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Search Results: 1 - 10 of 97659 matches for " I.; Mu?oz "
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Indicadores de Rentabilidad y Eficiencia Económica de la Producción de Manzanas cv. Gala en la Región del Maule, Chile
Lobos A,Germán; Muoz I,Tristán;
Agricultura Técnica , 2005, DOI: 10.4067/S0365-28072005000400008
Abstract: profitability and economic efficiency indicators of apple (malus domestica l.) cv. gala production of a farm located in the linares area (35o51’ s lat, 71o35’ w long), maule region, chile, were estimated. technical parameters of the orchard were obtained from historical farm records for different premises from the 1994-1995 to 2003-2004 agricultural seasons. for the valuation of the investment in the orchard and production costs, the prices for the 2003-2004 season were used. from the capital-asset-pricing model (capm), the weighted average cost of capital (wacc) was calculated, which was estimated at 8.71% annually. the profitability indicators calculated were net present value (van), internal rate of return (tir), net present value index (ivan) and cost benefit ratio (rbc), while the economic efficiency indicators were total mean production cost (cmet), unit margin (mu) and return on equity (rsc). the analysis was based upon one hectare. for the standard situation the results obtained were: 8,454 dollars per hectare van, 12.1% tir, 0.43 ivan, 1.51 rbc. the minimum cmet were estimated at 0.08 dollars per kilogram, the maximum mu at 0.14 dollars per kilogram and rsc up to 23.6%. the main conclusion, from an economic point of view, suggests that this activity is profitable for producers of cv. gala apples.
Control Difuso Adaptivo y su Aplicación a una Planta Piloto de Secado por Lecho Fluidizado
Velásquez,I.; Torres,F.; Muoz,C.; Shene,C.;
Información tecnológica , 2005, DOI: 10.4067/S0718-07642005000500011
Abstract: this work presents the design and implementation of a feed-forward proportional fuzzy controller with an adaptation mechanism (cdpp-ma). this controller was designed for temperature feedback control in a fluidized bed reactor. the fuzzy controller algorithm is programmed in intouch?s script language. matlab software was used for the design and configuration of the fuzzy controller?s parameters. experimental tests were carried out in a pilot plant and included changes of reference of the controller and applications of disturbances to the system. excellent performance was obtained with the controller, both in following the reference and in attenuation of the disturbances. the results show the implemented controller to be a feasible alternative to for use in control of highly non-linear or strongly disturbed processes
Tratamiento de la hipertensión intracraneal de origen tumoral maligno
Vázquez,A.; Portillo,P.; Zazpe,I.; Muoz,B.;
Anales del Sistema Sanitario de Navarra , 2004, DOI: 10.4321/S1137-66272004000600016
Abstract: brain tumours are a frequent cause of intracraneal hypertension syndrome, clinically manifested by headache, nausea and vomiting, and a decrease in the level of consciousness. the keypoint sign of intracraneal hypertension is papilloedema. other manifestations depend on the localization of the tumour, appearing as neurological focality and seizures. the causes of intracranial hypertension of tumoural origin are the mass effect of the tumour, brain edema, the possibility of intratumoural haemorrhage and hydrocephalus caused by obstruction in the circulation of cerebrospinal fluid. the treatments employed, medical or surgical, act against these causes.
Premedicación en anestesia pediátrica: citrato de fentanilo oral transmucoso frente a midazolam oral
Velázquez,I.; Muoz-Garrido,J.C.;
Revista de la Sociedad Espa?ola del Dolor , 2010,
Abstract: introduction: the aim of anaesthetic premedication is to reduce anxiety and stress prior to surgery. paediatric patients suffer even more anxiety due to fear of the unknown and the separation from parents. the need to find out a suitable way of administering premedication to paediatric patients without causing any more trauma is a challenge for the anaesthesiologist. objectives: the objective of the current study was to evaluate the efficacy, level of sedation and a way of accepting two different types of premedication for children: oral transmucosal fentanyl citrate (otfc) and oral midazolam dissolved in fruit juice. methods: in this study, 40 children who were going to be subjected to various types of surgery were randomised to receive otfc 10 μg/kg and midazolam 0.3 mg/kg 30 minutes before venipuncture. variables taken into account were: haemoglobin saturation from the beginning of premedication and inside the recovery room, way of accepting, level of sedation, child behaviour after separation from parents, venous puncture and anaesthetic induction, delay in wakening, need of post-surgical analgesia and appearance of secondary effects. results: results were compared using student?s t (p < 0.05) and there were significant differences in favour of the otfc group as far as the way of accepting a venous puncture was concerned. no differences in behaviour were observed after separation from parents and anaesthetic induction. there were no significant differences in haemoglobin saturation or secondary effects between both groups. conclusions: we believe that the use of otfc is safe, effective and a convenient way to premedicate a paediatric population, who will be undergoing a surgical procedure, with a reasonable degree of sedation which makes separation from their parents, venous catheterisation and anaesthetic induction easier.
