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61.
Karanja oil, containing 6.2% free fatty acids (FFAs), was considered for biodiesel production using a single-step solid-phase acid catalyzed process. Different types of zeolites and Amberlyst15 catalysts were tested and biodiesel was produced. Under similar conditions, the highest biodiesel yield was achieved using an Amberlyst15 catalyst, which contained 3–5% of moisture. The effects of operating parameters of the reaction such as reaction temperature, catalyst amount, and methanol-to-oil ratio were studied. An increase of methanol:oil ratio revealed a non-monotonic increase in biodiesel yields. Similar non-monotonic behavior was observed when Jatropha oil was used. Leaching and catalyst reusability were also considered. No significant effects of leaching were observed and catalyst reusability appeared to be affected by methanol interactions. The presence of a co-solvent, Tetrahydrofuran (THF), increased the biodiesel yield. Furthermore, an optimum amount of THF (THF:methanol volume ratio of 1:2) gave rise to the highest biodiesel yield. A biodiesel yield of 93% was achieved at 120 °C using a single-step process with Amberlyst15 as a catalyst, THF as a co-solvent, and a methanol:oil ratio of 30:1. 相似文献
62.
Munmun Chakarvorty Jayanta Kumar Pati Shiva Kumar Patil Swati Shukla Ambalika Niyogi Arun Kumar Saraf 《Environmental monitoring and assessment》2014,186(5):2965-2978
The winter fog in India is a recurrent phenomenon for more than a decade now affecting the entire Himalayan and sub-Himalayan regions covering an area of nearly 500,000 km2. Every winter (December–January), the air and surface transports in cities of northern India (Amritsar, New Delhi, Agra, Gwalior, Kanpur, Lucknow, and Allahabad) are severely disrupted with visibility reduced to <50 m at times. Since dust particles are known to act as nuclei for the fog formation, this study is aimed to carry out physicochemical characterization of the dust particulates accumulated during a protracted fog period from one of the severely fog affected cities of north India (Allahabad; 25°27′33.40″N–81°52′45.47″E). The dust-loaded tree leaves belonging to Ficus bengalensis and Ficus religiosa from 50 different locations between January 24 and 31, 2010 are sampled and characterized. The mass of dust, color, grain shape, size, phase constituents, and mineral magnetic parameters, such as magnetic susceptibility, SIRM, χ fd%, and S-ratio, show minor variation and the regional influence outweighs local anthropogenic contributions. The dust compositions show fractionated rare earth element pattern with a pronounced negative Eu anomaly similar to upper continental crust and further suggesting their derivation from sources located in parts of north and central India. 相似文献
63.
Ecotourism's Support of Biodiversity Conservation 总被引:17,自引:0,他引:17
Marnie P. Bookbinder Eric Dinerstein Arun Rijal Hank Cauley & Arup Rajouria 《Conservation biology》1998,12(6):1399-1404
64.
Arun Kumar Devendra P Saroj Vinod Tare Purnendu Bose 《Water environment research》2006,78(9):994-1004
This study is aimed at exploring strategies for mineralization of refractory compounds in distillery effluent by anaerobic biodegradation/ozonation/aerobic biodegradation. Treatment of distillery spent-wash used in this research by anaerobic-aerobic biodegradation resulted in overall COD removal of 70.8%. Ozonation of the anaerobically treated distillery spent-wash was carried out as-is (phase I experiments) and after pH reduction and removal of inorganic carbon (phase II experiments). Introduction of the ozonation step resulted in an increase in overall chemical oxygen demand (COD) removal, with the highest COD removals of greater than 95% obtained when an ozone dose of approximately 5.3 mg ozone absorbed/mg initial total organic carbon was used. The COD removal during phase II experiments was slightly superior compared with phase I experiments at similar ozone doses. Moreover, efficiency of ozone absorption from the gas phase into distillery spent-wash aliquots was considerably enhanced during phase II experiments. 相似文献
65.
