fresnel field integral, a further extension to the Gaussian-beam expansion. With a known result that the circ function is approximately decomposed into a sum of Gaussian functions, the zero-order Bessel function of the first kind is similarly expanded by the Bessel-Fourior transform. Two expansions are together inserted in this integral, which is then expressible in terms of the simple algebraic functions. The approach is useful in treatment of the field radiation problem for a large and important group of piston sources in acoustics. As examples, the calculation results for the uniform and the simply supported piston sources are presented, in a good agreement with those evaluated by numerical integration.%We provide alternatively a simple way of computing the Fresnel field integral,a further extension to the Gaussianbeam expansion.With a known result that the circ function is approximately decomposed into a sum of Gaussian functions,the zero-order Bessel function of the first kind is similarly expanded by the Bessel-Fourior transform.Two expansions are together inserted in this integral,which is then expressible in terms of the simple algebraic functions.The approach is useful in treatment of the field radiation problem for a large and important group of piston sources in acoustics.As examples,the calculation results for the uniform and the simply supported piston sources are presented,in a good agreement with those evaluated by numerical integration.
MAP-based infrared image expansion
Nan Zhang; Weiqi Jin; Binghua Su; Yangyang Liu; Hua Chen
2005-01-01
@@ Image expansion plays a very important role in image analysis. Common methods of image expansion, such as the zero-order hold method, may generate a visual mosaic to the expanded image, linear and cubic spline interpolation may blur the image data at peripheral regions. Since infrared images have the characteristics of low contrast and low signal-to-noise ratio (SNR), the expanded images derived from common methods are not satisfactory. As shown in the analysis of the course from images with low resolution to those with high resolution, the expansion of image is found to be an ill-posed inverse problem. An image interpolation algorithm based on MAP estimation under Bayesian framework is proposed in this paper,which can effectively preserve the discontinuities in the original image. Experimental results demonstrate that the expanded images by this method are visually and quantitatively (analyzed by using the criteria of mean squared error (MSE) and mean absolute error (MAE)) superior to the images expanded by common methods of linear interpolation. Even in expansion of infrared images, this method can also give good results. An analysis about choosing regularization parameter α in this algorithm is given.
THE COMPLETE ASYMPTOTIC EXPANSION FOR BASKAKOV OPERATORS
Chungou Zhang; Quane Wang
2007-01-01
In this paper, we derive the complete asymptotic expansion of classical Baskakov itly in terms of Stirling number of the first and second kind and another number G(I, p). As a corollary, we also get the Voronovskaja-type result for the operators.
Polytope expansion of Lie characters and applications
Walton, Mark A., E-mail: walton@uleth.ca [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada)
2013-12-15
The weight systems of finite-dimensional representations of complex, simple Lie algebras exhibit patterns beyond Weyl-group symmetry. These patterns occur because weight systems can be decomposed into lattice polytopes in a natural way. Since lattice polytopes are relatively simple, this decomposition is useful, in addition to being more economical than the decomposition into single weights. An expansion of characters into polytope sums follows from the polytope decomposition of weight systems. We study this polytope expansion here. A new, general formula is given for the polytope sums involved. The combinatorics of the polytope expansion are analyzed; we point out that they are reduced from those of the Weyl character formula (described by the Kostant partition function) in an optimal way. We also show that the weight multiplicities can be found easily from the polytope multiplicities, indicating explicitly the equivalence of the two descriptions. Finally, we demonstrate the utility of the polytope expansion by showing how polytope multiplicities can be used in the calculation of tensor product decompositions, and subalgebra branching rules.
Toeplitz Quantization and Asymptotic Expansions: Geometric Construction
Miroslav Englis
2009-02-01
Full Text Available For a real symmetric domain G_R/K_R, with complexification G_C/K_C, we introduce the concept of ''star-restriction'' (a real analogue of the ''star-products'' for quantization of Kähler manifolds and give a geometric construction of the G_R-invariant differential operators yielding its asymptotic expansion.
Platform Expansion Design as Strategic Choice
Staykova, Kalina S.; Damsgaard, Jan
2016-01-01
the main characteristics of the two approaches and to identify the potential trade-offs associated with the selection of particular expansion mode. To this end, we construct the Platform Strategy Framework and apply it to two exemplary cases – WeChat, which functions as a feature bundling platform...
Religiosity and the expansion of caregiver stress.
Leblanc, A J; Driscoll, A K; Pearlin, L I
2004-09-01
We present a stress process framework as a model for understanding how religiosity may influence the expansion of stress. Survey data from informal caregivers to a spouse with Alzheimer's disease or a related dementia (n = 200) were analyzed to observe the relationships among three variables: (1) care-related stress, (2) religiosity, and (3) depression. This sample, which has a mean age of 73 years, demonstrates high rates of self-described religiosity, church attendance and frequency of prayer. Using these criteria, women and racial/ethnic minority caregivers are the most religious. In a series of multivariate analyses, we found strong evidence to suggest that there is an expansion of care-related stressors leading to depression in this sample. Religiosity, as measured here, appears to be largely unrelated to stress and stress expansion. We found no evidence to suggest that it moderates stress expansion. However, these data do suggest that one stressor--feelings of role overload--is correlated with greater levels of self-perceived religiosity, which among caregivers who have health problems of their own is associated with greater depressive symptomatology. Thus, for a sub-sample of these caregivers, we find weak evidence of a mediation effect wherein one subjective, non-organizational dimension of religiosity is a conduit of the harmful effects of stress (rather than a suppressor). Results and data limitations are discussed in relation to better assessing the role of religiosity and spirituality in the experience of the stress process.
ENTRAINMENT AND EXPANSION CONTROLLED FIREBALL RISE
This paper reports on a detailed analysis of the buoyant rise of fireballs in the earth’s atmosphere. Formulae for the rise velocity and height, and...the density, mass, radius and expansion velocity of the fireball are given. The computation of fireball temperature is discussed in detail; no
Adapting Query Expansion to Search Proficiency
C. Boscarino (Corrado); V. Hollink (Vera); A.P. de Vries (Arjen); B. Carterette; E. Kanoulas; P. Clough; M. Sanderson
2012-01-01
htmlabstractWe argue that query expansion (QE) based on the full ses- sion improves the overall search experience provided that we know how to adapt the QE weighting schema to a user's search proficiency. We propose a strategy to predict search ability from session parameters. Us- ing an
A Pedagogical Approach to the Magnus Expansion
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 Schrodinger 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…
Stakeholder Support for School Food Policy Expansions
Pettigrew, Simone; Pescud, Melanie; Donovan, Robert J.
2012-01-01
The aim of this study was to assess the extent to which parents and school-based stakeholders (principals, teachers, canteen managers and Parents & Citizen Committee presidents) are supportive of potential expansions to a new school food policy. Eight additional policy components elicited in preliminary focus groups with parents and 19 additional…
Global Expansion and English Language Learning
Andrade, Maureen Snow
2016-01-01
Demand for higher education is global. As institutions extend opportunities beyond their borders, English language proficiency must be considered. This chapter focuses on considerations related to global expansion, with an emphasis on the role of distance English language courses and the distinct considerations in their development.
On Learning Ring-Sum-Expansions
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...
Yang Jun; Li Xinchun; Zhang Guodong; Tang Yunwei; Xie Zhigang
2013-01-01
This paper aims at widespread presence of expansive soil which can be obtained in the project from Xiaoxita to Yaqueling first-class highway rebuilding engineering in Yichang City of Hubei Province and weathered sand which can be made full use locally,many experiments have been made. Compaction experiments and expan-sibility index indoor experiments of undisturbed expansive soil and expansive soil mixed with sand ranging from 10%to 50%have been made. Through the test mixing undisturbed expansive soil with different content of weath-ered sand,it can change the expansive soil water characteristics and compaction characteristics. It can influence the expansibility of the expansive soil index and significantly inhibit the expansibility of the expansive soil and reach the standard of roadbed filler.
Causes and consequences of magnetic cloud expansion
Démoulin, P.; Dasso, S.
2009-05-01
Context: A magnetic cloud (MC) is a magnetic flux rope in the solar wind (SW), which, at 1 AU, is observed ~2-5 days after its expulsion from the Sun. The associated solar eruption is observed as a coronal mass ejection (CME). Aims: Both the in situ observations of plasma velocity distribution and the increase in their size with solar distance demonstrate that MCs are strongly expanding structures. The aim of this work is to find the main causes of this expansion and to derive a model to explain the plasma velocity profiles typically observed inside MCs. Methods: We model the flux rope evolution as a series of force-free field states with two extreme limits: (a) ideal magneto-hydrodynamics (MHD) and (b) minimization of the magnetic energy with conserved magnetic helicity. We consider cylindrical flux ropes to reduce the problem to the integration of ordinary differential equations. This allows us to explore a wide variety of magnetic fields at a broad range of distances to the Sun. Results: We demonstrate that the rapid decrease in the total SW pressure with solar distance is the main driver of the flux-rope radial expansion. Other effects, such as the internal over-pressure, the radial distribution, and the amount of twist within the flux rope have a much weaker influence on the expansion. We demonstrate that any force-free flux rope will have a self-similar expansion if its total boundary pressure evolves as the inverse of its length to the fourth power. With the total pressure gradient observed in the SW, the radial expansion of flux ropes is close to self-similar with a nearly linear radial velocity profile across the flux rope, as observed. Moreover, we show that the expansion rate is proportional to the radius and to the global velocity away from the Sun. Conclusions: The simple and universal law found for the radial expansion of flux ropes in the SW predicts the typical size, magnetic structure, and radial velocity of MCs at various solar distances.
216-B-3 expansion ponds closure plan
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.
Thermal Expansion of Vacuum Plasma Sprayed Coatings
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.
SEBASTIÁN BELMAR-LUCERO
2009-06-01
úan entre 46-70 cromosomas. En Chile se reconocen dos especies, Oligoryzomys longicaudatus (Bennet, 1832; "colilargo"; 2n = 56, desde los 27° S hasta aproximadamente 51° S, y Oligoryzomys magellanicus (Bennet, 1836; 2n = 54, al sur de los 51 ° S en la región Patagónica de Chile y Argentina. Como parte de una investigación en curso en la Patagonia sur de Chile, reportamos los resultados de muéstreos de pequeños mamíferos en seis localidades. Cariotipamos 28 especímenes y secuenciamos la región hipervariable I del mtDNA en 22 individuos, alineando estas secuencias con una filogenia de O. longicaudatus en desarrollo. Adicionalmente evaluamos la serología y la presencia de carga viral en todos los especímenes capturados con el objeto de detectar la presencia de anticuerpos anti-Andesvirus (ANDV mediante Strip Immunoblot Assay (SIA, y de genoma viral mediante RT-PCR. Los resultados muestran consistentemente que el cariotipo de los especímenes de la Patagonia sur de Chile es 2n = 56, similar al de O. longicaudatus, y que los individuos de esta región no se diferencian filogenéticamente de aquellos del norte del rango de distribución de esta especie. Adicionalmente, los análisis serológicos demostraron la presencia de anticuerpos IgG anti-ANDV y de genoma viral en corazón, riñon, bazo y pulmones de un espécimen de Oligoryzomys de la localidad de Fuerte Bulnes en la Región de Magallanes. Concluimos que todos los especímenes capturados al sur de los 51° S corresponden a Oligoryzomys longicaudatus, expandiendo así el rango de distribución de esta especie hasta al menos 55° S. Los resultados también extienden la distribución de la cepa Andes de Hantavirus al extremo sur de la Patagonia.
Tunable thermal expansion in framework materials through redox intercalation.
Chen, Jun; Gao, Qilong; Sanson, Andrea; Jiang, Xingxing; Huang, Qingzhen; Carnera, Alberto; Rodriguez, Clara Guglieri; Olivi, Luca; Wang, Lei; Hu, Lei; Lin, Kun; Ren, Yang; Lin, Zheshuai; Wang, Cong; Gu, Lin; Deng, Jinxia; Attfield, J Paul; Xing, Xianran
2017-02-09
Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework-type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF3, doped with 10% Fe to enable reduction. The small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. Redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion.
Homentcovschi, Dorel; Miles, Ronald N.
2012-01-01
The paper applies the re-expansion method for analyzing planar discontinuities at the junction of two axi-symmetrical circular waveguides. The normal modes in the two waveguides are expanded at the junction plane into a system of functions accounting for velocity singularities at the corner points. As the new expansion has a high convergence order, only a few terms have to be considered for obtaining the solution of most practical problems. This paper gives the equivalent impedance accounting for nonplanar waves into a plane-wave analysis and also the scattering matrix describing the coupling of arbitrary modes at each side of the discontinuity valid in the case of many propagating modes in both sides of the duct. The last section applies the re-expansion technique to some concentric expansion chambers providing an explicit formula for the transmission loss coefficient. PMID:22352491
Expansion of World Drylands Under Global Warming
Feng, S.; Fu, Q.; Hu, Q. S.
2012-12-01
The world drylands including both semi-arid and arid regions comprise of one-third of the global land surfaces, which support 14% of the world's inhabitants and a significant share of the world agriculture. Because of meager annual precipitation and large potential evaporative water loss, the ecosystems over drylands are fragile and sensitive to the global change. By analyzing the observations during 1948-2008 and 20 fully coupled climate model simulations from CMIP5 for the period 1900-2100, this study evaluated the changes of the world drylands that are defined with a modified form of the Thornthwaite's moisture index. The results based on observational data showed that the world drylands are steadily expanding during the past 60 years. The areas occupied by drylands in 1994-2008 is about 2.0×10^6km^2 (or 4%) larger than the average during the 1950s. Such an expansion is also a robust feature in the simulations of the 20 global climate models, though the rate is much smaller in the models. A stronger expanding rate is projected during the first half of this century than the simulations in the last century, followed by accelerating expansion after 2050s under the high greenhouse gas emission scenario (RCP8.5). By the end of this century, the world drylands are projected to be over 58×10^6km^2 (or 11% increase compared to the 1961-1990 climatology). The projected expansion of drylands, however, is not homogeneous over the world drylands, with major expansion of arid regions over the southwest North America, the northern fringe of Africa, southern Africa and Australia. Major expansions of semi-arid regions are projected over the north side of the Mediterranean, southern Africa, North and South America. The global warming is the main factor causing the increase of potential evapotranspiration estimated by Penman-Monteith algorithm, which in turn dominants the expansion of drylands. The widening of Hadley cell, which has impact on both temperature and precipitation
Defining chemical expansion: the choice of units for the stoichiometric expansion coefficient
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....
The Hydration Characteristics and Expansion Machanism of Expansive Cement at Low W/B Ratio
LU Lin-nu; HE Yong-jia; LI Yue; DING Qing-jun; HU Shu-guang
2003-01-01
The hydration characteristics and expansion impetus of three kinds of cement paste under freeand confined-curing conditions were investigated, which were respectively mixed with three different kinds of expansive agent at low W/ B ratio. The results show that the hydration products of pure cement paste and paste mixed with expansive agent are same, but the amount of hydration products , un-hydrated C3 S and C2 S are obviously different at the same hydration age. At 3 d age, the amount of CH in pure cement paste is less than that of paste mixed with expaasive agent, but it is reverse when at 28d age. The amount of AFt at 3d and 28d age in pure cement paste is less than those of paste mixed with expansive agent. Regardless of under free- or confined-curing condition, the amount of ettringite produced varies little since 3 d age. The joint effect of the tumefaction of gel-ettringite due to water absorption and the expansive pressure on the pore caased by the crystalloid ettringite is the cause of the volume expansion of cement paste, and the former effect is much greater than the latter .
The Nonexistence of Expansive Zd Actions on Graphs
En Hui SHI; Li Zhen ZHOU
2005-01-01
It is well known that if X is an arc or a circle, then there is no expansive homeomorphism on X. In this paper we prove that there is no expansive Zd action on X, which answers the two questions raised by us before. In 1979, Man?proved that there is no expansive homeomorphism on infinite dimensional spaces. Contrary to this result, we construct an expansive Z2 action on an infinite dimensional space. We also construct an expansive Z2 action on a zero dimensional space but no element in Z2 is expansive.
Fourier series expansion for nonlinear Hamiltonian oscillators.
Méndez, Vicenç; Sans, Cristina; Campos, Daniel; Llopis, Isaac
2010-06-01
The problem of nonlinear Hamiltonian oscillators is one of the classical questions in physics. When an analytic solution is not possible, one can resort to obtaining a numerical solution or using perturbation theory around the linear problem. We apply the Fourier series expansion to find approximate solutions to the oscillator position as a function of time as well as the period-amplitude relationship. We compare our results with other recent approaches such as variational methods or heuristic approximations, in particular the Ren-He's method. Based on its application to the Duffing oscillator, the nonlinear pendulum and the eardrum equation, it is shown that the Fourier series expansion method is the most accurate.
Working fluids and expansion machines for ORC
Richter, Lukáš; Linhart, Jiří
2016-06-01
This paper discusses the key technical aspects of the Organic Rankin - Clausius cycle (ORC), unconventional technology with great potential for the use of low-potential heat and the use of geothermal and solar energy, and in connection with the burning of biomass. The principle of ORC has been known since the late 19th century. The development of new organic substances and improvements to the expansion device now allows full commercial exploitation of ORC. The right choice of organic working substances has the most important role in the design of ORC, depending on the specific application. The chosen working substance and achieved operating parameters will affect the selection and construction of the expansion device. For this purpose the screw engine, inversion of the screw compressor, can be used.
Negative thermal expansion in framework compounds
R Mittal
2008-10-01
We have studied negative thermal expansion (NTE) compounds with chemi- cal compositions of NX2O8 and NX2O7 (N=Zr, Hf and X=W, Mo, V) and M2O (M=Cu, Ag) using the techniques of inelastic neutron scattering and lattice dynamics. There is a large variation in the negative thermal expansion coefficients of these compounds. The inelastic neutron scattering experiments have been carried out using polycrystalline and single crystal samples at ambient pressure as well as at high pressures. Experimental data are useful to confirm the predictions made from our lattice dynamical calculations as well as to check the quality of the interatomic potentials developed by us. We have been able to successfully model the NTE behaviour of these compounds. Our studies show that unusual phonon softening of low energy modes is able to account for NTE in these compounds.
Cosmic expansion in extended quasidilaton massive gravity
Kahniashvili, Tina; Kar, Arjun; Lavrelashvili, George; Agarwal, Nishant; Heisenberg, Lavinia; Kosowsky, Arthur
2015-02-01
Quasidilaton massive gravity offers a physically well-defined gravitational theory with nonzero graviton mass. We present the full set of dynamical equations governing the expansion history of the Universe, valid during radiation domination, matter domination, and a late-time self-accelerating epoch related to the graviton mass. The existence of self-consistent solutions constrains the amplitude of the quasidilaton field and the graviton mass, as well as other model parameters. We point out that the effective mass of gravitational waves can be significantly larger than the graviton mass, opening the possibility that a single theory can explain both the late-time acceleration of cosmic expansion and modifications of structure growth leading to the suppression of large-angle correlations observed in the cosmic microwave background.
Cosmic Expansion in Extended Quasidilaton Massive Gravity
Kahniashvili, Tina; Lavrelashvili, George; Agarwal, Nishant; Heisenberg, Lavinia; Kosowsky, Arthur
2014-01-01
Quasidilaton massive gravity offers a physically well-defined gravitational theory with non-zero graviton mass. We present the full set of dynamical equations governing the expansion history of the universe, valid during radiation domination, matter domination, and a late-time self-accelerating epoch related to the graviton mass. The existence of self-consistent solutions constrains the amplitude of the quasi-dilaton field and the graviton mass, as well as other model parameters. We point out that the effective mass of gravitational waves can be significantly larger than the graviton mass, opening the possibility that a single theory can explain both the late-time acceleration of the cosmic expansion and modifications of structure growth leading to the suppression of large-angle correlations observed in the cosmic microwave background.
Towards finite density QCD with Taylor expansions
Karsch, Frithjof; Wagner, Mathias; Wambach, Jochen
2010-01-01
Convergence properties of Taylor expansions of observables, which are also used in lattice QCD calculations at non-zero chemical potential, are analyzed in an effective N_f = 2+1 flavor Polyakov-quark-meson model. A recently developed algorithmic technique allows the calculation of higher-order Taylor expansion coefficients in functional approaches. This novel technique is for the first time applied to an effective N_f = 2+1 flavor Polyakov-quark-meson model and the findings are compared with the full model solution at finite densities. The results are used to discuss prospects for locating the QCD phase boundary and a possible critical endpoint in the phase diagram.
6th International Symposium on Thermal Expansion
1978-01-01
This 6th International Symposium on Thermal Expansion, the first outside the USA, was held on August 29-31, 1977 at the Gull Harbour Resort on Hecla Island, Manitoba, Canada. Symposium Chairman was Ian D. Peggs, Atomic Energy of Canada Limited, and our continuing sponsor was CINDAS/Purdue University. We made considerable efforts to broaden the base this year to include more users of expansion data but with little success. We were successful, however, in establishing a session on liquids, an area which is receiving more attention as a logical extension to the high-speed thermophysical property measurements on materials at temperatures close to their melting points. The Symposium had good international representation but the overall attendance was, disappointingly, relatively low. Neverthe less, this enhanced the informal atmosphere throughout the meeting with a resultant frank exchange of information and ideas which all attendees appreciated. A totally new item this year was the presentation of a bursary to ...
Nanoscale imaging of RNA with expansion microscopy.
Chen, Fei; Wassie, Asmamaw T; Cote, Allison J; Sinha, Anubhav; Alon, Shahar; Asano, Shoh; Daugharthy, Evan R; Chang, Jae-Byum; Marblestone, Adam; Church, George M; Raj, Arjun; Boyden, Edward S
2016-08-01
The ability to image RNA identity and location with nanoscale precision in intact tissues is of great interest for defining cell types and states in normal and pathological biological settings. Here, we present a strategy for expansion microscopy of RNA. We developed a small-molecule linker that enables RNA to be covalently attached to a swellable polyelectrolyte gel synthesized throughout a biological specimen. Then, postexpansion, fluorescent in situ hybridization (FISH) imaging of RNA can be performed with high yield and specificity as well as single-molecule precision in both cultured cells and intact brain tissue. Expansion FISH (ExFISH) separates RNAs and supports amplification of single-molecule signals (i.e., via hybridization chain reaction) as well as multiplexed RNA FISH readout. ExFISH thus enables super-resolution imaging of RNA structure and location with diffraction-limited microscopes in thick specimens, such as intact brain tissue and other tissues of importance to biology and medicine.
