Genetic diversity in some perennial plant species with-in short distances

Distinct morphophysiological variations observed for over 2 years with-in short distances among four perennial plants indicated genetic diversity among the lines growing at three places. The isozyme and SDS polyacrylamide gel banding patterns as genetic markers were used to investigate four perennial species, namely Dalbergia sissoo Roxb., Delonix regia (Boj.) Refin., Cassia fistula L. and Calotropis procera R. Br. Plant materials collected from three locations (Agra, Gwalior and Lucknow) differing in climo-edaphic variables were examined for 4 enzyme systems, viz., esterase, polyphenol oxidase, peroxidase and superoxide dismutase (EST, PPO, PRX and SOD). Among the four isozymes SOD and PRX revealed best discriminating power. Protein banding patterns as well as zymogram revealed that Dalbergia sissoo growing at Gwalior was closer to that of Agra; Delonix regia depicted highest similarity between Lucknow and Agra and Calotropis procera of Lucknow location was more closer to Gwalior than Agra. The results confirm genetic diversity in the species as a means of adaptation to differing climo-edaphic variables.     

Experimental investigation on CO2 absorption and physicochemical characteristics of different carbon-loaded aqueous solvents

Environmental Science and Pollution Research - The anthropogenic carbon dioxide (CO2) denseness in the earth’s atmosphere is increasing day-to-day by combusting fossil fuels for power...     

Utilisation of steel slags as neutralising agents in biooxidation of a refractory gold concentrate and their influence on the subsequent cyanidation

A study on the possibilities to utilise steel slag as neutralising agent in biooxidation of a refractory gold concentrate has been done with reference to commercial grade slaked lime. The idea has been to reduce the operating costs for neutralisation in the biooxidation plant, which is known to be the second largest operating cost. Other benefits would be savings in cost for landfilling of slag, possibilities to recycle elements present in the slag and savings of virgin limestone deposits. The slags used were an EAF slag and a slag from ladle refining; both originating from Swedish scrap based steel-making. Continuous biooxidation of the refractory gold concentrate was conducted in a single-stage 5 L reactor at a retention time of 56 h. The neutralisation capacity was determined by comparing the amount needed, per ton of feed concentrate added, to maintain the desired pH of 1.5 during steady state operation. Slaked lime had the highest neutralisation capacity with 110 kg/ton feed followed by ladle slag and EAF slag with values of 152 and 267 kg/ton feed, respectively. Sulphide mineral oxidation was similar and high in all cases although the ladle slag results were slightly better. Gold recoveries after cyanide leaching on the residues obtained were also similar and were in the range of 86-89%. However, the cyanide consumption expressed as kilogram cyanide per ton of concentrate fed to biooxidation, was double in the case of ladle slag and three times as much for the EAF slag compared to the slaked lime experiment. The increased cyanide consumption could not be explained only by the increased amount of elemental sulphur obtained in the slag experiments. The elemental sulphur formed had different reactivities as seen from the thiocyanate formation and cyanide losses due to thiocyanate formation were 16%, 32% and 40% for EAF slag, slaked lime and ladle slag, respectively. It is concluded that the ladle slag could be a possible replacement for limestone if they are mixed in proper proportions so that the microbial carbon dioxide demand is met whereas the EAF slag is less suitable due to the very fine reaction products obtained which gave operational problems with filtration and washing. To come further, experiments with the normal multi-stage biooxidation set-up with total retention time of 120 h should be performed which would increase the sulphur oxidation and eventually also reduce the cyanide consumption.     

Willingness to pay towards a public good: how does a refund option affect stated values?

Mandatory taxes and/or voluntary contributions are commonly adopted as the payment vehicle when eliciting willingness to pay (WTP) in environmental valuation studies. While mandatory taxes may arouse negative feelings, voluntary contributions may lead to strategic behaviour (over bidding) or free riding (under bidding). In this paper, we explore an alternative payment vehicle which avoids the draconian undertones associated with taxes and may be more incentive compatible than a voluntary contribution – a tax that incorporates a refund option. The template for such a payment vehicle is the value added tax charged to tourists in Ireland, but which can be reclaimed on exiting the country. In the context of raising public funds to support the conservation of rural countryside landscape, a comparison is made between the elicited WTP via a mandatory tax and that elicited via the alternative payment method incorporating a refund option. While we observe similar participation rates between the two payment methods, the refund option reveals a higher stated WTP.     

Thermodynamic analysis of in situ gasification-chemical looping combustion (<Emphasis Type="Italic">i</Emphasis>G-CLC) of Indian coal

Chemical looping combustion (CLC) is an inherent CO₂ capture technology. It is gaining much interest in recent years mainly because of its potential in addressing climate change problems associated with CO₂ emissions from power plants. A typical chemical looping combustion unit consists of two reactors—fuel reactor, where oxidation of fuel occurs with the help of oxygen available in the form of metal oxides and, air reactor, where the reduced metal oxides are regenerated by the inflow of air. These oxides are then sent back to the fuel reactor and the cycle continues. The product gas from the fuel reactor contains a concentrated stream of CO₂ which can be readily stored in various forms or used for any other applications. This unique feature of inherent CO₂ capture makes the technology more promising to combat the global climate changes. Various types of CLC units have been discussed in literature depending on the type of fuel burnt. For solid fuel combustion three main varieties of CLC units exist namely: syngas CLC, in situ gasification-CLC (iG-CLC) and chemical looping with oxygen uncoupling (CLOU). In this paper, theoretical studies on the iG-CLC unit burning Indian coal are presented. Gibbs free energy minimization technique is employed to determine the composition of flue gas and oxygen carrier of an iG-CLC unit using Fe₂O₃, CuO, and mixed carrier—Fe₂O₃ and CuO as oxygen carriers. The effect of temperature, suitability of oxygen carriers, and oxygen carrier circulation rate on the performance of a CLC unit for Indian coal are studied and presented. These results are analyzed in order to foresee the operating conditions at which economic and smooth operation of the unit is expected.     

