Impact of hydrogen generated by splitting water with nano-silicon and nano-aluminum on diesel engine performance

Efficient utilization of hydrogen generated during the reactions of nano-silicon/water and nano-aluminum/water in internal combustion engine has been investigated in the current work. Engine performance and emission studies of formulated and stabilized nanoemulsion fuels (water in diesel W/D), nano-aluminum in water/diesel (W/DA) and water in nano-silicon/diesel (W/DS) have been compared with those of diesel. Experimental investigations showed reduction in brake specific fuel consumption (BSFC) by 21% and 37%; rise in brake thermal efficiency (BTE) by 16% and 14% when engine was fueled with W/DA and W/DS respectively. For nanoemulsion fuels an increase in induced power was also recorded. Brake mean effective pressure, BTE and NOx emission dropped for W/D due to reduced exhaust gas temperatures. Nevertheless due to elevated peak cylinder pressures and exhaust gas temperatures a marginal rise in NOx, CO, HC and radiative heat emissions was observed with W/DA and W/DS.     

CO2 emissions structure of Indian economy

This paper analyses carbon dioxide (CO₂) emissions of the Indian economy by producing sectors and due to household final consumption. The analysis is based on an Input–Output (IO) table and Social Accounting Matrix (SAM) for the year 2003–04 that distinguishes 25 sectors and 10 household classes. Total emissions of the Indian economy in 2003–04 are estimated to be 1217 million tons (MT) of CO₂, of which 57% is due to the use of coal and lignite. The per capita emissions turn out to be about 1.14 tons. The highest direct emissions are due to electricity sector followed by manufacturing, steel and road transportation. Final demands for construction and manufacturing sectors account for the highest emissions considering both direct and indirect emissions as the outputs from almost all the energy-intensive sectors go into the production process of these two sectors. In terms of life style differences across income classes, the urban top 10% accounts for emissions of 3416 kg per year while rural bottom 10% class accounts for only 141 kg per year. The CO₂ emission embodied in the consumption basket of top 10% of the population in urban India is one-sixth of the per capita emission generated in the US.     

High efficiency ultra-thin sputtered CdTe solar cells

Large scale manufacturing of CdTe PV modules at the GW/yr level may be constrained due to the limited availability of the relatively rare (Te) element and the volume of potentially hazardous (Cd) material being used in the typically 3–8 μm thick CdTe absorber layer. However, we find that it is possible to reduce the CdTe layer thickness without much compromise in efficiency. The CdS/CdTe solar cells were fabricated using magnetron sputtering with ultra-thin CdTe layers in the range of 0.5–1.28 μm. The ultra-thin films and cells were characterized using X-ray diffraction (XRD), optical transmission, scanning electron microscopy (SEM), current–voltage and quantum efficiency measurements. These results were compared with those of standard 2.3 μm thick CdTe sputtered cells. Different post-deposition processing parameters were required for cells with ultra-thin and standard CdTe thicknesses to achieve high efficiency. Ultra-thin CdTe cells showed crystallographic texture and CdTe_1−xS_x alloy formation after CdCl₂ treatment very similar to standard CdTe cells. Optimization of the post-deposition CdCl₂ treatment and back-contact processing yielded cells of 11.2% efficiency with 0.7 μm CdTe compared to 13.0% obtained with standard 2.3 μm CdTe cells.     

Modeling energy and agriculture interactions—II: Food-fodder-fuel-fertilizer relationships for biomass in Bangladesh

The model developed by Parikh¹ is applied to Bangladesh for which the situation in 1976–1977 is simulated first. This base case provides insights into the present behavior of different income groups with regard to choices of fuels and allocation of biomass for various purposes.It is shown that, due to high needs and prices of fuels, the biomass allocation for fuels takes priority over feed and fertilizers. In fact, the landless burn all, and small farmers burn 80% of animal dung rather than use it for fertilizers.The model also shows that, unless substantial amounts of fertilizers are used, the small and middle farmers would have feed and fuel shortages on adopting high-yielding varieties (HYV) that minimize straw-grain ratios. Similarly, by 1990, when the population increases further, middle farmers also become vulnerable in meeting their feed, fuel, fertilizer requirements. To mitigate these effects, improved stoves and other measures would be necessary to increase biomass use efficiencies considerably. Since Bangladesh is a very low-income and resource-scarce country, the choices of biogas, charcoal kilns, and alcohol distilleries, and the choices of mechanization, all of which require investment, play a minor role.     