Tests for the Expansion of the Universe
Lopez-Corredoira, Martin
2015-01-01
Almost all cosmologists accept nowadays that the redshift of the galaxies is due to the expansion of the Universe (cosmological redshift), plus some Doppler effect of peculiar motions, but can we be sure of this fact by means of some other independent cosmological test? Here I will review some recent tests: CMBR temperature versus redshift, time dilation, the Hubble diagram, the Tolman or surface brightness test, the angular size test, the UV surface brightness limit and the Alcock--Paczy\\'nski test. Some tests favour expansion and others favour a static Universe. Almost all the cosmological tests are susceptible to the evolution of galaxies and/or other effects. Tolman or angular size tests need to assume very strong evolution of galaxy sizes to fit the data with the standard cosmology, whereas the Alcock--Paczynski test, an evaluation of the ratio of observed angular size to radial/redshift size, is independent of it.
Locally-smeared operator product expansions
Monahan, Christopher; Orginos, Kostantinos
2014-12-01
We propose a "locally-smeared Operator Product Expansion" (sOPE) to decompose non-local operators in terms of a basis of locally-smeared operators. The sOPE formally connects nonperturbative matrix elements of smeared degrees of freedom, determined numerically using the gradient flow, to non-local operators in the continuum. The nonperturbative matrix elements do not suffer from power-divergent mixing on the lattice, provided the smearing scale is kept fixed in the continuum limit. The presence of this smearing scale prevents a simple connection to the standard operator product expansion and therefore requires the construction of a two-scale formalism. We demonstrate the feasibility of our approach using the example of real scalar field theory.
Fock expansion of multimode pure Gaussian states
Cariolaro, Gianfranco; Pierobon, Gianfranco, E-mail: gianfranco.pierobon@unipd.it [Università di Padova, Padova (Italy)
2015-12-15
The Fock expansion of multimode pure Gaussian states is derived starting from their representation as displaced and squeezed multimode vacuum states. The approach is new and appears to be simpler and more general than previous ones starting from the phase-space representation given by the characteristic or Wigner function. Fock expansion is performed in terms of easily evaluable two-variable Hermite–Kampé de Fériet polynomials. A relatively simple and compact expression for the joint statistical distribution of the photon numbers in the different modes is obtained. In particular, this result enables one to give a simple characterization of separable and entangled states, as shown for two-mode and three-mode Gaussian states.
Development of new hole expansion testing method
Kim, Hyunok; Shang, Jianhui; Beam, Kevin; Samant, Anoop; Hoschouer, Cliff; Dykeman, Jim
2016-08-01
This paper introduces a new hole expansion (HE) testing method that could be more relevant to the edge cracking problem observed in stamping advanced high strength steel (AHSS). The new testing method adopted a large hole diameter of 75 mm compared to the standard hole diameter of 10 mm. An inline monitoring system was developed to visually monitor the hole edge cracking during the test and synchronize the load-displacement data with the recorded video for capturing the initial crack. A new hole expansion testing method was found to be effective in evaluating the edge cracking by considering the effects of material properties and trimming methods. It showed a much larger difference, up to 11%, of the HE ratio between DP980 and TRIP780 compared to the standard HE testing method giving less than a 2% difference.
How will oil palm expansion affect biodiversity?
Fitzherbert, E.B.; Struebig, M.J.; Morel, A.; Danielsen, F.; Brühl, C.A.; Donald, P.F.; Phalan, B.
2008-01-01
Metadata only record This article explores the impacts of oil palm expansion on biodiversity and tropical deforestation. Oil palm plantations support substantially less biodiversity than natural forest or even other tree crops. Because regions with favorable conditions for oil palm plantations tend to be areas of critical importance for biodiversity, the rising international demand for vegetable oils and biofuels could prompt further wide-scale tropical deforestation and large losses of bi...
Method of assembling a thermal expansion compensator
Determan, William (Inventor); Matejczyk, Daniel Edward (Inventor)
2012-01-01
A thermal expansion compensator is provided and includes a first electrode structure having a first surface, a second electrode structure having a second surface facing the first surface and an elastic element bonded to the first and second surfaces and including a conductive element by which the first and second electrode structures electrically and/or thermally communicate, the conductive element having a length that is not substantially longer than a distance between the first and second surfaces.
Spontaneous thermal expansion of nematic elastomers
Tajbakhsh, A. R.; Terentjev, E.M.
2001-01-01
We study the monodomain (single-crystal) nematic elastomer materials, all side-chain siloxane polymers with the same mesogenic groups and crosslinking density, but differing in the type of crosslinking. Increasing the proportion of long di-functional segments of main-chain nematic polymer, acting as network crosslinking, results in dramatic changes in the uniaxial equilibrium thermal expansion on cooling from isotropic phase. At higher concentration of main chains their behaviour dominates th...
An Anatomy Of The Export Expansion Process
Reid, S
1986-01-01
This paper examines the export market strategies and export modes used by small and medium sized Italian manufacturing firms. The firms vary extensively in their extent and type of export dependence on different channel arrangements and export markets. Moreover, the exporting modes used do show some peculiar links with export objectives specifically higher dependence on direct sales is associated with planned export expansion and higher dependence on agent/representatives and distributors is ...
Expansion-free Cylindrically Symmetric Models
Sharif, M
2013-01-01
This paper investigates cylindrically symmetric distribution of an-isotropic fluid under the expansion-free condition, which requires the existence of vacuum cavity within the fluid distribution. We have discussed two family of solutions which further provide two exact models in each family. Some of these solutions satisfy Darmois junction condition while some show the presence of thin shell on both boundary surfaces. We also formulate a relation between the Weyl tensor and energy density.
The Lorentz anomaly via operator product expansion
Fredenhagen, Stefan, E-mail: stefan.fredenhagen@aei.mpg.de [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut Am Mühlenberg 1, 14476 Golm (Germany); Hoppe, Jens, E-mail: hoppe@kth.se; Hynek, Mariusz, E-mail: mkhynek@kth.se [Department of Mathematics, Royal Institute of Technology, KTH 100 44 Stockholm (Sweden)
2015-10-15
The emergence of a critical dimension is one of the most striking features of string theory. One way to obtain it is by demanding closure of the Lorentz algebra in the light-cone gauge quantisation, as discovered for bosonic strings more than forty years ago. We give a detailed derivation of this classical result based on the operator product expansion on the Lorentzian world-sheet.
Eigenvalues and expansion of bipartite graphs
Høholdt, Tom; Janwa, Heeralal
2012-01-01
We prove lower bounds on the largest and second largest eigenvalue of the adjacency matrix of bipartite graphs and give necessary and sufficient conditions for equality. We give several examples of classes that are optimal with respect to the bouns. We prove that BIBD-graphs are characterized by ...... by their eigenvalues. Finally we present a new bound on the expansion coefficient of (c,d)-regular bipartite graphs and compare that with aclassical bound....
Ising Expansion for the Hubbard Model
Shi, Zhu-Pei; Singh, Rajiv R. P.
1995-01-01
We develop series expansions for the ground state properties of the Hubbard model, by introducing an Ising anisotropy into the Hamiltonian. For the two-dimensional (2D) square lattice half-filled Hubbard model, the ground state energy, local moment, sublattice magnetization, uniform magnetic susceptibility and spin stiffness are calculated as a function of $U/t$, where $U$ is the Coulomb constant and $t$ is the hopping parameter. Magnetic susceptibility data indicate a crossover around $U\\app...
Operator product expansion at finite temperature
Mallik, S.
1997-01-01
We extend an earlier, configuration space method to find the Wilson coefficients of operators appearing in the short distance expansion of thermal correlation functions of different quark bilinears. Considering all the different correlation functions, there arise, up to dimension four, two new operators, in addition to the two appearing already in the vacuum correlation functions. They would contribute substantially to the QCD sum rules, when the temperature is not too low.
Low-Thermal-Expansion Filled Polytetrafluoroethylene
Shapiro, Sanford S.
1989-01-01
PTFE made thermally compatible with aluminum without changing dielectric constant. Manufactured with fillers and pores to reduce coefficient of thermal expansion by factor of 6 to match aluminum. Material retains 2.1 dielectric constant of pure PTFE. Combines filler and micropore concepts. Particles and voids embedded in PTFE matrix function cooperatively. Particles take up compressive stress imposed by contracting PTFE, and voids take up expanding material. Increases dielectric constant, while voids reduce it.
Gaussian expansion approach to Coulomb breakup
Egami, T; Matsumoto, T; Iseri, Y; Kamimura, M; Yahiro, M
2004-01-01
An accurate treatment of Coulomb breakup reactions is presented by using both the Gaussian expansion method and the method of continuum discretized coupled channels. As $L^2$-type basis functions for describing Coulomb breakup processes, we take complex-range Gaussian functions, which form in good approximation a complete set in a large configuration space being important for the processes. Accuracy of the method is tested quantitatively for $^{8}{\\rm B}+^{58}$Ni scattering at 25.8 MeV.
Spatial Linkage and Urban Expansion: AN Urban Agglomeration View
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.
Forecasting Urban Expansion Based on Night Lights
Stathakis, D.
2016-06-01
Forecasting urban expansion models are a very powerful tool in the hands of urban planners in order to anticipate and mitigate future urbanization pressures. In this paper, a linear regression forecasting urban expansion model is implemented based on the annual composite night lights time series available from National Oceanic and Atmospheric Administration (NOAA). The product known as 'stable lights' is used in particular, after it has been corrected with a standard intercalibration process to reduce artificial year-to-year fluctuations as much as possible. Forecasting is done for ten years after the end of the time series. Because the method is spatially explicit the predicted expansion trends are relatively accurately mapped. Two metrics are used to validate the process. The first one is the year-to-year Sum of Lights (SoL) variation. The second is the year-to-year image correlation coefficient. Overall it is evident that the method is able to provide an insight on future urbanization pressures in order to be taken into account in planning. The trends are quantified in a clear spatial manner.
Frequency dependent thermal expansion in binary viscoelasticcomposites
Berryman, James G.
2007-12-01
The effective thermal expansion coefficient beta* of abinary viscoelastic composite is shown to be frequency dependent even ifthe thermal expansion coefficients beta A and beta B of both constituentsare themselves frequency independent. Exact calculations for binaryviscoelastic systems show that beta* is related to constituent valuesbeta A, beta B, volume fractions, and bulk moduli KA, KB, as well as tothe overall bulk modulus K* of the composite system. Then, beta* isdetermined for isotropic systems by first bounding (or measuring) K* andtherefore beta*. For anisotropic systems with hexagonal symmetry, theprincipal values of the thermal expansion beta*perp and beta*para can bedetermined exactly when the constituents form a layered system. In allthe examples studied, it is shown explicitly that the eigenvectors of thethermoviscoelastic system possess non-negative dissipation -- despite thecomplicated analytical behavior of the frequency dependent thermalexpansivities themselves. Methods presented have a variety ofapplications from fluid-fluid mixtures to fluid-solid suspensions, andfrom fluid-saturated porous media to viscoelastic solid-solidcomposites.
Anisotropic matching principle for the hydrodynamic expansion
Tinti, Leonardo
2016-10-01
Following the recent success of anisotropic hydrodynamics, I propose here a new, general prescription for the hydrodynamic expansion around an anisotropic background. The anisotropic distribution fixes exactly the complete energy-momentum tensor, just like the effective temperature fixes the proper energy density in the ordinary expansion around local equilibrium. This means that momentum anisotropies are already included at the leading order, allowing for large pressure anisotropies without the need of a next-to-leading-order treatment. The first moment of the Boltzmann equation (local four-momentum conservation) provides the time evolution of the proper energy density and the four-velocity. Differently from previous prescriptions, the dynamic equations for the pressure corrections are not derived from the zeroth or second moment of the Boltzmann equation, but they are taken directly from the exact evolution given by the Boltzmann equation. As known in the literature, the exact evolution of the pressure corrections involves higher moments of the Boltzmann distribution, which cannot be fixed by the anisotropic distribution alone. Neglecting the next-to-leading-order contributions corresponds to an approximation, which depends on the chosen form of the anisotropic distribution. I check the the effectiveness of the leading-order expansion around the generalized Romatschke-Stricklad distribution, comparing with the exact solution of the Boltzmann equation in the Bjorken limit with the collisional kernel treated in the relaxation-time approximation, finding an unprecedented agreement.
Foundations on Expansive Soils; A Review
Behzad Kalantari
2012-09-01
Full Text Available 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 damages to pavements as well as buildings. Every year millions of dollars spent dealing with the consequences of swelling soils. For design of foundations on swelling soil, it is first essential to recognize and evaluate the soil based on its swelling potential, and then determining the most proper foundation design that can be constructed on this problematic soil. In general, this study presents some of the most common techniques to evaluate the swelling potential of expansive soils. Also, it discusses problems associated with swelling soil, classification of structural damages caused to buildings, and various foundation designs to combat the problems based on the degree of detrimental effects of swelling potential to civil engineering projects.
Expansion Compression Contacts for Thermoelectric Legs
Sakamoto, Jeffrey
2009-01-01
In a proposed alternative to previous approaches to making hot-shoe contacts to the legs of thermoelectric devices, one relies on differential thermal expansion to increase contact pressures for the purpose of reducing the electrical resistances of contacts as temperatures increase. The proposed approach is particularly applicable to thermoelectric devices containing p-type (positive-charge-carrier) legs made of a Zintl compound (specifically, Yb14MnSb11) and n-type (negative charge-carrier) legs made of SiGe. This combination of thermoelectric materials has been selected for further development, primarily on the basis of projected thermoelectric performance. However, it is problematic to integrate, into a practical thermoelectric device, legs made of these materials along with a metal or semiconductor hot shoe that is required to be in thermal and electrical contact with the legs. This is partly because of the thermal-expansion mismatch of these materials: The coefficient of thermal expansion (CTE) of SiGe is 4.5 x 10(exp -6) C (exp -1), while the CTE of Yb14MnSb11 is 20 x 10(exp -6) C(exp -1). Simply joining a Yb14MnSb11 and a SiGe leg to a common hot shoe could be expected to result in significant thermal stresses in either or both legs during operation. Heretofore, such thermal stresses have been regarded as disadvantageous. In the proposed approach, stresses resulting from the CTE mismatch would be turned to advantage.
Monique Selim
2006-07-01
Full Text Available Con eje en los diferentes aspectos que adopta el actual proceso de mundialización de la lógica del mercado y expansión capitalista, aún en países socialistas, el presente artículo plantea la necesidad de una reflexión antropológica susceptible de articular el surgimiento de nuevas formas de dominación y representación simbólicas. Se discute el aparente efecto de unificación intelectual producido por la hegemonía del mercado respecto de hechos sociales heterogéneos dados en la historia reciente de las sociedades contemporáneas. Así, la renovada atracción que ejercen los nuevos escenarios sociales reconfigurados en virtud de las modalidades específicas de encarnación y operación de los procesos globalizantes, llama al estudio antropológico de las coyunturas. La autora despliega una interpretación del socialismo de mercado, conjunción -siempre en tensión- de un monopolio político estatal y una liberalización del mercado económico. En esta perspectiva se reubica el interés de una antropología del presente en relevar localmente, en este caso en Vietnam del Norte, la conformación de un nuevo mercado de demandas simbólicas, donde la reaparición de las prácticas culturales de comunicación con los antepasados expresa la necesidad de reunificación familiar y reconciliación con los muertos en la "larga guerra".Tendo como eixo os aspectos diferentes que adota o processo atual de mundialização da lógica do mercado e de expansão capitalista, até mesmo nos países socialistas, este artigo propoe a necessidade de uma reflexão antropológica capaz de articular o aparecimento de novas formas de dominação e de representação simbólica. Discute-se o efeito de superfície de unificação intelectual causado pela hegemonia do mercado em fatos sociais diversos em sociedades contemporâneas. Assim, a atração renovada de novos fatos sociais pelos modos específicos de incorporação e operação de processos de globaliza
Expansion/De-expansion Tool to Quantify the Accuracy of Prostate Contours
Chung, Eugene; Stenmark, Matthew H. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Evans, Cheryl [Department of Radiation Oncology, Providence Cancer Center, Novi, MI (United States); Narayana, Vrinda [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Department of Radiation Oncology, Providence Cancer Center, Novi, MI (United States); McLaughlin, Patrick W., E-mail: mclaughb@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Department of Radiation Oncology, Providence Cancer Center, Novi, MI (United States)
2012-05-01
Purpose: Accurate delineation of the prostate gland on computed tomography (CT) remains a persistent challenge and continues to introduce geometric uncertainty into the planning and delivery of external beam radiotherapy. We, therefore, developed an expansion/de-expansion tool to quantify the contour errors and determine the location of the deviations. Methods and Materials: A planning CT scan and magnetic resonance imaging scan were prospectively acquired for 10 patients with prostate cancer. The prostate glands were contoured by 3 independent observers using the CT data sets with instructions to contour the prostate without underestimation but to minimize overestimation. The standard prostate for each patient was defined using magnetic resonance imaging and CT on multiple planes. After registration of the CT and magnetic resonance imaging data sets, the CT-defined prostates were scored for accuracy. The contours were defined as ideal if they were within a 2.5-mm expansion of the standard without underestimation, acceptable if they were within a 5.0-mm expansion and a 2.5-mm de-expansion, and unacceptable if they extended >5.0 mm or underestimated the prostate by >2.5 mm. Results: A total of 636 CT slices were individually analyzed, with the vast majority scored as ideal or acceptable. However, none of the 30 prostate contour sets had all the contours scored as ideal or acceptable. For all 3 observers, the unacceptable contours were more likely from underestimation than overestimation of the prostate. The errors were more common at the base and apex than the mid-gland. Conclusions: The expansion/de-expansion tool allows for directed feedback on the location of contour deviations, as well as the determination of over- or underestimation of the prostate. This metric might help improve the accuracy of prostate contours.
Lessons from Early Medicaid Expansions Under Health Reform..
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...
Asymptotic expansion of the wavelet transform with error term
Pathak, R.S.; Pathak, Ashish
2014-01-01
UsingWong's technique asymptotic expansion for the wavelet transform is derived and thereby asymptotic expansions for Morlet wavelet transform, Mexican Hat wavelet transform and Haar wavelet transform are obtained.
A new low-expansion nonflammable printed circuit board
Kennedy, B. W.
1970-01-01
Printed circuit board has a thermal coefficient of expansion similar to that of the electronic component leads. High-expansion composite materials are sandwiched between the outer layers of copper and woven fiber glass.
A Revisit of Query Expansion with Different Semantic Levels
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...
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 < .001) in favor of BB rather than TB 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.
Edgeworth expansion for functionals of continuous diffusion processes
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....
Edgeworth expansion for functionals of continuous diffusion processes
Podolskij, Mark; Yoshida, Nakahiro
2016-01-01
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 second order Edgeworth expansion for power variation of diffus...... 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....
Consideraciones alrededor del Libro del Almismo, el Libro del Pensar.
MartaLucía Tamayo Fernandez
1999-01-01
La doctora MarthaLucía Tamayo comparte muchas inquietudes alrededor del Libro del Almismo, el Libro del Pensar; de dónde salió ese nombre; de juntar en medicina y en genética a tres escritores como lo son Jorge Luis Borges, Macedonio Fernández y Julio Cortázar. Su conferencia dice así:
El término almismo fue ideado por Macedonio Fernández porque defendía mucho el ensimismamiento y el pensamiento hacia el interior, mirar hacia adentro; cada uno somos un “sí mismo” qu...
Multiplier theorems for special Hermite expansions on Cn
无
2000-01-01
The weak type (1,1) estimate for special Hermite expansions on Cn is proved by using the Calderón-Zygmund decomposition. Then the multiplier theorem in Lp(1
expansions in twisted Hardy space are also considered. As an application, the multipliers for a certain kind of Laguerre expansions are given in Lp space.
12 CFR 34.84 - Future bank expansion.
2010-01-01
... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Future bank expansion. 34.84 Section 34.84... APPRAISALS Other Real Estate Owned § 34.84 Future bank expansion. A national bank normally should use real estate acquired for future bank expansion within five years. After holding such real estate for one...
49 CFR 178.255-3 - Expansion domes.
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false Expansion domes. 178.255-3 Section 178.255-3 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Specifications for Portable Tanks § 178.255-3 Expansion domes. (a) Expansion domes, if applied, must have...
Electrical Resistance Alloys and Low-Expansion Alloys
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...
46 CFR 154.432 - Expansion and contraction.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Expansion and contraction. 154.432 Section 154.432... Membrane Tanks § 154.432 Expansion and contraction. The support system of a membrane tank must allow for thermal and physical expansion and contraction of the tank. Semi-Membrane Tanks...
On the convergence of cluster expansions for polymer gases
Fernandez, R.; Bissacot, R.; Procacci, A.
2010-01-01
We compare the different convergence criteria available for cluster expansions of polymer gases subjected to hard-core exclusions, with emphasis on polymers defined as finite subsets of a countable set (e.g. contour expansions and more generally high- and lowtemperature expansions). In order of incr
14 CFR 23.969 - Fuel tank expansion space.
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...
El moho forma parte del medio ambiente natural. Afuera del hogar, el moho juega un papel en la naturaleza al desintegrar materias organicas tales como las hojas que se han caido o los arboles muertos. El moho puede crecer adentro del hogar cuando las espor
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.
Private randomness expansion with untrusted devices
Colbeck, Roger; Kent, Adrian, E-mail: rcolbeck@perimeterinstitute.ca, E-mail: a.p.a.kent@damtp.cam.ac.uk [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5 (Canada)
2011-03-04
Randomness is an important resource for many applications, from gambling to secure communication. However, guaranteeing that the output from a candidate random source could not have been predicted by an outside party is a challenging task, and many supposedly random sources used today provide no such guarantee. Quantum solutions to this problem exist, for example a device which internally sends a photon through a beamsplitter and observes on which side it emerges, but, presently, such solutions require the user to trust the internal workings of the device. Here, we seek to go beyond this limitation by asking whether randomness can be generated using untrusted devices-even ones created by an adversarial agent-while providing a guarantee that no outside party (including the agent) can predict it. Since this is easily seen to be impossible unless the user has an initially private random string, the task we investigate here is private randomness expansion. We introduce a protocol for private randomness expansion with untrusted devices which is designed to take as input an initially private random string and produce as output a longer private random string. We point out that private randomness expansion protocols are generally vulnerable to attacks that can render the initial string partially insecure, even though that string is used only inside a secure laboratory; our protocol is designed to remove this previously unconsidered vulnerability by privacy amplification. We also discuss extensions of our protocol designed to generate an arbitrarily long random string from a finite initially private random string. The security of these protocols against the most general attacks is left as an open question.
