Influencia del consumo mundial de biocombustibles en la seguridad alimentaria de Colombia en el periodo de tiempo del 2006 al 2010

En el trabajo de grado se realiza un analisis del mercado internacional de biocombustibles y como este ha afectado a la seguridad alimentaria de Colombia teniendo en cuenta la normativa del país en el tema de los biocombustibles y el estado actual del debate a nivel mundial.

Análisis del sector de energía eléctrica colombiano y regional-negociación de energía eléctrica CEMEX Colombia SA

En el área de Abastecimiento de CEMEX COLOMBIA SA se encuentra el foco de las negociaciones con proveedores de la empresa. Es en esta área donde se realizan contratos a largo plazo con las empresas que suministran los insumos vitales para la producción de cemento y concreto. Uno de estos insumos es la energía eléctrica. Necesaria en todo proceso productivo, la energía eléctrica se convierte, entonces, en una de las negociaciones más críticas para la empresa teniendo en cuenta el impacto en la operación y en el gasto. De igual forma, toda negociación requiere de un estudio riguroso previo por medio del cual se llegue a una postura informada al momento de negociar. Es así como CEMEX COLOMBIA SA, a través de sus negociadores, se prepara investigando el mercado nacional y regional de energía eléctrica, sus variables influyentes y las proyecciones de desarrollo. Luego de esta investigación y del análisis del sector, CEMEX COLOMBIA SA asume una posición firme en la que sabe que los planes de expansión y el desarrollo esperado del sector plantean un mercado con capacidad instalada suficiente para el suministro de energía hasta 2017. De esta manera, se cierra un contrato a dos años con Emgesa, filial de la multinacional española Endesa.

Las implicaciones de la expansión china en el sudeste asiático

El artículo presenta la génesis, proceso e implicaciones de la expansión estratégica de la República Popular China hacia el Sudeste asiático. En ese sentido, la hipótesis que se presenta es que Beijing aspira a un renacer pacífico en el Sur con objetivos en el campo económico, estratégico y político. En el plano de la economía lo que se pretende es la estabilidad en el vecindario, condición fundamental para el éxito de su modelo económico, financiero y comercial. En el ámbito estratégico se busca un acceso a fuentes de energía alternativas al carbón, y en lo político, China ha buscado reducir la influencia americana y disminuir el margen de maniobra de Taiwán. En una primera parte se presenta un análisis histórico para introducir al lector en las variables históricas más relevantes para la comprensión del tema en cuestión. En la segunda se estudia el litigio del Mar del Sur de China y la importancia que éste posee política y geoestratégicamente. Finalmente, se examina la influencia china en el Sudeste asiático en tres campos: el cultural, el económico del cual hace parte el financiero y comercial y por último en el geoestratégico.-----L’article illustre la genèse, le processus et les implications de l’expansion stratégique de la République Populaire Chine dans le Sud-est Asiatique. De ce fait, l’hypothèse qui nous présenterons demeure Sur l’idée que Pékin cherche une renaissance pacifique vers le Sud en vue des objectifs économiques, stratégiques et politiques. En ce qui concerne l’économie, la Chine veux la stabilité dans la région, car ceci est une condition essentielle pour la réussite du modèle économique, financer et commercial. Quant à la question stratégique, elle cherche l’accès aux sources alternatives d’énergie. Dans le domaine politique, Pékin aspire à réduire l’influence américaine et à isoler le Taiwan. Dans une première partie, nous introduirons les variables historiques les plus essentielles afin d’expliquer les racines de la problématique en question. Dans la deuxième, le contentieux pour la Mer du Sud de Chine sera analysé ainsi que son importance politique et geoestratégique. Finalement, nous étudierons le processus de l’influence chinoise dans le Sud-est Asiatique. Cela sera divisé en trois domaines, le culturel, l’économique dont le commercial et financière, et le geostratégique.-----This article illustrates the genesis, the process and the implications of the strategic expansion of the People’s Republic of China towards South East Asia. Therefore, the hypothesis that we present is that Beijing is pursuing a Pacific rise in the South aiming for economic, strategic and political goals. Regarding the subject of economy, China seeks stability in the region, due to the fact that it has become essential in the success of its economic, financial and commercial model. Regarding the strategic field China is looking for a way to access alternative energy sources. Politically speaking, Beijing has sought to reduce American influence in the region as well as the isolation of Taiwan. In the first part of the article the reader will find a historical introduction for a better understanding of the subject here treated. In the second part, the litigation of the South China Sea is analyzed due to its political and geostrategical importance. Finally, Chinese influence on South East Asia is examined in three fields: cultural, economic, including financial and commercial aspects as well as the geostrategic field.

