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Search Results: 1 - 10 of 375044 matches for " Díez Martín "
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Reassesment of the European Mode 1 occurrences: elements for their technological definition and interpretation
Díez Martín, Fernando
Trabajos de Prehistoria , 2002,
Abstract: The concepts of production and standardization are used to technologically characterize European Lower and Middle Pleistocene lithic assemblages without handaxes. It is argued that many of the sites without bifaces dated after 500 Ka. are examples of a Mode 2 technology. On the other hand, several factors, including lithic variability and migrations, are considered to provide explanations for Mode 1 occurrences. Los conceptos de producción y configuración son utilizados para caracterizar técnicamente los conjuntos líticos del Pleistoceno inferior y medio europeo sin bifaces, mostrando que la mayor parte de estos yacimientos, datados con posterioridad a los 500 Ka., forman parte integrante del Modo 2. También se analizan y discuten los factores de variabilidad que pueden asociarse a los conjuntos con tecnología del Modo 1 que aún se observan en el registro.
Ciberdemocracia y opinión pública, "Luces y sombras"
María Antonia Martín Díez
Palabra Clave , 2004,
Abstract: El desarrollo de la Internet tiene una dimensión no despreciable y su influjo en la política se está convirtiendo en un hecho. Es lo que se puede llamar la ciberdemocracia que, frente a la tradicional democracia representativa, se plantea como deliberativa o participativa, a pesar de que la utilización de la Internet sea todavía escasa. La prospectiva mundial que se realiza nos lleva a concluir que la Internet, desde sus diversas características técnicas, mantendrá el poder para unos pocos, aumentará las desigualdades y ofrecerá a los grupos de comunicación unas expectativas muy superiores a las actuales. Ello exigirá un ulterior perfeccionamiento y la asignación de los recursos según la demanda existente. Es lo que nos faltaría corregir para decir que todo el poder se asienta en la comunicación.
Performance Indicators for Sun-Tracking Systems: A Case Study in Spain  [PDF]
Miguel de Simón-Martín, Cristina Alonso-Tristán, Montserrat Díez-Mediavilla
Energy and Power Engineering (EPE) , 2014, DOI: 10.4236/epe.2014.69025
Abstract: Current PV cells technology takes advantage mainly from beam radiation. In this context the sun-trackers are such devices for efficiency improvement. On the other hand, projected shadows between devices make mandatory to increase the distances between mounting systems. Thus, the land’s capacity for mounting PV panels can be dramatically decreased. This fact conducts us to wonder where the optimum efficient point is. First, in this paper different types of sun-tracking systems are classified according to the movement they perform (cinematic classification). Further, three real PV installations-fixed, horizontal-axis tracking and dual-axis mount tracking—located in the same geographical area in Spain (they are approximately under the same weather conditions) are analyzed. These installations have been studied in order to establish which one is the most efficient and affordable—Specific Energy Production (SEP) and Performance Ratio (PR) analysis. PVGIS solar radiation estimate tool has been used for comparing the theoretical radiation potential on each plant. The land requirements have been considered in the analysis of the Ground Cover Ratio (GCR) and the Surface Performance Ratio (SPR). Moreover, comparing three main financial indicators let us carry out a financial study: Payback Time (PBT), Net Present Value (NPV) and Internal Rate of Return (IRR). In the case study, final annual energetic results demonstrate that the dual-axis plant shows a relevant SEP advantage, but if we take into account the land occupied for this sort of devices we find much more profitable the horizontal-axis sun-tracking system, with a SPR value 4.24% higher than the fixed system we have studied. Its PBT is also a 22% lower than the dual-axis tracking installation.
Impacto presupuestario de un programa de deshabituación tabáquico en empresas
Silvia,Díaz Cerezo; Martín Nu?ez,Iker;
Medicina y Seguridad del Trabajo , 2009, DOI: 10.4321/S0465-546X2009000300006
Abstract: objective: to estimate the budgetary impact of a smoking cessation programme in a company. methods: a model was developed to simulate a 1000-employee company, with a time horizon of 3 years. 26% of smoking prevalence was considered; 70% of smokers would be willing to quit (published national data). the smoking cessation rates where obtained from clinical trials (21% for varenicline, 13% for bupropion, 12% for nst and 7% for advice/counselling) and it was considered that the 25% of the smokers would take each of the therapies. the costs derived from the programme (treatment and initiation/counselling) and the savings due to the improvement in the work absenteeism and productivity were included. results: the investment that the company would need for starting up the program (?54,794) would be almost recovered in one year. after the third year, the total savings for the company would rise to ?85,445; ?4,092 for each employee who achieves to quit smoking. conclusions: the implementation of a smoking cessation programme would result in health benefits for the employees as well as savings for the company after the first year.