El uso de metodología estadística actualizada en la investigación biomédica: el ejemplo de metodología para análisis interino en ensayos clínicos
Muoz N,Sergio R; Bangdiwala,Shrikant I;
Revista médica de Chile , 2001, DOI: 10.4067/S0034-98872001000900002
Abstract: background: clinical research stresses the need for evidence as a basis for setting research agendas. the extent to which current clinical research involves recent advances in biostatistics is not well known. aim: this manuscript focuses on the use of interim analyses accumulating data in clinical trials. material and methods: a pubmed search was conducted for the period 1990-2000. keywords used included ?interim analysis?, ?alpha-spending function?, and ?early termination?, after subsetting to ?randomised controlled trials (rct)? that were ?multicenter? since these particular studies are more likely to have external monitoring boards conducting interim analyses. studies were grouped by clinical discipline and also by journals of high or low impact index. results: thirteen thousand two hundred eighty two articles with both ?rct? and ?multicenter? were found. of these, the ?interim analysis? keyword yielded 879 articles, of which only 163 (19%) studies reported their methodology. the percentages varied by clinical discipline and by journal type. a 25% random sample of the articles were further reviewed to investigate the appropriateness of the interim analysis methods used. discussion: recent articles in the medical literature attempt to make the interim analysis methods more accessible to clinicians. however, further training of statisticians involved in clinical trials is needed as well (rev méd chile 2001; 129: 983-8)
Análisis interino en ensayos clínicos: una guía metodológica
Muoz N,Sergio R; Bangdiwala,Shrikant I;
Revista médica de Chile , 2000, DOI: 10.4067/S0034-98872000000800014
Abstract: interim analysis of data accumulated in clinical trials is one aspect of the monitoring of the study progress. it is usually done to assess whether there are significant differences in efficacy between the experimental and control treatment groups, in order to decide whether to stop or no the trial prematurely. among many reasons for early interruption of a trial is the ethical consideration that subjects should not be exposed to an unsafe, inferior or ineffective treatment. statistical methods suited for doing interim analysis, that allow to control the probability of incorrectly rejecting the null hypothesis of no treatment differences, are often not well understood by researchers. in this article we present an intuitive, non-mathematical explanation and review of the statistical methods for doing interim analysis in clinical trials along with an illustrative example of the application of the methods on a hypothetical dataset (rev méd chile 2000; 128: 935-41).
