Sunday, December 21, 2014

 

 



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía
 

rss_1.0 Recursos de colección

DIALNET OAI Articles (578,815 recursos)
Dialnet (Difusión de Alertas en la Red) es una plataforma de recursos y servicios documentales, cuyo objetivo fundamental se centra en mejorar la visibilidad y el acceso a la literatura científica hispana a través de Internet.

Ciencias biológicas

Mostrando recursos 1 - 20 de 16,851

1. Gall midges (Diptera: Cecidomyiidae) of the Iberian Peninsula. 2. Zoogeographical analysis of the gall midge fauna - Skuhravá, Marcela; Skuhravy, Václav; Blasco Zumeta, Javier; Pujade Villar, Juli

2. Nuevos registros de Cléridos (Coleoptera: Cleridae) para la provincia de Huelva (Andalucía occidental) - López Pérez, Juan José

3. Presencia de Lutzomyia dubitans (Sherlock, 1962) (Diptera: Psychodidae: Phlebotominae) en la Ciudad de Sincelejo, Departamento de Sucre, Colombia - Pérez Doria, Alveiro; Bejarano, Eduar Elías; Blanco Tuirán, Pedro José

4. New records of Chrysomelidae (Coleoptera) from Region of Murcia (south east Iberian Peninsula) - Lencina Gutiérrez, José Luis; Ortiz Cervantes, Antonio Salvador; Rubio Lozano, Rosa María

5. Tricópteros de la Reserva de la Biosfera de Muniellos y de Asturias (N de España) - Ocharan, R.; Ocharan Larrondo, Francisco Javier; Anadón Álvarez, Araceli

6. Enfermedad cardiovascular en España: estudio epidemiológico descriptivo 1999-2010 - Aluja, María Pilar; Santos, Cristina; Umbria, Miriam; Rafel Ribera, Josefa
Objetivo. Las enfermedades cardiovasculares (ECV) son la principal causa de muerte y altas hospitalarias en nuestro país. El objetivo de este estudio es describir la mortalidad y la morbilidad hospitalaria para las enfermedades del sistema circulatorio de mayor relevancia, en las diferentes comunidades autónomas de España en el periodo de 1999 a 2010. Métodos. Los datos utilizados fueron obtenidos a través del Instituto Nacional de Estadística. Se calcularon las tasas brutas y específicas de mortalidad y morbilidad por 100.000 habitantes, para cada una de las comunidades autónomas, por sexo, por grupos de edad y por año. Resultados. Las enfermedades cardiovasculares presentan un...

7. Tipificación de dos nombres linneanos en Asparagus L. (Asparagaceae) - Ferrer-Gallego, Pedro Pablo; Laguna Lumbreras, Emilio; Pedrol Solanes, Joan

8. Notes on North African Andryala L. (Asteraceae): a new combination and typifications - Álvarez Fernández, Inés; Chrtek, Jindrich; Ferreira,, Maria Zita; Sequeira, Miguel Menezes de

9. El género Passiflora L. (Passifloraceae) en el Departamento de Lambayeque, Perú. - Rojas Idrogo, Consuelo; Esquerre Ibáñez, Boris; Llatas-Quiroz, Santos; Delgado Paredes, Guillermo E.
El género Passiflora L. (Passifloraceae) en el departamento de Lambayeque, Perú. El género Passiflora cuenta con un total de 13 especies hasta ahora determinadas para Lambayeque. Estas especies, algunas con sus taxones infraespecíficos, están incluidas en los subgéneros Passiflora y Decaloba. En el presente trabajo se reportan por primera vez para Lambayeque Passiflora cisnana, P. edulis f. flavicarpa, P. ligularis, P. manicata, P. mathewsii, P. quadrangularis, P. suberosa, P. tarminiana y P. tripartita var. mollissima. De entre ellas, 8 están restringidas a la zona andina del departamento, entre los 1000�4000 m, de elevación, y cinco especies habitan la franja costera....

