LA BIOENERGÍA EN AMÉRICA LATINA. UNA ESTRATEGIA PARA LA ENSEÑANZA DE LA GEOGRAFÍA EN EL BACHILLERATO

La energía es un recurso estratégico para cualquier nación; desde la revolución industrial la base energética proviene de fuentes fósiles: carbón, gas natural y petróleo, el resultado de su extracción, transformación y consumo ha sido el agotamiento de recursos no renovables y la contaminación de suelos, aguas y atmósfera. Ante la creciente preocupación por el deterioro del medio ambiente han surgido diversas alternativas para la obtención de energía por medio de fuentes renovables o limpias, entre las que se pueden citar, la bioenergía. Una de las consecuencias territoriales del surgimiento de la bioenergía es la dispersión espacial de las fuentes de suministro y la extensión de cultivos dedicados a los biocombustibles.El objetivo de este trabajo es caracterizar la bioenergía como actividad económica, por medio de estrategias didácticas que involucren su espacialidad y sus repercusiones ambientales, económicas y sociales. En el ámbito de la enseñanza, es importante considerar y relacionar la realidad ambiental con el aprendizaje significativo del alumno, en este caso, se utiliza a la bioenergía como un elemento para el aprendizaje de la geografía y actualidad latinoamericana. El tema se inscribe en los programas de geografía general y económica del bachillerato de la UNAM

O princípio constitucional da redução das desigualdades regionais e o transporte de gás natural

In a country of continental dimensions as Brazil, one of the top challenges to its economic growth is the logistic related to energetical demand supply. We live now in the era of environmental protection and, in this new context of priorizations, it passes trough the search for alternative energies for the energetic matrix, due the petroleum elevated costs in the global market (and its finitude), but also due its pollution over the environment. This attempt of substitution needs solutions related to the national reality, into a national long term developing plan and based at a juridical-economic analysis of its realization. This study will look for, also based in an economical analysis, the juridical legitimity of choosing natural gas as the new protagonist of national economic growth (as a substitute of petroleum) and the necessary boost that must be done by law, based on an economic policy focused strictly for that fact, as a modifying agent of this reality. This study, therefore, will always be turned to a constitutional aspect, respecting the principles of economic order and the goal of reducing regional inequalities, which must influence the making off of a developing plan. At the end, it will try to demonstrate the juridical viability of such undertaking, tuned in jus-economical criteria. Another goal is related to the analysis of the natural gas industry, due the regulation of its transport has a major importance for national energetic integration, not only because this activity be characterized as a net industry, still under control of a natural monopoly, but also because the competitive or cooperative profile that should be priorized at the beginning of the economic planning for this activity (such as investment policies and its own rules that will submit private agents)

Regulação do livre acesso no transporte de gás natural à luz da ordem econômica da Constituição de 1988

In the middle of modern social changes produced by globalization and capitalism, several markets have changed. States have left the direct coordination of these markets (chiefly public utility sector in the form of monopolies), introducing regulation in order to promote competition. These changes have affected natural gas industry by promoting competition as a key factor to the development and the increase of firms in this market. The regulatory reform of natural gas industry ocurred in EUA and Europe Union and it has produced its first results. In Brazilian context, Constitutional Amendment nbr. 09 and Federal Law nbr. 9.478/97 ( Petroleum Law ) opened the natural gas market to a broad range of private economic agents and they finished the monopoly over the industry before managed by Petrobras. The new regulatory framework of Brazilian natural gas industry has designed competition as a central element to the new form of managment of business and contractual relationships of this industry. Among the regulatory instruments, open access regulation in natural gas pipelines is directed to promote competition. The questions arised about its implementation in Brazilian context are studied in the present work, in which it is discussed the constitutional rules and principles are to be applied to the open access regulation within the theme of statal regulation of economy present in constitutional economic order

Radiactividad natural de los materiales de construcción. Aplicación al hormigón. Parte II. Radiación interna: el gas radón

El presente artículo analiza aspectos relacionados con los tipos de radiactividad natural presentes en el interior de las edificaciones, sus fuentes y sus influencias. Más concretamente, desarrolla el estudio de la radiactividad ambiental en el interior de los espacios construidos debida a la presencia del gas radón, así como sus fuentes de origen y los niveles recomendados. Este es un artículo que se presenta como la segunda parte de un trabajo sobre radiactividad natural en los materiales de construcción, cuya primera parte hace referencia a la radiación externa de dichos materiales y se publica por los mismos autores, en esta misma revista. Al mismo tiempo, se realiza un recorrido por el marco normativo, tanto internacional como nacional, relativo al radón y a sus descendientes de vida media corta. El presente trabajo es parte de la tesis doctoral de la primera autora del mismo, Beatriz Piedecausa García, a quien el resto de autores agradece su esfuerzo para preparar el texto que ahora se publica y la autorización y las facilidades ofrecidas para acceder a su trabajo.

