Simple Route for Synthesis of Nano-Crystalline Ni-Mg Ferrite Particles

Deraz N. M. and Abd-Elkader Omar H.

New route was used for preparation of mixed nickel-magnesium ferrite (Ni0.5Mg0.5Fe2O4). Various techniques were used to characterize the as prepared product such as X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron micrographs (SEM) and energy dispersive X-ray (EDX). The crystallite size, lattice constant, unit cell volume and density of Ni0.5Mg0.5Fe2O4 phase have been determined. The investigated method led to prepare single phase of spinel nickel-magnesium ferrite depending upon the XRD and IR results. SEM and EDX techniques showed the as synthesized materials were spongy, homogeneous and fragile. The concentrations of O, Ni, Fe and Mg species involved in Ni0.5Mg0.5Fe2O4 sample were investigated from the uppermost surface to the bulk layers.

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Analytical application of poly[dibenzo-18-crown-6] for chromatographic separation of Cobalt(II) in glycine medium

Kadam R. B. and Mohite B. S.

In present study, poly [dibenzo-18-crown-6] was used as a sorbent for chromatographic extraction and separation of cobalt(II) in glycine medium. The sorption of cobalt (II) was quantitative from 5x10-3 to 1x10-6 M glycine. Cobalt (II) was eluted quantitatively with 0.5–8.0 M HCl, 0.5-8.0 M HBr, 2.0-8.0 M HClO4, 0.5-8.0 M H2SO4 and 0.1-8.0 M CH3COOH. The capacity of poly[dibenzo-18-crown-6] for cobalt(II) was found to be 0.509 ±.0.1 mmol /g of crown polymer. The effect of concentration of glycine, metal ion, diverse ion and eluents has been studied. Cobalt (II) was separated from a number of cations in ternary and multicomponent mixtures. The applicability of the proposed method was checked for the determination of cobalt(II) in real samples such as composite materials and aquatic plants. The method is simple, rapid and selective with good reproducibility (approximately ± 2%).

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Research on immobilized ammonia-oxidizing bacteria by sodium alginate

Yuwei Dong, Yanqiu Zhang, Wenping Cao, Ling Sun and Liu Fei

Ammonia-oxidizing bacteria were immobilized by sodium alginate and calcium chloride. Immobilized conditions and ammonium removal ability of immobilized ammonia-oxidizing bacteria were researched. The results showed that the optimal immobilized conditions were: 4.5% sodium alginate with 2.0% calcium chloride, 2000 immobilized balls, 1000mL immobilized medium, pH 8, 30 oC, 110r/min. Immobilized ammonia-oxidizing bacteria were recycled six times under the optimal immobilized conditions. Immobilized ammonia-oxidizing bacteria at the optimal conditions had better ammonium removal ability than non-immobilized ammonia- oxidizing and were good for preservation. Removal rate of ammonia nitrogen of immobilized ammonia-oxidizing bacteria reached 89.51%.

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Adsorption properties of copper (II) ion from aqueous solution by starch-grafted polyacrylamide and cross-linked starch-grafted polyacrylamide

Jun Tan, Xiaoyan Wei, Yuxia Ouyang, Juhong Fan and Rui Liu

Starch-grafted polyacrylamide (SA) and cross-linked starch-grafted polyacrylamide (CSA) had been synthesized via grafting polymerization from corn starch and used as adsorbents for the removal of Cu(II) ion from aqueous solution. The equilibrium, kinetics,isotherm and thermodynamics of adsorption processes of SA and CSA were investigated and compared. It was found that the adsorption capacity of Cu(II) of SA and CSA could reach the maximum when the pH was 6, within 60 min. The present adsorption kinetics of CSA and SA for Cu(II) was favorably described by the pseudo-second-order kinetic model and the adsorption isotherm was described well with the Freundlich isotherm model. Thermodynamic study indicated that adsorption was spontaneous and endothermic process with increased entropy and the rise of temperature would benefit the adsorption. The enthalpy change(ΔH), the entropy change (ΔS) and free energy change (ΔG) of the adsorption process of Cu(II) on SA and CSA were calculated with adsorption isotherm data and basic thermodynamic relations.