10. Caracterización genética molecular de materiales procesados de Stevia rebaudiana utilizando la técnica de microsatélites - Garro Monge, Giovanni; Jiménez Quesada, Karol; Alvarenga Venutolo, Silvana
Stevia rebaudiana is a herbaceous and perennial plant belonging to the Asteraceae family, it is native of Paraguay and grows in tropical and subtropical climates. Due to the natural sweetness of its leaves, is known as a natural sweetener with no calories and with many applications in food industry. Therefore, it is of great commercial importance to have techniques for determinate the quality and purity of the raw material processed into powder for the production of sweeteners. Been used for the implementation of molecular markers ISSR, enabling amplify sequences that are between the microsatellites, which yields a characteristic banding pattern...

11. Algunas consideraciones acerca de la educación ambiental no formal (Nota técnica) - Villadiego Lorduy, Jorge; Huffman Schwocho, Dennis; Cortecero Bossio, Adolfo; Ortiz Sánchez, Richard
The purpose of this paper is to discuss the various conceptions of non-formal environmental education as well as developing an appreciation of the current economic model based on overproduction and overconsumption to a few and scarce for most, without omitting the distinction between growth and sustainable economic development. An analysis of some jobs or experiences delivered in non-formal environmental education at Latin America, as well as factors that do not favor the implementation of processes in non-formal environmental education is established. Finally, some general elements on which a model could be structured and participatory non formal environmental education are defined....

12. Experiencias en la aplicación operativa de un método multivariado de imputación de datos meteorológicos - Araya López, José Luis
Se han propuesto diferentes métodos y técnicas estadísticas para poder lidiar con el problema de los datos ausentes. En este estudio se analiza la aplicación de un método de imputación de datos usando componentes principales. El fin de este trabajo es discutir las posibilidades de este método para poder completar datos en resolución horaria generados por la red de estaciones del Instituto Meteorológico Nacional. Para lograr este fin se realizaron algunos experimentos con datos de prueba, a los que aleatoriamente se les eliminaron datos para su posterior estimación. Los resultados muestran que este método podría predecir la información que falta...

13. Diseño óptimo de un sistema de distribución de agua (SDA) aplicando el algoritmo Simulated Annealing (SA) - Méndez Morales, Maikel
In this paper, an application of the Simulated Annealing (SA) algorithm for the optimum design of a water distribution system (WDS) is presented. The SA is a metaheuristic search algorithm, based on the analogy between the physical process of annealing in metals (controlled cooling of a heated mass) and the resolution of combinatorial optimisation problems. The SA algorithm, along with mathematical models, has successfully been used in the optimum design of WDS. The real-scale Marsella WDS, a rural community located in San Carlos, Costa Rica was selected as case study. The SA algorithm was implemented in the well-known open-source model...

14. Estudio de generación y composición de residuos sólidos en el cantón de Guácimo, Costa Rica - Campos Rodríguez, Rooel; Soto Córdoba, Silvia
The Guacimo municipality is located in the pro-vince of Limón. They do not have composition and generation rates per capita studies, because of that they can not to plain adequacy their activities. We determinate the generation rates per capita and the percentage composition of solid waste materials according the Costa Rican law. We use the document of composition and generation studies, the data was analyzed using statistics, we determinate the generation index according the social economic status, and quantify the different kinds of materials that was produces in the place. The results are useful for the investment planning, elaborates the collection routes...

15. Síntesis de CeO2: propiedades del sol-gel y caracterización de las nanopartículas obtenidas - Vega Garita, Victor; Matamoros Quesada, Josué; Vega Baudrit, José
We propose an efficient sol-gel synthesis of a nanoparticled cerium oxide (IV) method. AFM micrographs confirm the presence of nanoparticles. Furthermore, TGA, FTIR and XRD measurements validate the absence of impurities. Scherrer’s law reveals a particle size of 11 nm, whereas DLS analysis shows an average diameter of 9.55 nm. Notably, viscosity and concentration behave proportionally. Contact angle measurements show that is more feasible to coat silicon (110) substrate than pure aluminum. Moreover, a filter for ultraviolet radiation is obtained when particle concentrations are larger than 13.74 mg/cm3. 