Bhadra B Mukherjee S Chakraborty R Nanda AK 《Journal of environmental biology / Academy of Environmental Biology, India》2003,24(2):125-133
A few physico-chemical and bacteriological parameters on certain locations of the river Torsa was studied. The major characteristics of Torsa river water were high alkalinity, high concentration of free ammonia with respect to albuminoid ammonia and the presence of bacteria of fecal origin. Marked seasonal variations of the parameters were also observed. 相似文献
66.
Four species of Dunaliella and a carbonic anhydrase deficient mutant of Dunaliella tertiolecta (Butcher), HL 25/8, developed a process for concentrating dissolved inorganic carbon when adapted on air or low CO2 for 24 h in the light. However, the external carbonic anhydrase activities in Dunaliella species were nil or low compared with those in Chlamydomonas reinhardtii (Danegard) or some Chlorella species. D. tertiolecta had low and about equal levels of external and internal carbonic anhydrase. D. parva (Lerche) and the D. tertiolecta mutant had negligible external carbonic anhydrase. D. viridis (Teodoresco) and D. salina (Teodoresco), high salt tolerant species, had high activities of intenal carbonic anhydrase but low levels of external carbonic anhydrase. Antiserum prepared against the 37 kDa peptide of extracellular carbonic anhydrase from Chlamydomonas reinhardtii was immunoreactive with a polypeptide of 30 kDa in D. tertiolecta and its salt sensitive external carbonic anhydrase (CA) mutant HL 25/8. External CA activity from D. tertiolecta was stimulated about three-fold, by including 0.5 M NaCl in the assay medium, while internal CA was not significantly affected by NaCl. External CA activities in the other species were insensitive to NaCl, while their internal activities were 90% inhibited by 0.5 M NaCl. Sorbitol only partly replaced NaCl in stimulating the external CA from D. tertiolecta. These experiments were performed with Dunaliella spp. grown in controlled laboratory cultures during September through November 1989. 相似文献
67.
Kumar T Stanley VA Lal AA Balasubramanian M Pillai KS 《Journal of environmental biology / Academy of Environmental Biology, India》2002,23(4):407-410
Alloxan-induced diabetic rats were treated with multiple herbal preparation besides a control group receiving distilled water. The levels of glucose and alkaline phosphatase (ALP) increased abnormally in the alloxan treated group and the same were normalized upon treatment with the herbal preparation. The levels of blood urea nitrogen (BUN), alanine aminotransferase (ALT), protein and albumin in all groups remained unaltered. However, weekly body weight gain which got significantly altered in the alloxan-treated group was normalized by treatment with the herbal preparation. On the whole, a profound hypoglycemic effect was observed by the multiple herbal treatment in the diabetic rats. 相似文献
68.
The paper presents the novel design of double glazing helical coil solar cavity receiver for solar thermal applications. Performance model has been developed for the experimental setup based on energy balance equations. The results obtained were compared with horizontal tube receiver for the same experimental setup. The result shows that the 87.96% improvement in the convective heat transfer coefficient for the double glazing helical coil solar cavity receiver. Maximum conversion efficiency achieved is 21% more than that would be obtained for horizontal tube receiver. This paper also investigates how the quality of vacuum degraded with the temperature of the glass cover. 相似文献
69.
Arun Kanagavel Sethu Parvathy Nithula Nirmal Nithin Divakar Rajeev Raghavan 《Ambio》2017,46(6):695-705
In the Western Ghats of India, amphibians are culled at cardamom plantations since they are perceived to consume cardamom. To better understand the relationship between amphibians and cardamom, a study was undertaken at these plantations, which harbor numerous threatened and range-restricted amphibians. We undertook questionnaire surveys with 298 respondents at 148 plantations across southern India. Time-activity budget and diet analysis surveys were undertaken to determine whether amphibians really consumed cardamom. The conception that amphibians eat cardamom was found to be widespread especially among small-sized plantations, leading to negative perceptions and a lack of interest in amphibian conservation. The plantation community perceives a substantial economic loss due to amphibians, even though this is non-existent as revealed by our field surveys. These perceptions would lead to a continued intolerance of amphibian presence in plantations. A suitable outreach initiative re-affirming facts and spreading awareness on the positive role of amphibians would need to be conducted to negate this age-old myth. 相似文献
70.