Recycling polymeric waste from electronic and automotive sectors into value added products

The environmentally sustainable disposal and recycling of ever increasing volumes of electronic waste has become a global waste management issue. The addition of up to 25% polymeric waste PCBs (printed circuit boards) as fillers in polypropylene (PP) composites was partially successful: while the tensile modulus, flexural strength and flexural modulus of composites were enhanced, the tensile and impact strengths were found to decrease. As a lowering of impact strength can significantly limit the application of PP based composites, it is necessary to incorporate impact modifying polymers such as rubbery particles in the mix. We report on a novel investigation on the simultaneous utilization of electronic and automotive rubber waste as fillers in PP composites. These composites were prepared by using 25 wt.% polymeric PCB powder, up to 9% of ethylene propylene rubber (EPR), and PP: balance. The influence of EPR on the structural, thermal, mechanical and rheological properties of PP/PCB/ EPR composites was investigated. While the addition of EPR caused the nucleation of the β crystalline phase of PP, the onset temperature for thermal degradation was found to decrease by 8%. The tensile modulus and strength decreased by 16% and 19%, respectively; and the elongation at break increased by ~71%. The impact strength showed a maximum increase of ~18% at 7 wt.%–9 wt.% EPR content. Various rheological properties were found to be well within the range of processing limits. This novel eco-friendly approach could help utilize significant amounts of polymeric electronic and automotive waste for fabricating valuable polymer composites.

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Transport of metanil yellow in the rat plasma and interaction of its metabolite,p‐aminodiphenylamine with serum proteins

Binding affinity of metanil yellow and its breakdown product p‐aminodiphenylamine to serum proteins has been studied employing chromatographic separation on Sephadex G‐200 and by paper and polyacrylamide gel electrophoresis. Metanil yellow has more affinity towards albumin than to globulins. The complexing is presumably through electrostatic forces. p‐Aminodiphenylamine on the other hand, preferably binds to globulin fractions of serum protein. However, a stable binding with BSA alone was also observed. The binding was quite stable and was accompanied by a shift in absorbance from 430 nm to 500 nm. Aspartic acid moiety of protein was found to be one of the units involved in the binding of p‐ADPA to proteins.     

Effect of endosulfan on blood glucose

Endosulfan was administered to cats intravenously at different doses. The compound (3 and 4 mg/kg) showed marked rise in blood glucose level after 15 and 30 minutes of treatment with a gradual fall upto 4 hrs. No change in blood glucose was observed at 2.0 mg/kg dose. Adrenalectomy prevented this rise in glucose level.     

Insecticidal activity of the plant Phyllanthus amarus against Tribolium castaneum

The plant Phyllanthus amarus is used as folk medicine since the year 1800 and has been established for its important medicinal properties particularly for liver ailments. The present communication explores the insecticidal activity of ethanolic extract of aerial and root parts of this plant against stored grain pest Tribolium castaneum. LC 50 values of ethanolic aerial part were 895.77, 473.91, 279.89 and 260.85 microg/cm2, while 512.62, 376.96, 248.88 and 209.79 microg/cm2 for ethanolic root part at the exposure of 3, 5, 7, 9 and 11 days respectively. Ethanolic root extract possessed significant insecticidal activity against T. castaneum.     

Carbon abatement in the fuel market with biofuels: Implications for second best policies

A carbon tax on fuel would penalize carbon intensive fuels like gasoline and shift fuel consumption to less carbon intensive alternatives like biofuels. Since biofuel production competes for land with agricultural production, a carbon tax could increase land rents and raise food prices. This paper analyzes the welfare effect of a carbon tax on fuel consisting of gasoline and biofuel in the presence of a labor tax, with and without a biofuel subsidy. The market impacts of a carbon tax are also compared with that of a subsidy. Findings show that if a carbon tax increases biofuel demand, the tax interaction effect due to higher fuel prices is exacerbated by higher land rent and food prices and greater erosion of the carbon tax base. Thus, the second best optimal carbon tax for fuel is lower with biofuel in the fuel mix, especially if biofuel is subsidized.     

Effects of the level of dietary protein on the toxicity of hexachlorocyclohexane in rats

Male albino rats were fed for 28 days from weaning on diets containing 5% (group 1), 10% (group 2) and 21% (group 3, normal protein) protein as casein. At the end of dietary period, HCH was administered daily for 30 days to investigate the interaction between protein deficiency and pesticide toxicity. The results indicated that rats fed a lower protein diet and HCH had a higher mortality, lower rate of growth, increased liver weight and deposition of the pesticide in blood and tissues in larger amounts. Blood pressure (systolic and diastolic) was significantly increased and the heart rate showed tachycardia in low protein exposed animals. A significant increase of total lipids, cholesterol, triglycirides, free fatty acids in serum and tissues of animals exposed to low protein was observed. A close correlation existed between lipid accumulation and storage of HCH in tissues and dietary protein seemed to play an important role in detoxification.     

Effect of PM2.5 chemical constituents on atmospheric visibility impairment

PM_2.5 sampling was conducted at a curbside location in Delhi city for summer and winter seasons, to evaluate the effect of PM_2.5 and its chemical components on the visibility impairment. The PM_2.5 concentrations were observed to be higher than the National Ambient Air Quality Standards (NAAQS), indicating poor air quality. The chemical constituents of PM_2.5 (the water-soluble ionic species SO₄^2-, NO₃^?, Cl^?, and NH₄⁺, and carbonaceous species: organic carbon, elemental carbon) were analyzed to study their impact on visibility impairment by reconstructing the light extinction coefficient, b_ext. The visibility was found to be negatively correlated with PM_2.5 and its components. The reconstructed b_ext showed that organic matter was the largest contributor to b_ext in both the seasons which may be attributed to combustion sources. In summer season, it was followed by elemental carbon and ammonium sulfate; however, in winter, major contributions were from ammonium nitrate and elemental carbon. Higher elemental carbon in both seasons may be attributed to traffic sources, while lower concentrations of nitrate during summer, may be attributed to volatility because of higher atmospheric temperatures.

Implications: The chemical constituents of PM_2.5 that majorly effect the visibility impairment are organic matter and elemental carbon, both of which are products of combustion processes. Secondary formations that lead to ammonium sulfate and ammonium nitrate production also impair the visibility.