Performance analysis of a biogas operated porous radiant burner for domestic cooking application

Environmental Science and Pollution Research - In this paper, the combustion characteristics of biogas in a Porous Radiant Burner (PRBBG) designed for domestic cooking appliances are presented....     

Dry reforming of methane to syngas: a potential alternative process for value added chemicals—a techno-economic perspective

During the past decade, there has been increasing global concern over the rise of anthropogenic CO₂ emission into the Earth’s atmosphere (J Air Waste Manage Assoc 53:645–715, 2003). The utilization of CO₂ to produce any valuable product is need of the hour. The production of syngas from CO₂ and CH₄ seems to be one of the promising alternatives in terms of industrial utilization, as it offers several advantages: (a) mitigation of CO₂, (b) transformation of natural gas and CO₂ into valuable syngas, and (c) producing syngas with H₂/CO ratio 1 which may further be used for the production of valuable petrochemicals (J Air Waste Manage Assoc 53:645–715, 2003). A conceptual design for the production of synthesis gas by dry reforming of methane is presented here. An economic assessment of this process with an integrated methanol production section as a case was conceptualized and compared with the conventional steam methane reforming route to produce methanol. The economic study indicated that dry reforming of natural gas/methane is a competitive process with lower operating and capital costs in comparison with steam reforming assuming negligible cost of CO₂ import.     

Study of two species prey-predator model in imprecise environment with MSY policy under different harvesting scenario

Parameters involve in various ecological models are mostly uncertain due to ever changing characteristic of nature. This article, deals with a basic predator–prey model where ecological parameters are considered as parametric-functional nature of interval numbers. The dynamical behaviors of the model system have been discussed in the imprecise environment. Moreover, the concept of maximum sustainable yield (MSY) has been incorporated in the model system under imprecise environment, and MSY policies under different harvesting scenarios have been discussed. Finally all the analytical findings are testified through extensive numerical simulations and the article ended with a conclusion.

     

Risk-based prediction of metal toxicity in sediment and impact on human health due to consumption of seafood (Saccostrea cucullata) found in two highly industrialised coastal estuarine regions of Eastern India: a food safety issue

Estuarine ecosystems of the Bay of Bengal, India, are considered as the most productive environment, which have been persistently threatened by substantial anthropogenic activity. This study aims to investigate the metal contamination in the sediment of two estuaries and possible biomagnifications in the indigenous edible oyster Saccostrea cucullata and related health hazards due to its consumption. The accumulative ecological risks indicated that the sediment is moderate to strongly contaminated with cadmium and lead. The sediment pollution index and pollution load index suggested that the sediment possesses a little ecological stress on the exposed flora and fauna. The statistical interpretation highlights the most metals which have a similar source of origin and are bound to the finer fractions of the sediment, except nickel. Bioaccumulation of sediment-associated Cu and Zn in oyster reflects their potential biomagnifications through aquatic food chain. HPI range was below the critical limit of safe human consumption. The non-carcinogenic (THQ) and carcinogenic (CR) health hazards were estimated from the PTDI provided by USEPA. Except Cr, Hg and Zn, the THQ of all other metals was > 1 suggesting detrimental non-carcinogenic health effects on humans. The TCR of Cr and Cd above safety limit indicates the exposed population might be under severe carcinogenic threat due to those metals.

     

Role of GSH in the amelioration of chromium-induced membrane damage

Membrane damage is one of the important consequences of chromium (Cr), an environmental toxicant, induced cytotoxicity. Reduced glutathione (GSH), a membrane protectant may be used to reduce the Cr-induced membrane damage. In the present study, the impact of Cr in presence and absence of GSH was studied on plasma membrane of the liver and kidneys in male Wistar rats. Significant increases in membrane cholesterol levels as well as significant decreases in membrane phospholipid levels in Cr exposed (0.8 mg per 100 g body weight, i.p., for 28 days) animals suggest structural alterations in both the liver and kidney plasma membranes. Alkaline phosphatase (ALP), total ATPase, and Na⁺–K⁺–ATPase activities of plasma membrane were significantly decreased in both the liver and kidneys after Cr treatment. This treatment also produced significant weight loss and increased Cr content in the liver and kidneys. However, GSH (8 mg per 100g body weight, i.p., daily at an interval of 6 h after injection of Cr for a period of 28 days) supplementation restored alterations induced by Cr in plasma membrane of both the liver and kidneys but was not able to eliminate the deposited Cr from the liver and kidney tissues.     

