1,556 research outputs found

    MODELO HIDROGEOLÓGICO CONCEPTUAL DE ACUÍFEROS EN COLOMBIA

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    Las aguas subterráneas se han venido utilizando como alternativa a las aguas superficiales. Normalmente, el volumen de agua almacenado en los acuíferos es grande, comparado con el flujo de recarga, esto implica que el tiempo de residencia de las aguas subterráneas de los acuíferos sea superior al de las aguas superficiales en su reservorio (ríos y lagos). El objetivo de este trabajo, es vincular estudios geológicos, hidrológicos, hidrogeológicos, geotécnicos, sociales, económicos y culturales, apoyados con SIG, permitiendo así, un diagnóstico acertado del estado actual de los acuíferos en Colombia (caso de estudio Duitama), y formulación de técnicas necesarias para su adecuado manejo, conservación y prevención de su contaminación. El alcance de este estudio implica, el desarrollo de un modelo hidrológico conceptual, evaluación de volúmenes de extracción anual, evaluación de reservas y de recarga del acuífero, determinación del rendimiento del acuífero en explotación, priorización del uso de las aguas subterráneas y elaboración de un plan de gestión de manejo ambiental, que permitan la implementación de medidas de protección de las aguas subterráneas

    Diferencias cuantitativas entre sistemas constructivos in situ y prefabricados para losas de entrepiso como soporte para la toma de decisiones

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    En Colombia, son muy pocas las investigaciones académicas que establezcan cuantitativamente la viabilidad en la implementación de soluciones prefabricadas en las construcciones del país y que permitan mejorar la toma de decisiones para el sector productivo. El estado del arte referente al uso de sistemas prefabricados en la construcción se limita esencialmente a un análisis cualitativo, donde únicamente se enumeran las ventajas y desventajas del uso del concreto prefabricado. En el presente documento, se examinan ciertos parámetros dentro de los procesos de diseño y construcción en losas de entrepiso que están presentes y son comunes tanto en sistemas tradicionales como en sistemas prefabricados. Por medio del concepto de cadena de valor de Porter y de la metodología Delphi, se describen y se generan para cada parámetro definido indicadores cuantitativos con el objetivo de generar herramientas que faciliten la toma de decisiones. Dichos indicadores concluirán que es más favorable el uso de soluciones prefabricadas frente a soluciones in situ o tradicionales. Esto supone como panorama positivo la aplicación de dichas soluciones en las construcciones colombianas. Haría falta, entonces, una mayor divulgación y el ajuste de las normas vigentes que le den lugar al prefabricado como un elemento tan confiable como cualquiera de los que se utilizan en la actualidad

    Implementação de um sistema de tratamento individual para melhorar a qualidade da  água na aldeia de Sabaneta Alta, San Francisco, Colômbia

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    This project focuses on providing solutions for the purification and distribution of drinking water in the rural Sabaneta Alta sector belonging to the municipality of San Francisco Cundinamarca, where two branches of engineering, civil and mechatronics, are implemented in order to develop a project, that benefits the rural community in the face of the problems that have arisen in the sector and that continue to arise today. In this way, the sector will have the opportunity to access drinking water, through a portable device that can be adapted to household pipes, since this filter is naturally designed using fine aggregates and coarse aggregates, which guarantees efficiency of turbidity suitable for water quality. In addition to this, this portable system will have UV rays that will help disinfect the water resource.Este estudio se enfoca en dar soluciones a la potabilización y distribución de agua potable en el sector rural Sabaneta Alta, perteneciente al municipio de San Francisco, Cundinamarca, donde se implementan dos ramas de ingeniería, civil y mecatrónica, con el fin de desarrollar un proyecto que beneficie a la comunidad rural ante las problemáticas que se han presentado en el sector y que se siguen presentando actualmente. De este modo, el sector tendrá la oportunidad de acceder al agua potable a través de un dispositivo portátil y adaptable a las tuberías de los hogares, ya que este filtro es diseñado de forma natural empleando agregados finos y agregados gruesos, lo cual garantiza una eficiencia de turbidez apta para la calidad del agua. Adem s, este sistema portable contará con rayos UV que ayudarán a la desinfección del recurso hídrico.Este projeto se concentra em fornecer soluções para a purificação e distribuição de água potável no setor rural Sabaneta Alta pertencente ao município de San Francisco Cundinamarca, onde dois ramos de engenharia, civil e mecatrônica, são implementados para desenvolver um projeto, que beneficia a comunidade rural diante dos problemas que surgiram no setor e que continuam a surgir até hoje. Desta forma, o setor terá a oportunidade de aceder à água potável, através de um dispositivo portátil que pode ser adaptado às canalizações domésticas, uma vez que este filtro é naturalmente concebido com agregados miúdos e graúdos, o que garante uma eficiência de turbidez adequada à qualidade da água. Além disso, este sistema portátil terá raios UV que ajudarão a desinfetar o recurso hídrico