TLC: Amazonía, pueblos indígenas y biodiversidad (Tema Central)

Este artículo hace un análisis sobre los problemas y desafíos que la firma de tratados de libre comercio plantea a los pueblos indígenas, específicamente a los pueblos amazónicos. Tres ámbitos de análisis son utilizados por el autor para presentar la temática: la disputa por el control de la biodiversidad, los derechos de los pueblos indígenas y la construcción de una agenda de debate frente a la actual coyuntura. Ortiz plantea que si los tratados de libre comercio son parte de la política hegemónica de Estados Unidos, basada en el establecimiento de un orden global y en el control de las fuentes de energía del planeta, la cuenca amazónica se ubica como unas de las áreas de interés para los capitales multinacionales.

On the energetics of stratified turbulent mixing, irreversible thermodynamics, Boussinesq models and the ocean heat engine controversy

In this paper, the available potential energy (APE) framework of Winters et al. (J. Fluid Mech., vol. 289, 1995, p. 115) is extended to the fully compressible Navier– Stokes equations, with the aims of clarifying (i) the nature of the energy conversions taking place in turbulent thermally stratified fluids; and (ii) the role of surface buoyancy fluxes in the Munk & Wunsch (Deep-Sea Res., vol. 45, 1998, p. 1977) constraint on the mechanical energy sources of stirring required to maintain diapycnal mixing in the oceans. The new framework reveals that the observed turbulent rate of increase in the background gravitational potential energy GPEr , commonly thought to occur at the expense of the diffusively dissipated APE, actually occurs at the expense of internal energy, as in the laminar case. The APE dissipated by molecular diffusion, on the other hand, is found to be converted into internal energy (IE), similar to the viscously dissipated kinetic energy KE. Turbulent stirring, therefore, does not introduce a new APE/GPEr mechanical-to-mechanical energy conversion, but simply enhances the existing IE/GPEr conversion rate, in addition to enhancing the viscous dissipation and the entropy production rates. This, in turn, implies that molecular diffusion contributes to the dissipation of the available mechanical energy ME =APE +KE, along with viscous dissipation. This result has important implications for the interpretation of the concepts of mixing efficiency γmixing and flux Richardson number Rf , for which new physically based definitions are proposed and contrasted with previous definitions. The new framework allows for a more rigorous and general re-derivation from the first principles of Munk & Wunsch (1998, hereafter MW98)’s constraint, also valid for a non-Boussinesq ocean: G(KE) ≈ 1 − ξ Rf ξ Rf Wr, forcing = 1 + (1 − ξ )γmixing ξ γmixing Wr, forcing , where G(KE) is the work rate done by the mechanical forcing, Wr, forcing is the rate of loss of GPEr due to high-latitude cooling and ξ is a nonlinearity parameter such that ξ =1 for a linear equation of state (as considered by MW98), but ξ <1 otherwise. The most important result is that G(APE), the work rate done by the surface buoyancy fluxes, must be numerically as large as Wr, forcing and, therefore, as important as the mechanical forcing in stirring and driving the oceans. As a consequence, the overall mixing efficiency of the oceans is likely to be larger than the value γmixing =0.2 presently used, thereby possibly eliminating the apparent shortfall in mechanical stirring energy that results from using γmixing =0.2 in the above formula.

Lessons learnt about water use, harvesting, recycling and drainage

This Information Paper is the third in a four-part series that looks at the lessons learnt from the BRE Innovation Park concerning compliance with the Code for Sustainable Homes published in November 2006. It focuses on water use, harvesting, recycling and drainage. The other parts deal with: building fabric; energy sources, overheating and ventilation; architecture, construction and sourcing.

