75 research outputs found

    Transesterification of Jatropha curcas Oil by using K Impregnated CaO Heterogeneous Catalyst

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    1080-1086Growing environmental concern and fast depletion of conventional fossil fuel resources have induced an urgent search for alternative energy sources. In this regard, biodiesel obtained from Jatropha oil (a non-food oil), seems to be a very promising alternative. Though a lot of research is already done in catalytic transesterification, in the present work, conversion of high FFA (5.5%) bearing Jatropha oil to methyl ester was studied using synthesized KF/CaO solid catalyst. The novelty of this heterogeneous catalyst is the omission of two major steps — neutralization step in which acid is used followed by transesterification using the basic homogeneous catalyst. The catalyst KF/CaO is easily prepared from cheap chemicals and is safe for the environment. The catalyst was characterized by mean of TPD of CO2, X-ray diffraction, BET surface area (SA) analyzer. Catalytic transesterification of this oil was studied with different reaction parameters to achieve a 97% conversion. Optimization of conditions (molar ratio of methanol/oil, time, temperature and catalyst dosage) was also established. The present work makes the process not only safer to the environment but also shows the gateway for greener alternatives to the energy of high FFA oils

    "The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire

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    Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work

    Surface complexation of antimony on kaolinite

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    Geochemical fate of antimony (Sb) - a similar oxyanion as arsenic (As) - in a variety of environment is largely unexplored. Kaolinite is an important, naturally occurring clay mineral in soils and aquifers and is known to control the fate of several contaminants via a multitude of geochemical processes, primarily adsorption. Here we report adsorption of antimony on kaolinite as a function of solution chemistry: initial antimony concentration, pH, ionic strength, and a competing anion. A surface complexation modeling (SCM) approach was undertaken to understand the potential mechanistic implications of sorption envelope data. In the SCM, a multicomponent additive approach, in which kaolinite is assumed to be a (1:1) mixture of quartz (SiOH) and gibbsite (AlOH), was tested. Results indicated that ionic strength has a minimal effect on antimony adsorption. For the lower initial antimony concentration (4.11 ÎźM), the additive model with binuclear surface complexes on quartz and gibbsite showed a better fit at pH \u3c 6, but somewhat under predicted the experimental data above pH 6. At the higher initial antimony concentration (41.1. ÎźM), the sorption envelope was of different shape than the lower load. The additive model, which considered binuclear surface complexes for quartz and gibbsite, resulted in over prediction of the adsorption data at pH \u3e 3.5. However, the additive model with binuclear surface complex on quartz and mononuclear surface complex on gibbsite showed an excellent fit of the data. Phosphate greatly influenced antimony adsorption on kaolinite at both low and high antimony loadings, indicating competition for available surface sites

    Neuromuscular degeneration and locomotor deficit in a Drosophila model of mucopolysaccharidosis VII is attenuated by treatment with resveratrol

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    Mucopolysaccharidosis VII (MPS VII) is a recessively inherited lysosomal storage disorder caused by β-glucuronidase enzyme deficiency. The disease is characterized by widespread accumulation of non-degraded or partially degraded glycosaminoglycans, leading to cellular and multiple tissue dysfunctions. The patients exhibit diverse clinical symptoms, and eventually succumb to premature death. The only possible remedy is the recently approved enzyme replacement therapy, which is an expensive, invasive and lifelong treatment procedure. Small-molecule therapeutics for MPS VII have so far remained elusive primarily due to lack of molecular insights into the disease pathogenesis and unavailability of a suitable animal model that can be used for rapid drug screening. To address these issues, we developed a Drosophila model of MPS VII by knocking out the CG2135 gene, the fly β-glucuronidase orthologue. The CG2135−/− fly recapitulated cardinal features of MPS VII, such as reduced lifespan, progressive motor impairment and neuropathological abnormalities. Loss of dopaminergic neurons and muscle degeneration due to extensive apoptosis was implicated as the basis of locomotor deficit in this fly. Such hitherto unknown mechanistic links have considerably advanced our understanding of the MPS VII pathophysiology and warrant leveraging this genetically tractable model for deeper enquiry about the disease progression. We were also prompted to test whether phenotypic abnormalities in the CG2135−/− fly can be attenuated by resveratrol, a natural polyphenol with potential health benefits. Indeed, resveratrol treatment significantly ameliorated neuromuscular pathology and restored normal motor function in the CG2135−/− fly. This intriguing finding merits further preclinical studies for developing an alternative therapy for MPS VII. This article has an associated First Person interview with the first author of the paper