Natural Gas location design and operation

A major determinant of the level of effective natural gas supply is the ease to feed customers, minimizing system total costs. The aim of this work is the study of the right number of Gas Supply Units – GSUs - and their optimal location in a gas network. This paper suggests a GSU location heuristic, based on Lagrangean relaxation techniques. The heuristic is tested on the Iberian natural gas network, a system modelized with 65 demand nodes, linked by physical and virtual pipelines. Lagrangean heuristic results along with the allocation of loads to gas sources are presented, using a 2015 forecast gas demand scenario.

Optimal location of gas supply units in natural gas system network

Natural gas industry has been confronted with big challenges: great growth in demand, investments on new GSUs – gas supply units, and efficient technical system management. The right number of GSUs, their best location on networks and the optimal allocation to loads is a decision problem that can be formulated as a combinatorial programming problem, with the objective of minimizing system expenses. Our emphasis is on the formulation, interpretation and development of a solution algorithm that will analyze the trade-off between infrastructure investment expenditure and operating system costs. The location model was applied to a 12 node natural gas network, and its effectiveness was tested in five different operating scenarios.

Optimization model for medium term natural gas commitment

In this paper we study the optimal natural gas commitment for a known demand scenario. This study implies the best location of GSUs to supply all demands and the optimal allocation from sources to gas loads, through an appropriate transportation mode, in order to minimize total system costs. Our emphasis is on the formulation and use of a suitable optimization model, reflecting real-world operations and the constraints of natural gas systems. The mathematical model is based on a Lagrangean heuristic, using the Lagrangean relaxation, an efficient approach to solve the problem. Computational results are presented for Iberian and American natural gas systems, geographically organized in 65 and 88 load nodes, respectively. The location model results, supported by the computational application GasView, show the optimal location and allocation solution, system total costs and suggest a suitable gas transportation mode, presented in both numerical and graphic supports.

Modelização do despacho económico de Gás Natural

Com as variações e instabilidade dos preços do petróleo, assim como as políticas europeias para adoção de estratégias para o desenvolvimento sustentável, têm levado à procura de forma crescente de novas tecnologias e fontes de energia alternativas. Neste contexto, tem-se assistido a políticas energéticas que estimulam o aumento da produção e a utilização do gás natural, visto que é considerado uma fonte de energia limpa. O crescimento do mercado do gás natural implica um reforço significativo das redes de transporte deste combustível, quer ao nível do armazenamento e fornecimento, quer ao nível dos gasodutos e da sua gestão. O investimento em gasodutos de transporte implica grandes investimentos, que poderiam não ser remunerados da forma esperada, sendo um dos motivos para que exista em Portugal cinco distritos se veem privados deste tipo de infraestruturas. O transporte de gás natural acarreta custos elevados para os consumidores, tanto maiores quanto maior forem as quantidades de gás transacionadas e quanto maior for o percurso pelo gás natural percorrido. Assim assume especial importância a realização de um despacho de gás natural: quais as cargas que cada unidade de fornecimento de gás irá alimentar, qual a quantidade de gás natural que cada UFGs deve injetar na rede, qual o menor percurso possível para o fazer, o tipo de transporte que será utilizado? Estas questões são abordadas na presente dissertação, por forma a minimizar a função custo de transporte, diminuindo assim as perdas na rede de alta pressão e os custos de transporte que serão suportados pelos consumidores. A rede de testes adotada foi a rede nacional de transporte, constituída por 18 nós de consumos, e os tipos de transporte considerados, foram o transporte por gasoduto físico e o transporte através de gasoduto virtual – rotas de transporte rodoviário de gás natural liquefeito. Foram criados diversos cenários, baseados em períodos de inverno e verão, os diferentes cenários abrangeram de forma distinta as variáveis de forma a analisar os impactos que estas variáveis teriam no custo relativo ao transporte de gás natural. Para dar suporte ao modelo de despacho económico, foi desenvolvida uma aplicação computacional – Despacho_GN com o objetivo de despachar as quantidades de gás natural que cada UFG deveria injetar na rede, assim como apresentar os custos acumulados relativos ao transporte. Com o apoio desta aplicação foram testados diversos cenários, sendo apresentados os respectivos resultados. A metodologia elaborada para a criação de um despacho através da aplicação “Despacho_GN” demonstrou ser eficiente na obtenção das soluções, mostrando ser suficientemente rápida para realizar as simulações em poucos segundos. A dissertação proporciona uma contribuição para a exploração de problemas relacionados com o despacho de gás natural, e sugere perspectivas futuras de investigação e desenvolvimento.

Anaerobic oxidation of methane associated with sulfate reduction in a natural freshwater gas source

The occurrence of anaerobic oxidation of methane (AOM) and trace methane oxidation (TMO) was investigated in a freshwater natural gas source. Sediment samples were taken and analyzed for potential electron acceptors coupled to AOM. Long-term incubations with 13C-labeled CH4 (13CH4) and different electron acceptors showed that both AOM and TMO occurred. In most conditions, 13C-labeled CO2 (13CO2) simultaneously increased with methane formation, which is typical for TMO. In the presence of nitrate, neither methane formation nor methane oxidation occurred. Net AOM was measured only with sulfate as electron acceptor. Here, sulfide production occurred simultaneously with 13CO2 production and no methanogenesis occurred, excluding TMO as a possible source for 13CO2 production from 13CH4. Archaeal 16S rRNA gene analysis showed the highest presence of ANME-2a/b (ANaerobic MEthane oxidizing archaea) and AAA (AOM Associated Archaea) sequences in the incubations with methane and sulfate as compared with only methane addition. Higher abundance of ANME-2a/b in incubations with methane and sulfate as compared with only sulfate addition was shown by qPCR analysis. Bacterial 16S rRNA gene analysis showed the presence of sulfate-reducing bacteria belonging to SEEP-SRB1. This is the first report that explicitly shows that AOM is associated with sulfate reduction in an enrichment culture of ANME-2a/b and AAA methanotrophs and SEEP-SRB1 sulfate reducers from a low-saline environment.

