OALib Journal期刊

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匹配条件: “Eriel Pérez Zapico” ,找到相关结果约212416条。
Origin Parameters of Fused Flux Grain Process Dispersion with Air Parámetros de origen del proceso de dispersión con aire de fundentes fundidos
Daniel Pérez Pérez,Carlos René Gómez Pérez,Francisco Arturo Ruiz Martínez,Eriel Pérez Zapico
Revista Cubana de Ingeniería , 2011, DOI: 10.1234/rci.v2i1.39
Abstract: Considerations about the fragmentation process with air of molten fluxes obtained by using raw Cuban materials for the welding process under submerged arch (S.A.W) are presented. The physical process of the flight trajectory and its validation during the granulation with air are not reported in the welding field. Therefore, the aim of this work is to establish a procedure that determines the rates and departure angles of pellets during impulsion and dispersion, in addition to contribute criteria on the frictional effect of the surrounding atmosphere on the shape of the trajectory curve of the pellets formed. These aspects may be corroborated with data obtained from the digital processing of filmed images of the fragmentation process and movement of the pellets formed. It is demonstrated that the efficiency of the procedure developed for the obtaining of the flight parameters and the non-influence of the air frictional force on the modification of the particle’s flight trajectory, allows the establishment of a methodology that makes it possible to begin studies about the fragmentation phenomena of molten fluxes by using air jets, which guarantee the necessary rank and granulometric types for an adequate performance of the welding process. Se plantean consideraciones sobre el proceso de fragmentación con aire de fundentes fundidos, obtenidos utilizando materias primas cubanas, para el proceso de soldadura bajo arco sumergido (SAW). El proceso físico de la trayectoria de vuelo y su validación durante la granulación con aire no se reportan en el campo de la soldadura. El objetivo de este trabajo es establecer un procedimiento para determinar las velocidades y ángulos de salida de los peles durante su impulsión y dispersión, además de aportar criterios del efecto friccional de la atmósfera circundante sobre la forma de la curva de trayectoria de los peles formados. Estos aspectos se pueden corroborar con los datos obtenidos mediante el procesamiento digital de las imágenes filmadas del proceso de fragmentación y desplazamiento de los peles formados. Se demuestran la eficacia del procedimiento desarrollado para la obtención de los parámetros de vuelo y la no influencia de la fuerza friccional del aire sobre la modificación de la trayectoria de vuelo de las partículas, permitiendo establecer una metodología, que posibilita iniciar estudios sobre los fenómenos de fragmentación de fundentes fundidos empleando chorros de aire, que garanticen los rangos y clases granulométricas necesarias para un adecuado desempe o del proceso de soldadura.
Revistas Científicas: Determinación de necesidades y usos
Reyes Barragán, María J.,Guerrero Bote, Vicente P.,Pulgarín Guerrero, Antonio,Zapico Alonso, Felipe
Revista Espa?ola de Documentación Científica , 2000,
Abstract: The information requirements of the scientific community of the areas of science and technology in the University of Extremadura were analysed quantitatively and qualitatively through journal citations. For this purpose, a retrospective search was made in the Science Citation Index database, considering multiple variables such as use by department, impact factor, journal citations, availability, localization, accessibility, and coverage. A set of (simple and complex) indicators was applied to these variables, using multiple association models (in particular, Kohonen's algorithm) to determine the degree of ínterdepartmental overlap in the real use of information. Se analizan tanto cuantitativa como cualitativamente las necesidades de información de la comunidad científica de las áreas de ciencia y tecnología de la Universidad de Extremadura a través de las citas a revistas. Para ello se lleva a cabo una búsqueda retrospectiva en la base de datos del Science Citation Index. Se consideraron múltiples variables, como usos por departamentos, factor de impacto, citas a revistas, disponibilidad, localización, accesibilidad y cobertura. A estas variables le fueron aplicadas una serie de indicadores (simples y complejos), recurriendo a modelos de asociacionismo múltiple (y en concreto al algoritmo de Kohonen), para determinar el grado de solapamiento interdepartamental en el consumo real de información.
New Evidence on Rotational Dynamics  [PDF]
Luis Alberto Pérez
World Journal of Mechanics (WJM) , 2013, DOI: 10.4236/wjm.2013.33016