Impacto presupuestario de un programa de deshabituación tabáquico en empresas Budgetary impact of a smoking cessation programme within companies
Díaz Cerezo Silvia,Iker Martín Nu?ez
Medicina y Seguridad del Trabajo , 2009,
Abstract: Objetivo: Estimar el impacto presupuestario de un programa de deshabituación tabáquica en la empresa. Métodos: se desarrolló un modelo para simular una empresa de 1000 trabajadores, con un horizonte temporal de 3 a os. Se consideró que la prevalencia media de fumadores era del 26% y que el 70% estaría dispuesto a dejar de fumar (datos nacionales publicados). Las tasas de cesación a un a o se obtuvieron de ensayos clínicos (21% para vareniclina, 13% para bupropion, 12% para TSN y 7% para consejo/seguimiento) y se consideró que el 25% de los fumadores recibirían cada una de estas terapias. Se incluyeron los costes derivados del programa (tratamientos y puesta en marcha/seguimiento) y los ahorros producidos por la mejoría en el absentismo y la productividad laboral. Resultados: La inversión que tendría que realizar la empresa para poner en marcha este programa (54.794€) se recuperaría prácticamente en un a o. Tras tres a os, los ahorros totales para la empresa llegarían a los 85.445€; 4.092€ por cada trabajador que consigue dejar de fumar. Conclusiones: La implementación de un programa de deshabituación tabáquica en empresa reportaría no solo beneficios en salud sino importantes beneficios económicos a partir del primer a o. Objective: To estimate the budgetary impact of a smoking cessation programme in a company. Methods: A model was developed to simulate a 1000-employee company, with a time horizon of 3 years. 26% of smoking prevalence was considered; 70% of smokers would be willing to quit (published national data). The smoking cessation rates where obtained from clinical trials (21% for varenicline, 13% for bupropion, 12% for NST and 7% for advice/counselling) and it was considered that the 25% of the smokers would take each of the therapies. The costs derived from the programme (treatment and initiation/counselling) and the savings due to the improvement in the work absenteeism and productivity were included. Results: The investment that the company would need for starting up the program (€54,794) would be almost recovered in one year. After the third year, the total savings for the company would rise to €85,445; €4,092 for each employee who achieves to quit smoking. Conclusions: The implementation of a smoking cessation programme would result in health benefits for the employees as well as savings for the company after the first year.
Políticas de comunicación en la empresa
Dra. María Antonia Martín Díez
Revista Latina de Comunicación Social , 2002,
Abstract: La realidad humana tanto en su perspectiva social como individual nos descubre una relación entre la política y la comunicación. "El mero hecho de la comunicación es una actividad política en su más prístino sentido". Esta afirmación del profesor García Fajardo muestra la relación entre la comunicación y la política. La interrelación que entre ambas existe aparece como jerarquizada. Desde nuestro punto de vista, el sistema político sería un subsistema del sistema social de difícil diferenciación respecto al sistema de comunicación.
Latinoamérica, en la comunicación mundial
Dra. María Antonia Martín Díez
Revista Latina de Comunicación Social , 2000,
Abstract: La estructura de la comunicación latinoamericana se encuentra inmersa dentro del sistema internacional de la información. En ella encontramos, obviamente, las tendencias de intercambio e interdependencia actuales. Estas se pueden producir bien como relaciones paralelas (junto a), bien como relaciones opuestas (frente a).
Interest groups and environmental pressure
FRANCISCO DíEZ MARTíN,MARIA LUISA MEDRANO GARCíA,EMILIO PABLO DíEZ DE CASTRO
Cuadernos de Gestión , 2008,
Abstract: The pressure exerted by interest groups is one of the main reasons that have led organizations to introduce Environmental Management Systems. Research provides evidence on the existing relationship between Stakeholders′ pressure and their infl uence on business environmental management. The aim of this paper is to analyze 142 Spanish business centers, holders of ISO 14000 and /or EMAS certifi cates, in order to empirically probe the relationship between different kind of stakeholders and environmental management. We found a signifi cant and positive relationship between stakeholders and environmental management within organizations. Additionally, the analysis clarifi ed the individual infl uence of stakeholders (normative, organizational and social) on different aspects of environmental management. According to our analysis, this infl uence varies depending on each type of stakeholder.