16. Evaluación de la corrosión por picadura en aluminio AA1050 - Garita Arce, Luis; Rodríguez Yáñez, Javier E.
The aluminum poses a versatility of uses in modern life. The possibility of deterioration of pitting them is one of the main considerations for the manufacturer, in order to avoid claims. In this sense ASTM G100-89 proposes a method of assessment of aluminum by means of the evaluation of potential versus applying cyclic galvanic polarizations afford it protection potentials (Eprot) below which it can be exposed without waiting aluminum pitting. In this work pose assessment technique, evaluating pitting in AA1050 type aluminum, used for most of the usual applications. The variables considered were the usual exposure to aluminum in normal environments: composition,...

17. Evaluación económica y social del uso del bagazo de caña en la generación de energía eléctrica en Nicaragua - Blanco Orozco, Napoleón Vicente; Arce Díaz, Eduardo
In this article, an economic and social assessment of the use of bagasse to generate electricity in Nicaragua has been made comparing the use of bagasse using fossil fuels for power generation. It has been concluded that generation of electricity using bagasse biomass has a positive impact on the social and economic development of Nicaragua because an economic assessment of sugar mills that generate electricity using bagasse shows they become economically more profitable. On the other hand, thermal plants that generate electricity through oil are not economically profitable. The Social assessment of the use of bagasse to generate energy using...

18. Consideraciones de las propiedades mecánicas y térmicas para la elaboración de un ducto de riego a partir de materiales poliméricos postconsumo - Barrios Hernández, Mary Luz
It aims to show the results to develop three new formulations of polymeric materials from household waste generated, in order to determine the best material to make irrigation pipeline in Costa Rica, using commercial pipeline reference. Polymeric material was recovered polyethylene and polypropylene post-consumer, with the help of ITCR waste recovery programs. The material required for processes such as cleaning, sorting, grinding and extrusion. The samples were prepared with different proportions of the polymers used. The first specimen was LDPE; another mix was 75 % of LDPE and 25 % HDPE and a final mixture of 75 % of HDPE...

19. Producción de hidrógeno a partir del tratamiento anaerobio de vinazas en un reactor UASB - González Ugalde, César; Durán Herrera, J. Esteban
Fermentative hydrogen production from sugar-cane vinasses was evaluated in a 3-L UASB reactor under mesophilic conditions. The seed sludge, taken from an industrial wastewater UASB reactor, was heat treated to inhibit non hydrogen producing bacteria. Hydrogen producing granules were first formed in a CSTR reactor and then transferred to the UASB reactor. Operating under mesophylic (37 °C) conditions, pH close to 5.5, inlet substrate concentration of 20 000 mg COD/L, and hydraulic retention time (HRT) of 6 hours, the average hydrogen production rate obtained in the UASB reactor was 1,68 mL H2/h/L, showing a maximum value of 13,4 mL H2/h/L....

20. Implementación de la metodología DMAIC-Seis Sigma en el envasado de licores en Fanal - Pérez López, Esteban; García Cerdas, Minor
This article discusses the proposal for improvement of efficiency in pet packaging line in fanal using six sigma dmaic methodology. The work was done in order to solve the problem presented packaging line pet bottle liquor, which was not operating at full capacity due to deficiencies in the line. During diagnosis of the situation, it was determined that in the packaging line pet liquor is effective times had very low production, excessive line stoppages, each thread machines not at any time reach their full potential production, quality defects in recurrent, repetitive and exhausting process by staff, there is no ability...

Página de resultados:
 

Busque un recurso