553 research outputs found

    Pill Power: The Prequel

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    Goldin and Katz [2002], in an influential paper, argued that giving unmarried minors access to the contraceptive Pill was instrumental for women's professional advancement, because such access allowed marriage to be postponed. However, by 1960, married women could get the Pill and thence it is not clear why early marriage would interfere with the pursuit of professional interests. We explore the effects of this alternative, earlier, and common, route to the Pill. Using variation in state minimum-age marriage laws (EMA), we find that EMA precipitated marriage, delayed fertility within marriage, and improved the educational and occupational outcomes of women, especially non-college women. Thus, fertility control, marriage notwithstanding, emerges as a key enabler of women's educational and professional advancement.education, marriage, contraceptive pill, occupation

    Logistics strategies for the perishables exports in Colombia

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    Este trabajo desarrolló sus objetivos a partir de la identificación de los promblemas generales existentes para los exportadores colombianos, de posicionar su producto perecedero en los mercados internacionales de manera eficiente con un estándar de calidad alto y a precios competitivos.The main objectives of this investigation were based on identifying the overall existing problems for colombian exporters to position their perishables product in international markets in an efficient manner witha high standard of quality and at competitive prices

    Centralized college admissions and student composition

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    Education markets are increasingly switching to centralized admission systems. However, empirical evidence of the effects of these transitions is scarce. We examine the consequences of introducing centralized admissions in the higher education market in Brazil. Using detailed administrative data, we exploit the staggered adoption of a centralized clearinghouse across institutions to investigate the impacts on student composition. Consistent with lower application frictions and higher competition, we find that centralization is associated with a decline in the share of female students and an increase in the average age of students. We also document that institutions under the centralized assignment attract students from other locations and with higher test scores. We present suggestive evidence that centralization increases stratification of institutions by quality, widening the gap between low and high quality institutions

    The Direct and Spillover Effects of Large-scale Affirmative Action at an Elite Brazilian University

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    We examine the effects of an affirmative action policy at an elite Brazilian university that reserved 45 percent of admission slots for Black and low-income students. We find that marginally-admitted students who enrolled through the affirmative action tracks experienced a 14 percent increase in early-career earnings. But the adoption of affirmative action also caused a large decrease in earnings for the university's most highly-ranked students. We present evidence that the negative spillover effects on highly-ranked students' earnings were driven by both a reduction in human capital accumulation and a decline in the value of networking

    Polyfluoroalkyl-silica porous coatings with high antireflection properties and low surface free energy for glass in solar energy application

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    Polyfluoroalkyl-silica porous coating stacks with durable antireflection (AR) properties have been obtained for photovoltaic (PV) application. An acid-catalyzed sol-gel process combined with evaporation induced self-assembly and the presence of a non-hydrolyzable polyfluoroalkyl group linked to the central atom of the silicon alkoxide was conducted. The aim was to obtain a low surface energy coating, devised to mitigate soiling adherence, without losing the AR properties of a baseline coating. In particular, the influence of polyfluoroalkyl chain length on the thickness, the water contact angle and optical transmission properties was first analyzed. The optimized polyfluoroalkyl-silica porous coating presented low surface energy < 20 mJ/m2, even with the desired low roughness values required for obtaining a negligible scattering of the incoming solar radiation. This coating was studied as an AR mono-layer and as an external coating in an AR bi-layer stack, with the presence of an inner dense-structured silica layer, that contributed to both the optical performance and durability, acting as an alkali diffusion preventing layer. The AR bi-layer stack deposited on two sides of glass provided a transmittance gain of 7.1%. Those optical properties were inalterable after accelerated aging tests, which sustains the reliability of the materials for solar energy applications.This work was supported by the Basque Government through EMAITEK 2017 program as well as the ELKARTEK projects FRONTIERS-2 (contract number KK2016-00093 ) and FRONTIERS-3 (contract number KK2017-00096 ). The authors thank ICV-CSIC, Yolanda Castro and Alicia Durán for their support with ellipsometry and EEP measurements. The authors thank Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) for their collaboration with the aging tests. The authors thank Miguel Pérez-Aradros for the help with graphical abstract illustration

    Antireflective mesoporous silica coatings by optimization of water content in acid-catalyzed sol-gel method for application in glass covers of concentrated photovoltaic modules

