La base fundamental de cualquier cultivo es la semilla. De su calidad física y genética depende en buena parte el éxito de una siembra. En algodón, desde hace muchos anos, primero por el Gobierno y posterior-mente por las entidades gremiales, se ha tenido una gran preocupación por el suministro de semillas de buena calidad. La mas antigua referencia que se tiene del control de semillas para siembra, data del año 1952.

El año de 1998 se constituyó el Acuerdo de Competitividad de la Cadena Láctea Colombiana, el cual se precedió de un trabajo con el apoyo y decidida participación de los Ministerios de Agricultura y Desarrollo Rural, Comercio Exterior, Desarrollo Económico y Salud, así como también el Instituto Interamericano de Cooperación para la Agricultura, IICA, Acoleche, Analac, Asociación de Procesadores Independientes de Leche; Cámara de Industria de Alimentos de la ANDI, Fedecoleche y Fedegan. Este fue el primer paso para concertar entre el sector productivo y el Gobierno Nacional. Este Acuerdo está constituido por estrategias, proyectos y acciones que comprometen al Gobierno, ganaderos, industriales Y cooperativas con una política de concertación, consenso y competitividad. Uno de los resultados del Acuerdo fue la Creación del Consejo Nacional Lácteo Colombiano, como organismo administrador de éste y promotor del desarrollo del sector, que además de fijar los precios de la leche, dio confianza para la inversión privada y permitió el arranque al desarrollo industrial de la leche en Colombia.

Microbial pollution of water is one of the principal causes of life-threatening diarrheal diseases in the developing world. Ultraviolet (UV) light is increasingly recognized as a viable alternative for the disinfection of drinking water and wastewater in developed countries, but its feasibility in low-income areas has to be assessed further. The rural community of Cerro Grande, in Bolivia, has been hit by outbreaks of gastrointestinal diseases, so two UV-based disinfection systems were implemented there. One of them was a fabricated unit, with materials available locally, whereas the other was a commercially-available unit. The fabricated unit was validated following USEPA procedures and was modeled using computational fluid dynamics. It was observed that a UV-based disinfection system can be sustainable for as few as 20 users, and even for 48 users in areas with poor feed water quality and lacking an electrical grid and distribution network, with a monthly cost of US$2.

The scope of this project is the redefinition of the algorithm of the wind-diesel hybrid system for rural electrification using ©IntiGIS, which is a methodology translated into a software developed by CIEMAT, useful for evaluating rural electrification projects that enables to compare different technologies based on the LEC, allowing to find which is the best and less costly technology. The analysis done considers the social and geographical particularities of the study area. The core of the new model is the definition of the renewable fraction for the wind-diesel hybrid system. For this, it was supposed that the renewable fraction will depend in first instance of the wind speed. Here, the objectives are: - find a relationship between the renewable fraction and the wind speed, and if there is a clear relationship, try to express it as a function, and – prove the influence of other parameters such as the fuel price and the consumption load in the renewable fraction behavior. The methodology followed to achieve the point above, was to use ©HOMER to simulate several wind-diesel hybrid systems and size the components of the system, in order to get the optimal renewable fraction in different scenarios. Other important point in the model is the wind capacity factor calculation for medium power wind turbines. As a result of the study, the model is more accurate estimating this factor, due to the fact the study was made, taking into account the power curves of some wind turbines that are in the market and are used for electrification purposes, in order to get an average behavior of the capacity factor when wind speed increases.

In this report we highlighted the significance of the taxicab industry for three main sectors of the economy and, furthermore, to what extent could some changes in labour and taxi regulations be detrimental to the perception of safety by taxicab passengers leading to a reduction in the number of journeys and an economic downturn in several industries. We considered the lack of effectiveness of current applications for giving security to the passengers when they hire a taxi in the street. Taking the taxicab regulation schemes and the issues concerning their passengers as a starting point, we set three groups of security requirements: User safety, Quality service and system’s capabilities and efficiency. The novel TAXI Authentication scheme was created as a response to the need to address those requirements. It is based on the increasingly accepted NFC technology and the tamper-resistant smart cards to construct the Front-office processes, particularly noteworthy is the TAXI Authentication protocol designed as a DDA authentication protocol for efficiency and scalability reasons and the quality service feedback that preserves the anonymity of users facilitating the quality assessment. Whereas, a robust Key Management System supports the Back-office processes grounded in certificates using ECDSA digital signatures due to its efficient performance in smart cards and short-length keys providing a high level of security. We conducted the preliminary security analyst against the proposed security requirements. After that, we applied to real world criminal use-cases concerning the taxicab passengers. The scheme shows promise of combating potential crime under whichever type of taxicab regulation scheme demonstrating great flexibility to adapt to a great number of circumstances and future attacks against the industry.

The communications services market is undergoing a transition as the growing interconnection of providers is diminishing the importance of coverage as a differentiator, and shifting the focus to the value-added service portfolio and customer experience. At the same time, new options are emerging to deliver optimized technologies for the IT service management framework within the internet sphere.  Orange Business Services, communications service provider, develops and understands together with Accenture consultants, both clients needs and customer experience strategies for deploying an improved management service portal. The process to enable this competitive strategy for OBS includes the research of new tends in technology, the comprehension of customers expectations and needs, and the introduction of the evolutions that competitors are implementing within the market.