Loss of crop yields in India due to surface ozone: an estimation based on a network of observations

Surface ozone is mainly produced by photochemical reactions involving various anthropogenic pollutants, whose emissions are increasing rapidly in India due to fast-growing anthropogenic activities. This study estimates the losses of wheat and rice crop yields using surface ozone observations from a group of 17 sites, for the first time, covering different parts of India. We used the mean ozone for 7 h during the day (M7) and accumulated ozone over a threshold of 40 ppbv (AOT40) metrics for the calculation of crop losses for the northern, eastern, western and southern regions of India. Our estimates show the highest annual loss of wheat (about 9 million ton) in the northern India, one of the most polluted regions in India, and that of rice (about 2.6 million ton) in the eastern region. The total all India annual loss of 4.0–14.2 million ton (4.2–15.0%) for wheat and 0.3–6.7 million ton (0.3–6.3%) for rice are estimated. The results show lower crop loss for rice than that of wheat mainly due to lower surface ozone levels during the cropping season after the Indian summer monsoon. These estimates based on a network of observation sites show lower losses than earlier estimates based on limited observations and much lower losses compared to global model estimates. However, these losses are slightly higher compared to a regional model estimate. Further, the results show large differences in the loss rates of both the two crops using the M7 and AOT40 metrics. This study also confirms that AOT40 cannot be fit with a linear relation over the Indian region and suggests for the need of new metrics that are based on factors suitable for this region.     

Big concerns with small projects: Evaluating the socio-ecological impacts of small hydropower projects in India

Although Small Hydropower Projects (SHPs) are encouraged as sources of clean and green energy, there is a paucity of research examining their socio-ecological impacts. We assessed the perceived socio-ecological impacts of 4 SHPs within the Western Ghats in India by conducting semi-structured interviews with local respondents. Primary interview data were sequentially validated with secondary data, and respondent perceptions were subsequently compared against the expected baseline of assured impacts. We evaluated the level of awareness about SHPs, their perceived socio-economic impacts, influence on resource access and impacts on human–elephant interactions. The general level of awareness about SHPs was low, and assurances of local electricity and employment generation remained largely unfulfilled. Additionally most respondents faced numerous unanticipated adverse impacts. We found a strong relationship between SHP construction and increasing levels of human–elephant conflict. Based on the disparity between assured and actual social impacts, we suggest that policies regarding SHPs be suitably revised.     

Studies on survival and growth rate of transplanted Acroporidae in Gulf of Kachchh Marine National Park,India

Fragments of live colonies of scleractinian coral Acropora sp. and Montipora sp. under the family Acroporiidae were collected from Gulf of Mannar and transplanted in Pirotan, Narara and Mithapur reefs of Gulf of Kachchh Marine National Park. All the transplanted corals survived one complete season and it was observed that 87 nubbins out of the total 110 samples survived in Narara reef and 70 nubbins out of 102 samples stayed alive in Pirotan Island. Growth rate was measured for four months period, and it was found maximum in Narara reef, while minimum in Pirotan Island. The rate of sedimentation was higher during monsoon and low in winter season. Present study showed that species of Acropora and Montipora are suitable for transplantation in Gulf of Kachchh Marine National Park, Gujarat, India.     

Future-year ozone prediction for the United States using updated models and inputs

The relationship between emission reductions and changes in ozone can be studied using photochemical grid models. These models are updated with new information as it becomes available. The primary objective of this study was to update the previous Collet et al. studies by using the most up-to-date (at the time the study was done) modeling emission tools, inventories, and meteorology available to conduct ozone source attribution and sensitivity studies. Results show future-year, 2030, design values for 8-hr ozone concentrations were lower than base-year values, 2011. The ozone source attribution results for selected cities showed that boundary conditions were the dominant contributors to ozone concentrations at the western U.S. locations, and were important for many of the eastern U.S. locations. Point sources were generally more important in the eastern United States than in the western United States. The contributions of on-road mobile emissions were less than 5 ppb at a majority of the cities selected for analysis. The higher-order decoupled direct method (HDDM) results showed that in most of the locations selected for analysis, NOx emission reductions were more effective than VOC emission reductions in reducing ozone levels. The source attribution results from this study provide useful information on the important source categories and provide some initial guidance on future emission reduction strategies.

Implications: The relationship between emission reductions and changes in ozone can be studied using photochemical grid models, which are updated with new available information. This study was to update the previous Collet et al. studies by using the most current, at the time the study was done, models and inventory to conduct ozone source attribution and sensitivity studies. The source attribution results from this study provide useful information on the important source categories and provide some initial guidance on future emission reduction strategies.