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71.
The very dynamic economies of Southeast Asia have recently been experiencing a rapid increase in energy demand. Parallel to this development, there has been an increase in the utilization of indigenous natural gas resources. This article reviews gas-pricing policies in the region, which partly explain the rise in gas utilization. Although diverse, energy pricing policies in Southeast Asia address the common objective of enhancing domestic gas production and utilization.
The article concludes that a more rational gas-pricing policy framework is emerging in the region. In global terms, gas pricing in the region tends to converge in a market-related framework, despite the many different pricing objectives of individual countries, and the predominance of non-economic pricing objectives in certain countries (especially gas-rich nations). Specifically, governments have been flexible enough to follow global trends and initiate changes in contractual agreements (pricing and profit-sharing), giving oil companies more favourable terms, and encouraging continued private investment in gas development. At the same time, promotional pricing has also been used to increase utilization of gas, through set prices and adjusted taxes achieving a lower price level compared to substitute fuels.
For an efficient gas-pricing mechanism, refinements in the pricing framework should be undertaken, as demand for gas approaches existing and/or forecast production capacities.  相似文献   
72.
The effect of arbuscular mycorrhiza on heavy metal uptake and translocation was investigated in Cannabis sativa. Hemp was grown in the presence and absence of 100 microg g-1 Cd and Ni and 300 microg g-1 Cr(VI), and inoculated or not with the arbuscular mycorrhizal fungus Glomus mosseae. In our experimental condition, hemp growth was reduced in inoculated plants and the reduction was related to the degree of mycorrhization. The percentage of mycorrhizal colonisation was 42% and 9% in plants grown in non-contaminated and contaminated soil, suggesting a significant negative effect of high metal concentrations on plant infection by G. mosseae. Soil pH, metal bioavailability and plant metal uptake were not influenced by mycorrhization. The organ metal concentrations were not statistically different between inoculated and non-inoculated plants, apart from Ni which concentration was significantly higher in stem and leaf of inoculated plants grown in contaminated soil. The distribution of absorbed metals inside plant was related to the soil heavy metal concentrations: in plant grown in non-contaminated soil the greater part of absorbed Cr and Ni was found in shoots and no significant difference was determined between inoculated and non-inoculated plants. On the contrary, plants grown in artificially contaminated soil accumulated most metal in root organ. In this soil, mycorrhization significantly enhanced the translocation of all the three metals from root to shoot. The possibility to increase metal accumulation in shoot is very interesting for phytoextraction purpose, since most high producing biomass plants, such as non-mycorrhized hemp, retain most heavy metals in roots, limiting their application.  相似文献   
73.
Castaldi P  Santona L  Melis P 《Chemosphere》2005,60(3):365-371
The effects of chemical amendments (zeolite, compost and calcium hydroxide) on the solubility of Pb, Cd and Zn in a contaminated soil were determined. The polluted soil was from the Southwest Sardinia, Italy. It showed very high total concentrations of Pb (19663 mgkg(-1) d.m.), Cd (196 mgkg(-1) d.m.) and Zn (14667 mgkg(-1) d.m.). The growth and uptake of heavy metals by white lupin (Lupinus albus L., cv. Multitalia) in amended soils were also studied in a pot experiment under greenhouse conditions. Results showed that the amendments increased the residual fraction of heavy metals in the soils, and decreased the heavy metals uptake by white lupin compared with the unamended control. Among the three amendments, compost and Ca(OH)2 were the most efficient at reducing Pb and Zn uptake, while zeolite was the most efficient at reducing Cd uptake by the plants. White lupin growth was better in amended soils than in unamended control. The above ground biomass increased with a factor 1.8 (soil amended with zeolite), 3.6 (soil amended with compost) and 3.1 (soil amended with Ca(OH)2) with respect to unamended soil. The roots biomass increased with a factor 1.4 (soil amended with zeolite), 5.6 (soil amended with compost) and 4.8 (soil amended with Ca(OH)2). Results obtained suggest that the soil chemical treatment improved the performance of crops by reducing bioavailability of metals in the soils. However it would be therefore interesting to find a suitable mixture of these amendments to contemporarily immobilize the three main pollutants in the polluted soils.  相似文献   
74.
