The aftershock sequence of the north-west Kashmir earthquake of September 3, 1972

Abstract

This paper is an attempt to study the aftershock sequence of the Northwest Kashmir earthquake of September 3, 1972. b value of the sequence is 1.59. The area of active strain zone is approximately 2.9 • ]013 sq. cm. The total average strain, average elastic energy and average stress of the rock before slip are 3.3 • 10~5, 3.2 ergs/cm3 and 19.8 kg/cm2. The strain rebound curve of the sequence has been constructed which shows a dual type of recovery where the compressional elastic creep is followed by the shear creep recovery. The relaxation time of the sequence is about 0.7 day, showing the Kelvin body like behaviour of the upper mantle.

Sulfur Dioxide Capture by Heterogeneous Oxidation on Hydroxylated Manganese Dioxide

“…The proposed process captures and oxidizes SO 2 into sulfate directly at the gas/solid interface, taking advantage of its reducibility. Avoiding the use of corrosive liquids can mitigate corrosion to the absorber system and preclude the pumping of sorbent slurry that is the most energy intensive component in conventional wet FGD system. , Moreover, the direct gas/solid reaction is capable of treating the flue gas to a much lower level of SO 2 as demonstrated in the activity tests (Figure ), while gas/liquid processes are limited by a slow mass transfer in the liquid phase. , Since more and more stringent regulations are being deployed in heavily polluted areas, such as 20 mg·Nm –3 in Beijing, our proposed process provides a more cost-effective approach for SO 2 abatement. This reaction is carried out under facile conditions, and requires no additional oxidants other than molecular oxygen.…”

“…As a dominant energy source at the current stage, the combustion of sulfur-containing fossil fuels generates sulfur dioxide (SO 2 ) pollutant, which has significant impact on the global climate, environmental quality, and human health. , The main disadvantage of the conventional flue gas desulfurization (FGD) processes is the requirement of SO 2 to dissolve into the aqueous phase before it is neutralized by an alkaline reagent and further oxidized into sulfate, because they are generally based on the acidic property of SO 2 . − For instance, in wet FGD processes which have been deployed widely for a long time, a large gas/liquid interface is required to attain adequate gas/liquid mass transfer of SO 2 . This gas/liquid interface is usually maintained by circulation and dispersion of a large quantity of slurry, − thus inducing high energy and water consumption, especially when high removal efficiency is a demand.…”

Metal-Based Ionic Liquids in Oxidative Desulfurization: A Critical Review

“…Wet flue-gas desulfurization catalyzed by metal ions with strong oxidation ability to convert S­(IV) to S­(VI) is one of the most important approaches for SO 2 removal and H 2 SO 4 /CaSO 4 ·2H 2 O recovery. ,, However, this process is usually carried out in an aqueous homogeneous phase, and it is difficult to separate the desulfurization product and reuse the catalysts.…”

“…However, several shortcomings such as pH control, decomposition of desulfurizer, and secondary pollution limited its further applications. Regarding the desulfurization of SO 2 , flue-gas desulfurization (FGD) processes are the most adopted commercial technologies. , Double alkali desulfurization is one of the widely used FGD processes for SO 2 capture, and afterward, the desulfurizer, for example, NaOH/Na 2 CO 3 aqueous solution, is regenerated by a sodium-alkali reaction. Although, the poor purity of the side product caused by the high solubility of sodium sulfite and the generation of solid waste remains a problem.…”

“…For example, organic sulfides can be oxidized to their corresponding sulfoxides or sulfones that present slightly higher polar properties than hydrocarbon molecules, which is beneficial to the sulfur removal from fuel oil . H 2 S and SO 2 can be converted into sulfur and SO 3 , respectively, which are conducive to conservation, transportation, and preparing chemical products. , To realize high efficient and selective catalysis, catalyst and reaction conditions are the key factors.…”