467 research outputs found
A note on the combustion of blends of diesel and soya, sunflower and rapeseed vegetable oils in a light boiler
Producción CientíficaThis paper deals with the study of the vegetable oils (VO) used as fuel for heating. The properties of sunflower, rape and soya oils are studied and these are compared with the properties of C-diesel fuel (used for heating domestic purposes in Spain). The mixtures of VO and diesel are studied and characterized and, finally, the results of a series of combustion trials of the mixtures in a conventional heating installation with a mechanical pulverization burner are presented. The results show that viscosity of VO limits the use of blends up to 40% of them, and the oxygen present in their structures contributes to an efficiency gai
Combustion of Soya Oil and Diesel Oil Mixtures for Use in Thermal Energy Production
Producción CientíficaIn August 2005, Spain approved the Plan for Renewable Energy Sources for the period 2005-2010 (P.E.R.), including co-combustion installations. Co-combustion in the P.E.R. aims to increase power output by 12,185.3 GWh in five years and shows great interest in studies of the combustion of mixtures of fossil and bio-combustible fuels.
This paper presents studies of the co-combustion of soya oil and diesel for thermal heating. The paper begins with a characterization of soya oil as well as mixtures of this oil, with diesel, as fuels. The combustion of the soya oil mixtures and diesel is made in an installation, where the pressure of injection as well as the air volume of the burner can be changed. The obtained results inside to be the environmental average legislation and a greater efficiency of combustion is found. The conclusions show that the use of mixtures of soya oil and Diesel for producing thermal energy in conventional equipment is feasible
Eficiencia semifuerte del mercado internacional del azúcar entre los años 2001 y 2011.
Este artículo tiene como objetivo comprobar la eficiencia en sentido semifuerte–de acuerdo a la definición de Fama (1970)– del mercado internacional del azúcar. Para lograr este objetivo, se seguirá a Ferré y Hall (2002), quienes demuestran que la existencia de cointegración es condición necesaria pero no suficiente para afirmar que el mercado no es eficiente. En este orden de ideas, para probar esta hipótesis se determinará la existencia de cointegración entre las dos series de precios del azúcar (contrato n.° 5 del mercado de Londres y el n.° 11 de Nueva York). Nuestros resultados muestran que existe una relación de largo plazo pero no una evidencia suficiente para rechazar la hipótesis de eficiencia en el sentido semifuerte para el mercado internacional del azúcar
Achievements of a Bilingual Policy: The Colombian Journey
The Colombian journey to become a country with an educational system that develops bilingual skills in students began in 1979. More recently, Colombia National Ministry of Education presented Colombia’s National Bilingualism Program 2004–2019, a policy that recognized for the first time that mastering English was a matter of advantages in competitiveness for the country. Two important goals were established under this policy for 2014. First, 40% of secondary graduates should achieve at least an intermediate level—B1or threshold or independent user following the Common European Framework of Reference for Languages (CEFRL). Second, 20% of Bachelor degree (under) graduates should achieve at least a vantage or upper intermediate—B2 level. A descriptive approach was applied to the data and it was found that the neither goal was met. The impact of the different programs implemented should be evaluated, so goals proposed for 2025 can be achieved
Determinantes de uma eleição errada ao escolher medicamentos de venda livre
Este estudo avalia a probabilidade de confusão do consumidor para seis categorias de medicamentos de venda livre. As estimativas realizam-se com base em um desenho experimental onde o tempo e a presença das marcas são as variáveis manipuladas. Adicionalmente, controla-se por memorização e hábito de consumo da marca. Através de três tipos de análises (tabela de contingência, árvores de decisão e regressão logit), os resultados indicam que a memorização e a presença da marca são duas variáveis que reduzem a probabilidade de confusão. Os resultados não são generalizáveis a outras categorias, sem embargo, a memorização e a presença da marca se mostraram variáveis importantes ao avaliar a probabilidade de confusão do consumidor.Cette étude évalue la probabilité de confusion du consommateur pour six catégories de médicaments de vente libre. Les estimations sont réalisées sur base d'un design expérimental dans lequel le temps et la présence des marques sont les variables manipulées. En outre, un contrôle est effectué par rappel et habitudes de consommation de la marque. Après avoir utilisé trois types d'analyses (tableau de contingence, arbre de régression et régression logit), les résultats indiquent que le rappel et la présence de la marque sont deux variables qui réduisent la probabilité de confusion. Les résultats ne sont pas généralisables pour d'autres catégories, cependant, le rappel et la présence de la marque sont des variables qui résultent importantes pour évaluer la probabilité de confusion du consommateur.Este estudio evalúa la probabilidad de confusión del consumidor para seis categorías de medicamentos de venta libre. Las estimaciones se realizan con base en un diseño experimental donde el tiempo y la presencia de las marcas son las variables manipuladas. Adicionalmente, se controla por recordación y hábito de consumo de la marca. A través de tres tipos de análisis (tabla de contingencia, regresión de árbol y regresión LO GIT), los resultados indican que la recordación y la presencia de la marca son dos variables que reducen la probabilidad de confusión. Los resultados no son generalizables a otras categorías; sin embargo, la recordación y presencia de la marca sí resultan ser variables importantes al evaluar la probabilidad de confusión del consumidor.This study evaluates the probability of confusion among consumers regarding six categories of over-the-counter medications. The estimates are based on an experimental design in which time and the presence of brands are the variables addressed. Additionally, it is controlled using recollection and consumption habits regarding brands. Using three types of analysis (contingency table, tree regression and logic regression), the results show that recollection and the presence of brands are the two variables that reduce the probability of confusion. The results are not applicable to other categories; however, recollection and the presence of brands do turn out to be significant variables when evaluating the probability of consumer confusion
