An erbium–organic framework as an adsorbent for the fast and selective adsorption of methylene blue from aqueous solutions

The applicability of erbium–metal–organic framework (Er-MOF) in the adsorption and removal of methylene blue from aqueous solution has been studied. Er-MOF was synthesized by hydrothermal method and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray powder diffraction. The high thermal stability, water stability and accessible nano-sized aperture for the Er-MOF could endow it with a very high potential in adsorption of dye pollutant. The adsorption isotherm, kinetic and thermodynamic investigations confirm that the adsorption behavior is based on Langmuir isotherm with an exothermic mechanism and enthalpy-driven process. The speed adsorption process (30 min), low cost, high efficiency, big surface area, selectivity and very high and rapid reusability are the main advantages of the proposed compound as a sorbent.     

Ethanol and chitosan production from wheat hydrolysate by Mucor hiemalis

BACKGROUND: High glucose and ethanol tolerance is among the most important requirements of ethanol‐producing microorganisms. The purpose of this study was evaluation of filamentous fungus Mucor hiemalis for ethanol production from wheat and starch hydrolysates with high glucose concentration. RESULTS: The results showed high tolerance of the fungus in fermentation of the hydrolyzates with high glucose concentrations (as high as 190 g L^?1). Interestingly, increasing the glucose concentration from 15 to 190 g L^?1 was accompanied by enhancement of initial sugar uptake rate. Ethanol was the most important metabolite obtained during all fermentations and its concentration reached over 50 g L^?1. Beside ethanol, chitosan was another valuable product of the process. Glucosamine, a precursor of chitosan, made up 37.3–46.7% of the cell wall of this fungus. CONCLUSIONS: M. hiemalis is a promising microorganism for simultaneous production of ethanol and chitosan from substrates with high sugar concentrations. © 2012 Society of Chemical Industry     

Kinetic Study of Sodium Cocoyl Sarcosinate Synthesis and Factors Affecting the Reaction on Bench and Pilot Scales

Sodium cocoyl sarcosinate is an important surfactant with a particular chemical structure and many practical applications in various industries. The synthesis of sodium cocoyl sarcosinate involves the reaction of cocoyl chloride and N-methyl glycine. The influences of reactant molar ratios, temperature, reaction time, pH, and solvent on the reaction yield were investigated and also the kinetics of the reaction was studied. It was found that the reaction follows second order kinetics and the reaction rate constant is 0.0153?mol^?1?L?s^?1 at 35?°C. Also production of sodium cocoyl sarcosinate was carried out at bench and pilot scales which is described in details.     

A developed single-phase cascaded multilevel inverter with reduced number of circuit devices

In this paper, an advanced configuration for multilevel voltage source inverters is proposed. The proposed topology can be used as symmetric and asymmetric inverter. In asymmetric mode, DC sources’ magnitudes are defined in a way that the number of output voltage levels gets more than the case when the symmetrical DC sources are applied. In this regard, to calculate the magnitudes of required DC voltage sources, several different solutions are proposed. In multilevel inverters, the overall cost, circuit size and so installation area, complexity of control scheme and reliability are directly dependent on the number of circuit devices needed. The provided comparison study among suggested inverter in all defined solutions, CHB and recently proposed converters validates that the proposed modular inverter uses reduced number of circuit devices. The provided simulation and experimental results confirm the feasibility of the proposed structure and show that the obtained results are in good agreements.     

Equilibrium, kinetic and thermodynamic studies of mercury adsorption on almond shell

The application of almond shell as a low cost natural adsorbent to remove Hg(2+) from aqueous solution was investigated. Batch experiments were carried out to evaluate the adsorption capacity of the material. The chemical and physical parameters such as pH, sorbent amount, initial ion concentration, and contact time were optimized for the maximum uptake of mercury onto the solid surface. Adsorption isotherms were expressed by Langmuir and Freundlich adsorption models, and the experimental data were found to fit the Langmuir model rather than the Freundlich. The maximum adsorption capacity obtained from the Langmuir isotherm was 135.13 mg/g. A kinetic study was carried out with pseudo-first-order and pseudo-second-order reaction equations and it was found that the Hg(2+) uptake process followed the pseudo-second-order rate expression. The thermodynamic values, ΔG(0), ΔH(0) and ΔS(0), indicated that adsorption was an endothermic and spontaneous process. The potential of this material for mercury elimination was demonstrated by efficient Hg(2+) removal from a synthetic effluent.     