Inequality and megaprojects: The Panama Canal expansion
2006-01-01
Cuando el control y gestión del Canal de Panamá pasó al estado panameño a finales de 1999, el gobierno comenzó a preparar un plan para su modernización. Este plan incluía la construcción de nuevas esclusas para que pudieran atravesarlo un mayor número de barcos y que admitiese los nuevos buques Post-Panamax de gran tamaño. El proyecto de Ampliación del Canal se ha seleccionado como ejemplo paradigmático de grandes Obras Públicas (GOP) por su impacto ambiental, económico y social. Este caso de...
Further analysis of the connected moments expansion
Amore, Paolo; Rodriguez, Martin [Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima, Colima (Mexico); Fernandez, Francisco M, E-mail: paolo.amore@gmail.com, E-mail: fernande@quimica.unlp.edu.ar, E-mail: martinalexander.rv@gmail.com [INIFTA (UNLP, CCT La Plata-CONICET), Division Quimica Teorica, Blvd. 113 S/N, Sucursal 4, Casilla de Correo 16, 1900 La Plata (Argentina)
2011-12-16
By means of simple quantum-mechanical models we show that under certain conditions the main assumptions of the connected moments expansion (CMX) are no longer valid. In particular, we consider two-level systems: the harmonic oscillator and the pure quartic oscillator. Although derived from such simple models, we think that the results of this investigation may be of utility in future applications of the approach to realistic problems. We show that a straightforward analysis of the CMX exponential parameters may provide a clear indication of the success of the approach. (paper)
Cosmic expansion from boson and fermion fields
De Souza, Rudinei C; Kremer, Gilberto M, E-mail: rudijantsch@gmail.com, E-mail: kremer@fisica.ufpr.br [Departamento de Fisica, Universidade Federal do Parana, Curitiba (Brazil)
2011-06-21
This paper consists in analyzing an action that describes boson and fermion fields minimally coupled to the gravity and a common matter field. The self-interaction potentials of the fields are not chosen a priori but from the Noether symmetry approach. The Noether forms of the potentials allow the boson field to play the role of dark energy and matter and the fermion field to behave as standard matter. The constant of motion and the cyclic variable associated with the Noether symmetry allow the complete integration of the field equations, whose solution produces a universe with alternated periods of accelerated and decelerated expansion.
Cosmic expansion from boson and fermion fields
de Souza, Rudinei C
2011-01-01
This paper consists in analyzing an action that describes boson and fermion fields minimally coupled to the gravity and a common matter field. The self-interaction potentials of the fields are not chosen a priori but from the Noether symmetry approach. The Noether forms of the potentials allow the boson field to play the role of dark energy and matter and the fermion field to behave as standard matter. The constant of motion and the cyclic variable associated with the Noether symmetry allow the complete integration of the field equations, whose solution produces a Universe with alternated periods of accelerated and decelerated expansion.
Capacity Expansion Modeling for Storage Technologies
Hale, Elaine; Stoll, Brady; Mai, Trieu
2017-04-03
The Resource Planning Model (RPM) is a capacity expansion model designed for regional power systems and high levels of renewable generation. Recent extensions capture value-stacking for storage technologies, including batteries and concentrating solar power with storage. After estimating per-unit capacity value and curtailment reduction potential, RPM co-optimizes investment decisions and reduced-form dispatch, accounting for planning reserves; energy value, including arbitrage and curtailment reduction; and three types of operating reserves. Multiple technology cost scenarios are analyzed to determine level of deployment in the Western Interconnection under various conditions.
Kato expansion in quantum canonical perturbation theory
Nikolaev, A S
2015-01-01
This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. The corresponding computational algorithm is more efficient for high perturbative orders than the algorithms of Van Vleck and Magnus methods.
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...
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...
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...
Condensate Accretion in Shock Tube's Expansion Fan
Mezonlin, Ephrem-Denis; DeSilva, Upul P.; Hunte, F.; Johnson, Joseph A., III
1997-01-01
It has been shown that turbulence and temperature influence the droplet sizes in expansion fan induced condensation by studying the Rayleigh scattering from one port in our shock tube's test section. We have modified our set-up so as to allow, using two ports, the real time measurement of the influence of turbulence and temperature on the rate at which these droplets grow. To do this, we looked at the Rayleigh scattering from two different ports for ten Reynolds numbers at five different temperatures. We modeled the time of flight of droplets, using the equations of one-dimensional gas dynamics and the measured shock wave speed in shock tube's driven section.
Huadong sintering model about expansion and shrinkage
无
2001-01-01
The whole sintering course from the beginning of heating to the end of heat preservation stage was studied by taking into account the influence of pressing. It was found that there exist expanding mechanism and shrinking mechanism in the sintering process, and the expanding mechanism is always acting before the shrinking mechanism. Whether the sintering body shrinks or expands depends on the interaction between the two mechanisms. And according to this, the Huadong sintering model in account of expansion and shrinkage mechanism was given.
Kato expansion in quantum canonical perturbation theory
Nikolaev, Andrey
2016-06-01
This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson's ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders.
Metalloprotein design using genetic code expansion.
Hu, Cheng; Chan, Sunney I; Sawyer, Elizabeth B; Yu, Yang; Wang, Jiangyun
2014-09-21
More than one third of all proteins are metalloproteins. They catalyze important reactions such as photosynthesis, nitrogen fixation and CO2 reduction. Metalloproteins such as the olfactory receptors also serve as highly elaborate sensors. Here we review recent developments in functional metalloprotein design using the genetic code expansion approach. We show that, through the site-specific incorporation of metal-chelating unnatural amino acids (UAAs), proton and electron transfer mediators, and UAAs bearing bioorthogonal reaction groups, small soluble proteins can recapitulate and expand the important functions of complex metalloproteins. Further developments along this route may result in cell factories and live-cell sensors with unprecedented efficiency and selectivity.
Multiparameter eigenvalue problems and expansion theorems
Volkmer, Hans
1988-01-01
This book provides a self-contained treatment of two of the main problems of multiparameter spectral theory: the existence of eigenvalues and the expansion in series of eigenfunctions. The results are first obtained in abstract Hilbert spaces and then applied to integral operators and differential operators. Special attention is paid to various definiteness conditions which can be imposed on multiparameter eigenvalue problems. The reader is not assumed to be familiar with multiparameter spectral theory but should have some knowledge of functional analysis, in particular of Brower's degree of maps.
Fast algorithms for spherical harmonic expansions, III
Tygert, Mark
2009-01-01
We accelerate the computation of spherical harmonic transforms, using what is known as the butterfly scheme. This provides a convenient alternative to the approach taken in the second paper from this series on "Fast algorithms for spherical harmonic expansions." The requisite precomputations become manageable when organized as a "depth-first traversal" of the program's control-flow graph, rather than as the perhaps more natural "breadth-first traversal" that processes one-by-one each level of the multilevel procedure. We illustrate the results via several numerical examples.
Expansion of Metallic Cylinders under Explosive Loading
M.S. Bola
1992-07-01
Full Text Available The behaviour of expanding metallic cylinders under explosive loading was studied. Using ultra high speed photography, the expansion characteristics of aluminium and copper metallic cylinders have been evaluated with different c/m ratio, and by changing the nature of high explosive. The results obtained are comparable to those predicted by the Gurney's energy and momentum balance equations. A cylinder test has been established for comparative to the metal by octol, TNT, PEK-1, baratol and composition B are calculated. The results are in close agreement with those calculated by Kury et al.
Singular asymptotic expansions in nonlinear rotordynamics
Day, W. B.
1985-01-01
During hot firing ground testing of the Space shuttle's Main Engine, vibrations of the liquid oxygen pump occur at frequencies which cannot be explained by the linear Jeffcott model of the rotor. The model becomes nonlinear after accounting for deadband, side forces, and rubbing. Two phenomena present in the numerical solutions of the differential equations are unexpected periodic orbits of the rotor and tracking of the nonlinear frequency. A multiple scale asymptotic expansion of the differential equations is used to give an analytic explanation of these characteristics.
Local spinfoam expansion in loop quantum cosmology
Henderson, Adam; Vidotto, Francesca; Wilson-Ewing, Edward
2010-01-01
The quantum dynamics of the flat Friedmann-Lemaitre-Robertson-Walker and Bianchi I models defined by loop quantum cosmology have recently been translated into a spinfoam-like formalism. The construction is facilitated by the presence of a massless scalar field which is used as an internal clock. The implicit integration over the matter variable leads to a nonlocal spinfoam amplitude. In this paper we consider a vacuum Bianchi I universe and show that by choosing an appropriate regulator a spinfoam expansion can be obtained without selecting a clock variable and that the resulting spinfoam amplitude is local.
Resonant-state expansion Born Approximation
Doost, M B
2015-01-01
The Born Approximation is a fundamental formula in Physics, it allows the calculation of weak scattering via the Fourier transform of the scattering potential. I extend the Born Approximation by including in the formula the Fourier transform of a truncated basis of the infinite number of appropriately normalised resonant states. This extension of the Born Approximation is named the Resonant-State Expansion Born Approximation or RSE Born Approximation. The resonant-states of the system can be calculated using the recently discovered RSE perturbation theory for electrodynamics and normalised correctly to appear in spectral Green's functions via the flux volume normalisation.
Maxillary protraction after surgically assisted maxillary expansion
Laurindo Zanco Furquim
2010-06-01
Full Text Available This case report describes the orthodontic treatment of a 32-year-old woman with a Class III malocclusion, whose chief compliant was her dentofacial esthetics. The pretreatment lateral cephalometric tracings showed the presence of a Class III dentoskeletal malocclusion with components of maxillary deficiency. After discussion with the patient, the treatment option included surgically assisted rapid maxillary expansion (SARME followed by orthopedic protraction (Sky Hook and Class III elastics. Patient compliance was excellent and satisfactory dentofacial esthetics was achieved after treatment completion.
Del territorio del sujeto al emplazamiento del Común
Mariano Adrían Ferretti
2016-01-01
Full Text Available La construcción de lo público abarca una variedad de dinámicas que condicionan el resultado físico de los espacios donde actúan los individuos en sus necesidades de habitar, modificando su realidad desde la diferenciación y la singularización subjetiva del entorno que derivan en nuevas formas de territorialidad de lo público a partir de la dialéctica entre lo público y lo privado. Sin embargo, los resultados de tales representaciones entendidas como acciones colectivas –y por tanto comunes- no siempre explican los valores que desde lo simbólico partiendo del sujeto constituyan un estatus diferente de lo público en los procesos de territorialización. Se propone una aproximación que aborde de manera teórica cuestiones tales como: los vínculos del individuo con los procesos de acumulación material y transformación del territorio y las implicaciones que dichos fenómenos tienen en la posibilidad de constitución de un sujeto que trascendiendo al individuo sea capaz de conformar un nuevo estatus del sujeto o, dicho de otro modo, un emplazamiento del Común.
Anisotropic expansion of a thermal dipolar Bose gas
Tang, Yijun; Burdick, Nathaniel Q; DiSciacca, Jack M; Petrov, Dmitry S; Lev, Benjamin L
2016-01-01
We report on the anisotropic expansion of ultracold bosonic dysprosium gases at temperatures above quantum degeneracy and develop a quantitative theory to describe this behavior. The theory expresses the post-expansion aspect ratio in terms of temperature and microscopic collisional properties by incorporating Hartree-Fock mean-field interactions, hydrodynamic effects, and Bose-enhancement factors. Our results extend the utility of expansion imaging by providing accurate thermometry for dipolar thermal Bose gases, reducing error in expansion thermometry from tens of percent to only a few percent. Furthermore, we present a simple method to determine scattering lengths in dipolar gases, including near a Feshbach resonance, through observation of thermal gas expansion.
Castaño Valencia, Óscar
2006-01-01
En 1990 el Doctor Charles de Lisi presentó el proyecto del GENOMA HUMANO en asocio del Instituto de Salud Americano, el Instituto Whithead de Cambridge, la Universidad de Washingtong, el Colegio Médico de Baylor y el Instituto del Genoma Humano, de California.Estos organismos han venido actuando desde esa época, contando con la financiación de los gobiernos del Japón, Alemania, Francia, China y naturalmente del americano.En sus fases iniciales fue orientado por el Dr. James Watson quien contó...
2000-01-01
Pieza central del antiguo régimen; pacto, acuerdo o trato con algunos actores decisivos del sistema político susceptible de ser revisado; forma cultural de relaciones de poder o de intercambio; pirámide de organizaciones o estructura sectorial: ¿qué tan invisible sigue siendo, qué tan montada sigue estando la pirámide del corporativismo mexicano antes y después del 2 de julio de 2000? Este fenómeno constituye el eje central de las reflexiones del presente ensayo. En torno al mismo, se pres...
Kaon Thresholds and Two-Flavor Chiral Expansions for Hyperons
Fu-Jiun Jiang, Brian C. Tiburzi, Andre Walker-Loud
2011-01-01
Two-flavor chiral expansions provide a useful perturbative framework to study hadron properties. Such expansions should exhibit marked improvement over the conventional three-flavor chiral expansion. Although one can theoretically formulate two-flavor theories for the various hyperon multiplets, the nearness of kaon thresholds can seriously undermine the effectiveness of the perturbative expansion in practice. We investigate the importance of virtual kaon thresholds on hyperon properties, specifically their masses and isovector axial charges. Using a three-flavor expansion that includes SU(3) breaking effects, we uncover the underlying expansion parameter governing the description of virtual kaon thresholds. For spin-half hyperons, this expansion parameter is quite small. Consequently virtual kaon contributions are well described in the two-flavor theory by terms analytic in the pion mass-squared. For spin three-half hyperons, however, one is closer to the kaon production threshold, and the expansion parameter is not as small. Breakdown of SU(2) chiral perturbation theory is shown to arise from a pole in the expansion parameter associated with the kaon threshold. Estimating higher-order corrections to the expansion parameter is necessary to ascertain whether the two-flavor theory of spin three-half hyperons remains perturbative. We find that, despite higher-order corrections, there is a useful perturbative expansion for the masses and isovector axial charges of both spin-half and spin three-half hyperons.
Estimation of thermal expansion properties of quasicrystalline alloys
齐育红; 张占平; 黑祖昆
2004-01-01
By investigating the thermal expansion properties of three quasicrystalline alloys Al65 Cu20 Cr15 quenched,Al65Cu20Cr15 cast and Al65Cu20Fe15 cast particles reinforced Al matrix composites from 25 ℃ to 500 ℃, the thermal expansion coefficients of three quasicrystalline alloys were theoretically estimated. The results show that the thermal expansion coefficients of the composites are much lower than that of pure Al, and the thermal expansion coefficients of the composites reinforced by Al-Cu-Cr quasicrystalline particles are lower than those of the composites reinforced by Al-Cu-Fe quasicrystalline particles. According to estimating, quasicrystalline alloys have negative thermal expansion coefficients, and the thermal expansion coefficients of Al-Cu-Cr quasicrystalline alloys are lower than those of Al-Cu-Fe quasicrystalline alloys. In the alloys, the more the qusicrystalline content, the lower the thermal expansion coefficient.
Tensor integrand reduction via Laurent expansion
Hirschi, Valentin
2016-01-01
We introduce a new method for the application of one-loop integrand reduction via the Laurent expansion algorithm, as implemented in the public C++ library Ninja. We show how the coefficients of the Laurent expansion can be computed by suitable contractions of the loop numerator tensor with cut-dependent projectors, making it possible to interface Ninja to any one-loop matrix element generator that can provide the components of this tensor. We implemented this technique in the Ninja library and interfaced it to MadLoop, which is part of the public MadGraph5_aMC@NLO framework. We performed a detailed performance study, comparing against other public reduction tools, namely CutTools, Samurai, IREGI, PJFry++ and Golem. We find that Ninja outperforms traditional integrand reduction in both speed and numerical stability, the latter being on par with that of the tensor integral reduction tool Golem which is however more limited and slower than Ninja. We considered many benchmark multi-scale processes of increasing ...
Renormalized Wick expansion for a modified PQCD
de Oca, Alejandro Cabo Montes
2007-01-01
The renormalization scheme for the Wick expansion of a modified version of the perturbative QCD introduced in previous works is discussed. Massless QCD is considered, by implementing the usual multiplicative scaling of the gluon and quark wave functions and vertices. However, also massive quark and gluon counter-terms are allowed in this mass less theory since the condensates are expected to generate masses. A natural set of expansion parameters of the physical quantities is introduced: the coupling itself and to masses $m_q$ and $m_g$ associated to quarks and gluons respectively. This procedure allows to implement a dimensional transmutation effect through these new mass scales. A general expression for the new generating functional in terms of the mass parameters $m_q$ and $m_g$ is obtained in terms of integrals over arbitrary but constant gluon or quark fields in each case. Further, the one loop potential, is evaluated in more detail in the case when only the quark condensate is retained. This lowest order...
Renormalized Wick expansion for a modified PQCD
Cabo Montes de Oca, Alejandro [Instituto de Cibernetica, Matematica y Fisica, Group of Theoretical Physics, Vedado, La Habana (Cuba); Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)
2008-05-15
The renormalization scheme for the Wick expansion of a modified version of the perturbative QCD introduced in previous works is discussed. Massless QCD is considered by implementing the usual multiplicative scaling of the gluon and quark wave functions and vertices. However, also massive quark and gluon counterterms are allowed in this massless theory since the condensates are expected to generate masses. A natural set of expansion parameters of the physical quantities is introduced: the coupling itself and the two masses m{sub q} and m{sub g} associated to quarks and gluons, respectively. This procedure allows one to implement a dimensional transmutation effect through these new mass scales. A general expression for the new generating functional in terms of the mass parameters m{sub q} and m{sub g} is obtained in terms of integrals over arbitrary but constant gluon or quark fields in each case. Further, the one loop potential is evaluated in more detail in the case when only the quark condensate is retained. This lowest order result again indicates the dynamical generation of quark condensates in the vacuum. (orig.)
Solving Operator Equation Based on Expansion Approach
A. Aminataei
2014-01-01
Full Text Available To date, researchers usually use spectral and pseudospectral methods for only numerical approximation of ordinary and partial differential equations and also based on polynomial basis. But the principal importance of this paper is to develop the expansion approach based on general basis functions (in particular case polynomial basis for solving general operator equations, wherein the particular cases of our development are integral equations, ordinary differential equations, difference equations, partial differential equations, and fractional differential equations. In other words, this paper presents the expansion approach for solving general operator equations in the form Lu+Nu=g(x,x∈Γ, with respect to boundary condition Bu=λ, where L, N and B are linear, nonlinear, and boundary operators, respectively, related to a suitable Hilbert space, Γ is the domain of approximation, λ is an arbitrary constant, and g(x∈L2(Γ is an arbitrary function. Also the other importance of this paper is to introduce the general version of pseudospectral method based on general interpolation problem. Finally some experiments show the accuracy of our development and the error analysis is presented in L2(Γ norm.
Analytical models of volcanic ellipsoidal expansion sources
Antonella Amoruso
2013-11-01
Full Text Available Modeling non-double-couple earthquakes and surficial deformation in volcanic and geothermal areas usually involves expansion sources. Given an ensemble of ellipsoidal or tensile expansion sources and double-couple ones, it is straightforward to obtain the equivalent single moment tensor under the far-field approximation. On the contrary, the moment tensor interpretation is by no means unique or unambiguous. If the far-field approximation is unsatisfied, the single moment tensor representation is inappropriate. Here we focus on the volume change estimate in the case of single sources, in particular finite pressurized ellipsoidal sources, presenting the expressions for the computation of the volume change and surficial displacement in a closed analytical form. We discuss the implications of different domains of the moment-tensor eigenvalue ratios in terms of volume change computation. We also discuss how the volume change of each source can be obtained from the isotropic component of the total moment tensor, in few cases of coupled sources where the total volume change is null. The new expressions for the computation of the volume change and surficial displacement in case of finite pressurized ellipsoidal sources should make their use easier with respect to the already published formulations.
Contradictions of TNCs’ Foreign Economic Expansion
Melnikov Aleksandr Borisovich
2014-11-01
Full Text Available Some directions of the external economic expansion of multinational corporations in modern conditions of globalization, the contradictions generated by these conditions and the conflicts in the system of world economy are presented in the article. The global strategy of functioning of multinational corporation professes the principle of “double standards”. Multinational corporations, on the one hand, support liberalization and internationalization in scales of world reproduction, on the other hand – further redistribution of spheres of influence, and imposing the new world economic order. The functional role of modern multinational corporations is inconsistent. Though they stimulate the tendency of increasing the competitiveness, concentration of the capital and production, at the same time, the monopolization and institutional barriers created by multinational corporation and its structural divisions. Multinational corporations determine the competitive struggle, implement the sanitation mechanism and optimization of world economy. The diversification of multinational corporations’ activity promotes the generation of new requirements and the markets (information, innovations, technologies, services, etc. where individual subjects and competitive forces are formed. It is caused by a progressive functional role of modern multinational corporations in the global economy. Massive penetration into the international business, external expansion of transnational monopolies stimulates economic growth in host countries, promotes specialization, division of labor, cooperation. At the same time, the monopolist form of these processes inevitably leads to numerous negative phenomena, a slow down and inconsistent development of production in the countries-recipients.
Notes on Mayer expansions and matrix models
Bourgine, Jean-Emile, E-mail: jebourgine@apctp.org
2014-03-15
Mayer cluster expansion is an important tool in statistical physics to evaluate grand canonical partition functions. It has recently been applied to the Nekrasov instanton partition function of N=2 4d gauge theories. The associated canonical model involves coupled integrations that take the form of a generalized matrix model. It can be studied with the standard techniques of matrix models, in particular collective field theory and loop equations. In the first part of these notes, we explain how the results of collective field theory can be derived from the cluster expansion. The equalities between free energies at first orders is explained by the discrete Laplace transform relating canonical and grand canonical models. In a second part, we study the canonical loop equations and associate them with similar relations on the grand canonical side. It leads to relate the multi-point densities, fundamental objects of the matrix model, to the generating functions of multi-rooted clusters. Finally, a method is proposed to derive loop equations directly on the grand canonical model.