Summary Planthopper (Insecta: Homoptera) feeding stress induces a senesence-like response in the leaves ofSpartina alterniflora characterized by decreased soluble protein, an increased total amino acid pool, and elevated levels of 10 individual amino acids. Increased proline and tryptophan in response to planthopper feeding could not be fully explained by protein degradation. Low degrees of soil salinity stress resulted in an increased total free amino acid pool and elevated levels of 7 amino acids. Anaerobic soil stress resulted in decreased glutamic acid and increased asparagine. Low salinity and anaerobic stress had no effect on soluble protein levels. Glycinebetaine was not affected by the stresses examined in this study.  相似文献   
75.
The potential of high pressure processing to inactivate hepatitis A virus (HAV) within Mediterranean mussels (Mytilus galloprovincialis) and blue mussels (Mytilus edulis) was evaluated. HAV was bioaccumulated within mussels to approximately 6-log10 PFU by exposure of mussels to HAV-contaminated seawater. After shucking, 5 min pressure treatments of 300, 325, 350, 375, and 400 MegaPascals (MPa) were performed at room temperature (18–22°C). For blue mussels, log10 PFU reductions of HAV averaged 2.1 and 3.6 for treatments of 350 and 400 MPa, while for Mediterranean mussels reductions of 1.7 and 2.9 log10 PFU MPa were observed for equivalent treatments. These results demonstrate that high pressure processing is capable of inactivating HAV within mussels.  相似文献   
76.
The uptake of cadmium by the Haptophyceae Hymenomonas elongata was studied as regards the energetic processes and Ca‐transport. For this purpose, experiments were carried out in the presence of an uncoupler of the phosphorylation : CCCP and of an inhibitor of calcium channels and also of Ca2+‐ATPase : verapamil. To reduce the number of assays, a factorial experimental design was used, in which all variables:— concentration of Cd in the medium—incubation time and—the presence of the inhibitor, are at two levels. In the absence of inhibitor, Cd uptake was found to vary as a function of metal concentration in the medium and of incubation time. CCCP significantly increased Cd uptake by H. elongata at sufficient incubation time. Therefore Cd uptake seemed linked to an energy‐dependent process, involving an ATPase. Verapamil immediately increased Cd uptake, implying an interaction between Cd and Ca.  相似文献   
77.
78.
The Interuniversity Consortium, Chemistry for the Environment (INCA), was founded in Venice in October 1993. It groups about thirty Italian universities and relies on the research contributions of chemists having different specialities (environmental, physical-chemical, organic, inorganic, analytic, industrial and biochemical), together with researchers coming from other disciplines engaged in environmental research. Consortium INCA has its administrative offices in Venice.  相似文献   
79.
The aim of this work was to comparatively assess the persistence of pirimiphos methyl residues in cereals and in their milling fractions after spray application in post harvest. An analytical method, based on a slightly modified QuEChERS extraction followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) determination was validated: mean recovery was in the range 73% to 92% depending on the spiking level, and precision as RSD ranged from 11% to 16%. The analysis of treated samples revealed that pirimiphos-methyl residues were highly persistent and that no differences could be observed between wheat, durum wheat and oat. As far as the impact of the milling process on residues is concerned, pirimiphos methyl contamination was significantly reduced during both cleaning and processing, and most of the contamination was related to outer kernel fractions.  相似文献   
80.
Residues of the marine plant posidonia (Posidonia oceanica, PO) beached in tourist zones represent a great environmental, economical, social and hygienic problem in the Mediterranean Basin, in general, and in the Apulia Region in particular, because of the great disturb to the bathers and population, and the high costs that the administrations have to bear for their removal and disposal.In the present paper, Authors determined the heating values of leaves and fibres of PO, the main offshore residues found on beaches, and, meantime, composted those residues with mowing and olive pruning wood. The final composts were characterized for pH, electrical conductivity, elemental composition, dynamic respiration index, phytotoxicity, fluorescence and infrared spectroscopic fingerprints.The aim of the paper was to investigate the composting and energy recovery of PO leaves and fibres in order to suggest alternative solutions to the landfill when offshore residues have to be removed from recreational beaches.The fibrous portion of PO residues showed heating values close to those of other biofuels, thus suggesting a possible utilization as source of energy.At the same time, compost obtained from both PO wastes showed high quality features on condition that the electrical conductivity and Na content are lowered by a correct management of wetting during the composting.  相似文献   
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