Clean energy by chemical looping combustion of coal

Jain Himani, Mathur Abhishek and Kale Ganesh R.

Chemical looping combustion (CLC) is an innovative technology to reduce CO2 emissions to the atmosphere from combustion processes that can be used for combustion of cheaply available abundant fuel like coal for the production of clean energy. A detailed thermodynamic analysis of chemical looping combustion of lignite coal using selected oxygen carriers (NiO, Fe2O3 and CaSO4) has been done to study the products trend distribution in the CLC process within the temperature range of 500–1300°C at three different pressures which are 1, 10 and 20 bar. Optimum operating conditions for CLC system were found in this study. The results showed the optimum condition for CLC which maximizes CO2 and steam production at 1 bar pressure at 900°C for NiO as oxygen carrier using 1.5 times of its stoichiometric amount.

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Cholesterol assimilation by intestinal Lactobacilus acidophilus

Nilakhe Smita and Sapre Vaijayanti

Cholesterol reducing abilities of five strains of intestinal Lactobacilus acidophilus originated from breastfed neonates were investigated in vitro. All the isolates were able to reduce cholesterol at various levels in broth. Among them Lactobacilus acidophilus_5 demonstrated maximum cholesterol reduction (58.99%) in presence of 0.3% sodium taurocholate. The result indicated that heat killed and resting cells showed a small degree of cholesterol removal (1.6 to 2 mg/dry weight) as compared to growing cells (10-12 mg/dry weight). Three possible mechanisms for removal of cholesterol from media by L. acidophilus are proposed: assimilation of cholesterol during growth, incorporation of cholesterol into the cellular membrane of cells and binding of cholesterol to cell surface. Results from this study indicate that in vitro hypocholesteremic ability is likely due to assimilation of cholesterol by Lactobacillus acidophilus.

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Thermal Properties of Tagetes

Golamari Siva Reddy and Mallu Maheswara Reddy

The estimations of specific heat, thermal conductivity and thermal diffusivity of Tagetes were resolved and their variety with moisture content (15-40% w.b.) and bulk density (578.7-750.5 kg/m3) explored. Thermal conductivity, thermal diffusivity and specific heat expanded with moisture content in the above moisture range. Thermal properties were discovered to be both moisture and bulk density subordinate. Bulk density of Tagetes took after an illustrative association with moisture content. It was observed that thermal conductivity, thermal diffusivity and specific heat of Tagetesspecimens were in the range of 0.989 to 1.564 W/m.k., 11 x 10-8 to 6 x10-8 m2 /s and 5 to 9 kj/kg.k.

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Removal of hazardous organic pollutants by adsorption on activated carbon prepared from amla seed coats

Singh Swati, Singh Shripal and Yenkie Mahesh Kumar N.

In the present study adsorption of hazardous organic pollutants on activated carbon prepared from amla seed coats has been carried out in batch system. Phenol (P), o-cresol (OC), p-nitro phenol (PNP) and aniline (A) were selected as absorbates and activated carbon prepared from amla seed coats was used as an adsorbent. Activated carbon was prepared by physical activation in a specially designed high temperature activation system (HTAS). Prepared activated carbon was characterized by proximate and ultimate analysis, Iodine value, N2-BET surface area, pore volume, scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). SEM analysis of the carbon reveals the presence of macro-, meso- and micro-pores, crakes and crevices. FT-IR spectrum shows the presence of various surface groups with a predominant presence of phenolic-OH group. The adsorption studies infer that the substituted phenols adsorb more than the phenol itself as the adsorption capacity for p-nitro phenol is more than other phenols studied. Solubility of the adsorbate also plays an important role in adsorption as more hydrophobic p-nitro phenol adsorbs more than less hydrophobic phenol, o-cresol and aniline.

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Oxidation of Phenylthioacetic Acid by Piperidinium Chlorochromate

Anbarasu K. and Selvi P.

The oxidation of phenylthioacetic acid by piperidinium chlorochromate has been studied in 50% acetic acid-water medium. The main product of oxidation is corresponding sulfoxide. The reaction shows first order with respect to piperidinium chlorochromate and phenylthioacetic acid and fractional order with respect to hydrogen ion concentration. Decrease in dielectric constant of the medium increases the rate of reaction. Ionic strength had a noticeable effect on the rate of reaction indicating the involvement of ion and neutral molecule in the rate determining step. The reaction does not induce the polymerization of acrylonitrile. The rate of reaction decreases with increase in the concentration of MnSO4. The thermodynamic and activation parameters have been calculated and a plausible mechanism has been proposed.

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Fire Characteristics and Conversion of Carbon Mass Balance from Leaf Litter Fuels to Residues after Burning in Mixed Deciduous Forest Fires in Thailand

Chaiyo U. and Garivait S.

This study focuses on the fire characteristics and carbon mass balance of dead leaves open burning from prescribed fires in mixed deciduous forest (MDF) in Ratchaburi Province, Thailand. The leaf litter fuel load and leaf litter consumed in MDF was 5.31±1.51 and 3.23±1.87 t/ha respectively. The only top layer of biomass fuel was burnt due to the compactness and the leaf litter load is composed of a mixture of tree and bamboo leaves that the later had low heating value. In addition, the combustion factor of leaf litter burning was lesser than 60% and the low level of fireline intensity was 42 kW/min. Carbon analysis in leaf litter fuel consumed and residues after burning was 120.68±40.38 and 11.81±0.44 gC/m2. The amount of carbon output to oxidize to the atmosphere was 108.87±39.95gC/m2 that is 11 times higher than residues after burned. Mixed deciduous forest fires released carbon into the atmosphere for more than 90% of carbon in leaf litter consumed and 10% of carbon on ground soil by residues after burnt form.