Private Randomness Expansion With Untrusted Devices
Colbeck, Roger
2010-01-01
Randomness is an important resource for many applications, from gambling to secure communication. However, guaranteeing that the output from a candidate random source could not have been predicted by an outside party is a challenging task, and many supposedly random sources used today provide no such guarantee. Quantum solutions to this problem exist, for example a device which internally sends a photon through a beam-splitter and observes on which side it emerges, but, presently, such solutions require the user to trust the internal workings of the device. Here we seek to go beyond this limitation by asking whether randomness can be generated using untrusted devices|even ones created by an adversarial agent|while providing a guarantee that no outside party (including the agent) can predict it. Since this is easily seen to be impossible unless the user has an initially private random string, the task we investigate here is private randomness expansion. We introduce a protocol for private randomness expansion ...
The Very Large Array Expansion Project
Rupen, Michael P.
2003-02-01
The National Radio Astronomy Observatory (NRAO) is undertaking a major expansion of the Very Large Array (VLA), the most powerful and flexible radio instrument in the world. This VLA Expansion Project combines the existing infrastructure with state-of-the-art electronics and instrumentation to improve the scientific capabilities of the array by a factor 10 or more in all key observational parameters. Some of the most important advances include: (1) replacing the existing waveguide with optical fiber, allowing total bandwidths of up to 16 GHz, rather than the current 200 MHz; (2) installing wideband receiver systems, for continuous coverage of the entire centimeter radio spectrum from Mexican National Council for Science and Technology (CONACyT). We plan to finish the entire project within a decade. The EVLA will inaugurate a new era in radio astronomy, allowing extinction-free imaging of star-forming galaxies out to z>5, measurements of the three-dimensional structure of magnetic fields in objects ranging from the Sun to nearby galaxies, and parallaxes and proper motion measurements of pulsars spread throughout the Galaxy. The EVLA is intended not to perform a single, particular experiment, but to provide an essential tool across the entire range of modern astrophysics.
Transmission network expansion planning with simulation optimization
Bent, Russell W [Los Alamos National Laboratory; Berscheid, Alan [Los Alamos National Laboratory; Toole, G. Loren [Los Alamos National Laboratory
2010-01-01
Within the electric power literatW''e the transmi ssion expansion planning problem (TNEP) refers to the problem of how to upgrade an electric power network to meet future demands. As this problem is a complex, non-linear, and non-convex optimization problem, researchers have traditionally focused on approximate models. Often, their approaches are tightly coupled to the approximation choice. Until recently, these approximations have produced results that are straight-forward to adapt to the more complex (real) problem. However, the power grid is evolving towards a state where the adaptations are no longer easy (i.e. large amounts of limited control, renewable generation) that necessitates new optimization techniques. In this paper, we propose a generalization of the powerful Limited Discrepancy Search (LDS) that encapsulates the complexity in a black box that may be queJied for information about the quality of a proposed expansion. This allows the development of a new optimization algOlitlun that is independent of the underlying power model.
Thermal expansion of glasses at low temperatures
Lyon, K.G.
1979-01-01
The linear thermal expansion coefficient (..cap alpha.. = (par. deltalnL/par. deltaT)/sub p/) was measured at temperatures to 1.2K for two amorphous solids, fused silica and PMMA (polymethylmethacrylate, plexiglas), using a parallel plate capacitor differential dilatometer. The low temperature expansion coefficients for these solids have the same temperature dependences as the specific heats, and show a contribution which is linear in the temperature and which can be associated with the postulate of a broad distribution of two level states. The Grueneisen parameters which are associated with this contribution are comparable for the two solids (Y approx. = -16), and suggest a further indication of common behavior for amorphous solids at low temperature. Large magnitudes for Grueneisen parameters (/..gamma../ > 5) generally are associated with tunneling models. A symmetric double harmonic oscillator tunneling model can be used to understand the sign and magnitude of ..gamma.. for these solids. This model is inconsistent with other thermal and thermodynamic data for fused silica. The existence of similar negative and large magnitude Grueneisen parameters for these two amorphous solids places an additional constraint on theories for the low temperature properties of glasses.
Extended Plefka expansion for stochastic dynamics
Bravi, B.; Sollich, P.; Opper, M.
2016-05-01
We propose an extension of the Plefka expansion, which is well known for the dynamics of discrete spins, to stochastic differential equations with continuous degrees of freedom and exhibiting generic nonlinearities. The scenario is sufficiently general to allow application to e.g. biochemical networks involved in metabolism and regulation. The main feature of our approach is to constrain in the Plefka expansion not just first moments akin to magnetizations, but also second moments, specifically two-time correlations and responses for each degree of freedom. The end result is an effective equation of motion for each single degree of freedom, where couplings to other variables appear as a self-coupling to the past (i.e. memory term) and a coloured noise. This constitutes a new mean field approximation that should become exact in the thermodynamic limit of a large network, for suitably long-ranged couplings. For the analytically tractable case of linear dynamics we establish this exactness explicitly by appeal to spectral methods of random matrix theory, for Gaussian couplings with arbitrary degree of symmetry.
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.
Amory, Alan; Molomo, Bolepo; Blignaut, Seugnet
2011-01-01
In this paper, the collaborative development, instantiation, expansion and re-representation as research instrument of the Game Object Model (GOM) are explored from a Cultural Historical Activity Theory perspective. The aim of the paper is to develop insights into the design, integration, evaluation and use of video games in learning and teaching.…
Algunas aclaraciones acerca del conocimiento del singular.
Carlos Llano Cifuentes
2013-11-01
Full Text Available Llano tries to explain the main purpose of El Conocimiento del Singular, showing how the individuals about which the book is concerned are basically human individuals: people as decision makers.
Optimal expansion planning of stand-alone systems with stochastic simulations
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.
Impacto del manejo del ecosistema del pastizal en la fertilidad natural y sostenibilidad del suelo
A. Senra
2009-01-01
Full Text Available Sobre la base de resultados, principalmente de Cuba, el objetivo del presente trabajo fue estudiar el impacto del manejo del ecosistema del pastizal, en condiciones del trópico estacional -en sistemas de explotación bovina- para conocer sus efectos en la sostenibilidad y eficiencia del pastizal y el suelo. Se discute el efecto del manejo del pastizal en la compactación, y el escurrimiento e infiltración del agua, así como la erosión pluvial de los suelos. Se señalan los impactos positivos de la inclusión de los árboles multipropósito en los pastizales y sus efectos en disminuir las radiaciones solares y evaporación en el suelo, así como suavizar el ambiente. Se indican índices fundamentales para el control sistemático de la sostenibilidad y eficiencia en los sistemas de explotación bovina con base de pastos; se enfatiza el papel decisivo del hombre en garantizar adecuadas tecnologías de manejo y su ajuste a las condiciones de explotación. Se llega a conclusiones y recomendaciones que podrán ayudar a la recuperación, sostenibilidad y eficiencia de la ganadería en nuestras condiciones.
Trinucleotide repeat expansions catalyzed by human cell-free extracts
Jennifer R Stevens; Elaine E Lahue; Guo-Min Li; Robert S Lahue
2013-01-01
Trinucleotide repeat expansions cause 17 heritable human neurological disorders.In some diseases,somatic expansions occur in non-proliferating tissues such as brain where DNA replication is limited.This finding stimulated significant interest in replication-independent expansion mechanisms.Aberrant DNA repair is a likely source,based in part on mouse studies showing that somatic expansions are provoked by the DNA repair protein MutSβ (Msh2-Msh3complex).Biochemical studies to date used cell-free extracts or purified DNA repair proteins to yield partial reactions at triplet repeats.The findings included expansions on one strand but not the other,or processing of DNA hairpin structures thought to be important intermediates in the expansion process.However,it has been difficult to recapitulate complete expansions in vitro,and the biochemical role of MutSβ remains controversial.Here,we use a novel in vitro assay to show that human cell-free extracts catalyze expansions and contractions of trinucleotide repeats without the requirement for DNA replication.The extract promotes a size range of expansions that is similar to certain diseases,and triplet repeat length and sequence govern expansions in vitro as in vivo.MutSβ stimulates expansions in the extract,consistent with aberrant repair of endogenous DNA damage as a source of expansions.Overall,this biochemical system retains the key characteristics of somatic expansions in humans and mice,suggesting that this important mutagenic process can be restored in the test tube.
Critical point anomalies include expansion shock waves
Nannan, N. R., E-mail: ryan.nannan@uvs.edu [Mechanical Engineering Discipline, Anton de Kom University of Suriname, Leysweg 86, PO Box 9212, Paramaribo, Suriname and Process and Energy Department, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands); Guardone, A., E-mail: alberto.guardone@polimi.it [Department of Aerospace Science and Technology, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Colonna, P., E-mail: p.colonna@tudelft.nl [Propulsion and Power, Delft University of Technology, Kluyverweg 1, 2629 HS Delft (Netherlands)
2014-02-15
From first-principle fluid dynamics, complemented by a rigorous state equation accounting for critical anomalies, we discovered that expansion shock waves may occur in the vicinity of the liquid-vapor critical point in the two-phase region. Due to universality of near-critical thermodynamics, the result is valid for any common pure fluid in which molecular interactions are only short-range, namely, for so-called 3-dimensional Ising-like systems, and under the assumption of thermodynamic equilibrium. In addition to rarefaction shock waves, diverse non-classical effects are admissible, including composite compressive shock-fan-shock waves, due to the change of sign of the fundamental derivative of gasdynamics.
Expansion of museums in Central Europe?
Jagodzińska, Katarzyna
2015-06-01
Full Text Available The paper presents reflections on the specificity of collections and museums of contemporary art in Central Europe and considers a possibility of creating a regional alternative for the West. The analysis is conducted in the context of the expansionist policy of contemporary museums – notably the Louvre, the Guggenheim Foundation, and the Hermitage – whose numerous new development projects gave rise to a number of dilemmas in the museological world. The author discusses global "museum brands" that invest in Central Europe and addresses the possible profits of the expansion of such "concerns" for culture in the region, as well as emphasises the potential of the region itself, which may be used for its development without the avail of the internationally renowned collectors' names.
Quantization Noise Shaping on Arbitrary Frame Expansions
Boufounos Petros T
2006-01-01
Full Text Available Quantization noise shaping is commonly used in oversampled A/D and D/A converters with uniform sampling. This paper considers quantization noise shaping for arbitrary finite frame expansions based on generalizing the view of first-order classical oversampled noise shaping as a compensation of the quantization error through projections. Two levels of generalization are developed, one a special case of the other, and two different cost models are proposed to evaluate the quantizer structures. Within our framework, the synthesis frame vectors are assumed given, and the computational complexity is in the initial determination of frame vector ordering, carried out off-line as part of the quantizer design. We consider the extension of the results to infinite shift-invariant frames and consider in particular filtering and oversampled filter banks.
The new Medicaid debate: expansion or retrenchment?
2001-01-01
Health advocates are facing a sea-change in Washington. Comprehensive federal health care reform eluded the nation under the Clinton Administration, but incremental progress through state-based Medicaid expansions and new CHIP programs was widespread, giving rise to some innovative state efforts to cover more of the uninsured. Washington's support was instrumental in those efforts, but the second Bush Administration seems intent on reversing that direction. To protect--and build upon--these nascent Medicaid efforts, advocates will have to mount careful strategies in defense of Medicaid. This States of Health looks at the dangers that may lie ahead and suggests how advocates can respond to keep Medicaid moving in the right direction.
Is cosmic expansion of the universe accelerating?
Choudhury, D C
2006-01-01
Currently available Type Ia distant supernovae observed data seem to support evidence that the cosmic expansion of the universe is accelerating. This unexpected result is beyond any standard model of modern cosmology. The new concept advanced to account for the acceleration is dark energy or quintessence with negative pressure. Most analyses using this new form of energy describe the observed data with great accuracy, although there has been no laboratory confirmation of it. The present work analyzes the consequences of Thomson scattering on Type Ia supernovae data for two significant reasons; (i) recently observed data reveal the existence of sufficient amount of ionized baryonic (hydrogen) dark matter in the intergalactic medium, a necessary ingredient for Thomson scattering, and (ii) its effects have not been considered previously in determining distances to the supernovae from their observed distance moduli. Quantitative results of the present investigation based on observed data and corrected for Thomson...
Population Genetics of Three Dimensional Range Expansions
Lavrentovich, Maxim; Nelson, David
2014-03-01
We develop a simple model of genetic diversity in growing spherical cell clusters, where the growth is confined to the cluster surface. This kind of growth occurs in cells growing in soft agar, and can also serve as a simple model of avascular tumors. Mutation-selection balance in these radial expansions is strongly influenced by scaling near a neutral, voter model critical point and by the inflating frontier. We develop a scaling theory to describe how the dynamics of mutation-selection balance is cut off by inflation. Genetic drift, i.e., local fluctuations in the genetic diversity, also plays an important role, and can lead to the extinction even of selectively advantageous strains. We calculate this extinction probability, taking into account the effect of rough population frontiers.
EMPIRE ULTIMATE EXPANSION: RESONANCES AND COVARIANCES.
HERMAN,M.; MUGHABGHAB, S.F.; OBLOZINSKY, P.; ROCHMAN, D.; PIGNI, M.T.; KAWANO, T.; CAPOTE, R.; ZERKIN, V.; TRKOV, A.; SIN, M.; CARSON, B.V.; WIENKE, H. CHO, Y.-S.
2007-04-22
The EMPIRE code system is being extended to cover the resolved and unresolved resonance region employing proven methodology used for the production of new evaluations in the recent Atlas of Neutron Resonances. Another directions of Empire expansion are uncertainties and correlations among them. These include covariances for cross sections as well as for model parameters. In this presentation we concentrate on the KALMAN method that has been applied in EMPIRE to the fast neutron range as well as to the resonance region. We also summarize role of the EMPIRE code in the ENDF/B-VII.0 development. Finally, large scale calculations and their impact on nuclear model parameters are discussed along with the exciting perspectives offered by the parallel supercomputing.
The Dynamics of Regional and Global Expansion
Geisler Asmussen, Christian; Nielsen, Bo Bernhard; Osegowitsch, Tom
2015-01-01
Purpose – The purpose of this paper is to model and test the dynamics of home-regional and global penetration by multi-national enterprises (MNEs). Design/methodology/approach – Drawing on international business (IB) theory, the authors model MNEs adjusting their home-regional and global market...... domain. Findings – The authors demonstrate that MNEs do penetrate both home-regional and global markets, often simultaneously, and that penetration levels often oscillate within an MNE over time. The authors show firms’ rates of regional and global expansion to be affected by their existing regional...... presence over time. The authors test the resulting hypotheses using sales data from a sample of 220 of the world’s largest MNEs over the period 1995-2005. The authors focus specifically on the relationship between levels of market penetration inside and outside the home region and rates of change in each...
A collisionless plasma thruster plume expansion model
Merino, Mario; Cichocki, Filippo; Ahedo, Eduardo
2015-06-01
A two-fluid model of the unmagnetized, collisionless far region expansion of the plasma plume for gridded ion thrusters and Hall effect thrusters is presented. The model is integrated into two semi-analytical solutions valid in the hypersonic case. These solutions are discussed and compared against the results from the (exact) method of characteristics; the relative errors in density and velocity increase slowly axially and radially and are of the order of 10-2-10-3 in the cases studied. The plasma density, ion flux and ambipolar electric field are investigated. A sensitivity analysis of the problem parameters and initial conditions is carried out in order to characterize the far plume divergence angle in the range of interest for space electric propulsion. A qualitative discussion of the physics of the secondary plasma plume is also provided.
How will oil palm expansion affect biodiversity?
Fitzherbert, Emily B; Struebig, Matthew J; Morel, Alexandra; Danielsen, Finn; Brühl, Carsten A; Donald, Paul F; Phalan, Ben
2008-10-01
Oil palm is one of the world's most rapidly increasing crops. We assess its contribution to tropical deforestation and review its biodiversity value. Oil palm has replaced large areas of forest in Southeast Asia, but land-cover change statistics alone do not allow an assessment of where it has driven forest clearance and where it has simply followed it. Oil palm plantations support much fewer species than do forests and often also fewer than other tree crops. Further negative impacts include habitat fragmentation and pollution, including greenhouse gas emissions. With rising demand for vegetable oils and biofuels, and strong overlap between areas suitable for oil palm and those of most importance for biodiversity, substantial biodiversity losses will only be averted if future oil palm expansion is managed to avoid deforestation.
Thermal expansion recovery microscopy: Practical design considerations
Mingolo, N., E-mail: nmingol@fi.uba.ar; Martínez, O. E. [Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colon 850, 1063 Buenos Aires (Argentina)
2014-01-15
A detailed study of relevant parameters for the design and operation of a photothermal microscope technique recently introduced is presented. The technique, named thermal expansion recovery microscopy (ThERM) relies in the measurement of the defocusing introduced by a surface that expands and recovers upon the heating from a modulated source. A new two lens design is presented that can be easily adapted to commercial infinite conjugate microscopes and the sensitivity to misalignment is analyzed. The way to determine the beam size by means of a focus scan and the use of that same scan to verify if a thermoreflectance signal is overlapping with the desired ThERM mechanism are discussed. Finally, a method to cancel the thermoreflectance signal by an adequate choice of a nanometric coating is presented.
Algorithm of capacity expansion on networks optimization
无
2003-01-01
The paper points out the relationship between the bottleneck and the minimum cutset of the network, and presents a capacity expansion algorithm of network optimization to solve the network bottleneck problem. The complexity of the algorithm is also analyzed. As required by the algorithm, some virtual sources are imported through the whole positive direction subsection in the network, in which a certain capacity value is given. Simultaneously, a corresponding capacity-expanded network is constructed to search all minimum cutsets. For a given maximum flow value of the network, the authors found an adjustment value of each minimum cutset arc's group with gradually reverse calculation and marked out the feasible flow on the capacity-extended networks again with the adjustment value increasing. All this has been done repeatedly until the original topology structure is resumed. So the algorithm can increase the capacity of networks effectively and solve the bottleneck problem of networks.
Legendre Expansions for Two-Hadron Reactions
Strakovsky, Igor; Azimov, Yakov; Briscoe, William
2017-01-01
Modern experimental facilities and detectors provide tremendous volumes of detailed data. For two-hadron reactions, they are usually presented as a set of multiple panels, e . g . , angular distributions at many particular energies. Such presentations lose visuality, and their physical content may be extracted only through some model-dependent treatment. Instead, we suggest to use expansion into the Legendre series with a relatively small number of essential coefficients. This approach was applied in several experimental investigations and demonstrated its higher visualization. This talk presents some general properties of the Legendre coefficients which allow one to extract physical information even without any model-dependent assumptions. The U.S. Department of Energy, Office of Science, Office of Nuclear Physics, Award Numbers DE-SC0014133 and DE-SC0016582 and the Russian Science Foundation, Award No.14-22-00281.
Conflation: a new type of accelerated expansion
Fertig, Angelika; Lehners, Jean-Luc; Mallwitz, Enno
2016-08-01
In the framework of scalar-tensor theories of gravity, we construct a new kind of cosmological model that conflates inflation and ekpyrosis. During a phase of conflation, the universe undergoes accelerated expansion, but with crucial differences compared to ordinary inflation. In particular, the potential energy is negative, which is of interest for supergravity and string theory where both negative potentials and the required scalar-tensor couplings are rather natural. A distinguishing feature of the model is that, for a large parameter range, it does not significantly amplify adiabatic scalar and tensor fluctuations, and in particular does not lead to eternal inflation and the associated infinities. We also show how density fluctuations in accord with current observations may be generated by adding a second scalar field to the model. Conflation may be viewed as complementary to the recently proposed anamorphic universe of Ijjas and Steinhardt.
Aeroacoustic sound generation in simple expansion chambers.
English, Emmet J; Holland, Keith R
2010-11-01
A method is presented for measuring the aeroacoustic source strength in ducts with flow at frequencies at which the wave motion can be considered substantially one-dimensional. The method is based on coherent power flux measurements using pairs of microphones positioned both upstream and downstream of the source region. The method is applied to a flow excited expansion chamber with aeroacoustic source measurements presented for chambers with a range of flow velocities and chamber lengths. The results indicate locked-on flow tones are generated in the chamber. The frequency of these locked-on flow tones is compared with that predicted using describing function theory applied to resonators with a grazing flow as well as that of other literature.
Associativity of the operator product expansion
Holland, Jan
2015-01-01
We consider a recursive scheme for defining the coefficients in the operator product expansion (OPE) of an arbitrary number of composite operators in the context of perturbative, Euclidean quantum field theory in four dimensions. Our iterative scheme is consistent with previous definitions of OPE coefficients via the flow equation method, or methods based on Feynman diagrams. It allows us to prove that a strong version of the "associativity" condition holds for the OPE to arbitrary orders in perturbation theory. Such a condition was previously proposed in an axiomatic setting in [1] and has interesting conceptual consequences: 1) One can characterise perturbations of quantum field theories abstractly in a sort of "Hochschild-like" cohomology setting, 2) one can prove a "coherence theorem" analogous to that in an ordinary algebra: The OPE coefficients for a product of two composite operators uniquely determine those for $n$ composite operators. We concretely prove our main results for the Euclidean $\\varphi^4_...
Sectoral and regional expansion of emissions trading
Boehringer, Christoph; Bouwe, Dijkstra; Rosendahl, Knut Einar
2011-07-01
We consider an international emissions trading scheme with partial sectoral and regional coverage. Sectoral and regional expansion of the trading scheme is beneficial in aggregate, but not necessarily for individual countries. We simulate international CO{sub 2} emission quota markets using marginal abatement cost functions and the Copenhagen 2020 climate policy targets for selected countries that strategically allocate emissions in a bid to manipulate the quota price. Quota exporters and importers generally have conflicting interests about admitting more countries to the trading coalition, and our results indicate that some countries may lose substantially when the coalition expands in terms of new countries. For a given coalition, expanding sectoral coverage makes most countries better off, but some countries (notably the USA and Russia) may lose out due to loss of strategic advantages. In general, exporters tend to have stronger strategic power than importers.(Author)
Constraining the Anisotropic Expansion of Universe
Cai, Rong-Gen; Tang, Bo; Tuo, Zhong-Liang
2013-01-01
We study the possibly existing anisotropy in the accelerating expansion Universe with the Union2 Type Ia supernovae data and Gamma-ray burst data. We construct a direction-dependent dark energy model and constrain the anisotropy direction and strength of modulation. We find that the maximum anisotropic deviation direction is $(l,\\,b)=(126^{\\circ},\\,13^{\\circ})$ (or equivalently $(l,\\,b)=(306^{\\circ},\\,-13^{\\circ})$), and the anisotropy level is $g_0=0.030_{+0.010}^{-0.030}$ (obtained using Union2 data, at $1\\sigma$ confidence level). Our results do not show strong evidence for the anisotropic dark energy model. We also discuss potential methods that may distinguish the peculiar velocity field from the anisotropic dark energy model.