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Preliminary study of thermal conductivity and viscosity of ethylene glycol with CuO nanorod inclusions

Khedkar Rohit, Sonawane Shriram and Wasewar Kailas

In the present work, we report measurements of the effective thermal conductivity and viscosity of dispersions of CuO nanorod suspensions in ethylene glycol. The CuO nanorods were synthesized using the hydrolysis reaction. XRD and TEM were employed to estimate morphology of CuO nanorods. It is found that nanoparticles were rod shape with average particle size of 28 nm. The ethylene glycol based nanofluids were prepared by two step method (dispersion of CuO nanorod into EG). Nanorod loading up to 5 vol% was used. Thermal conductivity and viscosity measurements were performed by the KD2 pro and ARG2 rheometer respectively. The enhancement in thermal conductivity was observed as CuO nanorod loading. The maximum enhancement in thermal conductivity was found to be 26.29% at 5 vol% loading. Viscosity of the all combination of nanofluids displays strong influence on CuO loading in the base fluid and shear rate, as the shear rate increases viscosity decreases. Newtonian behavior of the ethylene glycol changes to non-Newtonian with increase of CuO nanorod loading. Shear thinning is observed for nanofluids containing CuO volume fraction >1 vol. %. Experimental results were compared with theoretical model: Hamilton–Crosser model and Brinkman model for thermal conductivity and viscosity respectively. Both the comparison shows disagreement of predicted values with experimental values.

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Screening of intestinal Lactic Acid Bacteria of breastfed neonates for antimicrobial activity against Bacillus subtilis, Staph. aureus and E.coli

Nilakhe Smita, Bodhankar M. G. and Sapre Vaijayanti

The microflora of gastrointestinal tract of breast-fed infants consisted of the major groups of lactic acid bacteria (LAB) like bifidobacteria and lactobacilli. In the present study, the lactic acid bacteria (LAB) isolated from the feces of breastfed neonates were tested for their antibacterial activity against Staph aureus NCIM2079, E.coli NCIM 2345 and Bacillus subtilis. The major goal of this study was to investigate antibacterial activity of LAB against the pathogens and check their in vitro survival in gastric conditions. Dilution method and cultivation in selective media were used for the enumeration of LAB and the isolates were identified by their physiological and biochemical characteristics. The antibacterial activity of the isolates was checked by the agar well diffusion method. Cell free supernatant of all the isolates exhibited significantly higher antimicrobial activity against Bacillus subtilis than against Staphylococcus aureus and Escherichia. coli. All the tested isolates tolerated acidic gastric conditions (pH 1 to pH 3.5), bile salt (0.5 %), gastric enzymes like pepsin and Lysozyme and artificial gastric juice. In addition, they showed tolerance to 2% NaCl and 0.4% phenol.

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A logistic model for the electrochemical generation of active chlorine species on platinised platinum electrodes

Ciobotaru I. E. and Vaireanu D. I.

This paper presents a logistic model for the generation of chlorine in an undivided electrolytic cell employing a pair of platinised platinum electrodes. A series of operating parameters such as current density and flow rate were considered to study their influence on active chlorine generation. The experimental results were subjected to an optimisation procedure and the modelling was carried out for the experimental set of data corresponding to the optimum parameters. It was found that the logistic model fits very well the experimental data, the correlation coefficient being 0.998 out of 10 points and most of the relative errors being smaller than 5%.

