905 resultados para TRANSMISIÓN DE GAS NATURAL - MODELOS DE OPTIMIZACIÓN


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Las organizaciones y sus entornos son sistemas complejos. Tales sistemas son difíciles de comprender y predecir. Pese a ello, la predicción es una tarea fundamental para la gestión empresarial y para la toma de decisiones que implica siempre un riesgo. Los métodos clásicos de predicción (entre los cuales están: la regresión lineal, la Autoregresive Moving Average y el exponential smoothing) establecen supuestos como la linealidad, la estabilidad para ser matemática y computacionalmente tratables. Por diferentes medios, sin embargo, se han demostrado las limitaciones de tales métodos. Pues bien, en las últimas décadas nuevos métodos de predicción han surgido con el fin de abarcar la complejidad de los sistemas organizacionales y sus entornos, antes que evitarla. Entre ellos, los más promisorios son los métodos de predicción bio-inspirados (ej. redes neuronales, algoritmos genéticos /evolutivos y sistemas inmunes artificiales). Este artículo pretende establecer un estado situacional de las aplicaciones actuales y potenciales de los métodos bio-inspirados de predicción en la administración.

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Desde el inicio de las organizaciones han existido modelos de control rígidos como los sistemas mecanicistas y formales en donde la perspectiva racional sobresale y no se tienen en cuenta los aspectos humanos en el diseño de los sistemas. Estos modelos de control rígidos, estandarizados y centralizados suponen un problema para el adecuado desarrollo estratégico y operativo de las organizaciones. Sin embargo, desde los sistemas biológicos se pueden observar aportes de autores que destacan la ausencia de control y su consecuente funcionamiento armónico a través de propiedades como la auto-organización y la emergencia. De esta forma, este artículo de revisión tiene como objetivo identificar las aproximaciones teóricas que se han realizado en torno a los principales aportes que los modelos biológicos han hecho a la gestión administrativa y específicamente al control organizacional mediante el análisis de la producción bibliográfica realizada en los últimos 10 años.

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Greenhouse gas markets, where invisible gases are traded, must seem like black boxes to most people. Farmers can make money on these markets, such as the Chicago Climate Exchange, by installing methane capture technologies in animal-based systems, no-till farming, establishing grasslands, and planting trees.

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Groundwater from Maramarua has been identified as coal seam gas (CSG) water by studying its composition, and comparing it against the geochemical signature from other CSG basins. CSG is natural gas that has been produced through thermogenic and biogenic processes in underground coal seams; CSG extraction requires the abstraction of significant amounts of CSG water. To date, no international literature has described coal seam gas water in New Zealand, however recent CSG exploration work has resulted in CSG water quality data from a coal seam in Maramarua, New Zealand. Water quality from this site closely follows the geochemical signature associated with United States CSG waters, and this has helped to characterise the type of water being abstracted. CSG water from this part of Maramarua has low calcium, magnesium, and sulphate concentrations but high sodium (334 mg/l), chloride (146 mg/l) and bicarbonate (435 mg/l) concentrations. In addition, this water has high pH (7.8) and alkalinity (360 mg/l as CaCO3), which is a direct consequence of carbonate dissolution and biogenic processes. Different analyte ratios ('source-rock deduction' method) have helped to identify the different formation processes responsible in shaping Maramarua CSG water

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Current approaches to the regulation of coal mining activities in Australia have facilitated the extraction of substantial amounts of coal and coal seam gas. The regulation of coal mining activities must now achieve the reduction or mitigation of greenhouse gas emissions in order to address the challenge of climate change and achieve ecologically sustainable development. Several legislative mechanisms currently exist which appear to offer the means to bring about the reduction or mitigation of greenhouse gas emissions from coal mining activities, yet Australia’s emissions from coal mining continue to rise. This article critiques these existing legislative mechanisms and presents recommendations for reform.

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The current regulatory approach to coal seam gas projects in Queensland is based on the philosophy of adaptive environmental management. This method of “learning by doing” is implemented in Queensland primarily through the imposition of layered monitoring and reporting duties on the coal seam gas operator alongside obligations to compensate and “make good” harm caused. The purpose of this article is to provide a critical review of the Queensland regulatory approach to the approval and minimisation of adverse impacts from coal seam gas activities. Following an overview of the hallmarks of an effective adaptive management approach, this article begins by addressing the mosaic of approval processes and impact assessment regimes that may apply to coal seam gas projects. This includes recent Strategic Cropping Land reforms. This article then turns to consider the preconditions for land access in Queensland and the emerging issues for landholders relating to the negotiation of access and compensation agreements. This article then undertakes a critical review of the environmental duties imposed on coal seam gas operators relating to hydraulic fracturing, well head leaks, groundwater management and the disposal and beneficial use of produced water. Finally, conclusions are drawn regarding the overall effectiveness of the Queensland framework and the lessons that may be drawn from Queensland’s adaptive environmental management approach.

