Stochastic landslide vulnerability modeling in space and time in a part of the northern Himalayas, India

Little is known about the quantitative vulnerability analysis to landslides as not many attempts have been made to assess it comprehensively. This study assesses the spatio-temporal vulnerability of elements at risk to landslides in a stochastic framework. The study includes buildings, persons inside buildings, and traffic as elements at risk to landslides. Building vulnerability is the expected damage and depends on the position of a building with respect to the landslide hazard at a given time. Population and vehicle vulnerability are the expected death toll in a building and vehicle damage in space and time respectively. The study was carried out in a road corridor in the Indian Himalayas that is highly susceptible to landslides. Results showed that 26% of the buildings fall in the high and very high vulnerability categories. Population vulnerability inside buildings showed a value >0.75 during 0800 to 1000 hours and 1600 to 1800 hours in more buildings that other times of the day. It was also observed in the study region that the vulnerability of vehicle is above 0.6 in half of the road stretches during 0800 hours to 1000 hours and 1600 to 1800 hours due to high traffic density on the road section. From this study, we conclude that the vulnerability of an element at risk to landslide is a space and time event, and can be quantified using stochastic modeling. Therefore, the stochastic vulnerability modeling forms the basis for a quantitative landslide risk analysis and assessment.     

Evaporative Cooling of Water in a Small Vessel Under Varying Ambient Humidity

Evaporative cooling of water in a small porous clay vessel was studied under controlled humidity conditions. In steady-state experiments performed at an ambient temperature of 23 °C, the cooling effect increased from 4.7 to 8.3 °C as the ambient relative humidity decreased from 60 to 15%. External heat and mass transfer coefficients, estimated from the steady-state measurements, were used in mathematical models to predict the experimentally observed transient temperature variation of the water under ramp changes of the ambient relative humidity. With a prototypical cool chamber containing water tested in Kolkata, India under an ambient temperature of 34.5–35 °C, the cooling effect reached a maximum of 7 °C between 3 and 3:30 PM and then declined to 4.5 °C around 6 PM.     

Water management in the highlands of India

Conclusions In addition to this natural water-holding capacity of completely forested mountains, development for conservation of water should insure man-made mountain water storage systems, consisting of tanks, ponds, small dams and reservoirs, and artificial lakes at varying altitudes in the Himalayas. An elaborate system of canals would be needed to carry clean water for drinking and cultivation. Alternatively, adjacent highland lakes may be linked up by canals provided with wiers and sluice gates, to carry water to all levels.     

Effect of pH and temperature on the kinetics of odor oxidation using chlorine dioxide

Increasing public concerns over odors and air regulations in nonattainment zones necessitate the remediation of a wide range of volatile organic compounds (VOCs) generated in the poultry-rendering industry. Currently, wet scrubbers using oxidizing chemicals such as chlorine dioxide (ClO2) are utilized to treat VOCs. However, little information is available on the kinetics of ClO2 reaction with rendering air pollutants, limiting wet scrubber design and optimization. Kinetic analysis indicated that ClO2 does not react with hexanal and 2-methylbutanal regardless of pH and temperature and implied that aldehyde removal occurs primarily via mass transfer. Contrary to the aldehydes, ethanethiol or ethyl mercaptan (a model compound for methanethiol or methyl mercaptan) and dimethyl disulfide (DMDS) rapidly reacted with ClO2. The overall reaction was found to be second and third order for ethanethiol and DMDS, respectively. Moreover, an increase in pH from 3.6 to 5.1 exponentially increased the reaction rate of ethanethiol (e.g., k2 = 25-4200 L/mol/sec from pH 3.6 to 5.1) and significantly increased the reaction rate of DMDS if increased to pH 9 (k3 = 1.4 x 10(6) L2/mol2/sec). Thus, a small increase in pH could significantly improve wet scrubber operations for removal of odor-causing compounds. However, an increase in pH did not improve aldehyde removal. The results explain why aldehyde removal efficiencies are much lower than methanethiol and DMDS in wet scrubbers using ClO2.     

Wet scrubber analysis of volatile organic compound removal in the rendering industry

The promulgation of odor control rules, increasing public concerns, and U.S. Environmental Protection Agency (EPA) air regulations in nonattainment zones necessitates the remediation of a wide range of volatile organic compounds (VOCs) generated by the rendering industry. Currently, wet scrubbers with oxidizing chemicals are used to treat VOCs; however, little information is available on scrubber efficiency for many of the VOCs generated within the rendering process. Portable gas chromatography/mass spectrometry (GC/MS) units were used to rapidly identify key VOCs on-site in process streams at two poultry byproduct rendering plants. On-site analysis was found to be important, given the significant reduction in peak areas if samples were held for 24 hr before analysis. Major compounds consistently identified in the emissions from the plant included dimethyl disulfide, methanethiol, octane, hexanal, 2-methylbutanal, and 3-methylbutanal. The two branched aldehydes, 2-methylbutanal and 3-methylbutanal, were by far the most consistent, appearing in every sample and typically the largest fraction of the VOC mixture. A chlorinated hydrocarbon, methanesulfonyl chloride, was identified in the outlet of a high-intensity wet scrubber, and several VOCs and chlorinated compounds were identified in the scrubbing solution, but not on a consistent basis. Total VOC concentrations in noncondensable gas streams ranged from 4 to 91 ppmv. At the two plants, the odor-causing compound methanethiol ranged from 25 to 33% and 9.6% of the total VOCs (v/v). In one plant, wet scrubber analysis using chlorine dioxide (ClO2) as the oxidizing agent indicated that close to 100% of the methanethiol was removed from the gas phase, but removal efficiencies ranged from 20 to 80% for the aldehydes and hydrocarbons and from 23 to 64% for total VOCs. In the second plant, conversion efficiencies were much lower in a packed-bed wet scrubber, with a measurable removal of only dimethyl sulfide (20-100%).     

A study of ground water contamination by arsenic in the residential area of Behala, Calcutta due to industrial pollution

Due to the discharge of industrial effluent after production of the insecticide Paris-Green [Copper acetoarsenite Cu(CH(3)COO)(2).3Cu(AsO(2))(2)] by a local factory at the P. N. Mitra Lane, Behala, ground water has become contaminated with arsenic. More than seven thousand people were using this arsenic contaminated tube-well water for drinking and house-hold purposes. Many people of the area were hospitalised and symptoms of arsenic toxicity were visible amongst a large number of the population. Analytical study reveals that soil around the area of effluent dumping point, which is at the middle of the locality, contains a very high concentration of arsenic and copper. For the last 20 years this factory had been producing 20 tons of Paris-Green per year and had been dumping its effluent in that area. It seems, the effluent treatment for arsenic removal was not adequate and finally arsenic percolated to the underground aquifers. Consequently, arsenic concentration in the ground water is very high. Both arsenite and arsenate are present in ground water. An alternate source of water other than the ground water is immediately necessary for the people of P. N. Mitra Lane.     

Major ion chemistry and control of weathering of Bhimtal Lake, Humaun Himalaya, India

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