Flavanol monomer-induced changes to the human faecal microflora

We have investigated the bacterial-dependent metabolism of (-)-epicatechin and (+)-catechin using a pH-controlled, stirred, batch-culture fermentation system reflective of the distal region of the human large intestine. Incubation of (-)-epicatechin or (+)-catechin (150mg/l or 1000mg/l) with faecal bacteria, led to the generation of 5-(3,4'-dihydroxyphenyl)-gamma-valerolactone, 5-phenyl-gamma-valerolactone and phenylpropionic acid. However, the formation of these metabolites from (+)-catechin required its initial conversion to (+)-epicatechin. The metabolism of both flavanols occurred in the presence of favourable carbon sources, notably sucrose and the prebiotic fructo-oligosaccharides, indicating that bacterial utilisation of flavanols also occurs when preferential energy sources are available. (+)-Catechin incubation affected the growth of select microflora, resulting in a statistically significant increase in the growth of the Clostridium coccoides-Eubacterium rectale group, Bifidobacterium spp. and Escherichia coli, as well as a significant inhibitory effect on the growth of the C. histolyticum group. In contrast, the effect of (-)-epicatechin was less profound, only significantly increasing the growth of the C. coccoides-Eubacterium rectale group. These potential prebiotic effects for both (+)-catechin and (-)-epicatechin were most notable at the lower concentration of 150 mg/l. As both (-)-epicatechin and (+)-catechin were converted to the same metabolites, the more dramatic change in the growth of distinct microfloral populations produced by (+)-catechin incubation may be linked to the bacterial conversion of (+)-catechin to (+)-epicatechin. Together these data suggest that the consumption of flavanol-rich foods may support gut health through their ability to exert prebiotic actions.

The metabolic impact of zinc oxide on porcine intestinal cells and enterotoxigenic Escherichia coli K88

Pharmacological levels of zinc oxide (ZnO) incorporated into the post-weaning piglet diet reduce the incidence of diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) K88. The mechanism for this is not understood. Here, Intestinal Porcine Epithelial Cells (IPEC) J2 were used as an in vitro model of the porcine intestine. ZnO reduced IPEC J2 viability at concentrations >= 200 mu M, and ETEC adhesion to the host cell was unaffected by ZnO. Characterisation of the metabolism of IPEC J2 cells and ETEC established the effects of ZnO treatment on the metabolic profile of both. Although 100 mu M ZnO did not inhibit growth of either host or pathogen in fully supplemented media, metabolic profiles were significantly altered. Glucose and mannose were essential energy sources for IPEC J2 cells in the presence of ZnO, as the ability to utilise other sources was compromised. The increase in specificity of requirements to support respiration in ETEC was more pronounced, in particular the need for cysteine as a nitrogen source. These findings indicate that ZnO impacts on both host cell and pathogen metabolism and may provide insight into the mechanism for diarrhoea reduction. (C) 2010 Elsevier B.V. All rights reserved.

Introductory remarks

The very first numerical models which were developed more than 20 years ago were drastic simplifications of the real atmosphere and they were mostly restricted to describe adiabatic processes. For prediction of a day or two of the mid tropospheric flow these models often gave reasonable results but the result deteriorated quickly when the prediction was extended further in time. The prediction of the surface flow was unsatisfactory even for short predictions. It was evident that both the energy generating processes as well as the dissipative processes have to be included in numerical models in order to predict the weather patterns in the lower part of the atmosphere and to predict the atmosphere in general beyond a day or two. Present-day computers make it possible to attack the weather forecasting problem in a more comprehensive and complete way and substantial efforts have been made during the last decade in particular to incorporate the non-adiabatic processes in numerical prediction models. The physics of radiational transfer, condensation of moisture, turbulent transfer of heat, momentum and moisture and the dissipation of kinetic energy are the most important processes associated with the formation of energy sources and sinks in the atmosphere and these have to be incorporated in numerical prediction models extended over more than a few days. The mechanisms of these processes are mainly related to small scale disturbances in space and time or even molecular processes. It is therefore one of the basic characteristics of numerical models that these small scale disturbances cannot be included in an explicit way. The reason for this is the discretization of the model's atmosphere by a finite difference grid or the use of a Galerkin or spectral function representation. The second reason why we cannot explicitly introduce these processes into a numerical model is due to the fact that some physical processes necessary to describe them (such as the local buoyance) are a priori eliminated by the constraints of hydrostatic adjustment. Even if this physical constraint can be relaxed by making the models non-hydrostatic the scale problem is virtually impossible to solve and for the foreseeable future we have to try to incorporate the ensemble or gross effect of these physical processes on the large scale synoptic flow. The formulation of the ensemble effect in terms of grid-scale variables (the parameters of the large-scale flow) is called 'parameterization'. For short range prediction of the synoptic flow at middle and high latitudes, very simple parameterization has proven to be rather successful.