In a Fiber to the Home (FTTH) system, the fiber is connected until the household users. A passive optical network (PON) is a particular type of FTTH networks that uses P2MP (point-to-multipoint fiber premises) in which part of the infrastructure is shared, to allow sending information of multiple channels through one fiber. This study presents a summary of the main concepts about access networks and PON systems and some technologies used to its development, including Time Division Multiplexing (TDM) and Wavelength division multiplexing (WDM), independently or in hybrid configuration (TWDM). From here the key commercial devices for its implementation are identified and modelled, specifying its characteristic parameters to fulfill the minimum requirements of the new international standard ITU-T G.989 for FTTH networks. This project evaluates this standard, which proposes the implementation of NG-PON2 systems at 4x10Gbit/s, that will use the hybrid architecture TWDM and tunable transceivers and ensures coexistence with other legacy PON systems, allocating the downstream and upstream traffic in appropriate wavelength bands without overlapping. The work of analysis is focused in the identification of key devices, such as tunable transmitters and tunable receivers at ONU to achieve the minimum specified requirements. Besides, a first approximation to the coexistence element (CE) is made, for supporting the legacy PON systems. Once the minimum requirements are specified and the key devices identified, the network is designed and built in the commercial simulator VPIphotonicsTM, using CW lasers, external intensity modulators, wavelength multiplexers and the appropriate power splitters. In reception a direct detection scheme is implemented using PIN and APD photodiodes and tunable filters at ONU. Once the design is completed different test are run, the results are analyzed and the design is optimized, in order to dimension the network in terms of fiber reach, number of users, power budget, bandwidth capacity, etc. En un Sistema de Fibra hasta el hogar (FTTH, Fiber to the Home), la fibra es conectada hasta el hogar de los usuarios. Una red óptica pasiva (PON) es un tipo particular de red redes FTTH que utiliza instalaciones punto a multipunto (P2MP), en las cuales se comparte parte de la infraestructura permitiendo enviar información de múltiples canales a través de una sola fibra. Este trabajo presenta un compendio de los principales conceptos sobre redes de acceso y sistemas PON y algunas de las tecnologías usadas para el desarrollo de los mismos, incluyendo multiplexación por división en el tiempo (TDM, Time Division Multiplexing) y multiplexación por división de la longitud de onda (WDM, Wavelength Division Multiplexing), independientes o en configuración híbrida (TWDM). A partir de aquí se identifican y modelan los dispositivos comerciales clave para su implementación, especificando sus parámetros característicos para cumplir con los requerimientos del nuevo estándar internacional ITU-T G.989 para redes FFTH. Este proyecto evalúa dicho estándar, el cual plantea la implementación de sistemas NG-PON2 a 4x10GBit/s, los cuales usarán una arquitectura híbrida TWDM y transceptores sintonizables, además de garantizar la coexistencia con otros sistemas PON heredados, ubicando el tráfico en downstream y upstream en unas bandas de longitud de onda adecuadas sin solapamiento. El trabajo de análisis se enfoca en la identificación de los dispositivos clave, como transmisores y receptores ópticos sintonizables en la ONU para alcanzar los requerimientos mínimos especificados. Además se da una primera aproximación al diseño del elemento de coexistencia (CE, Coexistence element) para el soporte de los sistemas PON heredados. Una vez especificados los requerimientos mínimos e identificados los dispositivos clave, se diseña e implementa la red en el simulador VPIphotonicsTM usando láseres de onda continua, moduladores externos de intensidad, multiplexores de longitud de onda y divisores de potencia apropiados. En recepción se usa detección directa con fotodiodos PIN y APD y filtros ópticos sintonizables en la ONU. Una vez completado el diseño, se realizan diferentes test, se analizan los resultados y se optimiza el diseño para dimensionar la red en términos de número de usuarios, alcance, balance de potencias, capacidad de acho de banda, etc.

Due to the continue trend of technology for circuit scaling; optimal sizes for transistors and cables are needed, this scaling comes along with power increase and undesired cross talk effects between the wires which might affect the signal itself. A trade-off curve between power, area and delay is required so that a tuned solution for a specific problem might be found.  Here, an approach based on the dominant time constant optimization technique for modelling of the delay is investigated for an initial square topology with uniform wire and repeater sizing based on convex optimization and Linear Matrix Inequalities. Results with optimal buffer insertion across the bus are also investigated. 

Nordic countries experience post-glacial rebound, a movement where geographical contours slowly change elevation with respect to the mean sea level. The glacial isostatic adjustment (GIA) model aims to explain the phenomena, which combined with seismic data allows geoscientists to reconstruct elastic coefficients and viscosities of the Earth's lithosphere and upper mantle. The use of standard commercial codes are not adequate for GIA simulations and result in significant errors in the displacement field. This negative outcome suggests the development of GIA codes that include advection of pre-stress in the model. The problem set up consists on a solid 2D elastic layer under a flat Earth approximation, described by three different models suggested by current studies in geophysics.For space discretization the mixed finite element method (mFEM) is used and efficient preconditioners are built for the resulting algebraic system in saddle point form. A three level GMRES iterative solution strategy is proposed, based on Schur Complement preconditioners coupled with Multigrid techniques. The implementation is presented as a ready-to-use toolbox that easily deals with problem parameters, geometries, compressible and fully incompressible materials and provides higher accuracy for the displacement field compared with the previously existent codes. It also can be easily extended to 3D geometries and allows the implementation of a viscoelastic mantle. The code is written in C++ using the deal.II library designed for FEM, permitting the use of readily-made software packages, such as Trilinos that are straightforwardly parallelizable.

Este texto le permite al zootecnista identificar los procedimientos básicos a desarrollar con las carnes frescas tanto para conocer sus propiedades funcionales como para hacer un análisis microbiológico que permita asegurar el cumplimiento de la normativa legal vigente en Colombia.