oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 124 )

2018 ( 214 )

2017 ( 238 )

2016 ( 354 )

Custom range...

Search Results: 1 - 10 of 213508 matches for " Hurtado Pérez "
All listed articles are free for downloading (OA Articles)
Page 1 /213508
Display every page Item
Environmental Impacts (ER CO2) of an Improved Multi-Fuel Gasifier Forced Air Cookstove in the City of Kinshasa  [PDF]
Oscar Mulumba Ilunga, Hurtado Pérez Elías José
Journal of Environmental Protection (JEP) , 2018, DOI: 10.4236/jep.2018.96039
Abstract: Sub-Saharan African countries depend 80% on the biomass-wood to meet their daily needs in terms of cooking foods. Traditional cookstoves are much more used to this effect. Many change programmes for replacing cookstove model have been planned. Yet many of these programmes have not been preceded by environmental impact studies. This work offers high-performance cookstove models and determines their impact on the reduction of CO2 emissions, a very harmful greenhouse gas causing the planet warming and climate change. Replacing the traditional cookstove by an improved stove may lead to an economy in terms of fuel ranging from 33.2% to 75.4% according to the model of cookstoves. Yet the Gasifier using pellets as fuel remains the most beneficial stove in terms of fuel saving (75.4%) and in terms of ER CO2, i.e. 2748 t CO2/Year. An improved gasifier cookstove is multi-fuel. He can use charcoal, pellets and wood. This is an indispensable cooking tool with alternative fuels. In this work, the ER CO2 was evaluated using two methods. The KPT, which is a field method and the CCT which is a laboratory method. By the KPT method a gasifier ICS/GAS/P records up to an ERCO2 of 2748 t CO2/Year, while with the same gasifier, an ERCO2 of 2619 t CO2/year is found by the CCT method. The comparison between the two methods shows the same trend but with very high values of ERCO2 for the KPT method results. The variation between the two methods ranges between 1% approximately to 6.9 percent.
Computational Thermo-Fluid Dynamic Simulation of a Radiant Off-Gases Cooling System for Copper Smelting in a Pierce Smith Converter  [PDF]
Yerko Aguilera-Carvajal, Sebastián Pérez-Cortés, Juan Hurtado-Cruz, Erick Morales-Quezada
International Journal of Modern Nonlinear Theory and Application (IJMNTA) , 2014, DOI: 10.4236/ijmnta.2014.35026
Abstract:

In copper sulfide concentrates smelting, the off-gases from the Pierce Smith converter (PSC) furnace must be treated to prevent environmental impacts as they are highly corrosive and toxic. The purpose of this research project is to present a methodology for the simulation of a capture and cooling system of the smelting off-gases from a Pierce Smith copper converter, using computational fluid dynamics. Through this methodology, it is possible to obtain a simulation model of the smelting off-gases behavior with an average error of 9.88%. Basically, it demonstrates that the simulated tendencies of the metallurgical off-gases on the cooling hood and chamber can be reliable to predict the thermo-fluid dynamic behavior of the off-gases inside the studied off-gases handling system.