Introducing "ecoputation": a universal systems design process

A universal systems design process is specified, tested in a case study and evaluated. It links English narratives to numbers using a categorical language framework with mathematical mappings taking the place of conjunctions and numbers. The framework is a ring of English narrative words between 1 (option) and 360 (capital); beyond 360 the ring cycles again to 1. English narratives are shown to correspond to the field of fractional numbers. The process can enable the development, presentation and communication of complex narrative policy information among communities of any scale, on a software implementation known as the "ecoputer". The information is more accessible and comprehensive than that in conventional decision support, because: (1) it is expressed in narrative language; and (2) the narratives are expressed as compounds of words within the framework. Hence option generation is made more effective than in conventional decision support processes including Multiple Criteria Decision Analysis, Life Cycle Assessment and Cost-Benefit Analysis.The case study is of a participatory workshop in UK bioenergy project objectives and criteria, at which attributes were elicited in environmental, economic and social systems. From the attributes, the framework was used to derive consequences at a range of levels of precision; these are compared with the project objectives and criteria as set out in the Case for Support. The design process is to be supported by a social information manipulation, storage and retrieval system for numeric and verbal narratives attached to the "ecoputer". The "ecoputer" will have an integrated verbal and numeric operating system. Novel design source code language will assist the development of narrative policy. The utility of the program, including in the transition to sustainable development and in applications at both community micro-scale and policy macro-scale, is discussed from public, stakeholder, corporate, Governmental and regulatory perspectives.

Slutrapport för EU-projekt Polysmart P22374-1

Följande sammanfattar erfarenheterna inom projektet:- Besparing av primärenergi är väldigt beroende av ett fåtal faktorer där primärenergi faktor för generering av el till nätet är avgörande. I projektet använde man termen ”non-renewable primary energy” där förnybara källor som bioenergi och även sopförbränning har väldigt låga värden. Om man använder den europeiska mixen för elproduktion ger enbartkraftvärme nästan alltid besparing av primär energi. Det samma gäller system där man använder förnybar energi eller sopförbränning. För system med trigenerering som använder fossila bränslen måste man ha både hög andel elproduktion från kraftvärmeaggregatet och relativt hög COP för den värmedrivna kylmaskinen om man ska få en besparing av primärenergi.- Systemen är komplexa och man har lärt sig mycket inom projektet. Dock har man inte kommit så långt som standard systempaket.- Elförbrukning är oftast högre än förväntat och i verklighet högre än specificerat.- Värmesänkan i systemet är en nyckelkomponent som är kritiskt för bra systemprestanda. Mer FoU krävs för att få fram komponenter som lämpar sig väl till sådana system (och som skulle också gynna andra system).- Mätning av systemet med tillhörande analys har behövts för att förbättra systemprestanda, vilket är kopplat till att system är komplexa och att det inte fanns en grundläggande kompetens i början av projektet hos alla partners.- Lovande nischmarknader har identifierats men de kräver förmodligen paketlösningar som inte finns på marknaden än.- Man ska enbart täcka baslasten med trigenereringssystem.- Koppling med fjärrvärme kan fungera bra men leverantören måste acceptera relativt höga returtemperaturer.

Validação da termografia no diagnóstico de lesões por esforços repetitivos/distúrbios osteomusculares relacionados ao trabalho

As Lesões por Esforços Repetitivos e Doenças Osteomusculares Relacionadas ao Trabalho estão caracterizadas por queixas de grande incapacidade funcional, causadas pelo uso dos membros superiores em tarefas que envolvam movimentos repetitivos. Esses distúrbios também podem ocorrer nas atividades de lazer ou no cotidiano das pessoas, especialmente quando realizadas por períodos longos, sem pausas adequadas para recuperação muscular, ou ainda, sem devido acompanhamento médico. A avaliação de doenças ocupacionais é eminentemente clínica. São raros os casos em que os exames complementares apóiam o diagnóstico médico. Diante disso, o objetivo desta pesquisa foi verificar a eficácia da técnica de Termografia no diagnóstico de LER/DORT. A amostra (n=51) foi dividida em dois grupos. Um grupo experimental (n=41) composto por 26 Taquigrafas da Assembléia Legislativa do Rio Grande do Sul e 15 digitadores da Companhia Estadual de Energia Elétrica do Rio Grande do Sul e um grupo controle (n=10) composto por participantes com outras profissões. Todos eles estavam de acordo com o que prescreve a resolução 196/96 do Conselho Nacional de Saúde. Os resultados do teste Q de Cochran mostraram diferenças estatisticamente significativas entre os 3 observadores da Termografia nas regiões dos punhos, cotovelos e ombros para o teste. Os coeficientes de concordância Kappa de cada observador no teste e reteste foram elevados. O coeficiente de concordância Kappa entre os observadores no teste mostraram que os 3 observadores estavam seguros para diagnosticar punho direito e cotovelos. Tais resultados mostram que a Termografia foi mais sensível e específica que a Ecografia e o Exame Clínico nos punhos direito e esquerdo. Assim, podemos inferir que os dados obtidos através das imagens termográficas permitiram uma melhor visualização das áreas traumatizadas nos componentes da amostra.