Bias dependent microwave performance of AlGaN/GaN MODFET's up to100 V

1 μm gate-length AlGaN/GaN modulation doped field effect transistors (MODFET's) have been fabricated on an insulating GaN buffer layer for better carrier confinement. These devices demonstrate simultaneously high current levels (>500 mA/mm), excellent pinch-off and high gate-drain breakdown voltages (220 V for 3 μm gate-drain spacing). In contrast to their GaAs counterparts, the current-gain cutoff frequency of the AlGaN/GaN devices shows little degradation at high drain voltage biases. A power-gain cutoff frequency of 19 GHz is obtained at 100 V. ACW power density of 1.57 W/mm at 4 Ghz is also achieved when biased at 28 V and 205 mA/mm     

Probing the structure of the nicotinic acetylcholine receptor with the hydrophobic photoreactive probes [125I]TID-BE and [125I]TIDPC/16

The hydrophobic photoreactive compound 3-trifluoromethyl-3-(m-[125I]iodophenyl) diazirine ([125I]TID) has revealed important structural information about the pore of the ion channel and lipid-protein interface of the nicotinic acetylcholine receptor (AChR). To further characterize the structure of the AChR, we have mapped the sites of photoincorporation of a benzoic acid ester analogue of TID ([125I]TID-BE) and a phospholipid analogue ([125I]TIDPC/16). For each photoreactive probe, labeled sites were identified by amino-terminal sequencing of purified tryptic fragments of individual receptor subunits. [125I]TID-BE reacted with alphaCys-412, alphaMet-415, and alphaCys-418 in the M4 segment of the alpha-subunit and gammaCys-451 and gammaSer-460 in gammaM4. In the M1 segment of the alpha- and beta-subunits, [125I]TID-BE labeled alphaPhe-227, alphaLeu-228, and betaLeu-234, betaAla-235, respectively. The labeling pattern in the M1 and M4 segments indicate that TID and TID-BE interact with the AChR lipid-protein interface in a similar fashion, revealing the same lipid-exposed face of each transmembrane segment. In contrast to TID, there was, however, no detectable incorporation of [125I]TID-BE into the channel lining betaM2 segment when the AChR was labeled in the resting state conformation. In the presence of agonist (desensitized state), [125I]TID-BE reacted with betaLeu-257, betaVal-261, and beta-Leu-264 in betaM2; a labeling pattern which indicates that, in comparison to TID, the binding loci for TID-BE is located closer to the extracellular end of the channel. For [125I]TIDPC/16, receptor labeling was insensitive to the presence of agonist and the sites of incorporation mapped to the confines of the transmembrane segments alphaM4, alphaM1, and gammaM4, validating previous results found with small lipophilic probes.     

Thermal degradation and kinetic study for different waste/rejected plastic materials

A kinetic analysis based on thermal decomposition of rejected polypropylene, plastic film and plastic pellets collected from different industrial outlet has been carried out. Non-isothermal experiments using different heating rates of 5, 10, 20, 30, 40 and 50 °C min^?1 have been performed from ambient to 700 °C in a thermo-balance with the objective of determining the kinetic parameters. The values of activation energy and frequency factor were found to be in the range of 107–322 kJ/mol, 85–331 kJ/mol, 140–375 kJ/mol and 3.49E+07–4.74E+22 min^?1, 3.52E+06–2.88E+22min^?1, 7.28E+13–1.17E+25 min^?1 for rejected polypropylene, plastic film and plastic pellets, respectively, by Coats-Redfern and Ozawa methods including different models. Kissinger method, a model free analysis is also adopted to find the kinetic parameters. Activation energy and frequency factor were found to be 108 kJ/mol, 98 kJ/mol, 132 kJ/mol and 6.89E+03, 2.12E+02, 8.06E+05 min^?1 for rejected polypropylene, plastic film and plastic pellets, respectively, by using the Kissinger method.     