RETRACTED ARTICLE: Investigation of Frying Oil Quality Using VIS/NIR Hyperspectral Analysis

Traditional chemical methods of analyzing frying oil quality are time-consuming and not amenable to on-line measurement. The main objective of this study was to evaluate quality changes of heated oils based on visible/near infrared spectral analysis using a hyperspectroradiometer. The reflectance spectra of the heated oils were analyzed within the range 400–1,750 nm. Acid value, total polar component, and viscosity of oil samples were used as indicators of different quality levels of oil. Partial least squares calibration models were developed for quantitative evaluations of these parameters. The R ² and root mean square error for each prediction were calculated to assess the prediction capability of calibration models. The study demonstrated that using the established calibration models, quality parameters could be predicted with R ² values over 0.92.     

Numerical and Experimental Biomass Separation from Fermentation Process by Minihydrocyclones

Biomass particle separation is challenging in the pharmaceutical industry because of the smallness and lightness of such particles. Centrifugation is applied conventionally for batch separation. However, imposing multiple wash steps in order to eliminate culture residues and the high risk of extrinsic contamination hamper batch techniques. In this research, minihydrocyclones were introduced to provide a better solution for the mentioned limitations in continuous processes. Numerical separation of methylotrophic yeast from fermentation broth was carried out in three hydrocyclones with different lengths, and the most efficient one was examined experimentally. Three various feed flow rates and seven feed concentrations were evaluated. The concentration of biomass suspension in the product was raised to 20 %.     

Four Novel p.N385K,p.V36A,c.1033–1034insT and c.1417–1418delCT Mutations in the Sphingomyelin Phosphodiesterase 1 (SMPD1) Gene in Patients with Types A and B Niemann-Pick Disease (NPD)

Background: Types A and B Niemann-Pick disease (NPD) are autosomal-recessive lysosomal storage disorders caused by the deficient activity of acid sphingomyelinase due to mutations in the sphingomyelin phosphodiesterase 1 (SMPD1) gene. Methods: In order to determine the prevalence and distribution of SMPD1 gene mutations, the genomic DNA of 15 unrelated Iranian patients with types A and B NPD was examined using PCR, DNA sequencing and bioinformatics analysis. Results: Of 8 patients with the p.G508R mutation, 5 patients were homozygous, while the other 3 were heterozygous. One patient was heterozygous for both the p.N385K and p.G508R mutations. Another patient was heterozygous for both the p.A487V and p.G508R mutations. Two patients (one homozygous and one heterozygous) showed the p.V36A mutation. One patient was homozygous for the c.1033–1034insT mutation. One patient was homozygous for the c.573delT mutation, and 1 patient was homozygous for the c.1417–1418delCT mutation. Additionally, bioinformatics analysis indicated that two new p.V36A and p.N385K mutations decreased the acid sphingomyelinase (ASM) protein stability, which might be evidence to suggest the pathogenicity of these mutations. Conclusion: with detection of these new mutations, the genotypic spectrum of types A and B NPD is extended, facilitating the definition of disease-related mutations. However, more research is essential to confirm the pathogenic effect of these mutations.     

One-pot three-component synthesis of some novel ethyl 3-alkyl-2-thioxo-2,3-dihydrothiazole-4-carboxylates under solvent- and catalyst-free conditions at room temperature

A green and efficient one-pot three-component synthesis of some novel ethyl 3-alkyl-2-thioxo-2,3-dihydrothiazole-4-carboxylates from the reaction of primary alkyl or benzyl amines, carbon disulfide and ethyl bromopyruvate is introduced. This straightforward technique gave the looked-for products in high yields during 1.5–3?h without need for catalyst or solvent assistance.     

Synthesis,structure, and mechanical properties of castor oil‐based polyamidoamines toughened epoxy coatings

A series of toughened epoxy systems was prepared via crosslinking of diglycidyl ether of bisphenol A with castor oil‐based polyamidoamines as curing agents. To this aim two series of polyamidoamines were synthesized in two steps from the reaction of castor oil with triethylenetetramine and then reaction of these products with dissolved salicylic acid in dimethyl formamide (DMF). The structure of the compounds was confirmed by FTIR spectra, GC‐Mass and ¹H‐NMR spectroscopy. The mechanical properties, adhesion and water resistance of polyamine and polyamidoamines cured epoxy systems were studied. It was found that significant improvement in toughness and adhesion of the epoxy films was achieved by using polyamidoamines as curing agents. The results showed a great enhancement in toughness and adhesion properties of the epoxy coats proportional to increasing castor oil weight ratio, and/ or using salicylic acid and DMF. Furthermore, polyamidoamines cured samples showed higher water resistance and less degradation in hot water immersion tests than polyamine cured samples. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013