Industrial development has lead to higher energy consumption, emission of greenhouse gases, as well as air pollutants. Cement factories play an important role in over all greenhouse emissions. This study aims to investigate the role of Iranian cement industries and their contribution of greenhouse gases contribution. The measured emission factors for oil and fuel gas shows that carbon dioxide contribution from fuel oil based cement industries is almost 2.7 times higher than gas based cement factories. The strength, weakness, opportunity and threat technique analysis showed that the best strategy to combat greenhouse gases from Iranian cement factory is to implement energy efficiency measures. Further, strategic position and action evaluation matrix analysis indicates that Iranian cement industries fall within invasive category. Therefore, exploitation of opportunities must carefully be used. One of these opportunities is the utilization of financial assistance provided by clean development mechanism. The results show that replacement of ball mills with vertical roller mill can reduce the electricity consumption from 44.6 to 28 kWh/ton. As a result of such substitution about 720 million kWh/y of electricity would be saved (almost a power plant of 125 MW capacities). Though implementation of new mills may not be economic for the cement industries’ owner, but the overall gain for the government of Iran will be about US$ 304 million. If the duration of such efficiency measure is considered as about 12 y, then the overall CO2 reduction/phase-out would be around 4.3 million tons. 相似文献
A high-temperature solution calorimetric method suitable for thermochemical studies of anhydrous minerals containing Fe2+ ions has been developed. The method is based on an oxide melt solvent with 52 wt% LiBO2 and 48 wt% NaBO2 maintained at a temperature of 750°C. In a first application of this method the enthalpies of solution of synthetic almandine, fayalite, a mixture of fayalite plus quartz on FeSiO3 composition, and natural quartz were measured. For the reaction: the enthalpy change at 1023 K is ?3.82 ± 0.87 kcal, based on fayalite, quartz, corundum and almandine, and ?5.96 ± 0.90 kcal based on the fayalite plus quartz mixture, corundum, and almandine. These values lead to standard molar enthalpies of formation of almandine from the oxides at 1023 K of ?14.10 ± 1.22 kcal and ?16.24 ± 1.74 kcal, respectively. The measured enthalpy of formation of almandine is less negative by several kilocalories than values derived from analysis of the phase equilibrium work of Hsu (1968), but in closer agreement with the phase equilibrium study of O'Neill and Wood (1979) and similar to the phase equilibrium deduction of Froese (1973).The agreement of the present almandine enthalpy of formation with O'Neill and Wood (1979) and Froese (1973) suggests that almandine entropies at 298 K to be obtained from their studies, in the range 79–81 cal/K, are more nearly correct than the several estimates based on oxide sum and volume-entropy systematics, most of which are much lower. 相似文献
The thickness of varves in the sediments of Skilak Lake, Alaska, are correlated with the mean annual temperature (r = 0.574), inversely correlated with the mean annual cumulative snowfall (r = −0.794), and not correlated with the mean annual precipitation (r = 0.202) of the southern Alaska climatological division for the years 1907–1934 A.D. Varve thickness in Skilak Lake is sensitive to annual temperature and snowfall because Skilak Glacier, the dominant source of sediment for Skilak Lake, is sensitive to these climatic parameters. Trends of varve thickness are well correlated with trends of mean annual cumulative snowfall (
) of the southern Alaska climatological division and with trends of mean annual temperature of the southern (
) and northern (
) Alaska climatological divisions. Trends of varve thickness also correlate with trends of annual temperature in Seattle and North Head, Washington (
, respectively). Comparisons of trends of varve thickness with trends of annual temperature in California, Oregon, and Washington suggest no widespread regional correlation. Trends of annual snowfall in the southern Alaska climatological division and trends of annual temperature in the southern and northern Alaska climatological divisions are reconstructed for the years 1700–1906 A.D. Climatic reconstructions on the basis of varve thickness in Skilak Lake utilize equations derived from the regression of series of smoothed climatological data on series of smoothed varve thickness. Reconstruction of trends of mean annual cunulative snowfall in the southern Alaska climatological division suggests that snowfall during the 1700s and 1800s was much greater than that during the early and mid-1900s. The periods 1770–1790 and 1890–1906 show marked decreases in the mean annual snowfall. Reconstructed trends of the annual temperature of the northern and southern Alaska climatological divisions suggest that annual temperatures during the 1700s and 1800s were lower than those of the early and mid-1900s. Two periods of relatively high annual temperatures coincide with the periods of low annual snowfall thus determined. 相似文献
Summary Spectacular large (3 cm) euhedral trapezohedra composed of single crystals of analcime or aggregates of pumpellyite occur in three stratigraphically adjacent phonolitic lavas from Aghda. The trapezohedra contain concentrically arranged inclusions of plagioclase, pyroxene, titanomagnetite and apatite which are fresh in the analcime but extensively altered in the pumpellyite. The analcime crystals are remarkably homogeneous in composition and are interpreted as having formed by ion-exchange pseudomorphous replacement of primary leucite. In the lower phonolite, however, the analcime became unstable and was replaced by pumpellyite which has a wide compositional range, reflecting variable input of Fe, Mg, Ca and Al from the precursor analcime and alteration of inclusions. The occurrence of analcime and pumpellyite at Aghda is indicative of zeolite facies conditions with low fCO2and H2O activity and probably high Pfluid.