In this paper, the author confirmed a new theory to explain the mechanical behavior of macroscopic bodies. The confirmed hypothesis is the Theory of Dynamics Interaction by the Professor Gabriel Barceló. Barceló explained his theory in an article called “Analysis of Dynamics Fields in Noninertial Systems”, World Journal of Mechanics, Vol. 2, No. 3, 2012, pp. 175-180. This hypothesis holds that the mechanical behavior of macroscopic bodies in a non-inertial environment opens new assumptions on inertial fields and rotational dynamics. An associated experiment was presented to support the discussion in the paper. The author first became aware of the proposals of Professor Gabriel Barceló’s Theory of Dynamics Interaction through his 2006 article on Saturn planet rings, which suggested unsolved phenomena in rotational dynamics and the inception of a novel theory [1]. Intuitively, the author realized himself about the fact that the cosmos is mechanical from its smallest to its widest comprehensible appreciation. If material behavior is mechanical everywhere and every time, from a subatomic particle, wave or string, to a cluster of galaxies, then our understandable solutions must comply with the Laws of Motion, it could be believed.

CTXφ Replication Depends on the Histone-Like HU Protein and the UvrD Helicase
Eriel Martínez?,Evelyne Paly?,Fran?ois-Xavier Barre
PLOS Genetics , 2015, DOI: 10.1371/journal.pgen.1005256
Abstract: The Vibrio cholerae bacterium is the agent of cholera. The capacity to produce the cholera toxin, which is responsible for the deadly diarrhea associated with cholera epidemics, is encoded in the genome of a filamentous phage, CTXφ. Rolling-circle replication (RCR) is central to the life cycle of CTXφ because amplification of the phage genome permits its efficient integration into the genome and its packaging into new viral particles. A single phage-encoded HUH endonuclease initiates RCR of the proto-typical filamentous phages of enterobacteriaceae by introducing a nick at a specific position of the double stranded DNA form of the phage genome. The rest of the process is driven by host factors that are either essential or crucial for the replication of the host genome, such as the Rep SF1 helicase. In contrast, we show here that the histone-like HU protein of V. cholerae is necessary for the introduction of a nick by the HUH endonuclease of CTXφ. We further show that CTXφ RCR depends on a SF1 helicase normally implicated in DNA repair, UvrD, rather than Rep. In addition to CTXφ, we show that VGJφ, a representative member of a second family of vibrio integrative filamentous phages, requires UvrD and HU for RCR while TLCφ, a satellite phage, depends on Rep and is independent from HU.
Methodology and Equations of Mineral Production Forecast
—Part I. Crude Oil in the UK and Gold in Nevada, USA. Prediction of Late Stages of Production

Sergio Pérez Rodríguez
Open Journal of Geology (OJG) , 2013, DOI: 10.4236/ojg.2013.35040

The equations of mineral production forecast link the change in time of mineral reserves with the production and the ratio of reserves to production. These equations allow us to model the development of the mineral resources evaluated at any scale. Probabilistic bidimensional charts made from montecarlo simulations provide intervals of confidence for the forecasts. The set of equations is devised and presented for a variety of applications to the oil and gas industry, as well to the production of any other mineral resource, either metals or non metals, whose ore deposit volumes and production might be quantified. The cases studied in the UK and USA are at late stages of production, periods for what the equations are most suitable to be applied without further adjustments. Experimental design allows the diagnosis of the likely values of the variables pertaining to the equations, in order to achieve the results provided by conventional production forecasts or to explore other scenarios of investigation. The method can be practical to evaluate commitments of production of mineral resources with time, to support strategic plans for companies, corporations, countries or regions based on those evaluations, for the screening and ranking of mineral assets based on their production potential and many other tasks where the prediction of future volumes of mineral production is required.

Methodology and Equations of Mineral Production Forecast. Part II. The Fundamental Equation. Crude Oil Production in USA  [PDF]
Sergio Pérez Rodríguez
Open Journal of Geology (OJG) , 2013, DOI: 10.4236/ojg.2013.36044

The fundamental equation of mineral production allows to model and design the dynamics of mineral production, however complex they are or could be. It considers not only the case of a constant production to reserves ratio for given intervals of time, but with a piecewise approach, it is also enabled to account the variation on time of this ratio. With a constant production to reserves ratio, the limit expression of the fundamental equation takes the form of an Erlang distribution with a fixed shape parameter. The rate parameter equals the scale factor. The discrete piecewise version, instead of considering the reserves and the production to reserves ratio being constant through certain intervals of time, updates both variables by units of time. This version, using either lineal or non lineal functions for the variables involved, let to model known production profiles or to forecast them by experimental design. The Hubbert’s linearization updated with recent data and the p-box method applied to determine ultimate recovery of U.S. crude oil reserves indicate official accounts underestimate them. The analysis of the ideal model of production based on Hubbert’s linearization and curve, can be made by decomposing it in the distribution with time of the reserves and of the production to reserves ratio. The distribution of reserves with time is synchronized for both the ideal Hubbert’s curve and real profiles, disregarding whether they match or not. The departure of real profiles from the ideal Hubbert’s curve lies on the differences or correspondences of the distribution with time of the production to reserves ratio. The MonteCarlo simulation applied to forecast US crude oil production for the next five years points to a slow decline, with average annual yields presenting a difference lower than 10% between the start and the end of the simulation.