Indicadores de Rentabilidad y Eficiencia Económica de la Producción de Manzanas cv. Gala en la Región del Maule, Chile Profitability and Economic Efficiency Indicators of cv. Gala Apple Production in Maule Region, Chile
Germán Lobos A,Tristán Muoz I
Agricultura Técnica , 2005,
Abstract: En esta investigación se estimaron indicadores de rentabilidad y de eficiencia económica de la producción de manzanas (Malus domestica L.) cv. Gala para una explotación localizada en la zona de Linares (35o51’ lat. Sur, 71o35’ long. Oeste), Región del Maule, Chile. Los coeficientes técnicos de la plantación fueron tomados de los registros históricos de diferentes predios durante las temporadas agrícolas 1994-1995 a 2003-2004. Para la valorización de las inversiones en plantación y los costos de producción se utilizaron los precios de la temporada 2003-2004. A partir del Modelo de Valoración de Activos de Capital (CAPM) se calculó el costo promedio ponderado del capital (WACC), el cual fue estimado en 8,71% anual. Los indicadores de rentabilidad calculados fueron el valor actual neto (VAN), tasa interna de retorno (TIR), índice de valor actual neto (IVAN) y la razón beneficio-costo (RBC), mientras que los indicadores de eficiencia económica fueron el costo medio total (CMET), margen unitario (MU) y la rentabilidad sobre capital (RSC). Como unidad de análisis se consideró una hectárea. Para la situación estándar los resultados obtenidos fueron: $5,41 millones VAN, 12,1% TIR, 0,43 IVAN, y 1,51 RBC. Para la etapa de producción se proyectó un CMET mínimo de $52,3 kg-1, un MU máximo de $91,9 kg-1 y una RSC de hasta 23,6%. La principal conclusión sugiere que, desde el punto de vista económico, el cultivo es rentable para los productores de manzanas cv. Gala. Profitability and economic efficiency indicators of apple (Malus domestica L.) cv. Gala production of a farm located in the Linares area (35o51’ S lat, 71o35’ W long), Maule Region, Chile, were estimated. Technical parameters of the orchard were obtained from historical farm records for different premises from the 1994-1995 to 2003-2004 agricultural seasons. For the valuation of the investment in the orchard and production costs, the prices for the 2003-2004 season were used. From the capital-asset-pricing model (CAPM), the weighted average cost of capital (WACC) was calculated, which was estimated at 8.71% annually. The profitability indicators calculated were net present value (VAN), internal rate of return (TIR), net present value index (IVAN) and cost benefit ratio (RBC), while the economic efficiency indicators were total mean production cost (CMET), unit margin (MU) and return on equity (RSC). The analysis was based upon one hectare. For the standard situation the results obtained were: 8,454 dollars per hectare VAN, 12.1% TIR, 0.43 IVAN, 1.51 RBC. The minimum CMET were estimated at 0.08 dollars per
Un nuevo modelo fenomenológico y diferencial para predecir la respuesta mecánica de materiales metálicos policristalinos sometidos a deformación en caliente
Castellanos, J.,Muoz, J.,Gutiérrez, V.,Rieiro, I.
Revista de Metalurgia , 2012,
Abstract: This paper presents a new phenomenological and differential model (that use differential equations) to predict the flow stress of a metallic polycrystalline material under hot working. The model, called MCC, depends on six parameters and uses two internal variables to consider the strain hardening, dynamic recovery and dynamic recrystallization processes that occur under hot working. The experimental validation of the MCC model has been carried out by means of stress-strain curves from torsion tests at high temperature (900 oC a 1200 oC) and moderate high strain rate (0.005 s-1 to 5 s-1) in a high nitrogen steel. The results reveal the very good agreement between experimental and predicted stresses. Furthermore, the Garofalo a-parameter and the strain to reach 50 % of recrystallized volume fraction have been employed as a control check being a first step to the physical interpretation of variables and parameters of the MCC model. Este trabajo presenta un nuevo modelo fenomenológico y diferencial (que emplea ecuaciones diferenciales) para predecir la respuesta mecánica de un material metálico policristalino sometido a deformación en caliente. El modelo, llamado MCC, depende de seis parámetros y utiliza dos variables internas para considerar los procesos de endurecimiento por deformación, restauración y recristalización dinámicas. La validación experimental del modelo MCC se ha realizado empleando curvas tensión-deformación procedentes de ensayos de torsión a alta temperatura (900 oC a 1.200 oC) y moderadamente alta velocidad de deformación (0,005 s-1 a 5 s-1) sobre un acero de alto contenido en nitrógeno. Los resultados obtenidos revelan la concordancia significativa entre las tensiones experimentales y predichas. Además el parámetro a de Garofalo y la deformación para el 50 % de volumen recristalizado se han utilizado como elementos de control para realizar un primer paso en la interpretación física de las variables y parámetros del modelo MCC.