O impacto de reestruturação e privatização na gestão integrada do setor de energia elétrica: análise do setor a partir da abordagem de redes

The Brazilian energetic sector is passing through deep transformations. The restructure is mainly characterized by the passage from a vertical and centrally coordinated system, in hands of the State, to a more horizontal one, with characteristics of a network, in which organizations, such as the National Agency of Electric Energy (ANEEL), the new regulator entity, the Wholesaler Market of Electric Energy (MAE), the National Operator of Electric System (ONS), Eletrobrás and the National Bank of Economic and Social Development (BNDES) are designated as the principals integrators of the system. The objective of the present work was to analyze the influence of the privatization and restructuring processes in the integration of the Brazilian system of electric energy. The analysis was based on the instruments offered by the network approach. The results of the research show that the Brazilian sector of electric energy cannot be considered as a highly integrated network. In this new horizontal configuration, the social actors are affirming its roles, functions and objectives, while the key-organization like ANEEL, ONS, MAE, Eletrobrás, and BNDES are being structured to strengthen its integrative role.

Trajetória de desenvolvimento tecnológico na indústria de transmissão de energia elétrica: a experiência das Centrais Elétricas do Norte do Brasil S.A. - ELETRONORTE

Esta dissertação estuda as implicações dos processos de aprendizagem para acumulação de competências tecnológicas no nível de firmas. Este relacionamento foi examinado nas Centrais Elétricas do Norte do Brasil S.A. - Eletronorte, ao longo dos anos de 1990 a 2003. A empresa tem sua sede administrativa em Brasília e a sua área de atuação é caracterizada pela Amazônia Legal (Acre, Amapá, Amazonas, Maranhão, Mato Grosso, Pará, Rondônia, Roraima e Tocantins). A Eletronorte é uma empresa concessionária de geração e transmissão de energia elétrica, contudo, o presente trabalho enfocou apenas as atividades de transmissão, quer dizer, a geração está fora do escopo do estudo. A acumulação de competências tecnológicas para adaptar, modificar ou criar novas tecnologias é essencial para a sobrevivência e o desempenho competitivo das empresas. Para descrever o modo e a velocidade de acumulação de competências tecnológicas na Eletronorte, foram utilizadas estruturas analíticas existentes na literatura. Entretanto, tais estruturas foram adaptadas especificamente para a indústria de transmissão de energia elétrica. A acumulação de competências foi estudada para três funções tecnológicas: "engenharia, projetos e equipamento"; "operação e manutenção"; "processos operacionais". Os processos de aprendizagem foram examinados à luz de quatro características-chave: variedade, intensidade, funcionamento e interação. Durante o período de 1990 e 2003, a empresa construiu e acumulou diferentes níveis de competências tecnológicas nas funções estudadas. Com base nas evidências empíricas, verificou-se que a partir de 1995, quando a empresa passou a coordenar sistematicamente esforços para adquirir e converter conhecimentos do nível individual para o nível organizacional, a construção de capacitação tecnológica foi acelerada. Contudo, a partir do ano de 2000, em que foram diminuídos investimentos no setor elétrico brasileiro, o processo de capacitação tecnológica permaneceu estagnado. Assim, aliando-se a estudos anteriores realizados para outros tipos de indústria, a conclusão deste estudo sugere que o modo e a velocidade com que a firma acumulou capacitação tecnológica podem ser explicados pelos processos de aprendizagem (aquisição interna e externa, socialização e codificação do conhecimento) e pelas características-chave de como esses foram utilizados ao longo do tempo (variedade, intensidade, funcionamento e interação).