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Biosynthesis of Silver nanoparticles using isolated superoxide dismutase enzyme from novel source Papaverum somniferum L.

Kalyankar V. K., Dagade S.P. and Waghmode S. A.

In this paper, we have isolated a superoxide dismutase enzyme (SOD) from novel source Papaver somniferum L. (Poppy seeds). Isolated SOD enzyme was characterized by SOD assay, SDS-PAGE for molecular weight detection. The obtained metallo- enzyme was further processed to Apo enzyme on treatment with EDTA and acetic acid. This Apo enzyme was used as a source for the synthesis of Silver nanoparticles. The Apo enzyme was optimized for pH, temperature and concentration for biosynthesis of Silver nanoparticles. Synthesized silver nanoparticles were characterized by UV-VIS, TEM, XRD and FTIR measurements.

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Effect of marine biofilm on the electrochemical behavior of stainless steel and titanium

Ghemmit- Doulache Naima, Azzouni Bouchra and Meriouli Amina

The aim of this work is to study the electrochemical behavior of metals most often encountered in marine environment, simulating biofilm effect on stainless steels and titanium in natural seawater. The number of electrons exchanged per molecule of oxygen consumed by biofilm formed on steel is in range of two (n = 2) at -1.0 V/SCE while that of titanium is around six (n = 6) measured at -1.5 V/SCE. Immersion time effect of steel in seawater showed a significant variation of corrosion potential that goes from cathode to anode zone area. For short stay titanium in natural seawater, corrosion potential varies around -250 mV/SCE and then reached under cathodic values to longer stay.

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A Novel Class of COX-II Inhibitors: Computational and Docking Study of Pyran-Pyrimidine Hybrids

Gupta Girish Kumar and Kumar Vinod

A computational and docking study has been carried out on pyran-pyrimidine hybrids by using Molegro Virtual Docker software to predict their binding modes and orientation into the active site of cyclooxygenase-II enzyme. A series of 6-aryl-4-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-2-(S-benzylthio) pyrimidines has emerged as a novel class of COX-II inhibitors. The results obtained from the study revealed that pyran linked pyrimidines are able to fit into the active site of COX-II enzyme and thus may represent as potential anti-inflammatory agents in future.

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Study on the sorption kinetics and thermodynamics of Am (III) onto Attapulgite/Iron Oxide Magnetic Composites by linear and nonlinear methods

Yu T.

Attapulgite/Iron Oxide Magnetic Composites (ATP/IOMs) were prepared and characterized and the sorption behavior of Am(III) on ATP/IOMs was studied as a function of pH, ionic strength, the solid-to-liquid ratio (m/V), contact time and the concentration of Am(III) under ambient conditions using batch technique. Kinetic and thermodynamic study of Am(III) sorption on ATP/IOMs were investigated by linear and nonlinear methods. Linear and nonlinear regression methods in selecting the optimum sorption isotherm were applied on the experimental data. The results indicated that the sorption can be described by a pseudo-second-order rate equation and the nonlinear pseudo-second-order kinetic expression could fit the kinetics better compared to the linear forms. The nonlinear method is a better way to represent the sorption isotherm than the linear method and thus it should be primarily adopted to obtain the sorption isotherm parameters. Freundlich isotherm model is the best-fit model to the experimental data for the sorption. Nonlinear method is found to be the more appropriate method to determine kinetic and thermodynamic parameters.

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Resonance Energies Effects associated with Electron Delocalization on the Conformational Behaviors of 2,6-Disubstitued Cyclohexanone

Azarakhshi Fatemeh and Farhadyar Nazanin

The impacts of the generalized anomeric effect (GAE) and gauche effect (GE) associated with donor-acceptor electron delocalization, dipole-dipole interactions and steric effects on the conformational properties 2,6-dimethoxy- (1), 2,6-dimethylthio- (2), 2,6-dimethylseleno- (3), 2,6-difluoro- (4), 2,6-dichloro- (5), 2,6-dibromo cyclohexanone (6) have been studied by means of hybrid density functional theory (DFT: B3LYP/6-311+G**) and ab initio molecular orbital (MO: HF/6-311+G**) based methods and Natural Bond Orbital (NBO) interpretation. Both methods used show that the above compounds exist predominantly in the axial chair conformation. The NBO analysis of donor-acceptor (LP→σ*) interactions show that the generalized anomeric effect (GAE) and the axial conformation stability increase from compound 1 to compound 3 and also from compound 4 to compound 6. On the other hand, the calculated differences between the dipole moment values of the axial and equatorial conformations, Δ(μeq-μax), decrease from compound 1 to compound 3 and also decrease from compound 4 to compound 6. However, the variations of the calculated Δ(μeq-μax) values are not in the same trend observed for the corresponding GAE and ΔG values. These findings reveal that the GAE related to donor→acceptor hyperconjugation effect, is more significant for the explanation of the axial conformational preferences of compounds 1-3 and 4-6 than the electrostatic effect.

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