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Synthesis, spectroscopic characterization and antibacterial activity of Ti (IV) and Zr (IV) complexes containing salicylidene-thiosemicarbazone

Dubey Raj Kumar and Dwivedi Nalini

Some titanium(IV) and zirconium(IV) complexes of the type [(Cl)3M(sb)] (1-2) and [(Cl)2M(sb)2] (3-4) [M= Ti(IV) and Zr(IV); sb = Schiff base; salicylidene-thiosemicarbazone (stscH)] have been synthesized by the reactions of metal(IV) chloride(s) with sodium salts of Schiff base in 1:1 and 1:2 molar ratio(s) in THF-C6H6 mixture. These synthesized complexes are coloured solids and soluble in polar solvents in THF, DMSO, DMF, methanol and ethanol. These complexes have been characterized by melting points, elemental analysis (C, H, N, Zr/Ti) and spectral [IR, NMR (1H, 13C), ESI-MS] and thermal studies. X-ray powder diffraction data for complex (1) and (2) determine nano range crystallite size and monoclinic crystal system. Schiff base and synthesized complexes were screened for antibacterial activity against B. subtilis, E. coli and P. aeruginosa. Titanium(IV) and zirconium(IV) ions are proven to be essential for the growth inhibitor effect.

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Theoretical Study of Chemical looping combustion of ethanol with oxides

Kale Ganesh R., Joshi Ajit R. and Kshirsagar Sachin H.

Ethanol is a renewable energy source as it is manufactured from biomass. The potential of ethanol for chemical looping combustion for energy production has been explored in this study. Some common easily available cheap metal oxides were chosen as oxygen carriers for CLC of ethanol. A thermodynamic analysis using Gibbs free energy minimization module of HSC Chemistry software was done to predict equilibrium products of CLC fuel reactor within a temperature range of 500 – 1200 ºC at 1 bar pressure. The objective of this analysis was to identify better oxygen carrier among these oxides for CLC of ethanol, to study the variation of product composition with temperature, to describe the optimum conditions to maximize yield of desired product and to minimize undesired product formation. The product gas distribution for ethanol fuel in CLC showed different trends for different oxides. CuO was found to be the best oxygen carrier followed by NiO and CoO.

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Comparison of enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction for the detection of norovirus in fecal samples

Chien-Hsien Chen and Chia-Peng Yu

Human noroviruses (HNoVs) are major agents of viral gastroenteritis outbreaks and sporadicinfections worldwide. This study evaluated the sensitivity and specificity of immunological and molecular assays for the diagnosis of HNoV infections. The commercially available third-generation RIDASCREEN HNoV Enzyme-linked Immunosorbent assay (ELISA) kit compared to the reverse transcription-polymerase chain reaction (RT-PCR) detect HNoVs in acute gastroenteritis (AGE) and non gastroenteritis (Non-AGE) patients. Two hundred fifty-three stool samples were collected from August 2011 to July 2012 and analyzed using ELISA kit and RT-PCR method for HNoV. Sensitivity of 20.8% (5/24), 23.5% (4/17), 14.3% (1/7), 40% (4/10), 7.1% (1/14) and specificity of 99.6% (228/229), 99.3% (137/138), 100% (91/91), 100% (22/22), 99.1% (108/109) were demonstrated when comparing ELISA with RT-PCR in all samples, AGE, Non-AGE, <10 y and ≧ 10 y AGE patients. HNoVs were detected in 6 (2.4%) and 24 (9.5%) of 253 stool specimens using ELISA and RT-PCR. The results obtained in this study demonstrated the RIDASCREEN HNoV 3rd Generation exhibited low sensitivity, high specificity and did not match the performance of the RT-PCR.