Confirmation of natural gas explosion from methane quantification by headspace gas chromatography-mass spectrometry (HS-GC-MS) in postmortem samples: a case report.

A new analytical approach for measuring methane in tissues is presented. For the first time, the use of in situ-produced, stably labelled CDH(3) provides a reliable and precise methane quantification. This method was applied to postmortem samples obtained from two victims to help determine the explosion origin. There was evidence of methane in the adipose tissue (82 nmol/g) and cardiac blood (1.3 nmol/g) of one victim, which corresponded to a lethal methane outburst. These results are discussed in the context of the available literature to define an analysis protocol for application in the event of a gas explosion.

Compressed Natural Gas in Iowa State of Iowa Requirements and Procedures For Commercialization and Sale, June 2015

This document is specific to the state of Iowa and outlines the requirements and procedures necessary to use, distribute, and service compressed natural gas (CNG) and the equipment associated with it. Four state agencies’ requirements for CNG are covered in this document: The Iowa Utilities Board (IUB), Iowa Department of Agriculture and Land Stewardship (IDALS)/ Weights and Measures Bureau, Iowa Department of Revenue (IDR) and Iowa Department of Public Safety (IDPS) / Division of the State Fire Marshal.

Comparison of Biomass Gasification Technologies for Natural Gas Substitution in Iron Ore Pelletizing Plants

The iron ore pelletizing process consumes high amounts of energy, including nonrenewable sources, such as natural gas. Due to fossil fuels scarcity and increasing concerns regarding sustainability and global warming, at least partial substitution by renewable energy seems inevitable. Gasification projects are being successfully developed in Northern Europe, and large-scale circulating fluidized bed biomass gasifiers have been commissioned in e.g. Finland. As Brazil has abundant biomass resources, biomass gasification is a promising technology in the near future. Biomasses can be converted into product gas through gasification. This work compares different technologies, e.g. air, oxygen and steam gasification, focusing on the use of the product gas in the indurating machine. The use of biosynthetic natural gas is also evaluated. Main parameters utilized to assess the suitability of product gas were adiabatic flame temperature and volumetric flow rate. It was found that low energy content product gas could be utilized in the traveling grate, but it would require burner’s to be changed. On the other hand, bio-SGN could be utilized without any adaptions. Economical assessment showed that all gasification plants are feasible for sizes greater than 60 MW. Bio-SNG production is still more expensive than natural gas in any case.

Water relations, growth and gas exchange in Acacia auriculiformis under experimental and natural conditions

Investigations on the water relations and gas exchange of/tcacia aun'culiji_2rmis were carried out in natural and controlled environments. The experiments were performed in both seedlings and five year old trees. Different sets of experiments were conducted in Acacia plantations, at Kothachira, Palakkad District and in .seedlings, at KFRI campus nursery mainly during the summer months. Investigations were also extended to seedlings of A.mangium, Aaulacocarpa and /Lholocericea, which are also phyllodinous species with the intention of comparing their physiology with Acacia auriculifomus. Potted seedlings of four species of Acacia viz., A. auriculi/E)/7r:i.r, /I. aulacocarpa, A. holocericea and A. mangium were used for the study. Measurements of relative water content (RWC), water potential, photosynthetic rate, transpiration, stomatal conductance, water use efficiency etc. of phyllodes were measured diumally in plants subjected to three stress conditions namely, drought, salinity and flooding

Análisis de estructuras óptimas de tarifas en el trasporte de gas bajo un régimen de acceso abierto.

Este documento analiza los efectos de la política de regulación y competencia en la estructura del mercado de gas. Las características de monopolio natural de su transporte, junto con las características físicas y tecnológicas del gas como un bien, permiten que esta actividad sea el objeto de interesantes procedimientos regulatorios dirigidos a incrementar el nivel de competencia en la comercialización y oferta. Nos concentramos en el régimen de acceso abierto obligatorio, y utilizamos los enfoques analíticos más relevantes, que incluyen la estructura de precios de Ramsey y la regla de precios de componentes eficientes (ECPR). Mientras presentamos estos esquemas, tratamos de introducir los principios de la fijación no lineal de precios (discriminación de precios de segundo grado) con el fin de aprovechar la heterogeneidad de los compradores en una dimensión diferente, como lo es la duración de la confianza de los contratos. Como es tradicional en los estudios relacionados con la fijación de precios de activos, demostramos que bajo condiciones específicas, el criterio ECPR lleva los mismos resultados que la regla de precios de Ramsey.