Estudio documental sobre la viabilidad de la seguridad electrónica para la protección de estudiantes y docentes en instituciones educativas de básica primaria y media vocacional en Bogotá

En Colombia, específicamente en Bogotá, uno de cada dos estudiantes ha sido víctima de robo en el colegio, asimismo uno de cada tres ha sido agredido a golpes y expuesto a maltrato físico por parte de sus compañeros, un alto porcentaje de los agredidos requirió atención médica por esta causa y un alto porcentaje de los agredidos fue amenazado con arma de fuego, corto-punzante y contundente, todo esto asociado a la realidad del país, la cual está marcada por un conflicto armado prolongado, afecta de manera manifiesta la dinámica educativa e influye en las conductas agresivas de los estudiantes de cada región. Durante el 2007, y aún en años anteriores, se ha podido ver en diferentes partes del país manifestaciones de violencia en las instituciones educativas. La pobreza, el pandillismo, las drogas, la violencia intrafamiliar, los medios de comunicación, el conflicto armado y otros factores, se suman a las causas que liberan la violencia en las aulas clases. Por eso se hace necesario saber cómo es el estado del arte acerca de la implementación de tecnologías de vigilancia en escuelas de la ciudad de Bogotá, para lo cual se realizo una búsqueda bibliográfica y su posterior tabulación y análisis estadístico encontrando que el 52.9% de la información hallada es de procedencia colombiana, 54.5% de la información encontrada se hayo por medio del buscador Google y el 52.9% del fue escrito en formato de publicación de articulo de internetPregrad

Definition of safety stock and reorder point for the puerchase of equipment in a service business telecommunications sector

Este artículo muestra la problemática a la que se ven enfrentados los responsables de los inventarios y de la disponibilidad de activos de una empresa nueva en el mercado de prestación de servicios del sector telecomunicaciones, al no disponer de suficientes datos históricos de demanda, para el desarrollo de su actividad y por ende no poder planear de manera correcta las cantidades, el momento de comprar y los stocks de inventarios que satisfagan de manera oportuna la demanda de equipos para instalación en clientes. Aquí se revisan algunos conceptos de demanda, punto de reorden, stock de seguridad y se aplica el modelo EOQ (Cantidad económica de pedido) a los datos disponibles.This paper shows the problems which are faced those responsible for the inventory and availability of assets of a new company in the market for the provision of telecommunications services sector, the absence of sufficient historical data of purchase for the development of its activity and therefore can not properly plan how much to buy, when to buy and stocks of inventories to meet demand in a timely manner to customer installation. Here we review some concepts of demand, reorder point, safety stock and EOQ (economic order quantity) model is applied to the data available

New tension-compression damage model for complex analysis of concrete structures

A new damage model, based on continuum damage mechanics and simulating the opening, closing, and reopening of cracks in concrete using only one surface of discontinuity, is proposed in this article. The model complies with the thermodynamics principles of nonreversible, isothermal, and adiabatic processes. Two scalar internal variables have been defined: a tensile damage variable d+d+ and a compressive damage variable d-d-; the threshold of damage is controlled by only one surface of discontinuity and a new parameter controlling the damage variable that should be activated. This new parameter represents the ratio of tensile stress to compressive stress in the damaged material. The continuity of response under complex loads, which is one of the aims of this work, is ensured. An adequate response under different types of loads leads to the conclusion that the proposed model provides a powerful tool to numerically analyze reinforced concrete structures. Validation and illustrative examples are included in the article.Peer ReviewedPostprint (author's final draft

The Expression of Biodiversity in the Secondary Metabolites of Aromatic Plants and Flowers Growing in Colombia

A network of research groups has carried out a bioprospective study of Colombia’s vegetal biodiversity, with focus on aromatic plants. This chapter presents results on the chromatographic analysis of flower fragrances and essential oils obtained from vegetal material collected in botanical expeditions to various Colombian regions. Essential oils and flower fragrances are composed of volatile substances that differ greatly in polarity, functional groups, and relative amounts. The study of these complex mixtures requires special sampling and analysis techniques, described in this chapter. The large chemical diversity of the essential oil and flower fragrance constituents is a formidable characterization challenge. Typically, the number of essential oil components surpassed 50. It was rare to find an essential oil composition in which a single substance was present with a relative amount above 50%

Study of Essential Oils Obtained from Tropical Plants Grown in Colombia

Researchers from several Colombian universities have joined efforts for over 15 years to characterize the composition and biological properties of more than a thousand samples of essential oils (EOs) obtained from aromatic plants collected during at least 30 botanical outings in different regions of Colombia. This chapter presents a brief description of essential oil extraction and chemical characterization techniques, followed by a representative list of references to publications on EO composition obtained from tropical aromatic plants that grow in Colombia. Opportunities for the development of interesting products for the pharmaceutical, cosmetics, hygiene, and food industries are illustrated with a few selected works on the evaluation of cytotoxicity, antioxidant, antiviral, antigenotoxic activities, and repellence of these essential oils