Expansive focal cemento-osseous dysplasia.
Bulut, Emel Uzun; Acikgoz, Aydan; Ozan, Bora; Zengin, Ayse Zeynep; Gunhan, Omer
2012-01-01
To present a case of expansive focal cemento-osseous dysplasia and emphasize the importance of differential diagnosis. Cemento-osseous dysplasia is categorized into three subtypes on the basis of the clinical and radiographic features: Periapical, focal and florid. The focal type exhibits a single site of involvement in any tooth-bearing or edentulous area of the jaws. These lesions are usually asymptomatic; therefore, they are frequently diagnosed incidentally during routine radiographic examinations. Lesions are usually benign, show limited growth, and do not require further surgical intervention, but periodic follow-up is recommended because occasionally, this type of dysplasia progresses into florid osseous dysplasia and simple bone cysts are formed. A 24-year-old female patient was referred to our clinic for swelling in the left edentulous mandibular premolarmolar region and felt discomfort when she wore her prosthetics. She had no pain, tenderness or paresthesia. Clinical examination showed that the swelling in the posterior mandible that was firm, nonfluctuant and covered by normal mucosa. On panoramic radiography and computed tomography, a well defined lesion of approximately 1.5 cm in diameter of mixed density was observed. The swelling increased slightly in size over 2 years making it difficult to use prosthetics and, therefore, the lesion was totally excised under local anesthesia, and surgical specimens were submitted for histopathological examination. The histopathological diagnosis was focal cemento-osseous dysplasia. In the present case, because of the increasing size of the swelling making it difficult to use prosthetics, young age of the patient and localization of the lesion, in the initial examination, cemento-ossifying fibroma was suspected, and the lesion was excised surgically; the histopathological diagnosis confirmed it as focal cemento-osseous dysplasia. We present a case of expansive focal cemento-osseous dysplasia. Differential diagnosis
On MEG forward modelling using multipolar expansions
Jerbi, K. [Signal and Image Processing Institute, University of Southern California, Los Angeles, CA (United States); Cognitive Neuroscience and Brain Imaging Laboratory, Hopital de la Salpetiere, CNRS, Paris (France); Mosher, J.C. [Los Alamos National Laboratory, Los Alamos, NM (United States); Baillet, S. [Cognitive Neuroscience and Brain Imaging Laboratory, Hopital de la Salpetiere, CNRS, Paris (France); Leahy, R.M. [Signal and Image Processing Institute, University of Southern California, Los Angeles, CA (United States)]. E-mail: leahy@sipi.usc.edu
2002-02-21
Magnetoencephalography (MEG) is a non-invasive functional imaging modality based on the measurement of the external magnetic field produced by neural current sources within the brain. The reconstruction of the underlying sources is a severely ill-posed inverse problem typically tackled using either low-dimensional parametric source models, such as an equivalent current dipole (ECD), or high-dimensional minimum-norm imaging techniques. The inability of the ECD to properly represent non-focal sources and the over-smoothed solutions obtained by minimum-norm methods underline the need for an alternative approach. Multipole expansion methods have the advantages of the parametric approach while at the same time adequately describing sources with significant spatial extent and arbitrary activation patterns. In this paper we first present a comparative review of spherical harmonic and Cartesian multipole expansion methods that can be used in MEG. The equations are given for the general case of arbitrary conductors and realistic sensor configurations and also for the special cases of spherically symmetric conductors and radially oriented sensors. We then report the results of computer simulations used to investigate the ability of a first-order multipole model (dipole and quadrupole) to represent spatially extended sources, which are simulated by 2D and 3D clusters of elemental dipoles. The overall field of a cluster is analysed using singular value decomposition and compared to the unit fields of a multipole, centred in the middle of the cluster, using subspace correlation metrics. Our results demonstrate the superior utility of the multipolar source model over ECD models in providing source representations of extended regions of activity. (author)
Facies del subfondo del canal Beagle, Tierra del Fuego
Gustavo Bujalesky
2004-03-01
Full Text Available El canal Beagle conecta los océanos Pacífico y Atlántico en el extremo meridional de Sudamérica y se ubica en el ambiente subantártico. Conforma una cuenca de unos 300 m de profundidad máxima y está separada del océano Atlántico por un umbral de 30 m de profundidad. El canal es un valle tectónico que fue completamente cubierto por el hielo glacial durante la última glaciación. Posteriormente, el canal fue ocupado por un lago glacial desde los 12.000 a los 8.000 años A.P., cuando fue invadido por el mar que alcanzó un nivel máximo entre los 6.000 y 5.000 años A.P. Con el objetivo de analizar las facies sedimentarias superficiales y del subfondo del canal se realizó un relevamiento geofísico con sonar de barrido lateral y un perfilador de 3,5 kHz. Sobre un basamento constituido por rocas metamórficas del Mesozoico, se identificaron depósitos de till y secuencias granodecrecientes que representan distintos estadios del retroceso glaciar, evidenciando hacia la sección superior facies lacustres y por encima depósitos de la transgresión marina del Holoceno. Además, se han identificado paleocauces y secuencias fluviales cubiertas por sedimentos marinos transgresivos.
Adequacy of the virial equation of state and cluster expansion
Ushcats, M. V.
2013-04-01
The limits for the accuracy of the virial expansion and the problem of its divergence have been investigated using the exact cluster expansion of the configuration integral. In the subcritical temperature regimes the virial equation of state is applicable up to the singularity point of the isothermal compressibility, i.e., to the possible beginning of the condensation process. At supercritical temperatures this equation should be applicable within the region where the cluster expansion is adequate. The problem of the virial series divergence has been found to be irrelevant to the actual behavior of the cluster expansion. Considering the Lennard-Jones fluid as well as the system of hard spheres, the inadequate behavior of the cluster expansion has been discovered in the high density regime. The major reason for this inadequacy should be the basic simplification of the cluster expansion: the integration of irreducible diagrams over the infinite limits.
2010-01-01
Tanto las obras de arte como los animales nos ocultan información cuando se reúnen en un museo, pues quedan al margen del contexto espacial y temporal del que proceden. No obstante, el ojo avezado sabrá interpretar una parte de esa historia perdida. Del mismo modo, algunas especies vivas traslocadas conservan rasgos que nos ayudan a inferir las condiciones ambientales de su lugar de origen.
José Antonio Espina Barrio
1997-01-01
Full Text Available La pérdida de rituales agrava y alarga la reacción del duelo. Se define el Psicodrama Antropológico y su intervención en el proceso del duelo. El Psicodrama Focal del Duelo es una psicoterapia breve centrada en el proceso de Duelo. Se comentan varios casos y resultados. Se concluye con un programa sencillo para el duelo en Atención Primaria.
José Antonio Espina Barrio; Marisol Filgueira Bouza
1997-01-01
La pérdida de rituales agrava y alarga la reacción del duelo. Se define el Psicodrama Antropológico y su intervención en el proceso del duelo. El Psicodrama Focal del Duelo es una psicoterapia breve centrada en el proceso de Duelo. Se comentan varios casos y resultados. Se concluye con un programa sencillo para el duelo en Atención Primaria.
The tropical root weevil, Diaprepes abbreviatus (L.), has been a pest of citrus and ornamental plants since its introduction into Lake County, FL in 1964. Since then, it has colonized the Florida peninsula to the south of its point of introduction, but has not expanded its range to the north. A lowe...
Fractura triple del complejo suspensorio del hombro
Eraclio Delgado Rifá
2015-06-01
Full Text Available El complejo suspensorio del hombro es una estructura sumamente importante, compuesta por un anillo de huesos y tejidos blandos. Las lesiones aisladas de este complejo anatómico son frecuentes y no afectan su estabilidad. La interrupción doble conduce a la inestabilidad de esta estructura y usualmente requiere tratamiento quirúrgico. La triple interrupción, por su parte, es sumamente rara y es encontrada en casos de trauma de alta energía a menudo en asociación con otras lesiones. Se presenta una triple lesión del complejo suspensorio del hombro en un paciente de 46 años de edad, con una fractura de la glenoides, del acromion tipo III de Kuhn y de la coracoides tipo II de Ogawa. En este caso, la fractura del acromion fue tratada con fijación percutánea con alambres de Kirschner, por tener asociado lesiones de partes blandas que contraindicaron la reducción abierta. La fractura de la glenoides y de la apófisis coracoides fueron tratadas conservadoramente. Después de 6 meses de evolución, el paciente tuvo un resultado funcional aceptable, con una abducción de 90 grados, los 30 grados de rotación externa y 70 de rotación interna, además asintomático y consolidación de todas las fracturas. A pesar de ser catalogada de una lesión grave del cinturón escapular y estar asociada a otras lesiones se obtuvo un resultado satisfactorio al final del tratamiento.
Probing the physical determinants of thermal expansion of folded proteins.
Dellarole, Mariano; Kobayashi, Kei; Rouget, Jean-Baptiste; Caro, José Alfredo; Roche, Julien; Islam, Mohammad M; Garcia-Moreno E, Bertrand; Kuroda, Yutaka; Royer, Catherine A
2013-10-24
The magnitude and sign of the volume change upon protein unfolding are strongly dependent on temperature. This temperature dependence reflects differences in the thermal expansivity of the folded and unfolded states. The factors that determine protein molar expansivities and the large differences in thermal expansivity for proteins of similar molar volume are not well understood. Model compound studies have suggested that a major contribution is made by differences in the molar volume of water molecules as they transfer from the protein surface to the bulk upon heating. The expansion of internal solvent-excluded voids upon heating is another possible contributing factor. Here, the contribution from hydration density to the molar thermal expansivity of a protein was examined by comparing bovine pancreatic trypsin inhibitor and variants with alanine substitutions at or near the protein-water interface. Variants of two of these proteins with an additional mutation that unfolded them under native conditions were also examined. A modest decrease in thermal expansivity was observed in both the folded and unfolded states for the alanine variants compared with the parent protein, revealing that large changes can be made to the external polarity of a protein without causing large ensuing changes in thermal expansivity. This modest effect is not surprising, given the small molar volume of the alanine residue. Contributions of the expansion of the internal void volume were probed by measuring the thermal expansion for cavity-containing variants of a highly stable form of staphylococcal nuclease. Significantly larger (2-3-fold) molar expansivities were found for these cavity-containing proteins relative to the reference protein. Taken together, these results suggest that a key determinant of the thermal expansivities of folded proteins lies in the expansion of internal solvent-excluded voids.
Capacity expansion modelling to aid water supply investment decisions
Padula, S
2015-01-01
Increasing population, economic development, and environmental changes imply that maintaining the water supply-demand balance will remain a top priority. Water resource systems may need to be expanded in order to respond to demand growth. Capacity expansion studies can be used to answer the question of what the optimal expansion size, timing and location of new infrastructure should be. This thesis develops and applies capacity expansion optimisation modelling approaches. We begin with the 'E...
Geometry Modeling of an Electronic Expansion Valve Head
张川; 马善伟; 陈江平; 陈芝久; 陈文勇; 王健
2004-01-01
This paper proposed that the flow characteristic of electronic expansion valve should be adapted to the evaporator superheat gain to refrigerant flow rate under different working conditions. Two native methods of geometry modeling of electronic expansion valve head were introduced. By analysis of them, some shortcoming was detected and a universal modeling method of electronic expansion valve head was put forward. Through this model, the flow characteristic of EEV and the influence factors can be investigated more deeply.
High-order topological asymptotic expansion for Stokes equations
Mohamed Abdelwahed
2016-06-01
Full Text Available We use the topological sensitivity analysis method to solve various optimization problems. It consists of studying the asymptotic expansion of the objective function relative to a perturbation of the domain topology. This expansion becomes insufficient in some applications when it is limited to the first order topological derivative. We present a new topological sensitivity analysis for the Stokes equations based on a high order asymptotic expansion. The derived result is valid for different class of shape functions.
Free energy topological expansion for the 2-matrix model
Chekhov, Leonid [Steklov Mathematical Institute, ITEP and Poncelet Laboratoire, Moscow (Russian Federation); Eynard, Bertrand [Service de Physique Theorique de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Orantin, Nicolas [Service de Physique Theorique de Saclay, F-91191 Gif-sur-Yvette Cedex (France)
2006-12-15
We compute the complete topological expansion of the formal hermitian two-matrix model. For this, we refine the previously formulated diagrammatic rules for computing the 1/N expansion of the nonmixed correlation functions and give a new formulation of the spectral curve. We extend these rules obtaining a closed formula for correlation functions in all orders of topological expansion. We then integrate it to obtain the free energy in terms of residues on the associated Riemann surface.
49 CFR 179.220-16 - Expansion capacity.
2010-10-01
... 49 Transportation 2 2010-10-01 2010-10-01 false Expansion capacity. 179.220-16 Section 179.220-16... Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-16 Expansion capacity. Expansion capacity must be provided in the shell of the inner container as prescribed in § 179.221-1....
Morin, Edgar
1997-01-01
Este art??culo acomete la cuesti??n de la definici??n y unidad del g??nero humano. Tras poner de manifiesto la doble conciencia de la que depende la noci??n de hombre, se ocupa de la afirmaci??n humanista de la unidad del hombre, mostrando los reversos de esta afirmaci??n (separaci??n del hombre de la naturaleza e ignorancia de la unidad biol??gica de la especie homo), as?? como de las distintas envestidas contra el humanismo cuestionadoras de la unidad del hombre lanzadas durante el siglo XX...
Concepto del Derecho Mercantil
Morelli C., Francisco
2014-01-01
No existe nada más difícil en el campo del Derecho Mercantil que pretender dar un concepto orgánico del mismo. La razón fundamental de esta imposibilidad estriba precisamente en la falta de concordancia entre el derecho mercantil y el derecho de comercio. Una definición que considera el derecho mercantil como la parte del derecho privado encargada de regular las relaciones que se derivan del comercio, como lo hacen todas las definiciones clásicas, pecaría de un doble defecto que la harían i...
A Bayesian approach to image expansion for improved definition.
Schultz, R R; Stevenson, R L
1994-01-01
Accurate image expansion is important in many areas of image analysis. Common methods of expansion, such as linear and spline techniques, tend to smooth the image data at edge regions. This paper introduces a method for nonlinear image expansion which preserves the discontinuities of the original image, producing an expanded image with improved definition. The maximum a posteriori (MAP) estimation techniques that are proposed for noise-free and noisy images result in the optimization of convex functionals. The expanded images produced from these methods will be shown to be aesthetically and quantitatively superior to images expanded by the standard methods of replication, linear interpolation, and cubic B-spline expansion.
Cardiorenal-endocrine dynamics during and following volume expansion
Zimmerman, R.S.; Edwards, B.S.; Schwab, T.R.; Heublein, D.M.; Burnett, J.C. Jr.
1987-02-01
The relationship between atrial pressure, atrial natriuretic peptide (ANP), the renin-angiotensin-aldosterone system, and renal hemodynamic and excretory function was examined during and following acute 10% body weight saline volume expansion and measurements were made at 3.3, 6.6, and 10% body weight volume expansion in pentobarbital anesthetized dogs. Right atrial pressure (RAP), pulmonary capillary wedge pressure (PCWP), fractional excretion of Na (FE/sub Na/), and ANP all increased in parallel during volume expansion. Plasma renin activity (PRA) and aldosterone decreased in parallel during 10% volume expansion. ANP, PRA and aldosterone were measured by radioimmunoassay. Following 10% volume expansion, saline was infused at the peak urine flow rate to maintain peak volume expansion. Despite continued saline infusion, RAP, PCWP, and ANP decreased in parallel. In contrast, FE/sub Na/ remained increased, and aldosterone and PRA remained depressed. These studies demonstrate that atrial pressures, ANP, and FE/sub Na/ increase in parallel during volume expansion; this suggests a role for ANP in modulating acute atrial volume overload. During stable volume expansion periods, however, despite a decrease in ANP levels, Na excretion remains elevated, suggesting that non-ANP mechanisms may be important in maintaining natriuresis during stable volume expansion.
Eigenfunction expansions and scattering theory in rigged Hilbert spaces
Gomez-Cubillo, F [Dpt. de Analisis Matematico, Universidad de Valladolid. Facultad de Ciencias, 47011 Valladolid (Spain)], E-mail: fgcubill@am.uva.es
2008-08-15
The work reviews some mathematical aspects of spectral properties, eigenfunction expansions and scattering theory in rigged Hilbert spaces, laying emphasis on Lippmann-Schwinger equations and Schroedinger operators.
Cycle expansions with pruned orbits have branch points
Mainieri, R
1994-01-01
Cycle expansions are an efficient scheme for computing the properties of chaotic systems. When enumerating the orbits for a cycle expansion not all orbits that one would expect at first are present --- some are pruned. This pruning leads to convergence difficulties when computing properties of chaotic systems. In numerical schemes, I show that pruning reduces the number of reliable eigenvalues when diagonalizing quantum mechanical operators, and that pruning slows down the convergence rate of cycle expansion calculations. I then exactly solve a diffusion model that displays chaos and show that its cycle expansion develops a branch point.
Orthogonal Expansions for VIX Options Under Affine Jump Diffusions
Barletta, Andrea; Nicolato, Elisa
2017-01-01
In this work we derive new closed–form pricing formulas for VIX options in the jump-diffusion SVJJ model proposed by Duffie et al. (2000). Our approach is based on the classic methodology of approximating a density function with an orthogonal expansion of polynomials weighted by a kernel....... Orthogonal expansions based on the Gaussian distribution, such as Edgeworth or Gram–Charlier expansions, have been successfully employed by a number of authors in the context of equity options. However, these expansions are not quite suitable for volatility or variance densities as they inherently assign...
The self consistent expansion applied to the factorial function
Cohen, Alon; Bialy, Shmuel; Schwartz, Moshe
2016-12-01
Most of the interesting systems in statistical physics can be described as nonlinear stochastic field theories. A common feature in the theoretical study of such systems is that ordinary perturbation theory seldom works. On the other hand, there exists a useful tool for the study of systems of that generic nature. That tool, the Self Consistent Expansion (SCE) is technically similar to the ordinary perturbation expansion, in the sense that it is an expansion around a solvable problem. The key point which distinguishes the SCE from an ordinary perturbation expansion, is that the small parameter of the expansion is adjustable and determined inherently by optimization of the expansion. Therefore, it allows the adaptive SCE to remain accurate relative to the inflexible ordinary expansion. The goal of the present paper is to present the SCE by applying it to a well-known zero dimensional problem. We choose the evaluation of the factorial function, x!, as the test case for the SCE, because the Stirling approximation for that function is one of the best known asymptotic expansions, with a very wide use in statistical physics. We show that the SCE approximation holds for small and even negative arguments of the factorial function, where the Stirling expansion fails miserably. It does so without paying any penalty at high values of the argument, where the Stirling formula is excellent. We present numerical as well as analytic SCE approximations of the factorial function.
Stability analysis of slopes of expansive soils considering rainfall effect
ZHU Fang-cai
2007-01-01
Typical failure types of slopes of expansive soils are divided to two kinds: slip in surface layer and slip in shallow layer. Based on total strength law of expansive soils, the relationship between its water content and shear strength inculding cohesion and friction angle, was studied in detail. Acoording to change of water content and depth effect during rainfall, distribution of shear strength in slopes of expansive soils was analyzed. Finally,with a slope of expansive soils in Nanning city of Guangxi Autonomous Region of China as a case, safety factor and slip surface was studied.
LA POLITICA SOCIAL DEL "GOBIERNO DEL CAMBIO"
Laura Mota Díaz
2002-01-01
Full Text Available El artículo se centra en la política social del actual sexenio foxista , la cual se ha definido como incluyente y equitativa dentro del marco de un gobierno autodenominado del cambio, no sólo por lo que se refiere a la alternancia política del poder, sino porque además pretende ser un gobierno con una visión más amplia del desarrollo. Todo ello se traduce en nuevas estrategias para alcanzar la democracia, la equidad, la justicia social y el bienestar general de la población. El objetivo es analizar las posibilidades y limitaciones de un verdadero cambio que contribuya a mejorar la calidad de vida de la población en su sentido más amplio, pues los retos son cada vez mayores dado el incremento en los niveles de pobreza, el creciente desempleo y la constante violación a los derechos humanos.
Computational Aspects of Normal Form Perturbation Expansions.
Murray, Diana
The method of normal forms is used to develop analytic solutions to weakly nonlinear ordinary differential equations about an equilibrium solution of the system. Such equations arise in a broad spectrum of areas where one models vibrations and oscillations of mechanical systems, oscillations and feedback in biological and ecological systems, tracking of particles in an accelerator and long -time planetary motion in astronomy. An approximation to the true solution is sought that is valid for a long time with a prescribed error. It is constructed by means of a near-identity transformation from the original system to a nearby one. The transformation is determined by a perturbation expansion as a power series in a small parameter. The method of normal forms, introduced by Poincare in his Ph.D. thesis, was further expanded by Bruno, Arnold, Kummer and others who have emphasized the nonuniqueness of the transformation. Recently, Kahn and Zarmi (1991) developed the method of minimal normal forms (MNF) which uses the nonuniqueness to terminate the normal form equation in an early order of the expansion. In the past, investigators may have missed exploiting this "freedom" because traditionally calculations were carried only to first or second order and for Hamiltonian systems this nonuniqueness is fixed when one requires that the transformation be canonical. The work presented in this thesis centers on three main aspects: (1) establishing the numerical efficacy of MNF for conservative planar systems (Kahn, Murray and Zarmi (1993)), (2) displaying the computational and conceptual simplicity of MNF for dissipative systems (Murray 1994a)), (3) and demonstrating the utility of computer algebra programs in performing very high-order calculations (Forest and Murray) and in exploring the different dynamical features of a system (Kahn, Murray and Zarmi (1994a and b)). In sections 4-11 we have included many examples in order to illustrate the wide applicability of the method of MNF
La luz del origen del universo
Casas, Alberto
2015-10-01
Full Text Available Penzias and Wilson discovered the cosmic microwave background, a luminous echo of the Big Bang, in 1965. The amount of information encoded in this relic of the early universe is truly extraordinary. At present, the most precise data about the origin and structure of the universe comes from the study of this primordial light, the full potential of which has yet to be explored.En 1965 se descubrió el fondo de radiación de microondas, un eco luminoso de la Gran Explosión (Big Bang. La cantidad de información contenida en esta reliquia del universo primitivo es verdaderamente extraordinaria. En la actualidad los datos más precisos sobre el origen y estructura del universo provienen del estudio de esta luz primigenia, que aún no ha sido explorada en todo su potencial.