Premedicación en anestesia pediátrica: citrato de fentanilo oral transmucoso frente a midazolam oral Premedication in paediatric anaesthesia
I. Velázquez,J.C. Muoz-Garrido
Revista de la Sociedad Espa?ola del Dolor , 2010,
Abstract: Introducción: La premedicación anestésica está destinada a reducir la ansiedad y la respuesta al estrés que supone el período anterior a la intervención quirúrgica. El temor a lo desconocido, al dolor y la separación de los padres son elementos que se a aden a la ansiedad perioperatoria en la población pediátrica. La necesidad de encontrar una vía de administración idónea en ni os que no a ada más sufrimientos a los ya existentes, es un reto para los anestesiólogos. Objetivo: Los objetivos del presente estudio eran valorar la eficacia, el grado de sedación y el modo de aceptación de 2 modalidades de premedicación para ni os: citrato de fentanilo oral transmucoso (CFOT) y midazolam oral disuelto en zumo de fruta. Material y método: Se estudiaron 2 grupos aleatorizados de 40 ni os que iban a someterse a cirugía de diversas especialidades. Las dosis administradas fueron de 10 μg/kg de CFOT y 0,3 mg/kg de midazolam, administrados 30 minutos antes de la punciσn venosa. Las variables consideradas fueron: saturaciσn de hemoglobina desde el inicio de la premedicaciσn y en la sala de despertar, modo de aceptaciσn, grado de sedaciσn, actitud del niρo al separarlo de los padres, ante la punción venosa y ante la inducción anestésica, retraso en el despertar, requerimiento de analgesia postoperatoria, aparición de efectos secundarios. Resultados: Los resultados se compararon utilizando la t de Student (p < 0,05), y se obtuvieron diferencias significativas en el grado de aceptación favorable al grupo de CFOT, así como la actitud del ni o en la canalización venosa. No hubo diferencias en la separación de los padres y en la inducción anestésica. No se presentaron secundarismos significativos en ningún grupo, ni se apreció tampoco desaturación importante de hemoglobina tras la administración de la premedicación. Conclusiones: Creemos que el CFOT se nos plantea como una administración de premedicación segura, eficaz y cómoda para población pediátrica, que vaya a someterse a intervención quirúrgica, con un adecuado grado de sedación que facilita la separación de los padres, la canalización venosa y la inducción anestésica. Introduction: The aim of anaesthetic premedication is to reduce anxiety and stress prior to surgery. Paediatric patients suffer even more anxiety due to fear of the unknown and the separation from parents. The need to find out a suitable way of administering premedication to paediatric patients without causing any more trauma is a challenge for the anaesthesiologist. Objectives: The objective of the current study was to evaluate the efficacy, level of se
Control Difuso Adaptivo y su Aplicación a una Planta Piloto de Secado por Lecho Fluidizado Adaptive Fuzzy Control with an Application to a Fluidized Dryer Bed Pilot Plant
I. Velásquez,F. Torres,C. Muoz,C. Shene
Información Tecnológica , 2005,
Abstract: En el presente trabajo, se muestra el dise o e implementación de un controlador difuso proporcional-prealimentado con Mecanismo de Adaptación (CDPP-MA) para regular la temperatura en el interior del de un secador por lecho fluidizado. El algoritmo del controlador difuso se programa en el “Script” de Intouch, mientras que para dise ar y configurar los diferentes parámetros del controlador difuso se utiliza el software Matlab. Las pruebas se llevaron a cabo en una Planta Piloto e incluyeron cambios en la referencia del controlador y la aplicación de perturbaciones al sistema. El controlador presenta buen desempe o, tanto en el seguimiento de la referencia como en la atenuación de las perturbaciones. Los resultados indican que el controlador implementado es una alternativa factible de ser usado en el control de procesos no lineales o fuertemente perturbados. This work presents the design and implementation of a feed-forward proportional fuzzy controller with an adaptation mechanism (CDPP-MA). This controller was designed for temperature feedback control in a fluidized bed reactor. The fuzzy controller algorithm is programmed in Intouch’s Script language. Matlab software was used for the design and configuration of the fuzzy controller’s parameters. Experimental tests were carried out in a pilot plant and included changes of reference of the controller and applications of disturbances to the system. Excellent performance was obtained with the controller, both in following the reference and in attenuation of the disturbances. The results show the implemented controller to be a feasible alternative to for use in control of highly non-linear or strongly disturbed processes
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