Accounting Analysis of Economic Policy of Spain (2012)  [PDF]
Miguel Angel Pérez Benedito
Theoretical Economics Letters (TEL) , 2014, DOI: 10.4236/tel.2014.43035
Abstract: The analysis of economic policy is made through a new methodology using the information provided by businesses to the Bank of Spain. The financial statements are the result of economic and financial transactions in a year and show a behavior that is likely to be measured by applying the Edgeworth’s box for analysis. This means that it is possible to measure the response of firms against market disruptions through an accounting interpretation of the information contained in the financial statements. The indicators obtained through this methodology measure a position taken in the Edgeworth’s box. Consequently, the observations obtained are random and therefore may explain the evolution of the economy of any country.
Pérez Pérez,Cruz;
Estudios pedagógicos (Valdivia) , 1999, DOI: 10.4067/S0718-07051999000100007
Abstract: education for co-existence is becoming a priority in many educational centres, to the extent that they are being overwhelmed by high levels of conflictiveness in the classroom. making it necessary for teachers to equip themselves with new methods and techniques in order to face the problem in a global and precautionary way. in this article i analyze the matter from a curricular point of view, in considering that education for co-existence constitutes a content, or a group of contents concerning attitude, which must be the aim of teaching, learning and evaluation. the proposals for participation are based on four important areas: educative project, climate of democratic participation, class assemblies and learning of rules.
Conferencia internacional para la medida y valoración del trabajo no remunerado: procedimientos
Gabriel Pérez Pérez
Política y Sociedad , 1995, DOI: -
Abstract: Sin resumen
Determinantes de la oferta y la demanda del mercado de arrendamientos urbano para el segmento de población de bajos ingresos The Urban Rental Market for the Low-income Population: main Determinants of Supply and Demand (Colombia) Determinantes da oferta e a demanda do mercado das loca es urbanas para o segmento da popula o de rendas baixas
Elizabeth Pérez Pérez
Cuadernos de Vivienda y Urbanismo , 2009,
Abstract: Resumen Frente al propósito de disminución del déficit habitacional del país, la figura del arrendamiento cobra importancia como herramienta que, además de contribuir de manera directa a su disminu-ción, puede llegar a constituir una opción de inversión rentable. Adicionalmente, en un contexto caracterizado por limitaciones fiscales del estado, precariedades de las viviendas existentes, difi-cultades en el acceso a créditos hipotecarios e ineficiencia en la gestión urbana, entre otras, el arrendamiento se convierte en una alternativa de solución habitacional, en el corto plazo, para los hogares más pobres. Por lo anterior, la investigación adelantada responde a la necesidad de caracterizar el mercado de arrendamiento urbano, enfocado en el segmento de población más pobre. Buscando identificar las posibilidades de articular estos mercados en un marco formal que posibilite su interrelación con instrumentos financieros que apalanquen la oferta de vivienda en arriendo, para los estratos bajos de la población. Abstract Given the aim of decreasing Colombia’s housing shortage, the possibility of renting is important as a tool that, in addition to contributing directly to the reduction of housing shortage, can be a profitable investment option. Additionally, in a context of fiscal constraints at national level, poor conditions of existing homes, difficult access to mortgages and inefficiency in public administration at municipality level, among other aspects, renting is an alternative short term solution for the poorest. The present research was carried out in order to respond to the need for a characterization of the urban rental market, focusing on the poorest segment. It seeks to identify the possibilities of fitting these markets in a legal framework that enables their interaction with financial instruments, so that the supply of rental housing for the lower strata of the population can be stimulated. Resumo Diante do desafio da diminui o do déficit habitacional do país, a figura do aluguel gana importancia como ferramenta que, além de contribuir de maneira direta com a sua diminui o, pode chegar a constituir uma op o de investimento rentável. Adicionalmente, em um contexto caracterizado pelas limita es fiscais do Estado, precariedades das moradias existentes, dificuldades no acesso a créditos hipotecários e ineficiência na gest o urbana, entre outras, o aluguel converte-se em una alternativa de solu o habitacional, a curto prazo, para as famílias com menores recursos. Por isso, a pesquisa realizada, responde à necessidade de caracterizar o mercado de

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