Polito, Paola
1998-01-01
'importanza assunta nel romanzo dal piano dell'enunciazione come luogo privilegiato di manifestazione del soggetto quale esperiente una vicenda di maturazione. Il protagonista, qui, non solo si rappresenta in ciò che enuncia e riferisce, ma anche e soprattutto si svela nelle modalità specifiche del proprio discorso...
Ferrera, Tamara
2010-01-01
Photos taken from the Archive of Mourning following the March 11 terrorist attacks El Archivo del Duelo. Creaci?n de un archivo etnogr?fico de los Atentados del 11 de marzo en Madrid. Ministerio de Educaci?n y Ciencia HUM2005-03490.
Ricardo Goñi
2006-01-01
Full Text Available Se sintetiza una concepción del desarrollo sustentable elaborada por los autores de este trabajo desde una perspectiva multidimensional (social, económica y ambiental, fundamentalmente signada por una impronta político-social y una visión crítica del "sustentabilismo" ecologista hegemónico.
Villacrés, Elena; Rubio, Armando; Egas, Luis; Segovia, Gabriela
2006-01-01
La valorización del chocho exige conocer tecnologías de transformación, técnicas para aumentar la vida útil, minimizar los riesgos y mejorar las propiedades nutritivas, funcionales y sensoriales, con el objeto de diversificar e incrementar la utilización y el consumo del grano…
Il corpo del mostro: retoriche del neofantastico
Simona Micali
2014-06-01
Full Text Available Attraverso l’analisi di alcuni testi di Julio Cortázar e Tommaso Landolfi, l’articolo illustra alcune delle strategie retoriche attraverso le quali il fantastico del Novecento affronta la rappresentazione propriamente fisica del 'corpo mostruoso', e in particolare di quello femminile, portatore di un’alterità tanto più inconcepibile e inaccettabile quanto più si impone con la propria evidenza corporea nell’orizzonte di realtà in cui il testo è collocato.
Elementos del sistema electoral del Congreso Mexicano
Aldo Medina García; Irina Cervantes Bravo
2013-01-01
El presente artículo es un estudio de los componentes del sistema electoral, diseñado por el legislador mexicano para integrar al parlamento federal. Estudio desarrollado a sabiendas de la importancia que reviste el sistema electoral como un medio que permite a los ciudadanos convertir su voto expresado en las urnas en escaños a favor de determinado candidato o partido. En dicho análisis tomamos en cuenta la evolución constitucional del sistema electoral mexicano, la participación de las fuer...
Thermal expansion as a precision actuator
Miller, Chris; Montgomery, David; Black, Martin; Schnetler, Hermine
2016-07-01
The UK ATC has developed a novel thermal actuator design as part of an OPTICON project focusing on the development of a Freeform Active Mirror Element (FAME). The actuator uses the well understood concept of thermal expansion to generate the required force and displacement. As heat is applied to the actuator material it expands linearly. A resistance temperature device (RTD) is embedded in the centre of the actuator and is used both as a heater and a sensor. The RTD temperature is controlled electronically by injecting a varying amount of current into the device whilst measuring the voltage across it. Temperature control of the RTD has been achieved to within 0.01°C. A 3D printed version of the actuator is currently being used at the ATC to deform a mirror but it has several advantages that may make it suitable to other applications. The actuator is cheap to produce whilst obtaining a high accuracy and repeatability. The actuator design would be suitable for applications requiring large numbers of actuators with high precision.
Recursive Construction of Operator Product Expansion Coefficients
Holland, Jan; Hollands, Stefan
2015-06-01
We derive a novel formula for the derivative of operator product expansion (OPE) coefficients with respect to a coupling constant. The formula involves just the OPE coefficients themselves but no further input, and is in this sense self-consistent. Furthermore, unlike other formal identities of this general nature in quantum field theory (such as the formal expression for the Lagrangian perturbation of a correlation function), our formula requires no further UV-renormalization, i.e., it is completely well-defined from the start. This feature is a result of a cancelation of UV- and IR-divergences between various terms in our identity. Our proof, and an analysis of the features of the identity, is given for the example of massive, Euclidean theory in 4 dimensional Euclidean space. It relies on the renormalization group flow equation method and is valid to arbitrary, but finite orders in perturbation theory. The final formula, however, makes neither explicit reference to the renormalization group flow, nor to perturbation theory, and we conjecture that it also holds non-perturbatively. Our identity can be applied constructively because it gives a novel recursive algorithm for the computation of OPE coefficients to arbitrary (finite) perturbation order in terms of the zeroth order coefficients corresponding to the underlying free field theory, which in turn are trivial to obtain. We briefly illustrate the relation of this method to more standard methods for computing the OPE in some simple examples.
Recursive construction of operator product expansion coefficients
Holland, J
2014-01-01
We derive a novel formula for the derivative of operator product expansion (OPE) coefficients with respect to a coupling constant. The formula only involves the OPE coefficients themselves, and no further input, and is in this sense self-consistent. Furthermore, unlike other formal identities of this general nature in quantum field theory (such as the formal expression for the Lagrangian perturbation of a correlation function), our formula is completely well-defined from the start, i.e. requires no further UV-renormalization. This feature is a result of a cancelation of UV-divergences between various terms in our identity. Our proof, and an analysis of the features, of our identity is given for the example of massive, Euclidean $\\varphi^4$ theory in 4 dimensional Euclidean space, and relies heavily on the framework of the renormalization group flow equations. It is valid to arbitrary, but finite orders in perturbation theory. The final formula, however, makes no explicit reference to the renormalization group...
Oil sector expansion hits small road bump
Budd, G.
2002-04-01
Indications are that the upward production trend in Saskatchewan's oil industry, evident in recent years, will be reversed in 2002. Predictions are that the drop in production will be a modest one, reflecting the slower economy and the lag time between drilling activity and produced barrels of oil. Also a contributing factor is the fact that the year 2001 marked a decline of 20 per cent in oil well drilling from the previous year, down from 2,401 wells drilled to 1,931 wells. Expansions of last year such as PanCanadian's carbon dioxide project, Husky Energy's heavy oil project at Pike's Peak, northeast of Lloydminster, PanCanadian's SAGD project, Conoco's project at the Kerrobert Pool and Apache Canada's Midale area project southeast of Regina, are all likely to see more modest development during 2002. Similar retrenchment is expected at Nexen's (Wascana) Williston Basin area operations, due in part to the increased drilling cost resulting from the intense activity during 2001, and a 5 to 10 per cent rise in operating costs.
The optimizied expansion method for wavefield extrapolation
Wu, Zedong
2013-01-01
Spectral methods are fast becoming an indispensable tool for wave-field extrapolation, especially in anisotropic media, because of its dispersion and artifact free, as well as highly accurate, solutions of the wave equation. However, for inhomogeneous media, we face difficulties in dealing with the mixed space-wavenumber domain operator.In this abstract, we propose an optimized expansion method that can approximate this operator with its low rank representation. The rank defines the number of inverse FFT required per time extrapolation step, and thus, a lower rank admits faster extrapolations. The method uses optimization instead of matrix decomposition to find the optimal wavenumbers and velocities needed to approximate the full operator with its low rank representation.Thus,we obtain more accurate wave-fields using lower rank representation, and thus cheaper extrapolations. The optimization operation to define the low rank representation depends only on the velocity model, and this is done only once, and valid for a full reverse time migration (many shots) or one iteration of full waveform inversion. Applications on the BP model yielded superior results than those obtained using the decomposition approach. For transversely isotopic media, the solutions were free of the shear wave artifacts, and does not require that eta>0.
Perturbative expansions for area-preserving maps
Servizi, G.; Turchetti, G.
1986-10-11
The structure of perturbation series for area-preserving maps is investigated. A basically different behaviour is found between the Birkhoff series, which formally conjugate with circles all the orbits in a neighbourhood of the origin, and the series which map into circles the individual invariant curves with fixed diophantine winding number. The former series exhibit an asymptotic character, the latter a convergent one, as one should expect from the KAM theorem. The source of this difference is found to be the different way in which the contributions of the relevant resonances propagate. In the first case, if epsilon is the size of the divisor associated to a resonance M/N, then at each order n>N an epsilon/sup -1/ contribution occurs, in the second case subtle cancellations provide a new epsilon/sup -1/ only when a harmonic (that is n=pN) is reached. This precise asymptotic statement and the properties of the relevant resonances obtained from the continued fraction expansion allow us, in the case of quadratic irrationals, to understand the limit process which leads to divergence or convergence. In the divergent case the asymptotic properties of the series are exhaustively described.
Testing option pricing with the Edgeworth expansion
Balieiro Filho, Ruy Gabriel; Rosenfeld, Rogerio
2004-12-01
There is a well-developed framework, the Black-Scholes theory, for the pricing of contracts based on the future prices of certain assets, called options. This theory assumes that the probability distribution of the returns of the underlying asset is a Gaussian distribution. However, it is observed in the market that this hypothesis is flawed, leading to the introduction of a fudge factor, the so-called volatility smile. Therefore, it would be interesting to explore extensions of the Black-Scholes theory to non-Gaussian distributions. In this paper, we provide an explicit formula for the price of an option when the distributions of the returns of the underlying asset is parametrized by an Edgeworth expansion, which allows for the introduction of higher independent moments of the probability distribution, namely skewness and kurtosis. We test our formula with options in the Brazilian and American markets, showing that the volatility smile can be reduced. We also check whether our approach leads to more efficient hedging strategies of these instruments.
Theology and development as capability expansion
Séverine Deneulin
2016-05-01
Full Text Available For the last 25 years, human development has become part of official development discourses. It takes the normative position that the success of policies depends on whether they have expanded human flourishing, or expanded the ‘freedoms’ or ‘capabilities’ people have ‘reason to value’, as Amartya Sen would put it. It emphasises the importance of institutions to facilitate such expansion, and the agency of people to create such institutions. The ability of institutions to be conducive to human flourishing depends on the nature of human interaction. When human interaction no longer has the flourishing of other persons as its aim, it can create structures which then constrain human agency. The article argues that the human development perspective could be enriched by theological insights such as structural sin and the contribution of religious narratives to public reasoning. It concentrates on the idea of justice of one biblical parable, and illustrates its argument with examples from the Argentine labour context.
Is Hubble's Expansion due to Dark Energy
Gupta, R C
2010-01-01
{\\it The universe is expanding} is known (through Galaxy observations) since 1929 through Hubble's discovery ($V = H D$). Recently in 1999, it is found (through Supernovae observations) that the universe is not simply expanding but is accelerating too. We, however, hardly know only $4\\%$ of the universe. The Wilkinson Microwave Anisotropy Probe (WMAP) satellite observational data suggest $73\\%$ content of the universe in the form of dark-energy, $23\\%$ in the form of non-baryonic dark-matter and the rest $4\\%$ in the form of the usual baryonic matter. The acceleration of the universe is ascribed to this dark-energy with bizarre properties (repulsive-gravity). The question is that whether Hubble's expansion is just due to the shock of big-bang & inflation or it is due to the repulsive-gravity of dark-energy? Now, it is believed to be due to dark-energy, say, by re-introducing the once-discarded cosmological-constant $\\Lambda$. In the present paper, it is shown that `the formula for acceleration due to dark...
The Early Expansion of Cluster Cores
Bastian, N; Goodwin, S P; Trancho, G; Smith, L J; Konstantopoulos, I; Efremov, Yu
2008-01-01
The observed properties of young star clusters, such as the core radius and luminosity profile, change rapidly during the early evolution of the clusters. Here we present observations of 6 young clusters in M51 where we derive their sizes using HST imaging and ages using deep Gemini-North spectroscopy. We find evidence for a rapid expansion of the cluster cores during the first 20 Myr of their evolution. We confirm this trend by including data from the literature of both Galactic and extra-galactic embedded and young clusters, and possible mechanisms (rapid gas removal, stellar evolutionary mass-loss, and internal dynamical heating) are discussed. We explore the implications of this result, focussing on the fact that clusters were more concentrated in the past, implying that their stellar densities were much higher and relaxation times correspondingly shorter. Thus, when estimating if a particular cluster is dynamically relaxed, (i.e. when determining if a cluster's mass segregation is due to primordial or dy...
Host range expansion is density dependent.
Castagneyrol, Bastien; Jactel, Hervé; Brockerhoff, Eckehard G; Perrette, Nicolas; Larter, Maximilien; Delzon, Sylvain; Piou, Dominique
2016-11-01
The realized host range of herbivores is expected to increase with herbivore population density. Theory also predicts that trait similarity and phylogenetic relatedness between native and exotic plants is expected to increase the susceptibility of introduced plants to feeding by native herbivores. Whether the ability of native herbivores to extend their host range to introduced species is density dependent is still unknown. We addressed this question by monitoring pine processionary moth (PPM, Thaumetopoea pityocampa) attacks during nine consecutive years on 41 pine species (8 native and 33 introduced) planted in an arboretum. The survey encompassed latent and outbreak periods. A total of 28 pine species were attacked by PPM. There was no difference in the probability of attack between native and introduced pine species. Host range increased and was more phylogenetically clustered during outbreak than latent periods. When population density increased, PPM expanded its diet breadth by attacking introduced pine species that were closely related to native hosts. This study demonstrates the density dependence of host range expansion in a common pine herbivore. Importantly, it supports the idea that the degree of phylogenetic proximity between host species can be a better predictor of attacks than the introduction status, which may help to predict the outcomes of new plant-herbivore interactions.
Extended Analytic Device Optimization Employing Asymptotic Expansion
Mackey, Jonathan; Sehirlioglu, Alp; Dynsys, Fred
2013-01-01
Analytic optimization of a thermoelectric junction often introduces several simplifying assumptionsincluding constant material properties, fixed known hot and cold shoe temperatures, and thermallyinsulated leg sides. In fact all of these simplifications will have an effect on device performance,ranging from negligible to significant depending on conditions. Numerical methods, such as FiniteElement Analysis or iterative techniques, are often used to perform more detailed analysis andaccount for these simplifications. While numerical methods may stand as a suitable solution scheme,they are weak in gaining physical understanding and only serve to optimize through iterativesearching techniques. Analytic and asymptotic expansion techniques can be used to solve thegoverning system of thermoelectric differential equations with fewer or less severe assumptionsthan the classic case. Analytic methods can provide meaningful closed form solutions and generatebetter physical understanding of the conditions for when simplifying assumptions may be valid.In obtaining the analytic solutions a set of dimensionless parameters, which characterize allthermoelectric couples, is formulated and provide the limiting cases for validating assumptions.Presentation includes optimization of both classic rectangular couples as well as practically andtheoretically interesting cylindrical couples using optimization parameters physically meaningful toa cylindrical couple. Solutions incorporate the physical behavior for i) thermal resistance of hot andcold shoes, ii) variable material properties with temperature, and iii) lateral heat transfer through legsides.
Medicaid Expansion: A Tale of Two Governors.
Flagg, Robin
2016-10-01
This is a study of why two seemingly similar governors made divergent decisions on expanding Medicaid under the Patient Protection and Affordable Care Act (ACA). Performing a case study of Governors John Kasich (OH) and Scott Walker (WI), I explore the roles played by electoral pressures, political party, governor's ideology, the state's policy heritage, stakeholder advocacy, and the economy in each governor's decision about whether to expand Medicaid. Electoral pressure was the most significant factor for both governors. I demonstrate that even Walker succumbed to state electoral pressures and expanded Medicaid, albeit in a manner unique to Wisconsin. He did this despite his emphatic national rhetoric rejecting Obamacare and expansion. Additionally, existing state political institutions drove each governor to decide in a manner unique to his state: previous Medicaid decisions in Wisconsin and direct democracy in Ohio provided additional pressures and divergent starting points. The remaining factors served less as a driving force behind the decision and more as a frame to justify the decision ex post facto. Case studies allow for a more complex view of how political pressures fit together; differences can be explained and expanded, and an enhanced understanding of political processes can be gleaned.
Rectangle expansion A∗ pathfinding for grid maps
Zhang An
2016-10-01
Full Text Available Search speed, quality of resulting paths and the cost of pre-processing are the principle evaluation metrics of a pathfinding algorithm. In this paper, a new algorithm for grid-based maps, rectangle expansion A∗ (REA∗, is presented that improves the performance of A∗ significantly. REA∗ explores maps in units of unblocked rectangles. All unnecessary points inside the rectangles are pruned and boundaries of the rectangles (instead of individual points within those boundaries are used as search nodes. This makes the algorithm plot fewer points and have a much shorter open list than A∗. REA∗ returns jump and grid-optimal path points, but since the line of sight between jump points is protected by the unblocked rectangles, the resulting path of REA∗ is usually better than grid-optimal. The algorithm is entirely online and requires no offline pre-processing. Experimental results for typical benchmark problem sets show that REA∗ can speed up a highly optimized A∗ by an order of magnitude and more while preserving completeness and optimality. This new algorithm is competitive with other highly successful variants of A∗.
Structured Counseling for Auditory Dynamic Range Expansion.
Gold, Susan L; Formby, Craig
2017-02-01
A structured counseling protocol is described that, when combined with low-level broadband sound therapy from bilateral sound generators, offers audiologists a new tool for facilitating the expansion of the auditory dynamic range (DR) for loudness. The protocol and its content are specifically designed to address and treat problems that impact hearing-impaired persons who, due to their reduced DRs, may be limited in the use and benefit of amplified sound from hearing aids. The reduced DRs may result from elevated audiometric thresholds and/or reduced sound tolerance as documented by lower-than-normal loudness discomfort levels (LDLs). Accordingly, the counseling protocol is appropriate for challenging and difficult-to-fit persons with sensorineural hearing losses who experience loudness recruitment or hyperacusis. Positive treatment outcomes for individuals with the former and latter conditions are highlighted in this issue by incremental shifts (improvements) in LDL and/or categorical loudness judgments, associated reduced complaints of sound intolerance, and functional improvements in daily communication, speech understanding, and quality of life leading to improved hearing aid benefit, satisfaction, and aided sound quality, posttreatment.
Application of DAC Codeword Spectrum: Expansion Factor
Fang, Yong
2010-01-01
Distributed Arithmetic Coding (DAC) proves to be an effective implementation of Slepian-Wolf Coding (SWC), especially for short data blocks. To study the property of DAC codewords, the author has proposed the concept of DAC codeword spectrum. For equiprobable binary sources, the problem was formatted as solving a system of functional equations. Then, to calculate DAC codeword spectrum in general cases, three approximation methods have been proposed. In this paper, the author makes use of DAC codeword spectrum as a tool to answer an important question: how many (including proper and wrong) paths will be created during the DAC decoding, if no path is pruned? The author introduces the concept of another kind of DAC codeword spectrum, i.e. time spectrum, while the originally-proposed DAC codeword spectrum is called path spectrum from now on. To measure how fast the number of decoding paths increases, the author introduces the concept of expansion factor which is defined as the ratio of path numbers between two co...
di Pietro, L.; Komargodski, Z.; Shamir, I.; Stamou, E.
We study Quantum Electrodynamics in d = 3 (QED3) coupled to Nf flavors of fermions. The theory flows to an IR fixed point for Nf larger than some critical number N_f^c. For N_f ≤ N_f^c, chiral symmetry breaking is believed to take place. In analogy with the Wilson-Fisher description of the critical O(N) models in d = 3, we use the existence of a fixed point in d = 4 - 2∈ to study the three-dimensional theory. We show how the ∈-expansion can be used to study the anomalous dimension of 2- and 4-fermion operators. The latter leads to an estimate of the critical number N_f^c. An important novelty compared to the O(N) models is that, because of the structure of spinors, the theory in d = 3 has an enhanced symmetry. We identify the operators in d = 4 - 2∈ that correspond to the additional conserved currents at d = 3.
Local gravitational physics of the Hubble expansion
Kopeikin, Sergei
2014-01-01
We study physical consequences of the Hubble expansion of FLRW manifold on measurement of space, time and light propagation in the local inertial frame. We analyse the solar system radar ranging and Doppler tracking experiments, and time synchronization. FLRW manifold is covered by global coordinates (t,y^i), where t is the cosmic time coinciding with the proper time of the Hubble observers. We introduce local inertial coordinates x^a=(x^0,x^i) in the vicinity of a world line of a Hubble observer with the help of a special conformal transformation. The local inertial metric is Minkowski flat and is materialized by the congruence of time-like geodesics of static observers being at rest with respect to the local spatial coordinates x^i. We consider geodesic motion of test particles and notice that the local coordinate time x^0=x^0(t) taken as a parameter along the world line of particle, is a function of the Hubble's observer time t. This function changes smoothly from x^0=t for a particle at rest (observer's c...
Silva Villena Omer
2004-06-01
Full Text Available
E. Owens Robert (2003. Desarrollo del lenguaje. Madrid: Pearson Education, S.A. , 2003, (463 páginas. Estamos ante un texto destinado a entender el dominio o ámbito de la "psicolingüística del desarrollo" en el que terapeutas del lenguaje, psicólogos, profesores y lingüistas encontrarán información actualizada y amplia en lo que respecta a los avances que este campo ha experimentado en las dos últimas décadas. Tanto en las cinco ediciones en lengua inglesa desde 1998 a esta esperada edición en español, el propósito del autor es entregar una visión profunda de los procesos de adquisición y desarrollo del lenguaje.
Modelling autogenous expansion for magnesia concrete in arch dams
Feng JIN; Guoxin ZHANG; Xiaoqing LUO; Chuhan ZHANG
2008-01-01
Magnesia Concrete is a kind of expansive con-crete used in Chinese hydraulic engineering more and more widely. To evaluate the effects of autogenous expan-sion on the stresses of arch dams, a simple model of auto-genous expansion for Magnesia Concrete in dam engineering is presented. This model is based on three assumptions: 1) the total amount of autogenous expan-sion of Magnesia Concrete is related only to the properties of materials and mixing of concrete; 2) the autogenous expansion of Magnesia Concrete is irreversible due to the irreversibility of hydration reaction of Magnesia in the concrete; 3) the autogenous expansion strain rates of Magnesia Concrete bear a relation between temperature and residual Magnesia per unit volume of concrete. The model is verified by some experimental data of autogen-ous expansion of Magnesia Concrete and field-measured data of an arch dam in China. Embedded into finite ele-ment arch dam simulation software, this model is employed to simulate the effects of autogenous expansion of Magnesia Concrete in hydraulic engineering.
