992 resultados para Oil Shale


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In this paper, we test whether oil price uncertainty predicts credit default swap (CDS) returns for eight Asian countries. We use the Westerlund and Narayan, 2011 and Westerlund and Narayan, 2012 predictability test that accounts for any persistence in and endogeneity of the predictor variable. The estimator also accounts for any heteroskedasticity in the regression model. In-sample evidence reveals that oil price uncertainty predicts CDS returns for three Asian countries, whereas out-of-sample evidence suggests that oil price uncertainty predicts CDS returns for six countries.

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A novel recyclable and flexible membrane was prepared for the removal of oil spills and organic dye pollutants, by functionalizing polyester textiles with reduced graphene oxide@ZnO nanocomposites using a layer-by-layer technique. The membrane showed efficient water/oil separation, and the amount of oil adsorbed by the membrane could be up to 23 times its own weight. The adsorption capacity was largely retained during many adsorption recycling cycles. The membrane also displayed highly efficient removal of a dye pollutant from water under simulated sunlight. The membrane maintained a near-original removal efficiency after five cycles of dye removal. This new type of membrane may find practical applications in the large-scale separation of organic pollutants from water, particularly in the field of oil spills clean-up and dye removal from industrial effluent.

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A novel chitosan-based microcapsule containing patchouli oil was developed by a non-toxic procedure for the purpose of improving the stability of patchouli oil and achieving a durable controlled release effect. The microcapsules were characterized in case of morphology, particle size and size distribution, infrared spectrum, and the drug controlled-release properties of microcapsules were investigated under constant temperature of 25 °C. The results indicated that the microcapsules were spherical in shape with good dispersibility and smooth surface, and the particle size of microcapsules ranged from 1 to 10 ?m. The controlled-release of patchouli oil could still be remained about 60% in the microcapsules after 10 days, which demonstrated that the stability of patchouli oil were effectively improved after being encapsulated in microcapsules. It is believed that this study will not only provide a novel chitosan-based microcapsule production containing patchouli oil, but also promote the applications of microcapsule technology for improving the bioavailability of active volatile oils.

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Following the intervention in Iraq by coalition forces one decade ago, the Bush Administration underwent an enormous and unprecedented project to bring the ‘Western’ liberal model of democracy to Iraq. For the first few years the project to bring democracy to Iraq had its share of successes as the Iraqi people proved themselves capable of understanding and utilizing democratic mechanisms and institutions. This culminated in a series of nation-wide elections from 2005 onwards that brought a democratically elected government to power (Isakhan, 2012). However, one of the unfortunate consequences of the war and the US effort to bring democracy to Iraq was that many key ethno-religious political factions viewed it as an opportunity to pedal their own relatively narrow and very divisive political rhetoric (Davis, 2007). This meant that the Iraqi government was constituted not so much by a body who wanted to draw Iraq together behind a common ideology and to work towards a collective and egalitarian future, as it was by representatives who would fight on behalf of their ethno-religious constituencies. Not surprisingly, a great deal of academic literature has emerged which has analysed and criticised the formal political parties and institutions of the post-Saddam era (Dawisha, 2009). Indeed, the bulk of contemporary scholarship on Iraqi politics focuses on issues such as: the increasingly authoritarian tendencies of the Iraqi government; the obstinacy and ineptitude of many elements of Iraq’s political elite; the systemic corruption that is hollowing out the coffers of the state; the moribund bureaucracy that are struggling to deliver basic services and; of course, the deep-seated divisions within and between those that represent Iraq’s three main ethno-religious blocks: the Shia Arabs, the Sunni Arabs and the Kurds.

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In this paper, we test whether oil price predicts economic growth for 28 developed and 17 developing countries. We use predictability tests that account for the key features of the data, namely, persistency, endogeneity, and heteroskedasticity. Our analysis considers a large number of countries, shows evidence of more out-of-sample predictability with nominal than real oil prices, finds in-sample predictability to be independent of the use of nominal and real prices, and reveals greater evidence of predictability for developed countries.

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Teleost fish, as with all vertebrates, are capable of synthesizing cholesterol and as such have no dietary requirement for it. Thus, limited research has addressed the potential effects of dietary cholesterol in fish, even if fish meal and fish oil are increasingly replaced by vegetable alternatives in modern aquafeeds, resulting in progressively reduced dietary cholesterol content. The objective of this study was to determine if dietary cholesterol fortification in a vegetable oil-based diet can manifest any effects on growth and feed utilization performance in the salmonid fish, the rainbow trout. In addition, given a series of studies in mammals have shown that dietary cholesterol can directly affect the fatty acid metabolism, the apparent in vivo fatty acid metabolism of fish fed the experimental diets was assessed. Triplicate groups of juvenile fish were fed one of two identical vegetable oil-based diets, with additional cholesterol fortification (high cholesterol, H-Chol) or without (low cholesterol, L-Chol), for 12 weeks. No effects were observed on growth and feed efficiency, however, in fish fed H-Col no biosynthesis of cholesterol, and a remarkably decreased apparent in vivo fatty acid b-oxidation were recorded, whilst in LChol fed fish, cholesterol was abundantly biosynthesised and an increased apparent in vivo fatty acid b-oxidation was observed. Only minor effects were observed on the activity of stearyl-CoA desaturase, but a significant increase was observed for both the transcription rate in liver and the apparent in vivo activity of the fatty acid D-6 desaturase and elongase, with increasing dietary cholesterol. This study showed that the possible effects of reduced dietary cholesterol in current aquafeeds can be significant and warrant future investigations.