Große pseudomorphe Trapezoeder von Analcim im Pumpellyit nach Leuzit, Aghda-Gebiet Zentraliran
Zusammenfassung Ungewöhnlich große idiomorphe Trapezoeder, die aus einzelnen Kristallen von Analcim oder aus Aggregaten von Pumpellyit bestehen, kommen in drei stratigraphisch benachbarten phonolitischen Lagen von Aghda vor. Die Trapezoeder enthalten konzentrisch verteilte Einschlüsse von Plagioklas, Pyroxen, Titanomagnetit und Apatit, die im Analcim frisch, im Pumpellyit jedoch intensiv umgewandelt sind. Die Analcim-Kristalle sind von bemerkenswerter Homogenität in ihrer Zusammensetzung und werden auf pseudomorphe Verdrängung von primärem Leucit durch Ionenaustausch zurück-geführt. Im unteren Phonolit ist der Analcim jedoch instabil geworden, und wurde durch Pumpellyit ersetzt, der ein weites Spektrum von Zusammensetzungen erkennen läßt und auf variierende Zufuhr von Fe, Mg, Ca, and Al vom Vorläuferanalcim und auf Umwandlung von Einschlüssen hinweist. Das Vorkommen von Analcim und Pumpellyit bei Aghda ist ein Hinweis auf Zeolithfazies-Bedingungen mit niedrigen fCO2 und H2O und hohem Pfluid.
This paper examines the advantages of the traditional cattlepost system against the recent drive towards the fencing of Botswana's rangelands and the establishment of privatised, commercial beef ranches. Consideration of operational and environmental factors emphasise the benefits of the cattlepost system, while socio-economic and political factors explain why the current drive towards fenced ranches will continue for the foreseeable future. It is concluded that while the degradation issue on Botswana's rangelands has been overstated, alleged concern for the conservation of the grazing resource is explicitly driving Botswana's current New Agricultural Policy. By accentuating the existing marked socio-economic inequalities within the livestock sector, such misplaced policies will fuel much graver environmental problems, as the underlying equity issue remains unaddressed. 相似文献
The Meseta and Fuego volcanoes closely overlap and collectively are known as the Fuego Volcanic Complex. Historic activity occurs exclusively at Fuego, the southern center, and consists of high-Al basalts. Meseta, the inactive northern center, is predominantly composed of basaltic andesites with minor basalt and andesite. A thick sequence of lava flows and dikes is exposed by a steep collapse escarpment on the east flank of Meseta. The upper 75% of the sequence was sampled from three interfingering stratigraphic sections consisting of 27, 10 and 4 lavas, respectively. Temporal geochemical trends of each section indicates a complex evolutionary history. A major trend toward more evolved compositions upward in the section is consistent with crystal fractionation. This trend is sharply interrupted by the youngest lavas which become distinctly more mafic in composition. Magma mixing is apparently the dominant magmatic evolution process that generated these lavas. The two trends have distinct Sr signatures that suggest a change in parental magma compositions. This abrupt change in composition is interpreted to signal high input rates of mafic magma into the subvolcanic magma chamber. These changes eventually led to sector collapse of Meseta volcano and deposition of the Escuintla debris avalanche. Eruptive activity then migrated to the Fuego volcano where historic activity is similar to that of Meseta immediately prior to its collapse. 相似文献