    Effect of solution properties, competing ligands, and complexing metal on sorption of tetracyclines on Al-based drinking water treatment residuals

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    In the current batch study, we investigated the effect of solution properties, competing ligands (phosphate (P(V)) and sulfate), and complexing metal (calcium (Ca2+)) on tetracycline (TTC) and oxytetracycline (OTC) sorption by Al-based drinking water treatment residuals (Al-WTR). The sorption behavior for both TTC and OTC on Al-WTR was pH dependent. The sorption in absence of competing ligands and complexing metal increased with increasing pH up to circum-neutral pH and then decreased at higher pH. The presence of P(V) when added simultaneously had a significant negative effect (p \u3c 0.001) on the sorption of TTC and OTC adsorbed by Al-WTR at higher TTC/OTC:P ratios. However, when P(V) was added after the equilibration of TTC and OTC by Al-WTR, the effect was minimal and insignificant (p \u3e 0.1). The presence of sulfate had a minimal/negligible effect on the sorption of TCs by Al-WTR. A significant negative effect (p \u3c 0.001) on the adsorption of TCs by Al-WTR was observed in the pH range below 5 and at higher TCs:Ca2+ ratios, probably due to TCs-Ca2+ complex formation. Fourier transform infrared (FTIR) analysis indicated the possibility of inner-sphere-type bonding by the functional groups of OTC/TTC on Al-WTR surface. Results from the batch sorption study indicate high affinity of Al-WTR for TCs in the pH range 4–8 (majorly encountered pH in the environment) in the presence of competing ligands and complexing metal

    Reactivity and kinetic study of high ash Indian coal and biomass blends

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    In the present study, char samples of two biomasses and their blends with high ash Indian coal wee prepared at 900°C and then gasified in the temperature range of 850°C to 1000°C in Co2 atmosphere using thermogravimetric analyzer (TGA). It is observed that the char gasification reactivity of coal-biomass blend is lesser in comparison with the gasification reactivity of pure biomass. The effect of gasification temperature on reactivity as well as comparison between gasification of two pure biomasses and their blends with coal have been studied. The activation energy of biomass and their blends has also been discussed in this paper. The gasification reactivity and kinetic data developed from thermogravimetric analysis study may be useful for modeling and designing of suitable gasifier as per the available feedstocks

    Analysis of Genetic Parameters on Mutant Populations of Mungbean (Vigna radiata L.) after Ethyl Methane Sulphonate Treatment

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    In the present study, pure line seeds of mungbean (Vigna radiata L. Wilczek) were treated with four doses (0.2%, 0.4%, 0.6% and 0.8% as w/v) of ethyl methane sulphonate (EMS) to analyse the genetic variability and heritability for some prime agro-metrical traits in second mutant (M2) generation. The analysis of variance revealed highly significant differences among the studied characters. The phenotypic coefficient of variation (PCV) was higher than its genotypic counterpart (GCV) for all the studied traits. The highest GCV (0.537) for number of seeds per pods and highest PCV (0.635) for plant height were recorded in 0.4% EMS treatment. The lowest GCV (0.179) and PCV (0.214) were recorded in the control set for number of pods per plant. The highest broad sense heritability estimate (92.33%) was recorded on 0.4% EMS for plant height. The expected genetic advance was high (42.39%) in 0.4% dose for days to flowering. The lowest heritability (38.43) and genetic advance (5.37) were noticed in control for the total seed yield per plant. EMS at 0.4% and 0.6% concentration gave the maximum values of all the genetic parameters. The increased genetic variability in treated population for these traits has a high scope for selection and can be exploited for the further improvement of mungbean
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