981 resultados para economic trends
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The demand for petroleum has been rising rapidly due to increasing industrialization and modernization. This economic development has led to a huge demand for energy, most of which is derived from fossil fuel. However, the limited reserve of fossil fuel has led many researchers to look for alternative fuels which can be produced from renewable feedstock. Increasing fossil fuel prices have prompted the global oil industry to look at biodiesel, which is from renewable energy sources. Biodiesel is produced from animal fats and vegetable oils and has become more attractive because it is more environmentally friendly and is obtained from renewable sources. Glycerol is the main by-product of biodiesel production; about 10% of the weight of biodiesel is generated in glycerol. The large amount of glycerol generated may become an environmental problem, since it cannot be disposed of in the environment. In this paper, an attempt has been made to review the different approaches and techniques used to produce glycerol (hydrolysis, transesterification, refining crude glycerol). The world biodiesel/glycerol production and consumption market, the current world glycerin and glycerol prices as well as the news trends for the use of glycerol mainly in Brazil market are analyzed. The technological production and physicochemical properties of glycerol are described, as is the characterization of crude glycerol obtained from different seed oil feedstock. Finally, a simple way to use glycerol in large amounts is combustion, which is an advantageous method as it does not require any purification. However, the combustion process of crude glycerol is not easy and there are technological difficulties. The news and mainly research about the combustion of glycerol was also addressed in this review. © 2013 Elsevier Ltd.
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Transport planning necessarily takes into account more than just the immediate time-frame. In the case of urban transport, planning needs to come up with solutions in regard to infrastructure which is expensive and may have a useful life extending over several decades. Therefore, planning must take note of economic, technological, social and demographic changes that influence trips undertaken.The purpose of this article is to explore some of the trends that may well be observed in upcoming decades. The article arrives at the conclusion that, in a period of considerable change and uncertainty, failure to take heed of recent trends may result in the construction of infrastructure that is not always the most appropriate and, what is more, that urban development militates against the efficient operation of public transport and, as a result, is likely to jeopardize the sustainability of cities in the long term.
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The study recently published by the Division of International Trade and Integration of ECLAC considers that 2005 will be a good year for trade in the countries of the region. Despite a favourable international context, there are still serious problems of competitiveness. The region needs to increase productivity, promote technological innovation and take a proactive part in worldwide networks. The conclusions of the study include the need to update integration; to take a strategic view of the links to be constructed with China and the countries of the Pacific; to manage free-trade agreements so as to increase and diversify exports; to step up the pace of work and improve coordination with the developing countries on the Doha Round, and to gradually incorporate the demands of security into competitiveness policies, ensuring that they do not become protectionist barriers (traceability, food safety and maritime and port security).
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