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Effects of burnt and un-burnt rice straw on methane and nitrous oxide emissions in water drainage rice fields

Tassanee Jiaphasuanan and Sirintornthep Towprayoon

Air pollution problem from rice fields burning has been steadily increasing in Thailand. The rice straw incorporated to the rice field is promoted to avoid air pollution problem. However, this practice is known to enhance CH4 emission from paddy fields. The objective of this study is to quantify greenhouse gas emissions as affected by rice straw incorporation in comparison with rice straw burning under mid-season drainage and local drainage in order to find the compromised conditions. This experiment consisted of burnt (B) and stubble incorporated or un-burnt (S) treatments of rice straw applied with two different water drainage schemes, local and mid-season drainage. It was found that incorporated rice straw increased CH4 emission during the vegetative phase while mid-season drainage showed effective reduction during reproductive phase in un-burnt field. Water drainage showed stronger impact on methane reduction in un-burnt treatment (50% and 23% in wet and dry season) than burnt treatment (8% and 3% in wet and dry season). The results using net global warming potentials (GWPs) suggest that the combination of un-burnt practice and mid-season drainage showed the smallest emission and can reduce air pollution from field burning.

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Transformation of E.coli bacteria using PAMAM dendrimers

Alirezaee Kobra, Asadi Asadollah, Hamidi Aliasghar and Amani Amin

Transformation is as an essential and inseparable part of recombinant in the production of drugs, plants and animals. Nanotechnology advances may lead to the nanoparticles production that has the ability to transfer genes into bacterial cells. In this paper a new method is presented for transformation of E.coli bacteria using PAMAM G2 dendrimer nano polymer. Therefore, PAMAM-DNA complex was prepared by combining the one micrograms of PUC-18 plasmid vector and two micrograms of PAMAM dendrimer polymer. Then, the obtained complex whit bacterial suspension was prepared in 50 mM CaCl2 combined during 7 hours. Also, bacterial suspensions treated with ultrasound were used to facilitate the transfer of PAMAM-DNA complexes. The results showed that PAMAM G2 nanoparticles have the ability to transform bacterial suspension prepared in 50 mM CaCl2. The results showed that cell suspensions treatment with ultrasonication significantly increased the transformation efficiency.

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Phosphate removal from aqueous solution using enhanced chitosan/bentonite composite

Bingchao Yang

A low-lost adsorbent, enhanced chitosan/bentonite composite was prepared by incorporating chitosan in bentonite and further treated with concentrated HCl. The enhanced chitosan/bentonite composite was applied to remove phosphate from aqueous solution. The optimal pH lay in the pH ranged from 3 to 6. The maximum adsorption capacity was achieved at 7.73 mg/g at 293K. The phosphate adsorption followed both Langmuir and Redlich–Peterson isotherms. The adsorption process was described by pseudo-second-order kinetic model. The composite may be regenerated using 0.1 M HCl. Electrostatic interaction was the main mechanism for the adsorption of phosphate onto this adsorbent.

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Production of Poly (3-hydroxybutyrate) Biopolyester from Glycerol using Anaerobic Sludge Seed

Wattanaphon Hathairath T. and Pisutpaisal Nipon

The production of polyhydroxyalkanoate (PHA) by a mixed culture using glycerol as a sole carbon source was achieved. The effect of the initial glycerol concentration on the PHA contents, production, productivity and yield was assessed. Fourier-transform mass spectrometry (FTIR), proton-nuclear magnetic resonance (1H-NMR) and high-performance liquid chromatography (HPLC) analyses indicated that the produced biopolyester is poly-3-hydroxybutyrate (P3HB). At 10%(v/v) glycerol in 1 l reactor, pH of 7.0 ± 0.02 at 30˚C, P3HB content and production were 50.09 ± 1.25 % and 3.95 ± 0.10 g P3HB/l after 120 h incubation. The P3HB content and production were 51.13 ± 1.70 % and 3.28 ± 0.16 g P3HB/l respectively under the fermentation in 10 l reactor using the similarly condition in the 1 l reactor. Denaturing gradient gel electrophoresis (DGGE) showed the significant dynamic change in community structure based on 16S rDNA band patterns between the original seed and that cultured in glycerol containing media after 120 h incubation. The dominant bacteria in the optimal P3HB production were closely related to Bacillus, Bacteroides, Citrobacter, Clostridium and Klebsiella.

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