Acoustic waves in shock tunnels and expansion tubes
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.
Convergence of Wavelet Expansions in the Orlicz Space
Chang Mei TAN
2011-01-01
In this paper we study the convergence in norm and pointwise convergence of wavelet expansion in the Orlicz spaces, and prove that, under certain conditions on the wavelet, the wavelet expansion converges in the Orlicz-norm and also converges almost everywhere.
17 CFR 240.17Ad-3 - Limitations on expansion.
2010-04-01
... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Limitations on expansion. 240.17Ad-3 Section 240.17Ad-3 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... expansion. (a) Any registered transfer agent which is required to file any notice pursuant to §...
Harmonious Expansion of China's Higher Education: A New Growth Pattern
Gu, Jiafeng
2012-01-01
How can one country narrow the regional disparity during the tremendous expansion of higher education? This issue remains unexamined and critical analysis is needed to unveil the spatial dynamics behind expansion of higher education. The spatial analysis shows that there is significant strategic interaction among neighboring provinces in China…
Endoscopic Approach for Tissue Expansion for Different Cosmetic ...
xp
Results: Twenty two expanders were inserted in 15 cases .operating time ranged ... Conclusion: Tissue expansion in the pediatric population has its implication in ... he concept of tissue expansion in surgical practice .... compressed but show no evidence of degeneration. ... increased risk of expander related complications.
Did the Higgs boson drive the universe's expansion?
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.
Rational Expansion for Nonlinear Input-Output Maps
1988-01-01
This paper introduces a Rational Expansion for Nonlinear Input-Output MAPS. The method is new and is based on the rational expansion of functions of several complex variables. If truncated, this series reduces to a ratio of truncated Volterra series, A "feedback form" will be presented.
URBAN EXPANSION AND LOSS OF AGRICULTURAL LAND IN ...
Dr Osondu
1987-09-23
Sep 23, 1987 ... technology and field studies were applied to carry out this research. ... urban Expansion, Agricultural Land, Home Garden, Agricultural Business ... factors. Urban expansion appears to have direct effect ... about increase in population and human activities, ... area boundary, georeferencing of the digital data,.
Expansion of U. S. uranium enrichment capacity. Final environmental statement
1976-04-01
Reasonably foreseeable environmental, social, economic, and technological costs and benefits of postulated expansion of U. S. enrichment capacity through the year 2000 and reasonably available alternatives to such expansion are described. Both the gas centrifuge and gaseous diffusion methods for the enrichment of uranium are considered in this impact assessment. (JGB)
Series Expansion of Functions with He's Homotopy Perturbation Method
Khattri, Sanjay Kumar
2012-01-01
Finding a series expansion, such as Taylor series, of functions is an important mathematical concept with many applications. Homotopy perturbation method (HPM) is a new, easy to use and effective tool for solving a variety of mathematical problems. In this study, we present how to apply HPM to obtain a series expansion of functions. Consequently,…
Studies of Expansive Learning: Foundations, Findings and Future Challenges
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.
Asymptotic expansions for high-contrast linear elasticity
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.
New optical field operator expansion in number state representation
Yang Yang; Fan Hong-Yi
2013-01-01
By virtue of the Weyl ordering method,we find a new formalism of optical field operator expansion in number state representation.Miscellaneous optical fields' (coherent state,squeezed field,Wigner operator,etc.) new expansions are therefore exhibited.Some new generating functions of special polynomials are derived herewith.
Anode Plasma Expansion in Pinch-Reflex Diodes.
1983-08-16
the expansion. Prono et a12 have studied a charge-exchange mechanism to account for the large expansion velocity but this mechanism does not explain...1978). 2. D. S. Prono , H. Ishizuka, E. P. Lee, B. W. Stallard and W. C. Turner, J. App. Phys. 52, 3004 (1981). 3. S. A. Goldstein, D. W. Swain, G. R
Dynamics of Organizational Expansion in National Systems of Education.
Carroll, Glenn R.
1981-01-01
Using a nonlinear differential equation model based on ecological theory to explain differences in the speed of expansion in national systems of education, suggests that organizational expansion in large, geographically decentralized systems follows a process of logistic growth with a ceiling set by environmental resources. (Author/GC)
34 CFR 361.35 - Innovation and expansion activities.
2010-07-01
... Council, consistent with the plan prepared under 34 CFR 364.21(i). (b) The State plan must— (1) Describe... 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 convergence theorem for asymptotic expansions of Feynman amplitudes
Mabouisson, A.P.C. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)
1999-06-01
The Mellin representations of Feynman integrals is revisited. From this representation, and asymptotic expansion for generic Feynman amplitudes, for any set of invariants going to zero or to {infinity}, may be obtained. In the case of all masses going to zero in Euclidean metric, we show that the truncated expansion has a rest compatible with convergence of the series. (author)
Cross-Symmetric Expansion of $\\pi \\pi$ Amplitude Near Threshold
Bolokhov, A A; Manida, I S; Polyakov, M V; Sherman, S G
1996-01-01
The near-threshold expansion of the $\\pi \\pi$ amplitude is developed using the crossing-covariant independent variables. The independent threshold parameters entering the real part of the amplitude in an explicitly Lorentz-invariant way are free from restrictions of isotopic and crossing symmetries. Parameters of the expansion of the imaginary part are recovered by the perturbative unitarity relations.
14 CFR 27.969 - Fuel tank expansion space.
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...
14 CFR 25.969 - Fuel tank expansion space.
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...
14 CFR 29.969 - Fuel tank expansion space.
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...
Electric Grid Expansion Planning with High Levels of Variable Generation
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
Differential expansion of space and the Hubble flow anisotropy
Bolejko, Krzysztof; Wiltshire, David L
2015-01-01
The Universe on scales $10-100~h^{-1}$ Mpc is dominated by a cosmic web of voids, filaments, sheets and knots of galaxy clusters. These structures participate differently in the global expansion of the Universe: from non-expanding clusters to the above average expansion rate of voids. In this paper we characterize Hubble expansion anisotropies in the COMPOSITE sample of 4534 galaxies and clusters. We concentrate on the dipole and quadrupole in the rest frame of the Local Group. These both have statistically significant amplitudes. These anisotropies, and their redshift dependence, cannot be explained solely by a boost of the Local Group in the Friedmann-Lema\\^{i}tre-Robertson-Walker (FLRW) model which expands isotropically in the rest frame of the cosmic microwave background (CMB) radiation. We simulate the local expansion of the Universe with inhomogeneous Szekeres models, which match the standard FLRW model on $> 100~ h^{-1}$ Mpc scales but exhibit nonkinematic differential expansion on small scales. We res...
NUMERICAL METHOD AND RANDOM ANALYSIS OF CEMENT CONCRETE EXPANSION
无
2000-01-01
The numerical method and random analysis of cement concrete expansion are given. A mathematical procedure is presented which includes the nonlinear characteristics of the concrete. An expression is presented to predict the linear restrained expansion of expansive concrete bar restrained by a steel rod. The results indicate a rapid change in strains and stresses within initial days, after which the change gradually decreases. A reliable and accurate method of predicting the behavior of the concrete bulkheads in drifts is presented here. Extensive sensitivity and parametric studies have been performed. The random density distributions of expansive concrete are given based on the restricted or unrestricted condition. These studies show that the bulkhead stress fields are largely influenced by the early modulus of the concrete and the randomness of the ultimate unrestrained expansion of the concrete.
Micro-architected Composite Lattices with Tunable Negative Thermal Expansions
Wang, Qiming
Solid materials with minimum or negative thermal expansion (NTE) have broad applications, from dental fillings to thermal-sensitive precision instruments. Previous studies on NTE structures were mostly focused on theoretically design and 2D experimental demonstrations. Here, aided with multimaterial projection micro-stereolithography, we experimentally fabricate multi-material composite lattices that exhibit significant negative thermal expansion in three directions and over a large range of temperature variations. The negative thermal expansion is induced by the structural interaction of material components with distinct thermal expansion coefficients. The NTE performance can be tuned over a large range by varying the thermal expansion coefficient difference between constituent beams and geometrical arrangement. Our experimental results match qualitatively with a simple scaling law and quantitatively consistently with computational models.
Thermal expansion accompanying the glass-liquid transition and crystallization
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.
Mechanism of actuation in conducting polymers: Osmotic expansion
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 expansi...... and designing actuator experiments and when comparing experimental results from different sources.......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...
Expansive Learning in Construction Projects - a Contradiction in terms?
Klitgaard, Anne; Nissen, Søren Bülow; Beck, Frederikke
2016-01-01
of a workshop was conducted where coordination and collaboration meetings were observed. The data was analysed using activity theory and the expansive learning model. The analysis shows that the strong focus on object by project’s activity system hinders expansive learning. The students learned through...... acquisition and participation but not by expansive learning. The construction industry needs to accept that the learning generated from projects will be limited to learning by acquisition and participation. The interorganizational network cannot facilitate expansive learning while working on object......This research is a preliminary study performed as part of a primary research into expansive learning in interorganizational network set up to solve a construction project. The construction industry has long had issues about productivity, which can be an indication of lack of learning. A case study...
Expansion of IFC model with structural sensors
Rio, J.
2013-06-01
Full Text Available The instrumentation and structural health monitoring, SHM, of buildings is a growing field in the construction industry. The goal of this research work is to explore ways of modeling SHM systems, and the resulting data collected from buildings, in standard information management system such as Building Information Models, BIM. These models need to be stored in digital databases with structures suitable for the specific building related information. In this work the Industry Foundation Classes, IFC, data model was used. A case study is presented to assess the applicability of the present IFC standard as a tool to build a three-dimensional digital model of a real instrumented building, as well as some of the structural sensors and their results. The interoperability of the digital model was verified by using different modeling, viewing and analysis software tools. Limitations of the current IFC model were explored and extensions to the sensor classes are proposed.La instrumentación y monitorización de la salud estructural de edificios, SHM, es un campo creciente en la industria de la construcción. El objetivo del presente trabajo es estudiar la modelación de sistemas SHM tomados de edificios en un modelo digital BIM e la sua integración de datos. Estos modelos deben almacenarse en bases de datos con una estructura apropiada para albergar información específica relacionada con la construcción. En este trabajo se utilizó el estándar Industry Foundation Classes, IFC. Se presenta un estudio de caso para evaluar la norma IFC como herramienta para modelar un edificio real instrumentado, así como algunos sensores estruturales e sus resultados. La inter-operatividad de lo modelo digital se ha comprobado mediante el uso de diferentes herramientas de software de modelación, visualización y análisis. Se exploran además limitaciones del modelo IFC y se proponen extensiones de las clases de sensores.
La crisi del diritto del lavoro
Alessandro Garilli
2012-01-01
Full Text Available Riassunto - L’Autore ripercorre in chiave critica l’evoluzione delle politiche legislative in materia di lavoro, alla luce dell’attuale fase di crisi economico finanziaria. Nell’esaminare i principali interventi normativi attuati da inizio secolo, l’Autore mette in evidenza le scelte di metodo e gli elementi di continuità che accomunano i vari provvedimenti, individuandoli nell’affannosa ricerca del punto di equilibrio tra flessibilità e garantismo. La riflessione si chiude con alcuni interrogativi sulle ultime linee di riforma del mercato del lavoro e con l’auspicio che, anche al cospetto delle imprescindibili ragioni dell’economia, il diritto del lavoro possa continuare a svolgere il proprio tradizionale ruolo di disciplina di tutela della persona. Abstract - The author analyzes, with a critically oriented approach, the development of the employment law, in the light of the current economic and financial crisis. In examining the main regulatory measures implemented since the beginning of the century, the author highlights the methodological choices and the elements of continuity that unite the various measures, focusing them in a hard research of a point of balance between flexibility and security. The discussion concludes with some questions about the last lines of the reform of the labor market and with the hope that, even in the face of compelling reasons of economy, labor law can continue to play its traditional role of governing the protection of person.
OBJETIVO DEL DESARROLLO DEL MILENIO 7
Margarita M. Pérez O.
2013-10-01
Full Text Available Los Objetivos de Desarrollo del Milenio, también conocidos como los Objetivos del Milenio, constituyeron las metas finales que aprobaron los dirigentes mundiales, 189 jefes de estado y de gobierno en la Cumbre del Milenio de las Naciones Unidas celebrada en Nueva York en el año 2000, en la cual los Estados miembros de la organización reafirmaron su compromiso de luchar por un mundo en el que el desarrollo sostenible y la eliminación de la pobreza tuvieran máxima prioridad1 . En la cumbre se definió la Declaración del Milenio, la cual detalla los objetivos, principios, valores, metas y acciones para erradicar la pobreza Mundial hacia el año 2015, todos ellos ratificados con alto interés y acción estratégica de carácter global, como marco para la medición de los progresos en materia de desarrollo.
Elementos del sistema electoral del Congreso Mexicano
Aldo Medina García
2013-08-01
Full Text Available El presente artículo es un estudio de los componentes del sistema electoral, diseñado por el legislador mexicano para integrar al parlamento federal. Estudio desarrollado a sabiendas de la importancia que reviste el sistema electoral como un medio que permite a los ciudadanos convertir su voto expresado en las urnas en escaños a favor de determinado candidato o partido. En dicho análisis tomamos en cuenta la evolución constitucional del sistema electoral mexicano, la participación de las fuerzas minoritarias en la integración del Senado y de la Cámara de Diputados, la división que se hace del territorio en circunscripciones electorales, la barrera electoral que se fija a los partidos políticos para acceder a la representación en el Parlamento, la fórmula de asignación que se aplica a la votación obtenida, para finalmente concluir que el sistema electoral mexicano es esencialmente mayoritario aun cuando se vista de proporcional.
Elementos del sistema electoral del Congreso Mexicano
Aldo Medina García
2013-07-01
Full Text Available El presente artículo es un estudio de los componentes del sistema electoral, diseñado por el legislador mexicano para integrar al parlamento federal. Estudio desarrollado a sabiendas de la importancia que reviste el sistema electoral como un medio que permite a los ciudadanos convertir su voto expresado en las urnas en escaños a favor de determinado candidato o partido. En dicho análisis tomamos en cuenta la evolución constitucional del sistema electoral mexicano, la participación de las fuerzas minoritarias en la integración del Senado y de la Cámara de Diputados, la división que se hace del territorio en circunscripciones electorales, la barrera electoral que se fija a los partidos políticos para acceder a la representación en el Parlamento, la fórmula de asignación que se aplica a la votación obtenida, para finalmente concluir que el sistema electoral mexicano es esencialmente mayoritario aun cuando se vista de proporcional.
A meta-analysis of global urban land expansion.
Karen C Seto
Full Text Available 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.
A meta-analysis of global urban land expansion.
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.
Valverde Sánchez, Ricardo
2016-06-01
Full Text Available El pronosticado ascenso en el nivel medio del mar convierte a los litorales costarricenses en espacios vulnerables. Las características geomorfológicas predominantes de la costa pacífica costarricense, consistente de playas en el frente de llanuras aluviales y marismas, convierte a esta región en una zona susceptible a la expansión marina como resultado del ascenso del nivel del mar. Es bajo este contexto que la presente investigación busca analizar la vulnerabilidad de poblaciones y ecosistemas costeros, en una unidad geográfica específica del litoral del pacífico sur costarricense: el manglar del Humedal Nacional Térraba-Sierpe (HNTS, así como dotar a estos entornos y comunidades humanas dependientes de los mismos de herramientas que ayuden a reducir su vulnerabilidad. El análisis socioespacial evidencia espacios costeros donde coexisten poblaciones humanas y bosques de mangle vulnerables a la trasgresión y expansión marinas asociadas con el ascenso del nivel del mar. La percepción de la población consultada y las observaciones de campo, constatan que el crecimiento del nivel del mar constituye un factor que está generando modificaciones en la dinámica costera, con las consecuentes repercusiones sobre el manglar y sus poblaciones. The geomorphologic traits of Costa Rica's Pacific coastline, consisting of beachfronts on coastal plains and sea marshes, turn it into a vulnerable spatial unit to the predicted rise in the average sea level with its subsequent sea water expansion. Under this scenario, the current research focuses on analyzing the vulnerability of coastal ecosystems and their human settlements, in a specific geographical unit of Costa Rica's south Pacific coast: The mangrove of the Terraba-Sierpe National Wetland, as well as on providing these surroundings and their depending communities with some tools oriented to diminish their vulnerability. The socio-spatial analysis shows coastal areas with human populations
Influencia del manejo del riego en el rendimiento del cafeto
Enrique Cisneros Z.
2006-01-01
Full Text Available El trabajo trata sobre una investigación de manejo del riego en el cafeto (Coffea Arábica Lin Var. Caturra Rojo de 12 años de edad en la provincia de Pinar del Rió, plantado sobre un suelo Ferralítico Amarillento Lixiviado Cuarcitico. Fueron estudiados 6 tratamientos con un diseño experimental de bloques al azar, el momento de riego y el volumen de aplicación se controló por el método gravimétrico. La técnica de riego empleada fue la microaspersión bajo el principio de cobertura total (no localizada. Como promedio de los cuatro años de estudio se obtuvo que el mejor tratamiento fue el de regar todo el año al 85 % del límite superior de agua disponible, donde fue necesario aplicar 21 riegos con norma parcial neta de 355 m3/ha y norma total neta de 7 455 m3/ha, esta variante produjo 17,94 t/ha de café cereza para un incremento de 3,98 t/ha (29 % con respecto al secano. La rentabilidad más alta se detectó en el tratamiento de riego todo el año (Tratamiento 1 con 236,93 % en comparación con el testigo (Tratamiento 6
Spatial Assortment of Mixed Propagules Explains the Acceleration of Range Expansion
Andriamihaja Ramanantoanina; Aziz Ouhinou; Cang Hui
2014-01-01
Range expansion of spreading organisms has been found to follow three types: (i) linear expansion with a constant rate of spread; (ii) bi-phase expansion with a faster linear expansion following a slower linear expansion; and (iii) accelerating expansion with a continuously increasing rate of spread. To date, no overarching formula exists that can be applied to all three types of range expansion. We investigated how propagule pressure, i.e., the initial number of individuals and their composi...
Multivariable Lagrange expansion and generalization of Carlitz-Srivastava mixed generating functions
Dattoli, G. [ENEA, Centro Ricerche Frascati, Rome (Italy). Dipt. Innovazione; Lorenzutta, S. [ENEA, Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Innovazione; Sacchetti, D. [Rome Univ. La Sapienza, Rome (Italy). Dipt. di Statistica, Probabilita' e Stat. Applicate
1999-07-01
Families of mixed generating functions, generalizing those of the Carlitz-Srivastava type, are derived by exploiting methods based on the multivariable extension of the Lagrange expansion. It is also shown that the combination with techniques of operational nature offers a wide flexibility to explore a wealth of mixed bilateral generating functions for special functions with many variables. [Italian] In questo lavoro si derivano famiglie di funzioni generatrici che generalizzano quelle del tipo Carlitz-Srivastava. I metodi utilizzati sono basati su una estensione a piu' variabili della espansione di Lagrange. Si dimostra anche che una opportuna combinazione con tecniche di natura operatoriale offre un'ampia flessibilita' per lo studio di funzioni generatrici viste per funzioni speciali con piu' variabili.
Kolmogorov turbulence by matched asymptotic expansions
Lundgren, Thomas S.
2003-04-01
The Kolmogorov [Dokl. Akad. Nauk. SSSR 30, 299 (1941), hereafter K41] inertial range theory is derived from first principles by analysis of the Navier-Stokes equation using the method of matched asymptotic expansions without assuming isotropy or homogeneity and the Kolmogorov (K62) [J. Fluid Mech. 13, 82 (1962)] refined theory is analyzed. This paper is an extension of Lundgren [Phys. Fluids 14, 638 (2002)], in which the second- and third-order structure functions were determined from the isotropic Karman-Howarth [Proc. R. Soc. London, Ser. A 164, 192 (1938)] equation. The starting point for the present analysis is an equation for the difference in velocity between two points, one of which is a Lagrangian fluid point and the second, slaved to the first by a fixed separation r, is not Lagrangian. The velocity difference, so defined, satisfies the Navier-Stokes equation with spatial variable r. The analysis is carried out in two parts. In the first part the physical hypothesis is made that the mean dissipation is independent of viscosity as viscosity tends to zero, as assumed in K41. This means that the mean dissipation is finite as Reynolds number tends to infinity and leads to the K41 inertial range results. In the second part this dissipation assumption is relaxed in an attempt to duplicate the K62 theory. While the K62 structure is obtained, there are restrictions, resulting from the analysis which shows that there can be no inertial range intermittency as Reynolds number tends to infinity, and therefore the mean dissipation has to be finite as Reynolds number tends to infinity, as assumed in part one. Reynolds number-dependent corrections to the K41 results are obtained in the form of compensating functions of r/λ, which tend to zero slowly like Rλ-2/3 as Rλ→∞.
Anisotropic expansion and SNIa: An open issue
Jose Beltrán Jiménez
2015-02-01
Full Text Available We review the appropriateness of using SNIa observations to detect potential signatures of anisotropic expansion in the Universe. We focus on Union2 and SNLS3 SNIa datasets and use the hemispherical comparison method to detect possible anisotropic features. Unlike some previous works where non-diagonal elements of the covariance matrix were neglected, we use the full covariance matrix of the SNIa data, thus obtaining more realistic and not underestimated errors. As a matter of fact, the significance of previously claimed detections of a preferred direction in the Union2 dataset completely disappears once we include the effects of using the full covariance matrix. Moreover, we also find that such a preferred direction is aligned with the orthogonal direction of the SDSS observational plane and this suggests a clear indication that the SDSS subsample of the Union2 dataset introduces a significant bias, making the detected preferred direction unphysical. We thus find that current SNIa surveys are inappropriate to test anisotropic features due to their highly non-homogeneous angular distribution in the sky. In addition, after removal of the highest inhomogeneous sub-samples, the number of SNIa is too low. Finally, we take advantage of the particular distribution of SNLS SNIa sub-sample in the SNLS3 data set, in which the observations were taken along four different directions. We fit each direction independently and find consistent results at the 1σ level. Although the likelihoods peak at relatively different values of Ωm, the low number of data along each direction gives rise to large errors so that the likelihoods are sufficiently broad as to overlap within 1σ.