Virus de rabia en cultivos de neuronas sensoriales de ratón adulto
R. Pérez,Jaime E. Castellanos,H. Hurtado
Iatreia , 2000,
Abstract: Introducción: Las neuronas sensoriales de los ganglios de la raíz dorsal (GRD) del ratón adulto, son un modelo interesante en el estudio de la infección in vitro por virus de rabia. Su importancia radica puesto que es una de las vías que tiene el virus para llegar a sistema nervioso central. El virus de la rabia usualmente entra por la mordedura de un animal infectado, inicialmente llega al músculo, replicándose localmente, pasa a terminales nerviosas adyacentes, sube a través del sistema nervioso periférico y llega a los ganglio de la raíz dorsal. Durante el transporte del virus no hay síntomas y la enfermedad sólo se inicia con la llegada del virus al sistema nervioso central, donde la replicación del virus es seguida por su transporte en sentido centrífugo, teniendo un particular e inexplicable tropismo por las glándulas salivares y lacrimales. Objetivo: Describir el proceso de infección del virus de la rabia en neuronas GRD. Metodología: Cultivos de neuronas de GRD de ratón adulto fueron inoculados con virus de rabia cepa CVS, siendo observada la ultraestructura en tiempos progresivos de infección desde 5 minutos hasta 60 horas. Los resultados obtenidos en los que no se observaron viriones, nos llevaron a hacer un marcaje con inmunoperoxidasas para evidenciar este proceso. Para corroborar los resultados obtenidos fue necesario comparar ultraestructuralmente y con la técnica de inmunoperoxidasas la infección en tejido cerebral de ratones adultos inoculados experimentalmente. Resultados: Este estudio nos permite afirmar que la producción de partículas virales en neuronas de ganglio de raíz dorsal de ratón adulto, cultivadas in vitro, e inoculadas con virus de rabia es escasa, comparada con la gran cantidad de antígeno viral observada en vesículas de 0,5 mm localizadas en el citoplasma de estas mismas células. Los resultados más importantes del estudio revelan que las neuronas sensoriales de ratón adulto son susceptibles a la infección demostrada mediante técnicas de inmunofluorescencia e inmunoperoxidasa, pero tienen una baja producción de viriones. La ultraestructura de las neuronas infectadas revela matrices sugestivas de ser ribonucleoproteína viral y la inmunomicroscopía electrónica muestra vesículas de 0,5 mm con precipitados de DAB, indicando la presencia de antígenos del virus de rabia en ellas.
Cerramiento de vidrio para un edificio. Polideportivo en Madrid/Espa a
Pérez Arroyo, Salvador,Hurtado Torán, Eva
Informes de la Construccion , 1988,
Abstract: This is an analysis of a glass wall realized in a sports centre in Madrid, in which sport takes place above ground level, in a building of five storeys. The fa ade of one storey is designed to be totally transparent, so that the building from the outside gives the impression of being in sections . The window-wall, with a surface area of approximately 47.11 m by 20.24 m, Is achieved by using large sheets of laminated glass, approximately 2.20 m by 3.00 m, tield in place by six suction devices in a metal frame suspended without other support from the roof. From the exterior this material appears with no visible carpentry, with open joints which act as drainage channels. With recent developments in building and technology we can consider using wall materials adaptable to all external conditions, and which allow more possibilities than traditional construction materials. This is especially important for public amenity buildings which, like this one, must present an original and stimulating image, at times, as in this case, displaying to the outside word the activity within. Presentamos un análisis del cerramiento de vidrio realizado en un edificio polideportivo en Madrid, en el que el deporte se organiza en altura, en una construcción de cinco plantas, una de cuyas fachadas se concibe como totalmente transparente, mostrando el edificio "seccionado" al exterior El muro cortina, de 47,11x20,24 m de superficie, se resuelve con grandes piezas de vidrio laminado, de 2,20x3,00 m, aproximadamente, sujetas mediante seis piezas de presión a la estructura metálica que cuelga enteramente de la cubierta. Aparece este material al exterior sin carpintería, con juntas abiertas que funcionan como canales de drenaje. Hoy el desarrollo de la construcción y la tecnología hacen posible el planteamiento de cerramientos cuya flexibilidad de funcionamiento se adapta a las condiciones exteriores y proporciona mayores prestaciones que los de construcción tradicional. Ello es especialmente importante en edificios de uso público que, como éste, tienen que aparecer en la ciudad con una imagen singular y estimulante, mostrando a veces, como en este caso, su actividad hacia la calle.
The American Way. Los abogados latinoamericanos como estudiantes de maestría en Estados Unidos de América
Marta VIDES,Manuel GóMEZ,Luis Fernando PéREZ HURTADO
Boletín mexicano de derecho comparado , 2011,
Abstract: El presente trabajo explora las razones por las cuales los abogados latinoamericanos deciden realizar cursos de maestría en los Estados Unidos, y por qué las escuelas de derecho estadounidenses ofrecen posgrados para extranjeros.
Efecto de diferentes variables sociodemográficas en la progresión de la infección por el virus de la inmunodeficiencia humana en una cohorte de usuarios de drogas
Hurtado,Isabel; Hernández-Aguado,Ildefonso; Ferreros,Inmaculada; Lumbreras,Blanca; Pérez-Hoyos,Santiago;
Gaceta Sanitaria , 2008, DOI: 10.1590/S0213-91112008000600007