Immunoprotective effect of curcumin on cypermethrin-induced toxicity in rats

Immunotoxicological effects of cypermethrin and their reversal by curcumin following oral administration were evaluated in rats. Mature male Wistar rats were orally administered cypermethrin (25?mg?kg^?1 body wt), curcumin (100?mg?kg^?1 body wt) or both daily for 4 weeks. At the end of fourth week, hematological, serum biochemical, and immunological parameters were studied. Subchronic exposure to cypermethrin significantly reduced body weight, total leukocyte count, lymphocyte count, serum total protein, serum albumin, serum globulin, antibody titer against sheep red blood cells, and cell-mediated immunity. Concomitant curcumin administration restored the changes in the body weight, hematological parameters, and serum biochemical indices and significantly increased the antibody titer, and cell mediated immunity. These results suggest that concurrent curcumin treatment has a beneficial role in mitigating immunotoxicological and other adverse effects of cypermethrin.     

Spatial assessment of groundwater quality in Mamundiyar basin, Tamil Nadu, India

Understanding the groundwater quality is important as it is the main factor determining its suitability for drinking, domestic, agricultural, and industrial purposes. In order to assess the groundwater quality, 30 groundwater samples have been collected in year 2008. The water samples collected in the field were analyzed for electrical conductivity, pH, total dissolved solids (TDS), major cations like calcium, magnesium, sodium, potassium, and anions like bicarbonate, carbonate, chloride, nitrate, and sulfate, in the laboratory using the standard methods given by the American Public Health Association. The groundwater locations were selected to cover the entire study area and attention was been given to the area where contamination is expected. The expected groundwater contaminants were chloride, nitrate, TDS, etc. The results were evaluated in accordance with the drinking water quality standards given by the World Health Organization (WHO 1993). To know the distribution pattern of the concentration of different elements and to demarcate the higher concentration zones, the contour maps for various elements were also generated, discussed, and presented.     

Alpha-tocopherol supplementation on chromium toxicity: a study on rat liver and kidney cell membrane

Membrane damage is one of the important consequence of chromium,an environmental toxicant,to produce cytotoxicity.α-tocopherol,a membrane protectant can be used to reduce the chromium-induced membrane damage.In the present study,the impact of chromium in presence and absence of α-tocopherol was studied on plasma membrane of live and kidney in male Wistar rats(80-100g body weight).Significant increase in membrane cholesterol level as well as significant decrease in membrane phospholipid level in chromium exposed(0.8mg/100g body weight/d,i.p.,for 4 weeks)animals suggest structural alteration of both liver and kidney plasma memebrane.The alkaline phosphatase,total ATPase and Na^ -K^ -ATPase activities of plasma membrane were significantly decreased in both liver and kidney after chromium treatment.However,α-tocopherol (30mg/100g diet)supplementation can restrict the changes in these membrane-bound enzyme activities.Thus,the usefulness of dietary supplementation of α-tocopherol to restrain the chromium-induced membrane damage is suggested.     

Monitoring of ocean surface algal blooms in coastal and oceanic waters around India

The National Aeronautics and Space Administration’s (NASA) sensor MODIS-Aqua provides an important tool for reliable observations of the changing ocean surface algal bloom paradigms in coastal and oceanic waters around India. A time series of the MODIS-Aqua-derived OSABI (ocean surface algal bloom index) and its seasonal composite images report new information and comprehensive pictures of these blooms and their evolution stages in a wide variety of events occurred at different times of the years from 2003 to 2011, providing the first large area survey of such phenomena around India. For most of the years, the results show a strong seasonal pattern of surface algal blooms elucidated by certain physical and meteorological conditions. The extent of these blooms reaches a maximum in winter (November–February) and a minimum in summer (June–September), especially in the northern Arabian Sea. Their spatial distribution and retention period are also significantly increased in the recent years. The increased spatial distribution and intensity of these blooms in the northern Arabian Sea in winter are likely caused by enhanced cooling, increased convective mixing, favorable winds, and atmospheric deposition of the mineral aerosols (from surrounding deserts) of the post-southwest monsoon period. The southward Oman coastal current and southwestward winds become apparently responsible for their extension up to the central Arabian Sea. Strong upwelling along this coast further triggers their initiation and growth. Though there is a warming condition associated with increased sea surface height anomalies along the coasts of India and Sri Lanka in winter, surface algal bloom patches are still persistent along these coasts due to northeast monsoonal winds, enhanced precipitation, and subsequent nutrient enrichment in these areas. The occurrence of the surface algal blooms in the northern Bay of Bengal coincides with a region of the well-known Ganges–Brahmaputra Estuarine Frontal (GBEF) system, which increases supply of nutrients in addition to the land-derived inputs triggering surface algal blooms in this region. Low density (initiation stage) of such blooms observed in clear oceanic waters southeast and northeast of Sri Lanka may be caused by the vertical mixing processes (strong monsoonal winds) and the occurrence of Indian Ocean Dipole events. Findings based on the analyses of time series satellite data indicate that the new information on surface algal blooms will have important bearing on regional fisheries, ecosystem and environmental studies, and implications of climate change scenarios.