    Desenvolvimento rural sustentável: análise da infraestrutura de Veraguas-Pacho, Cundinamarca

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    Sustainable development is very important so that rural populations can have socioeconomic growth, maintaining their customs and beliefs. In Colombia, some of these rural populations are made up of displaced persons from the armed conflict, women, men, children and the elderly, who must leave behind their roots to face the uncertainty of a new beginning in an unknown environment. The research related in this article describes the study carried out in the Vereda de Veraguas belonging to the Municipality of Pacho, Cundinamarca, where there is a rural community made up of families who were displaced and who seek to integrate sustainable development to improve their quality of life. In order to generate sustainable rural development, it is necessary to know the problems that can prevent this from being generated. For the case under study, several needs were observed regarding infrastructure, as well as low levels of education and social inequality. As a result, it was possible to define a socioeconomic model that helps to propose a guide for rural sustainable development according to the problems of the Veraguas community.El desarrollo sostenible es muy importante para que las poblaciones rurales puedan tener un crecimiento socioeconómico, manteniendo sus costumbres y creencias. En Colombia algunas de esas poblaciones rurales están conformadas por desplazados del conflicto armado, mujeres, hombres, niños y ancianos, quienes deben dejar sus arraigos para enfrentarse a la incertidumbre de un nuevo inicio en un ambiente desconocido. La investigación relacionada en este artículo describe el estudio realizado en la Vereda de Veraguas perteneciente al Municipio de Pacho, Cundinamarca, donde se encuentra una comunidad rural conformada por familias que fueron desplazadas y que buscan integrar el desarrollo sostenible para mejorar su calidad de vida. Para poder generar desarrollo sostenible rural es necesario conocer las problemáticas que pueden impedir que esto se genere, para el caso en estudio se observaron varias necesidades respecto a la infraestructura, además de bajos niveles de educación y desigualdad social. Como resultado se pudo definir un modelo socioeconómico que ayude a proponer una guía para el desarrollo sostenible rural acorde a la problemática de la comunidad de Veraguas.O desenvolvimento sustentável é muito importante para que as populações rurais possam ter crescimento socioeconômico, mantendo seus costumes e crenças. Na Colômbia, algumas dessas populações rurais são formadas por deslocados do conflito armado, mulheres, homens, crianças e idosos, que devem deixar para trás suas raízes para enfrentar a incerteza de um novo começo em um ambiente desconhecido. A pesquisa relacionada neste artigo descreve o estudo realizado na Vereda de Veraguas pertencente ao município de Pacho, Cundinamarca, onde existe uma comunidade rural composta por famílias que foram deslocadas e que buscam integrar o desenvolvimento sustentável para melhorar sua qualidade de vida vida. Para gerar um desenvolvimento rural sustentável é necessário conhecer os problemas que podem impedir que este seja gerado.Para o caso em estudo, foram observadas diversas carências em relação à infraestrutura, bem como baixos níveis de escolaridade e desigualdade social. Como resultado, foi possível definir um modelo socioeconômico que ajuda a propor um guia para o desenvolvimento rural sustentável de acordo com os problemas da comunidade de Veraguas

    Investigation of Vorticity during Prevalent Winter Precipitation in Iran

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    Publisher's version (útgefin grein)In this study, precipitation data for 483 synoptic stations, and the U&V component of wind and HGT data for 4 atmospheric levels were respectively obtained from IRIMO and NCEP/NCAR databases (1961–2013). The precipitation threshold of 1 mm and a minimum prevalence of 50% were the criteria based on which the prevalent precipitation of Iran was identified. Then, vorticity of days corresponding to prevalent winter precipitation was calculated and, by performing cluster analysis, the representative days of vorticity were specified. The results showed that prevalent winter precipitation vorticity in Iran is related to the vorticity patterns of low pressure of Mediterranean-low pressure of Persian Gulf dual-core, low pressure closed of central Iran-high pressure of East Europe, Ural low pressure-Middle East High pressure, Saudi Arabia low pressure-Europe high pressure, and high-pressure belt of Siberia-low pressure of central Iran. At the same time, the most intense vorticity occurred when the climate of Iran was influenced by a massive belt pattern of Siberian high pressure-low pressure of central Iran. However, at the time of prevalent winter precipitation in Iran, an intense vorticity is drawn with the direction of Northeast and Northwest from the center of Iraq to the south of Iran.This work was supported by Vedurfelagid, Rannis, and Rannsoknastofa I VedurfraediPeer Reviewe

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

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    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

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