Abstract: objective: to analyze whether the effectiveness of combined antiretroviral therapy in delaying progression to aids and death is affected by social inequities in a cohort of hiv-positive injecting drug users (idus). methods: a cohort of 3,122 hiv-positive idus identified in the aids information and prevention centers of the autonomous region of valencia was analyzed, with further follow-up in 1,876. progression to aids and death after seroconversion were calculated by kaplan-meier estimation according to sociodemographic variables (age, sex, education, marital status, length of addiction). cox regression models were also fitted. results: no significant differences were observed according to the variables considered when analyzing time to aids development. evaluation of survival time revealed that individuals with further follow-up showed an excess of mortality (hr = 1.35; 95%ci: 0.20-1.54). for individuals without follow-up, mortality risk was reduced in those with secondary school education (hr = 0.51; 95%ci: 0.35-0.74) and with university education (hr = 0.41; 95%ci: 0.18-0.93) compared with those with no education. when individuals with follow-up were analyzed, the differences lost significance for those with secondary school education (hr = 0.92; 95%ci: 0.72-1.19) and university education (hr = 0.62; 95%ci: 0.35-1.11). conclusions: the mortality excess found in idus with lower educational levels, especially among those not seeking healthcare in the initial period after being identified as hiv-positive, highlights the need for interventions aimed at facilitating access to health systems, especially among the socially disadvantaged.
Increased syphilis trend among patients in an AIDS information and prevention center
Hurtado,Isabel; Alastrue,Ignacio; Pavlou,Menelaos; Tasa,Teresa; Pérez-Hoyos,Santiago;
Gaceta Sanitaria , 2011,
Abstract: objective: a rebound of syphilis cases has recently been observed. this study describes the trend in syphilis infection among persons attending the aids information and prevention center of valencia, spain. methods: we performed a cohort study of all persons attended from 2000 to 2006. the calendar effect was assessed by a logistic regression model adjusted by sexual and sociodemographic variables. results: a total of 71% were heterosexuals (ht) and 19% were men who had sex with men (msm). among the 10,850 users of the center, the prevalence of syphilis was 0.7%. among msm, the prevalence of syphilis was 2.4% for the whole period and was 4.6% for 2006. multivariate analysis showed that the risk of infection was lower in persons with a university education (or=0.10; 95%ci: 0.03-0.59) than in those without. the risk was higher in persons who took drugs (or=5.49; 95%ci: 1.55-19.43) or who practiced prostitution (or=6.83; 95%ci: 2.52-18.53). in 2006, the risk of having syphilis was greater (or=5.05; 95%ci: 1.12-22.72). conclusions: syphilis infection increased substantially among msm. in this collective, the prevalence of infection is related to educational level, prostitution and the use of non-injected recreational drugs.
Ultrastructural description of rabies virus infection in cultured sensory neurons
Velandia, Myriam L;Pérez-Castro, Rosalía;Hurtado, Hernán;Castellanos, Jaime E;
Memórias do Instituto Oswaldo Cruz , 2007, DOI: 10.1590/S0074-02762007005000030
Abstract: primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (rabv) infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. the monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. as previously reported, sensory neurons showed great susceptibility to infection by rabv; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. when infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. sensory neurons infected in vitro by rabv produced a large amount of unassembled viral ribonucleoprotein. however, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. it can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy.
Diseminación tisular de Cryptosporidium SPP en hospedadores murinos experimentalmente inmunosuprimidos
de la Parte-Pérez,María Antonia; Bruzual,Elizabeth; Hurtado,Pilar; Arcay,Lucila;
Archivos Venezolanos de Farmacología y Terapéutica , 2008,
Abstract: cryptosporidium spp. is a protozoan parasite icluded in the phylum apicomplexa, that has been well studied in humans and animals for being the agent that causes cryptosporidiosis. in this experiment we studied the parasite dissemination to organs and systems in two groups of murine hosts: one constituted by infected mice treated with cyclophosphamide (cpa) to produce immunosuppression and the group control, which included infected animals not treated with cpa. the analysis of tissue specimens pertaining to the group of infected and treated animals, showed wide dissemination of the parasite in intestine, trachea, lung, spleen, lymph nodes, thyroid gland and liver, while tissue specimens from controls showed scarce dissemination to the intestine. observations in organs and systems of the immunosuppressed mice suggest similar parasite behaviour in the immunodeficient human being, therefore the importance for the application of the preventive measures for the infection by this coccidia in cases of immunodeficient individuals.
Tuberculosis en el Nuevo Milenio
De la Parte-Pérez,M; Hurtado,MP; Rivera,M;
Revista de la Facultad de Medicina , 2001,
Abstract: revision is made to gather up-to-date information as regards to such an important disease, putting highlights in the cellular events that take place when mycobacteria enter the human cell and the immune system is activated. mention is made on topics such as genetic epidemiology of the disease, newer ways to detect the infection, tb in the pregnant woman, newborn and aids patient. the national program on tb is included to make it available to the interested professional.
Page 1 /213508
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.