Corrosion inhibition effectiveness of zeolite ZSM-5 coating on mild steel against various organic acids and its antimicrobial activity

Zeolite ZSM-5 coating on mild steel had been assessed for its corrosion resistance property against organic acids, namely, acetic acid, formic acid and citric acid of varying concentrations at temperatures up to 60 °C under stagnant as well as stirred conditions by weight-loss and polarization methods. Biocidal activity of the zeolite coating against Gram-negative bacteria Escherichia coli, Pseudomonas putida, Salmonella typhi and Gram-positive bacteria Staphylococcus aureus by using minimum inhibitory concentration (MIC) was also studied. With zeolite coating, corrosion inhibition efficiency up to 98% was achieved for 6 h of duration of contact between coating and acid solutions. Similar resistance persisted for the duration of 7 days too. Results obtained showed that extent of corrosion of mild steel decreased in the order, formic acid > citric acid > acetic acid. Also as expected, corrosion resistance though only slightly, decreased with solution temperature and concentration. High anti-microbial activity was observed at very low values of MIC (100 μg/mL). In light of reported literature, the presence of the structure directing agent within the channels of the zeolite has been attributed for the high corrosion resistance as well as anti-microbial activity observed here. Thus, zeolite offers a “greener” alternate to chromium and epoxy polymers based corrosion resistance coating.     

Cone calorimeter evaluation of two flame retardant cotton fabrics

Unbleached (gray) cotton needle‐punched nonwoven (NW) fabrics with 12.5% polypropylene scrim were treated with two phosphate–nitrogen‐based flame retardant (FR) formulations, Southern Regional Research Center (SRRC)‐1 and SRRC‐2. The SRRC‐1 formulation contains diammonium phosphate as the FR chemical along with urea and dimethyloldihydroxyethyleneurea. Because a trace amount of formaldehyde was still expected to be released from SRRC‐1‐treated FR cotton under high heat, it was preferable to eliminate the dimethyloldihydroxyethyleneurea, leading to the revised formulation SRRC‐2. It has a higher content of diammonium phosphate and did not use the polyethylene emulsion that was in SRRC‐1. Both formulations were of low cost as they were developed at SRRC using industrial grade chemicals. The fabrics were evaluated with a cone calorimeter using three heat flux levels, 20, 30, and 50 kW/m². On the basis of the overall cone calorimeter results for heat released and ignition times, FR NW fabrics that were treated with SRRC‐2 were found to be slightly superior in flammability properties to those treated with the earlier SRRC‐1 formulation, but the differences were statistically insignificant. Both preparations were much less flammable than the untreated control cotton NW fabrics. Compared with the untreated NW fabrics, the FR fabrics had higher visible smoke production. Copyright © 2012 John Wiley & Sons, Ltd.     

Effect of copolymer ratio on hydrolytic degradation of poly(lactide-co-glycolide) from drug eluting coronary stents

The in vitro hydrolytic degradation behavior of poly(d,l-lactide-co-glycolide) (PLGA) has been systematically investigated from the drug eluting coronary stents with respect to different copolymer compositions. The drug-polymer coated stents were incubated in phosphate buffer saline (pH 7.4) at 37 °C and 120 rpm up to 12 months to facilitate hydrolytic degradation. Gel permeable chromatography, differential scanning calorimetry and scanning electron microscopy were employed to characterize their degradation profiles. The study supports the bulk degradation behavior for PLGA from coated stents. Molecular weight of polymer decreased immediately after immersion in PBS but mass loss was not observed during first few days. The rate of hydrolytic degradation was influenced by copolymer ratio, i.e., degradation of 50:50 PLGA was fastest followed by 65:35 PLGA and 75:25 PLGA. The drug release from PLGA coated stent followed biphasic pattern which was governed by surface dissolution and diffusion of drug rather than polymer degradation.