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    Porous silica layers with outstanding antireflective properties have been prepared by acid-catalyzed sol-gel process in presence of organic phases as structure directing agents (SDA) and excess water, with the aim of offering a cost-competitive, easy up-scaling and high efficiency process that contributes to reduce current levelized cost of energy (LCOE) of concentrating photovoltaics (CPV). The process has been optimized by controlling the water/alkoxide ratio, which is an important structure-regulating tool, having a strong influence in the structural properties of sol-gel synthesized materials. Hydrolysis of the inorganic precursor has been accomplished in high water/alkoxide conditions and in the presence of SDAs. Evaporation induced self-assembly (EISA) during coating deposition and the scanning of four types of SDAs have permitted to select the coating that fulfilled specific thickness and refractive index values with, in parallel, excellent results on sol stability. The final optimization has produced mesoporous coatings with ∼9 nm mean pore size, leading to an enhancement in transmittance up to 7.4% over bare glass in the 300–1500 nm wavelength range. The transmittance spectra have been used as inputs for the theoretical calculation of the short-circuit current density of a commercially available multijunction solar cell for CPV applications.This work was supported by the Basque Government for EMAI-TEK 2017 program as well as theELKARTEK projects FRONTIERS-2(contract number KK2016-00093) and FRONTIERS-3 (contractnumber KK2017-00096). The authors thank ICV-CSIC, Yolanda Cas-tro and Alicia Durán for ellipsometry and EEP measurements. Theauthors thank Miguel Pérez-Aradros for the help with graphicalabstract illustration

    Impacto del trabajo de Latindex en las revistas científicas uruguayas

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    Se describe el desarrollo del centro de acopio Latindex en Uruguay, con énfasis en la aplicación de las características de calidad editorial diseñadas por Latindex, la relación con los editores, la interacción con otros organismos nacionales, y las diferentes actividades que se llevan a cabo. A través de análisis cuantitativos se presenta el importante rol del centro de acopio y su influencia en la mejora de la normalización, visibilidad, calidad y difusión de las publicaciones científicas uruguayas

    Auditoría de gestión al Departamento de Crédito de la Cooperativa de Ahorro y Crédito Educadores de Chimborazo, a julio del 2015

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    El presente trabajo de investigación tiene como objetivo desarrollar una Auditoria de Gestión al Departamento de Crédito de la Cooperativa de Ahorro y Crédito Educadores de Chimborazo. Ltda., a Julio del 2015. Los métodos de investigación que se aplicaron para su desarrollo son los métodos: Inductivo, deductivo, analítico, experimental, sintético y estadístico porcentuado. Para la ejecución de la auditoria de gestión fue necesario la conformación de un equipo multidisciplinario, que dependiendo de las áreas a examinarse, a más de los auditores estaba integrado por especialistas en otras disciplinas, manifestando la importancia en el uso de materiales como: cuestionarios, papeles de trabajo, hojas de hallazgos entre otros. Efectuado el estudio y análisis del control interno administrativo bajo la aplicación del método COSO y en base a otros procedimientos analizados en las áreas de créditos y recursos humanos encontramos algunos importantes hallazgos. Deficiencias en los procesos administrativos y operativos, de las áreas críticas identificadas luego del análisis de elementos básicos. También se comprobó que la Cooperativa no tiene los respaldos en otros sitios fuera de la entidad para precautelar su historial en caso de siniestros.- como recomendación; toda entidad debe seleccionar y poseer capital humano especializado y actualizado permanentemente, pues al trabajar con un buen equipo de trabajo los resultados son satisfactorio y su rendimiento es productivo.This research work aims to develop a management audit departament Credit credit union Educators Chimborazo. Ltda, to July 2015. The methods used were: inductive, deductive, analytical, experimental, synthetic and statistical. For de execution od the audit was necessary the creation of a multidisciplinary team, which, depending on the áreas to be examined more auditors was composed of specialists in other disciplines, demostrating the importance in the use of materials such as questionnaires, leaves findigs among others. Onducted the estudy and analysis of the administrative internal control under the aplication of the COSO method and base on other procedures discussed in the áreas of credit and human resources, we find some important weaknesses, shortcomings in administrative and operational processes of critical tasks identified after analyzing basic elements. It was also found that the cooperative does not have the backing elsewhere outside the entity to forewarn its history in case of disaster. It is recommended that any entity should select and possess specialized human capital and constantly updated, because working with a good team and the results satisfactoy performance is productive

    Herbart y la memoria activa del saber pedagógico

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    RESUMEN: El trabajo tiene como finalidad hacer una relectura de los planteamientos y las ideas pedagógicas de Herbart. El objetivo es describir y ubicar los planteamientos pedagógicos Herbart en el marco general de sus posiciones teóricas y esbozar el significado que tienen los conceptos pedagógicos que maneja como: educación, instrucción, enseñanza, didáctica, formación, multiplicidad del interés y tacto pedagógico; y el concepto de educabilidad en Herbart y la discusión actual sobre formación de maestros
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