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A number of regulatory statutes provide for agreements with landowners which are given extended effect, that is, are binding upon the landowner’s successors (‘statutory agreements’). Several Queensland statutes require a project proponent to enter into a statutory agreement with a landowner before a resource development activity can be carried out on private land or by accessing private land. Provisions of Queensland’s Petroleum and Gas (Production and Safety) Act 2004 make certain types of statutory agreements binding upon successors and assigns of the landowner, but do not clearly prescribe the nature and contents of an agreement, nor require that the agreement be recorded on the land title or petroleum register. If statutory agreements are to be used for such purposes, their purpose and content should be more clearly defined by statute and they should be recorded on a searchable register.

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Coal Seam Gas (CSG) is a form of natural gas (mainly methane) sorbed in underground coal beds. To mine this gas, wells are drilled directly into an underground coal seam and groundwater (CSG water) is pumped out to the surface. This lowers the downhole piezometric pressure and enables gas desporption from the coal matrix. In the United States, this gas has been extracted commercially since the 1980s. The economic success of US CSG projects has inspired exploration and development in Australia and New Zealand. In Australia, Queensland’s Bowen and Surat basins have been the subject of increased CSG development over the last decade. CSG growth in other Australian basins has not matured to the same level but exploration and development are taking place at an accelerated pace in the Sydney Basin (Illawarra and the Hunter Valley, NSW) and in the Gunnedah Basin. Similarly, CSG exploration in New Zealand has focused in the Waikato region (Maramarua and Huntly), in the West Coast region (Buller, Reefton, and Greymouth), and in Southland (Kaitangata, Mataura, and Ohai). Figure 1 shows a Shcoeller diagram with CSG samples from selected basins in Australia, New Zealand, and the USA. CSG water from all of these basins exhibit the same geochemical signature – low calcium, low magnesium, high bicarbonate, low sulphate and, sometimes, high chloride. This water quality is a direct result of specific biological and geological processes that have taken part in the formation of CSG. In general, these processes include the weathering of rocks (carbonates, dolomite, and halite), cation exchange with clays (responsible for enhanced sodium and depleted calcium and magnesium), and biogenic processes (accounting for the presence of high bicarbonate concentrations). The salinity of CSG waters tends to be brackish (TDS < 30000 mg/l) with a fairly neutral pH. These particular characteristics need to be taken into consideration when assessing water management and disposal alternatives. Environmental issues associated with CSG water disposal have been prominent in developed basins such as the Powder River Basin (PRB) in the United States. When disposed on the land or used for irrigation, water having a high dissolved salts content may reduce water availability to crops thus affecting crop yield. In addition, the high sodium, low calcium and low magnesium concentrations increase the potential to disperse soils and significantly reduce the water infiltration rate. Therefore, CSG waters need to be properly characterised, treated, and disposed to safeguard the environment without compromising other natural resources.

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Concern about the increasing atmospheric CO2 concentration and its impact on the environment has led to increasing attention directed toward finding advanced materials and technologies suited for efficient CO2 capture, storage and purification of clean-burning natural gas. In this letter, we have performed comprehensive theoretical investigation of CO2, N2, CH4 and H2 adsorption on B2CNTs. Our study shows that CO2 molecules can form strong interactions with B2CNTs with different charge states. However, N2, CH4 and H2 can only form very weak interactions with B2CNTs. Therefore, the study demonstrates B2CNTs could sever as promising materials for CO2 capture and gas separation.