Efecto de la crisis económica sobre el consumo de psicofármacos en Asturias
ResumenObjetivoEvaluar si la crisis económica de 2008ha comportado cambios en la evolución del consumo de ansiolíticos, hipnótico-sedantes y antidepresivos en Asturias.MétodoEstudio descriptivo y de utilización de medicamentos durante 2003-2013. Se calcularon las dosis diarias definidas por 1000 habitantes/día (DHD) de ansiolíticos, hipnótico-sedantes y antidepresivos. Se obtuvieron coeficientes de regresión lineal (b) de las DHD de la etapa precrisis (2003-2008) y de la etapa de crisis (2009-2013).ResultadosEl consumo de ansiolíticos creció un 40,25%, el de hipnóticos un 88,11% y el de antidepresivos un 80,93%. Para los ansiolíticos: b-(2003-2008)=4,38 DHD/año y b-(2009-2013)=1,08 DHD/año. Para los hipnótico-sedantes: b-(2003-2008)=2,30 DHD/año y b-(2009-2013)=0,40 DHD/año. Para los antidepresivos: b-(2003-2008)=5,79 DHD/año y b-(2009-2013)=2,83 DHD/año.ConclusionesEl incremento del consumo para los tres subgrupos en la época de crisis fue menor que en la época precrisis. No se confirma que la crisis económica haya influido aumentando el consumo de estos medicamentos.AbstractObjectiveTo assess whether the economic crisis of 2008 has changed the consumption of anxiolytics, hypnotics-sedatives and antidepressants in Asturias (Spain).MethodWe conducted a descriptive study of drug use from 2003 -2013. The defined daily doses of 1000 inhabitants per day (DHD) were calculated for anxiolytics, hypnotics-sedatives and antidepressants. Linear regression coefficients (b) of the DHD were obtained for the pre-crisis period (2003-2008) and the crisis period (2009-2013).ResultsThe consumption of anxiolytics increased by 40.25%, that of hypnotics by 88.11% and that of antidepressants by 80.93%. For anxiolytics: b-(2003-2008)=4.38 DDI/year and b-(2009-2013)=1.08 DDI/year. For hypnotics-sedatives: b-(2003-2008)=2.30 DDI/year and b-(2009-2013)=0.40 DDI/year. For antidepressants: b-(2003-2008)=5.79 DDI/year and b-(2009-2013)=2.83 DDI/year.ConclusionsThe rise in consumption of the three subgroups during the crisis period was lower than that of the pre-crisis period. This study does not confirm the influence of the economic crisis on the rise in consumption of these drugs
Taxes, Transfers and the Distribution of Employment in Mexico
The informal sector accounts for a substantial fraction of employed population in Mexico and other Latin American countries. In this paper we study the interaction between the tax and transfers system and the size and composition of informal sector. To do that we build a search model that can be calibrated to the Mexican data. Our model features two employment statuses: employed and unemployed; and two sectors: formal and informal. We estimate our model to data from Encuesta Nacional de Ocupaci ́on y empleo (ENOE) by simulated GMM. Then we perform three different policy analyses: changes in the distribution of the transfers between formal and informal sector workers, changes in the size of the transfer system, and changes in the progressivity of taxes and transfers (pending). Our model is able to capture key features of Mexican labor markets, such as the distribution of the labor force across sectors and the distribution of accepted wage offers. Dividing transfers equally between formal and informal sector workers increases the size of the informal sector by 5 percentage points, it also increases average wages in the formal sector by 6% whereas wages in the informal sector fall by 4%. When we double the size of transfers, the size of informal sector falls by 5 percentage points. However, it has a big effect on the distribution of accepted wage offers: average wages increase by 10% in the formal sector and they raise by 16% in the informal sector
Taxes, Transfers and the Distribution of Employment in Mexico
The informal sector accounts for a substantial fraction of employed population in Mexico and other Latin American countries. In this paper we study the interaction between the tax and transfers system and the size and composition of informal sector. To do that we build a search model that can be calibrated to the Mexican data. Our model features two employment statuses: employed and unemployed; and two sectors: formal and informal. We estimate our model to data from Encuesta Nacional de Ocupaci ́on y empleo (ENOE) by simulated GMM. Then we perform three different policy analyses: changes in the distribution of the transfers between formal and informal sector workers, changes in the size of the transfer system, and changes in the progressivity of taxes and transfers (pending). Our model is able to capture key features of Mexican labor markets, such as the distribution of the labor force across sectors and the distribution of accepted wage offers. Dividing transfers equally between formal and informal sector workers increases the size of the informal sector by 5 percentage points, it also increases average wages in the formal sector by 6% whereas wages in the informal sector fall by 4%. When we double the size of transfers, the size of informal sector falls by 5 percentage points. However, it has a big effect on the distribution of accepted wage offers: average wages increase by 10% in the formal sector and they raise by 16% in the informal sector
Un modelo de predicciones diarias para contratos de futuros del azúcar
El objetivo de este trabajo es estimar el mejor modelo que permita pronosticar los precios internacionales del azúcar en los mercados de Nueva York y Londres. Para ello, se busca alguna relación de largo plazo entre la cotización diaria del WTI y los precios del azúcar en esos dos mercados. Se concluye que no existe cointegración entre estas series, lo que indica la no existencia de dicha relación en el largo plazo. Para identificar la relación en el corto plazo se estimó un VAR diferenciando las series. Se encontró que un modelo ARIMA univariado es el mejor para predecir el precio internacional del azúcargráficos, tablas.Incluye referencias bibliográficas (página 47)
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