Effects of Trinexapac-Ethyl on different wheat varieties under desert conditions of Mexico  [PDF]
Raúl Leonel Grijalva-Contreras, Rubén Macías-Duarte, Gerardo Martínez-Díaz, Fabián Robles-Contreras, Fidel Nu?ez-Ramírez
Agricultural Sciences (AS) , 2012, DOI: 10.4236/as.2012.35079
Abstract: A field study was conducted to determine the effect of Trinexapac-Ethyl (TE) on four wheat varieties (Rafi C97, Altar C84, Nacori C97 and Rayon F86) at three growth stages (first node, second node and flag leaf). TE application (150 g a.i. ha-1) reduced plant height and decreased grain yield at any growth stage. Yield decrease was associated to a significant reduction in the number of grains per spike and in grain weight. TE delayed flowering time and grain maturity, while stem diameter and spikes m-2 were not affected. Further studies are needed to clarify the effect of TE on wheat under desert conditions of Mexico.
Texturas relícticas en las metaignimbritas neoproterozoicas del basamento del cerro del Corral, Sierras Australes de Buenos Aires Relictic textures in the Neoproterozoic meta-ignimbrites of the basement of Cerro del Corral, Sierras Australes de Buenos Aires
Pablo D. González,Gerardo N. Páez,Fernando M. Cervera,Martín Iribarne
Revista de la Asociación Geológica Argentina , 2004,
Abstract: Relictos de textura eutaxítica, vitroclastos desvitrificados y litoclastos andesíticos fueron encontrados en rocas ígneas ácidas con escasa deformación y bajo grado metamórfico, en el margen oriental del cerro del Corral (Sierras Australes de Buenos Aires, Argentina). Sobre la base de estas características piroclásticas y la presencia de fenocristales de cuarzo, plagioclasa y feldespato potásico, re-interpreta al protolito de estas rocas como ignimbritas de composición fenodacítica a fenoriolítica. Los fenocristales de cuarzo (de hasta 1,5 cm de diámetro) tienen engolfamientos, canalículos e inclusiones redondeadas, rellenos con el mismo material fino (felsítico a esferulítico), no foliado y desvitrificado de la matriz piroclástica. Además, esta matriz también está preservada como peque os remanentes adosados a los fenocristales y lateralmente pasa a una matriz milonítica moderadamente foliada, rica en cuarzo y sericita, con textura granoblástica a granolepidoblástica. La redefinición de estas rocas como metaignimbritas tiene una gran importancia estratigráfica y grandes implicancias geológicas para el basamento de las Sierras Australes de Buenos Aires. La depositación de estas metaignimbritas se habría producido a partir de flujos piroclásticos, y habría ocurrido en un ambiente geológico dominado por estratovolcanes que, probablemente, habrían estado vinculados a un arco magmático Neoproterozoico perteneciente al ciclo Brasiliano - Panafricano. Relicts of eutaxitic texture, devitrified vitric fragments and andesitic lithoclasts occur in low-grade and weakly deformed acid meta-magmatic rocks of the eastern margin of the Cerro del Corral (Sierras Australes de Buenos Aires, Argentina). On the basis of the pyroclastic characteristics and the presence of quartz, plagioclase and K-feldspar phenocrysts, we re-interpreted the protolith of these rocks as ignimbrites of fenodacitic to fenorhyolitic composition. Embayed quartz phenocrysts (up to 1.5 mm diameter) show micro-channels and rounded inclusion filled with the same fine-grained, devitrified and non-foliated material (with felsitic to spherulitic texture) of the pyroclastic matrix. This matrix is also preserved as small remnants attached to the phenocrysts (or wrapping them) and passing laterally into a mylonitic matrix (quartz and sericite-rich and moderately foliated), with granoblastic to granolepidoblastic texture. We emphasize the stratigraphical importanceand the geological implications for the basement of the Sierras Australes of Buenos Aires that can be derived from the re-examination of these roc
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