Natural Weathering Studies of Polypropylene

Polypropylene (PP) has achieved a dominating position and hence, their consumption increases thereby littering, which lead to environmental pollution. Photodegradation seems to be a better choice because of naturally available sunlight as energy source for degradation. The present work involves the study of the variation of degradation behavior of PP film during tropical summer and winter seasons. The photodegradation is followed by Fourier transform infrared (FTIR) spectroscopic technique. Various indices like hydroxyl, carbonyl, vinylidene, lactones, ester, carboxylic acid and crystallinity are calculated and these values increased after a brief induction period. The variation in the mechanical properties like tensile strength and elongation at break percentages are determined. The scanning electron microscopic (SEM) images of weathered PP showed surface cracks when carbonyl index value increases sharply and the mechanical properties show a sudden decrease. Attempted life time prediction using mathematical models showed that the carbonyl growth is more affected by ultraviolet (UV) and cumulative total solar radiation for PP weathered during summer. The loss in tensile strength of PP weathered during summer is more dependent on the average temperature and the UV portion of the total solar radiation whereas, intensity of UV radiation has profound effect on the tensile strength of PP weathered during winter.     

A multibiomarker approach to assess lead toxicity on the black clam,Villorita cyprinoides (Gray, 1825), from Cochin estuarine system (CES), southwest coast,India

Environmental Science and Pollution Research - The southwest coast of India along the Cochin region is seriously affected by metal contamination from increasing industrial activities. This...     

CO<Subscript>2</Subscript>-fertilization and potential future terrestrial carbon uptake in India

There is huge knowledge gap in our understanding of many terrestrial carbon cycle processes. In this paper, we investigate the bounds on terrestrial carbon uptake over India that arises solely due to CO ₂ -fertilization. For this purpose, we use a terrestrial carbon cycle model and consider two extreme scenarios: unlimited CO₂-fertilization is allowed for the terrestrial vegetation with CO₂ concentration level at 735 ppm in one case, and CO₂-fertilization is capped at year 1975 levels for another simulation. Our simulations show that, under equilibrium conditions, modeled carbon stocks in natural potential vegetation increase by 17 Gt-C with unlimited fertilization for CO₂ levels and climate change corresponding to the end of 21st century but they decline by 5.5 Gt-C if fertilization is limited at 1975 levels of CO₂ concentration. The carbon stock changes are dominated by forests. The area covered by natural potential forests increases by about 36% in the unlimited fertilization case but decreases by 15% in the fertilization-capped case. Thus, the assumption regarding CO₂-fertilization has the potential to alter the sign of terrestrial carbon uptake over India. Our model simulations also imply that the maximum potential terrestrial sequestration over India, under equilibrium conditions and best case scenario of unlimited CO₂-fertilization, is only 18% of the 21st century SRES A2 scenarios emissions from India. The limited uptake potential of the natural potential vegetation suggests that reduction of CO₂ emissions and afforestation programs should be top priorities.     

Impact of temperature on heat shock protein expression of Bombyx mori cross-breed and effect on commercial traits

The present study investigated the effect of increasing temperature stress on the thermotolerance of B. mori cross-breed PM x CSR2 and tissue specific differential expression of heat shock proteins at IVth and Vth instars. The larvae reared at 25 +/-1 degrees C and 70 +/- 5% relative humidity were treated as control. Larvae were subjected to heat shock temperatures of 34, 38 and 42 degrees C for 3 hr followed by 3 hr recovery. Expression of Heat shock protein 72 were analyzed by SDS-PAGE and confirmed by western blotting analysis. The impact of heat shock on commercial traits of cocoons was analyzed by following different strategies in terms of acquired thermotolerance over control. Resistance to heat shock was increased as larval development proceeds and increased thermotolerance is achieved with the induction of Heat shock protein 72 in the Vth instar larval haemolymph. Relative influence of heat shock temperatures on commercial traits corresponding to the generation of heat shock protein 72 was significantly improved over control. In PM x CSR2, cocoon and shell weight significantly increased to 9.90 and 11.90% over control respectively.     

Impact of climate change on Indian forests: a dynamic vegetation modeling approach

We make an assessment of the impact of projected climate change on forest ecosystems in India. This assessment is based on climate projections of the Regional Climate Model of the Hadley Centre (HadRM3) and the dynamic global vegetation model IBIS for A2 and B2 scenarios. According to the model projections, 39% of forest grids are likely to undergo vegetation type change under the A2 scenario and 34% under the B2 scenario by the end of this century. However, in many forest dominant states such as Chattisgarh, Karnataka and Andhra Pradesh up to 73%, 67% and 62% of forested grids are projected to undergo change. Net Primary Productivity (NPP) is projected to increase by 68.8% and 51.2% under the A2 and B2 scenarios, respectively, and soil organic carbon (SOC) by 37.5% for A2 and 30.2% for B2 scenario. Based on the dynamic global vegetation modeling, we present a forest vulnerability index for India which is based on the observed datasets of forest density, forest biodiversity as well as model predicted vegetation type shift estimates for forested grids. The vulnerability index suggests that upper Himalayas, northern and central parts of Western Ghats and parts of central India are most vulnerable to projected impacts of climate change, while Northeastern forests are more resilient. Thus our study points to the need for developing and implementing adaptation strategies to reduce vulnerability of forests to projected climate change.     

Kinetics of IO radicals with C1, C2 aliphatic alcohols in tropospherically relevant conditions

Environmental Science and Pollution Research - Kinetics of the reaction of IO radicals with methanol (MeOH) and ethanol (EtOH) were experimentally studied in the gas phase using pulsed laser...     

Budget-Balancing Incentive Mechanisms

A. P. Xepapadeas [J. Environ. Econom. Management20, 113-26, 1991] developed a pollution abatement incentive mechanism that both reduces the information requirements of a regulator and is "budget-balancing," drawing only on the social gains from pollution abatement to encourage firm compliance. This paper demonstrates that, contrary to Xepapadeas, the budget-balancing system of random penalties cannot be used to induce compliance with the regulator′s objectives if firms are risk neutral. However, the mechanism can be successfully applied if firms are sufficiently risk averse [E. Rasmusen, RAND J. Econom.18, 428-435, 1987].     

Organopesticides and fertility: where does the link lead to?

Environmental Science and Pollution Research - Organopesticides (OPs) are a group of various synthetic chemicals prevalently used in agriculture and homestead plantations. OPs were originally...