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According to a study conducted by the International Maritime organisation (IMO) shipping sector is responsible for 3.3% of the global Greenhouse Gas (GHG) emissions. The 1997 Kyoto Protocol calls upon states to pursue limitation or reduction of emissions of GHG from marine bunker fuels working through the IMO. In 2011, 14 years after the adoption of the Kyoto Protocol, the Marine Environment Protection Committee (MEPC) of the IMO has adopted mandatory energy efficiency measures for international shipping which can be treated as the first ever mandatory global GHG reduction instrument for an international industry. The MEPC approved an amendment of Annex VI of the 1973 International Convention for the Prevention of Pollution from Ships (MARPOL 73/78) to introduce a mandatory Energy Efficiency Design Index (EEDI) for new ships and the Ship Energy Efficiency Management Plan (SEEMP) for all ships. Considering the growth projections of human population and world trade the technical and operational measures may not be able to reduce the amount of GHG emissions from international shipping in a satisfactory level. Therefore, the IMO is considering to introduce market-based mechanisms that may serve two purposes including providing a fiscal incentive for the maritime industry to invest in more energy efficient manner and off-setting of growing ship emissions. Some leading developing countries already voiced their serious reservations on the newly adopted IMO regulations stating that by imposing the same obligation on all countries, irrespective of their economic status, this amendment has rejected the Principle of Common but Differentiated Responsibility (the CBDR Principle), which has always been the cornerstone of international climate change law discourses. They also claimed that negotiation for a market based mechanism should not be continued without a clear commitment from the developed counters for promotion of technical co-operation and transfer of technology relating to the improvement of energy efficiency of ships. Against this backdrop, this article explores the challenges for the developing counters in the implementation of already adopted technical and operational measures.

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International shipping is responsible for about 2.7% of the global emissions of CO2. In the absence of proper action, emissions from the maritime sector may grow by 150% to 250% by 2050, in comparison with the level of emissions in 2007. Against this backdrop, the International Maritime Organisation has introduced a mandatory Energy Efficiency Design Index (EEDI) for new ships and the Ship Energy Efficiency Management Plan (SEEMP) for all ships. Some Asian countries have voiced serious reservations about the newly adopted IMO regulations. They have suggested that imposing the same obligations on all countries, irrespective of their economic status, is a serious departure from the Principle of Common but Differentiated Responsibility, which has always been the cornerstone of international climate change law discourse. Against this backdrop, this article presents a brief overview of the technical and operational measures from the perspective of Asian countries.

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With increasing signs of climate change and the influence of national and international carbon-related laws and agreements, governments all over the world are grappling with how to rapidly transition to low-carbon living. This includes adapting to the impacts of climate change that are very likely to be experienced due to current emission levels (including extreme weather and sea level changes), and mitigating against further growth in greenhouse gas emissions that are likely to result in further impacts. Internationally, the concept of ‘Biophilic Urbanism’, a term coined by Professors Tim Beatley and Peter Newman to refer to the use of natural elements as design features in urban landscapes, is emerging as a key component in addressing such climate change challenges in rapidly growing urban contexts. However, the economics of incorporating such options is not well understood and requires further attention to underpin a mainstreaming of biophilic urbanism. Indeed, there appears to be an ad hoc, reactionary approach to creating economic arguments for or against the design, installation or maintenance of natural elements such as green walls, green roofs, streetscapes, and parklands. With this issue in mind, this paper will overview research as part of an industry collaborative research project that considers the potential for using a number of environmental economic valuation techniques that have evolved over the last several decades in agricultural and resource economics, to systematically value the economic value of biophilic elements in the urban context. Considering existing literature on environmental economic valuation techniques, the paper highlights opportunities for creating a standardised language for valuing biophilic elements. The conclusions have implications for expanding the field of environmental economic value to support the economic evaluations and planning of the greater use of natural elements in cities. Insights are also noted for the more mature fields of agricultural and resource economics.

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Given the increased importance of adaptation debates in global climate negotiations, pressure to achieve biodiversity, food and water security through managed landscape-scale adaptation will likely increase across the globe over the coming decade. In parallel, emerging market-based, terrestrial greenhouse gas abatement programs present a real opportunity to secure such adaptation to climate change through enhanced landscape resilience. Australia has an opportunity to take advantage of such programs through regional planning aspects of its governance arrangements for NRM. This paper explores necessary reforms to Australia's regional NRM planning systems to ensure that they will be better able to direct the nation's emerging GGA programs to secure enhanced landscape adaptation. © 2013 Planning Institute Australia.

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Voluntary and compliance markets for forest carbon and other (emission avoidance and biosequestration) activities are growing internationally and across Australia. Queensland and its Natural Resource Management (NRM) regions have an opportunity to take a variety of actions to help guide these markets to secure multiple landscape benefits and to build landscape resilience in the face of climate change. As the national arrangements for offsets within Australia’s Clean Energy Package (CEP) and emissions trading environment emerge, Queensland’s regions can prepare themselves and their landholding communities to take advantage of these opportunities to deliver improved climate resilience in their regional landscapes.

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Plasmas, the 4th state of matter, uniformly transform natural precursors with different chemical composition in solid, liquid, and gas states into the same functional vertical graphenes in a single-step process within a few minutes. Functional vertical graphenes show reliable biosensing properties, strong binding with proteins, and improved adhesion to substrates.