Health-Related Outcomes among the Poor: Medicaid Expansion vs. Non-Expansion States.
Xuesong Han
Full Text Available States' decisions not to expand Medicaid under the Affordable Care Act (ACA could potentially affect access to care and health status among their low-income residents.The 2010-2012 nationally representative Medical Expenditure Panel Survey data were analyzed in 2015 to compare 9755 low-income adults aged 18-64 years from Medicaid-expanding states with 7455 adults from nonexpanding states. Multivariate logistic regression models were fitted to evaluate the differences in access to care, receipt of preventive services, quality of care, attitudes about health and self-reported health status by Medicaid expansion status. The differences in care utilization and medical expenditures between the two groups were examined using a 2-part modeling approach.Compared to their counterparts in Medicaid expansion states, low income adults in the nonexpanding states were more likely to be black and reside in rural areas and were less likely to have a usual source of care (prevalence ratio[PR] 0.86, 95% confidence interval[CI] 0.82-0.91 and recommended preventive services such as dental checkups (PR = 0.86; CI = 0.79-0.94, routine checks (PR = 0.89; CI = 0.83-0.95, flu vaccinations (PR = 0.89; CI = 0.81-0.98, and blood pressure checks (PR = 0.96; CI = 0.94-0.99. They also had less care utilization, fewer prescriptions, and less medical expenditures, but more out-of-pocket expenditures (all p-value <0.05.Low-income adults in Medicaid nonexpanding states, who are disproportionately represented by blacks and rural residents, were worse off for multiple health-related outcomes compared to their counterparts in Medicaid expanding states at the baseline of ACA implementation, suggesting that low income adults residing in nonexpanding states may benefit markedly from the expansion of Medicaid.
Del Ver y del Decir en Merleau-Ponty
Mont Verdaguer, Maria
2016-01-01
[spa] El presente trabajo busca determinar la relación entre los ejes del lenguaje y la visión como entidades propias y fundantes del saber a través de la obra de Merleau-Ponty. Se trata pues de comprender cómo y en qué medida las dimensiones lingüística y visual del conocer construyen en el hombre un poso de conocimiento, un asiento positivo del saber. A partir del estudio de la evolución del primer al segundo Merleau-Ponty y del anàlisis de algunos de sus conceptos fundamentales tales co...
Secretos del test extraterrestre
Hybris, Profesor
2016-01-01
Por el parasicólogo y astrólogo Profesor Hybris La prensa mundial ha revelado recientemente los detalles del extraño caso de Asdrúbal Carrasquilla, el camionero chileno que desapareciera misteriosamente en su país, ante el asombro de varios automovilistas que lo vieron desvanecerse en el aire, junto con su camión, en la muy transitada vía entre Las Fraguas y San Venancio, en la provincia chilena de Valverde. El hecho ocurrió a las 16.55 del 15 de diciembre de 1981. A las 16.58 del mismo día, ...
Aspectos sociales del emprendedor
2014-01-01
Hoy en día es de vital importancia el papel de los emprendedores en la sociedad. Por lo que, es importante analizar los aspectos sociales que les rodean, los que influyen para tomar la decisión de crear una nueva empresa y adentrarse en el mundo del emprendimiento. A partir de esta realidad, se busca explicar, mediante un estudio bibliográfico de la literatura científica del emprendimiento, y más tarde con un análisis de datos obtenidos del GEM 2012, GEM 2013, y otros facilitados por el p...
Santiago Salas Espinosa
2009-07-01
Full Text Available El presente ensayo pretende abarcar algunos puntos de vista (no todos, en lo concerniente a la Razón de la Sinrazón del Derecho. Sí, por decirlo así, se puede o ha podido pensarse en una razón del Derecho, por qué cuánto más no, en una “sinrazón” o más bien unas cuántas “sinrazones” del mismo.
Hipertrofia del proceso coronoideo
E. Moretti
2014-06-01
Full Text Available Entre las principales causas de la reducción progresiva y sin dolor de la apertura bucal en pacientes jóvenes, se encuentra la denominada hipertrofia del proceso coronoideo. Se trata de una patología secundaria a la elongación anormal del proceso coronoideo por el crecimiento del hueso que provoca una alteración mecánica al abrir la boca. Presentamos nuestra experiencia con la recogida de 5 casos clínicos.
Guerrero-Anaya, Luis J.; Núñez-DelaPeña, Francisco J.
1985-01-01
En la primera parte del artículo se analizan, como antecedentes remotos de la fundación del ITESO, la inserción en el artículo tercero constitucional, del calificativo "socialista" a la educación, que causa el inicio de la educación privada en México, y se plantea el ambiente local en Guadalajara, marcado por la clausura de la Universidad de Guadalajara (1934-1937) y la fundación de la Universidad Autónoma de Guadalajara (1935). En la segunda parte se presentan algunos hitos de la expansión d...
Mario Bernardo Figueroa Muñoz
2009-01-01
La palabra del delator es degradada:deja de constituir un mensajeen el que se articula el deseo delsujeto para quedar convertida enobjeto. El delator, reducido a puravoz, es instrumentalizado paracompletar al Otro. La voz es causaen el imperativo al heroísmo, a laobediencia. Aquello del cuerpoque debe ser sacrificado para queel lenguaje opere en el sujeto, esrecuperado en la delación. A estosplanteamientos se llega a partir delanálisis del material de divulgaciónde una campaña para fomentarla...
Estenosis malignas del estomago
Jácome Valderrama, José A.; Gutiérrez Arango, Roberto; Parra Torres, Augusto; Forero Laverde, Humberto; Medina Medina, Julio
2011-01-01
Al hablar de estenosis malignas del estomago, no vamos a referirnos a las obstrucciones producidas por lesiones extrínsecas, en las cuales influye como causa determinante el fenómeno mecánico de compresión exterior, sino a aquellas lesiones que primitivamente se originan en los tejidos del estomago, vale decir en sus paredes u orificios. Las estenosis intrínsecas malignas del estomago son producidas generalmente por tumores derivados de sus diferentes tejidos y por consiguiente se agrupan en ...
Envejecimiento del sistema cardiovascular
2005-01-01
Las principales características del envejecimiento del sistema cardiovascular reflejan cambios anatómicos y estructurales a nivel de la pared de los vasos, la relajación miocárdica, el llenado ventricular y la respuesta a las catecolaminas . Muchos de los cambios funcionales asociados con la edad están relacionados con estos fenómenos. Esta revisión describe los cambios relacionados con el envejecimiento a nivel estructural y funcional del sistema cardiovascular, sus posibles factores etiológ...
Hipertrofia del proceso coronoideo
Moretti, E.; I.O. Cal; Galetto, M.; L. Londoño; Blanco, R
2014-01-01
Entre las principales causas de la reducción progresiva y sin dolor de la apertura bucal en pacientes jóvenes, se encuentra la denominada hipertrofia del proceso coronoideo. Se trata de una patología secundaria a la elongación anormal del proceso coronoideo por el crecimiento del hueso que provoca una alteración mecánica al abrir la boca. Presentamos nuestra experiencia con la recogida de 5 casos clínicos.
Robles, Fernanda
2012-01-01
El pie equino varo es una patología frecuente en los pacientes con Encefalopatía crónica no evolutiva (ECNE).Se observó que existe una mayor frecuencia en el sexo masculino. Se realizó un estudio descriptivo, comparativo y secundario, durante el periodo de septiembre del 2006 a septiembre del 2011, con un total de 125 pacientes con Ecne, de los cuales se encontraron 101 con pie equino varo congénito. Objetivo: observar los resultados obtenidos en la rehabilitación del pie equino, en niños de ...
Torres-Silva,H; J.L. López-Bonilla
2011-01-01
El grafeno, una alotropía del carbono, es un logro de los avances de la nanotecnología. Siendo una nanoestructura, este componente estructural del grafito posee propiedades que lo han convertido en un potencial sustituto del silicio en el diseño y fabricación de circuitos integrados. Este artículo resume sus orígenes, posibilidades teóricas, así como sus propiedades prácticas. Se presentan aspectos teóricos de quiralidad en el grafeno, específicamente una teoría quiral para el grafeno, vincul...
Sánchez-Biosca, Vicente
1990-01-01
Habría de ser de nuevo John Ford quien sentenciará la defunción del western en cuanto mito, su imposibilidad de construirse en el vacío de la historia. Y habría de ser en uno de los más lúcidos films de la historia del cine: The Man who shot Liberty Valance (El hombre que mató a Liberty Valance, 1962). Todo en este film posee un reverso: un viaje en ferrocarril abre paso al pueblecito de Shinbone. Pero, en el interior del relato, otro emprendido por el antes pionero y ho...
Raffo Lecca, Eduardo; FII-UNMSM
2014-01-01
Este es un famoso problema desde los anales de la literatura en investigación de operaciones. G. Dantzig en [1] se refiere a W.W. Jacobs con su paper "The Caterer Problem" del Nav. Res. Log. Quart. 1, 1954; como también a Gaddum, Hoffman y Sokolowsky en "On the Solution of the Caterer Problem" del Naval Res, Logist. Quart., Vol. 1, N°3, september, 1954 y a William Prager en "On the Caterer Problem" del Management Sci., Vo...
Bimaxillary expansion therapy for pediatric sleep-disordered breathing.
Quo, Stacey D; Hyunh, Nelly; Guilleminault, Christian
2017-02-01
The aim of this retrospective study was to evaluate the results of bimaxillary expansion as a treatment option for pediatric sleep-disordered breathing. Forty-five children, aged 3-14 years, with sleep-disordered breathing underwent bimaxillary expansion. They were subjected to baseline clinical evaluations, cephalometric X-rays, and polygraphic sleep studies. Three to six months after bimaxillary expansion, posttreatment sleep studies were performed. Data were analyzed with nonparametric Wilcoxon signed-rank test, and Spearman's correlations were performed to correlate cephalometric facial structures to the effectiveness of treatment. The majority of the children (n = 30) showed improvement in their sleep scores and symptoms after bimaxillary expansion. The initial severity of the obstructive sleep apnea (OSA) indicated by the apnea-hypopnea index (AHI) was a much better predictor of positive results. However, in the "mild OSA" group, patients with smaller MP-SN or counterclockwise mandibular growth, worsened with bimaxillary expansion, while patients with clockwise mandibular growth showed greater improvement; in the "severe OSA" group, patients who initially had shorter mandibular base lengths showed lesser AHI improvements. Bimaxillary expansion can be a treatment option for improving respiratory parameters in children with sleep-disordered breathing. This study also suggests that retrognathia in an anterior growth rotation pattern may not respond to efforts of bimaxillary expansion. Copyright © 2016 Elsevier B.V. All rights reserved.
Controlling Thermal Expansion: A Metal-Organic Frameworks Route.
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.
On the stress-free lattice expansion of porous cordierite
Bruno, Giovanni, E-mail: brunog@corning.com [Corning SAS, CS and S, CETC, F-77210 Avon (France); Efremov, Alexander M. [Corning Inc., Modeling and Simulation, CSC, St Petersburg, 194021 (Russian Federation); Clausen, Bjorn [Los Alamos National Laboratory, LANSCE, Los Alamos, NM 87545 (United States); Balagurov, Anatoly M.; Simkin, Valeriy N. [FLNP, JINR, Dubna, 141980 (Russian Federation); Wheaton, Bryan R.; Webb, James E. [Corning Inc., CS and S, SP, Corning, NY 14830 (United States); Brown, Donald W. [Los Alamos National Laboratory, LANSCE, Los Alamos, NM 87545 (United States)
2010-04-15
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 {mu}m particle size) cannot be considered completely stress-free. This conclusion is supported by microstructural observations.
Asymptotic expansions for high-contrast elliptic equations
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.
Minerals of expansive and non-shrinkage sulfomineral cements
Samchenko Svetlana V.
2017-01-01
Full Text Available Usually to obtain expansive cements sulfoaluminate clinker or mix aluminate clinker with calcium sulfates (gypsum, hemihydrate, anhydrate are used. For these cements ettringite is an important hydration product and kinetic reaction of this phase plays an important role in determinаting performance. The alternative aluminate phases may be ferrite containing ones. This article deals with the composition and properties of solid solution of calcium sulfoaluminate, sulfoferrite and sulfoaluminoferrite cements. It was studied an influence of calcium sulfate on structure and properties of calcium aluminate and ferrite phases, and their stability under high temperatures. Beside that the properties of cements containing these phases were studied. The investigation of hydration and properties of sulfomineral cements shows that ettringite and its analogies are formed in such way to provide expansion and compression of cement stone. Degree of expansion and self-stressing of cement stone depends not only on composition of sulfated minerals but on ratio and types of clinkers. The higher expansion is reached by the use of high alite containing Portland cement clinker together with sulfoaluminate or sulfoalumoferrite one, the lower expansion is reached by addition of sulfoalumoferrite and sulfoferrite clinkers. These cements are classified as self-stressing, expansive or shrinkage-compensating ones depend on the degree of their expansion after 28 days of curing.
Multiple pathways of commodity crop expansion in tropical forest landscapes
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
Evaluating expansion strategies for startup European Union dairy farm businesses.
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.
Advanced divertor configurations with large flux expansion
Soukhanovskii, V.A., E-mail: vlad@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA (United States); Bell, R.E.; Diallo, A.; Gerhardt, S.; Kaye, S.; Kolemen, E.; LeBlanc, B.P. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); McLean, A. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Menard, J.E.; Paul, S.F.; Podesta, M. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Raman, R. [University of Washington, Seattle, WA (United States); Ryutov, D.D. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Scotti, F.; Kaita, R. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Maingi, R. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Mueller, D.M.; Roquemore, A.L. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Reimerdes, H.; Canal, G.P. [Ecole Polytechnique Fédérale de Lausanne, Centre de Recherches en Physique des Plasmas, Association Euratom Confédération Suisse, Lausanne (Switzerland); and others
2013-07-15
Experimental studies of the novel snowflake divertor concept (D. Ryutov, Phys. Plasmas 14 (2007) 064502) performed in the NSTX and TCV tokamaks are reviewed in this paper. The snowflake divertor enables power sharing between divertor strike points, as well as the divertor plasma-wetted area, effective connection length and divertor volumetric power loss to increase beyond those in the standard divertor, potentially reducing heat flux and plasma temperature at the target. It also enables higher magnetic shear inside the separatrix, potentially affecting pedestal MHD stability. Experimental results from NSTX and TCV confirm the predicted properties of the snowflake divertor. In the NSTX, a large spherical tokamak with a compact divertor and lithium-coated graphite plasma-facing components (PFCs), the snowflake divertor operation led to reduced core and pedestal impurity concentration, as well as re-appearance of Type I ELMs that were suppressed in standard divertor H-mode discharges. In the divertor, an otherwise inaccessible partial detachment of the outer strike point with an up to 50% increase in divertor radiation and a peak divertor heat flux reduction from 3–7 MW/m{sup 2} to 0.5–1 MW/m{sup 2} was achieved. Impulsive heat fluxes due to Type-I ELMs were significantly dissipated in the high magnetic flux expansion region. In the TCV, a medium-size tokamak with graphite PFCs, several advantageous snowflake divertor features (cf. the standard divertor) have been demonstrated: an unchanged L–H power threshold, enhanced stability of the peeling–ballooning modes in the pedestal region (and generally an extended second stability region), as well as an H-mode pedestal regime with reduced (×2–3) Type I ELM frequency and slightly increased (20–30%) normalized ELM energy, resulting in a favorable average energy loss comparison to the standard divertor. In the divertor, ELM power partitioning between snowflake divertor strike points was demonstrated. The NSTX
Guillermo Hernández De Alba
1963-06-01
Full Text Available El doctor Rafael Martínez Briceño, eminente médico legista y abogado con notables títulos en la cultura colombiana como humanista y bibliófilo de rara erudición, posee una de las bibliotecas privadas más ricas del país, donde están representados en ediciones príncipes o rarísimas, los ingenios del Renacimiento y de la cultura universal del Barroco, así como las más raras ediciones impresas en hispanoamérica a partir del siglo XVI, especialmente relacionadas con las letras neogranadinas y colombianas.
Patricio Landaeta Mardones
2013-11-01
Full Text Available Si la creación de una imagen fidedigna del mundo fue la condición de la conquista cognitiva y económica de la tierra, las imágenes mediáticas circulan hoy en día a la manera de un montaje que organiza los sujetos como elementos de un territorio. En esta presentación abordaremos el cruce entre estos dos hechos, entre la escritura del mundo y la de los sujetos, a partir de la idea de Fabulación para mostrar otra escritura del mundo y del yo, leyendo textos e imágenes de la Primera buena Corónica y Buen Gobierno de Felipe Guaman Poma de Ayala.
Niveles del aprendizaje organizacional
Garzón Castrillón, Manuel Alfonso
2005-01-01
En la propuesta de modelo de aprendizaje organizacional (AO), la segunda variable se denomina niveles del aprendizaje organizacional ; los niveles de aprendizaje que contemplamos para nuestra investigación son: individual, de equipo, organizacional e interorganizacional.
Brainworkers: Trabajadores del conocimiento
Óscar Abellón García
2004-02-01
Full Text Available Los trabajadores del conocimiento realizan trabajos que requieren el empleo de la inteligencia, de la facultad de entender: son intelectuales. Se crecen ante los problemas complejos, aprecian la dificultad de la abstracción simplificada, juegan con modelos de realidades virtuales, razonan con transversalidad e intuición, son creativos e innovadores, transfieren informaciones y conceptos, en redes que vinculan conocimientos y amistades; manifiestan, en ese sentido, un espíritu renacentista. La mejor novedad que aporta el trabajador del conocimiento es su alto estado de alerta, su buen manejo de la información y por lo mismo es un guía en adaptación a los cambios del entorno. Las crisis de sectores son precisamente una prueba del funcionamiento ecosistémico de los procesos de cambio.
Jaime Álvarez
2010-04-01
Full Text Available El virus del oeste del Nilo (VON y el virus de la encefalitis de San Luis (VESL pertenece a la familia Flaviviridae, género Flavivirus y hacen parte del serocomplejo de la encefalitis japonesa (1. Estos virus se encuentran distribuidos en Estados Unidos, centro América y suramerica (2. Son mantenidos en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Humanos, équidos y otros vertebrados se infectan por la picadura de mosquitos del genero Culex principalmente (1,2. En humanos se han identificado y descrito nuevos modos de transmisión de VON incluyendo infección a través de productos sanguíneos contaminados (3, transplante de órganos (4, transmisión a través de la leche materna (5, transmisión intrauterina (6, y exposición ocupacional (7.
Jose Luis Leiva Olivencia
2015-01-01
Full Text Available Actualmente existen aplicaciones orientadas al turismo basadas en realidad aumentada, pero no integran técnicas de recomendación. Este articulo describe RAMCAT (Realidad Aumentada Móvil Contextual Aplicada al Turismo un modelo de guía turística, que recomienda puntos de interés, teniendo en cuenta factores como preferencias personales y atributos contextuales. Se presentan los componentes teóricos de la arquitectura propuesta, así como sus características, destacando la integración de diferentes sistemas de recomendación, que permiten añadir nuevos motores en el futuro. El articulo se centra en describir sus funcionalidades y el modulo correspondiente al sistema de recomendación basado en el perfil del turista. Otra característica importante del sistema propuesto es la retroalimentación del mismo mediante calificaciones del turista y su trazabilidad.
Enrique Ayala Mora
2008-06-01
Full Text Available El artículo analiza el crimen político durante las primeras décadas de vida de la República del Ecuador. Específicamente centra su estudio en el período dominado por la figura de Juan José Flores, primer presidente del Ecuador. La inestabilidad política, la precariedad de las alianzas entre las élites regionales, la crisis económica generada por las guerras de Independencia, las conspiraciones y la violencia que caracterizaron al período de surgimiento de las repúblicas andinas hicieron del crimen político un “vicio de nacimiento”. El asesinato del general Antonio José de Sucre, la muerte de los miembros de la sociedad El Quiteño Libre, el homicidio de Juan Otamendi, entre otros, hicieron patente esta característica.
Chemical Expansion: Implications for Electrochemical Energy Storage and Conversion Devices
Bishop, S.R.; Marrocchelli, D.; Chatzichristodoulou, Christodoulos
2014-01-01
Many energy-related materials rely on the uptake and release of large quantities of ions, for example, Li+ in batteries, H+ in hydrogen storage materials, and O2− in solid-oxide fuel cell and related materials. These compositional changes often result in large volumetric dilation of the material...... modeling and an overview of factors impacting chemical expansion. We discuss the implications of chemical expansion for mechanical stability and functionality in the energy applications above, as well as in other oxide-based systems. The use of chemical expansion as a new means to probe other materials...... properties, as well as its contribution to recently investigated electromechanical coupling, is also highlighted....
Negative thermal expansion induced by intermetallic charge transfer.
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 SaCu3Fe4O12 and LaCu3Fe4-x Mn x O12, as well as in Bi or Ni substituted BiNiO3. 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.
The Boundary Layer Interaction with Shock Wave and Expansion Fan
MaratA.Goldfeld; RomanV.Nestoulia; 等
2000-01-01
The results of experimental investigation of a turbulent boundary layer on compression and expansion surfaces are presented.They include the study of the shock wave and /or expansion fan action upon the boundary layer,boundary layer sepqartion and its relaxation.Complex events of paired interactions and the flow on compression convex-concave surfaces were studied.The posibility and conditions of the boundary layer relaminarization behind the expansion fan and its effect on the relaxation length are presented.Different model configurations for wide range conditions were investigated.Comparison of results for different interactions was carried out.
Anisotropic Expansion of a Thermal Dipolar Bose Gas.
Tang, Y; Sykes, A G; Burdick, N Q; DiSciacca, J M; Petrov, D S; Lev, B L
2016-10-07
We report on the anisotropic expansion of ultracold bosonic dysprosium gases at temperatures above quantum degeneracy and develop a quantitative theory to describe this behavior. The theory expresses the postexpansion aspect ratio in terms of temperature and microscopic collisional properties by incorporating Hartree-Fock mean-field interactions, hydrodynamic effects, and Bose-enhancement factors. Our results extend the utility of expansion imaging by providing accurate thermometry for dipolar thermal Bose gases. Furthermore, we present a simple method to determine scattering lengths in dipolar gases, including near a Feshbach resonance, through observation of thermal gas expansion.