Synthesis and Characterization of Carbon Steel Corrosion Inhibitors Based on 4,5,6,7-tetrahydrobenzo[b]thiophene Scaffold

Protection of Metals and Physical Chemistry of Surfaces - Three novel inhibitors based on 4,5,6,7-tetrahydrobenzo[b]thiophene scaffold were synthesized and characterized. The inhibitive action of...     

A multi-variate heart disease optimization and recognition framework

Neural Computing and Applications - Cardiovascular diseases (CVD) are the most widely spread diseases all over the world among the common chronic diseases. CVD represents one of the main causes of...     

Main and Interactive Effects of Polyaromatic Sulfur Heterocyclic Compounds on Growth and Biodegradation Efficiencies of Bacillus sphaericus HN1: Modeling and Statistical Analysis

Bioremediation is an effective technique to remediate soil and water contaminated with a mixture of recalcitrant polyaromatic sulfur heterocyclic (PASH) compounds. Based on two levels of full factorial design, a statistical design of experiments was used in this study to investigate the interactive effects of three PASHs; thiophene (Th), benzothiophene (BT), and dibenzothiophene (DBT) on their biodegradation in multisubstrate batch process using Bacillus sphaericus HN1. Kinetic modeling was performed to estimate the rate of biodegradation of each PASH in single-, binary-, and tertiary-substrate systems. Biodegradation of BT, DBT, and total PASHs follows the first order kinetic reaction in the single- and multisubstrate batch systems, while biodegradation of Th follows the first-order kinetic reaction, in single-substrate system, but second-order kinetic reaction in multisubstrate batch system. Four linear interaction regression models were estimated and validated to describe the interactive effect of the three PASHs on their biodegradation. Statistical analysis of the results in the form of analysis of variance and Student t test indicated significant role played by the main effects of Th, BT and DBT on their biodegradation (p < 0.01). Th and the interactive effect between Th and DBT has statistically significant negative effect on DBT removal (p = 0.0665). However, DBT expresses higher statistically significant positive effect on total PASHs removal than that of Th (p = 0.0178 and p = 0.026, respectively), but their interaction has a significantly negative effect (p = 0.0143).     

Thermodynamic,adsorption and electrochemical studies for corrosion inhibition of carbon steel by henna extract in acid medium

Corrosion inhibition of carbon steel in the presence of different concentrations of aqueous extract from henna leaves in 1 M HCl solution has been studied using the weight loss and potentiodynamic polarization techniques. The effect of temperature on the corrosion behavior of carbon steel was studied in the temperature range 293–333 K. The inhibition efficiency increases with increasing inhibitor concentration but decreases with increasing temperature. The activation and free energies for the inhibition reactions support the mechanism of physical adsorption. The adsorption of henna extract on C-steel surface is endothermic, spontaneous and consistent with the Langmuir adsorption isotherm. The potentiodynamic polarization measurements indicate that henna extract acts as a mixed inhibitor. Surface and protective film analysis have been carried out using; energy dispersive X-ray (EDX), scanning electron microscopy (SEM), Fourier transforms infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) analysis.     

Biosorption of Astrazone Blue basic dye from an aqueous solution using dried biomass of Baker's yeast

In this study dried biomass of Baker's yeast, Saccharomyces cerevisiae, is used as a sorbent for Astrazone Blue basic dye aqueous solution. Factors affecting the adsorption process: dye concentration, contact time, temperature and pH were investigated. The equilibrium concentration and the adsorption capacity at equilibrium were determined using three different sorption models namely: Langmuir, Freundlich and Temkin isotherms. It was found that increasing temperature and pH result in higher dye loadings per unit weight of the sorbent. The results gained from this study were described by Langmuir isotherm model better than Freundlich and Temkin isotherm models. The calculated heat of adsorption of the dye-yeast system indicates that the bio-sorption process is taking place by chemical adsorption and has an endothermic nature. The maximum adsorption capacity at 30 degrees C and pH 7 was calculated as 70 mg/g for dried biomass of Baker's yeast compared to 18.5mg/g for commercial granular activated carbon, indicating that dried biomass of Baker's yeast can be considered as a good sorbent material for Astrazone Blue solution.     

The synthesis of carbon coated Fe, Co and Ni nanoparticles and an examination of their magnetic properties

Carbon coated Fe, Co and Ni nanoparticles (Fe@C, Co@C, and Ni@C, respectively) have been produced by high pressure chemical vapour deposition. Scanning electron microscopy images prove that carbon coated particles with a Fe, Co, and Ni core are formed. High-resolution transmission electron microscopy images show that the nanoparticles have a size distribution from 2 to 100 nanometers and display the core/shell structure with one or more particles forming the core in a particular shell. From X-ray diffraction peaks the phase of the core material is confirmed and the average particle size is determined from the width of the peaks to be 16, 21, and 19 nm for Fe@C, Co@C, and Ni@C, respectively. The coated nanoparticles are ferromagnetic at least up to 400 K. AC magnetic heating studies have been performed which imply their potential for applications in hyperthermia therapy.     

Growth and biosynthesis of aflatoxin by Aspergillus parasiticus in cultures containing nisin

Nisin, 200 or 5000 Reading units/ml, was added to Aspergillus parasiticus cultures. The cultures were incubated at 28 degrees C for 3, 7 or 10 days and analyzed for mycelial dry weight, pH and accumulation of aflatoxin B1 and G1. During the first 3 days of incubation, dry weight, pH decrease and aflatoxin accumulation were suppressed by nisin, when compared with similar values for the nisin-free control. After longer incubation, differences in dry weight nd pH values decreased, whereas accumulation of aflatoxin in the nisin-containing cultures surpassed that of the control.     

Synthesis and structural assignment of certain pyrimido[1,2-a]benzimidazole derivatives

The pyrimido[1,2-a]benzimidazole derivatives compounds 1–8 were synthesized through cyclocondensation of 2-aminobenzimidazole with the appropriate benzsubstituted benzoylacetone by fusion at 150–170°C for 5 h. Quaternary salts compounds 9–22 were obtained by quaternization of compounds 1–8 with dimethyl or diethyl sulfate and subsequent isolation as the relatively insoluble perchlorate salts. Assignment and confirmation of the structures of the newly synthesized compounds were based upon elemental microanalyses and other spectral evidence.     

Growth and biosynthesis of aflatoxin by Aspergillus parasiticus in cultures containing nisin

Summary Nisin, 200 or 5000 Reading units/ml, was added toAspergillus parasiticus cultures. The cultures were incubated at 28 °C for 3, 7 or 10 days and analyzed for mycelial dry weight, pH and accumulation of aflatoxin B₁ and G₁. During the first 3 days of incubation, dry weight, pH decrease and aflatoxin accumulation were suppressed by nisin, when compared with similar values for the nisin-free control. After longer incubation, differences in dry weight and pH values decreased, whereas accumulation of aflatoxin in the nisin-containing cultures surpassed that of the control.

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Wachstum und Aflatoxin-Biosynthese von Aspergillus parasiticus in Nisin-enthaltenden Kulturen

Zusammenfassung Nisin (200 oder 5000 Reading-Einheiten/ml) wurdeAspergillus parasiticus Kulturen zugegeben. Die Kulturen wurden bei 28 °C für 3, 7 oder 10 Tage bebrütet und auf Mycel-Trockengewicht, pH und Aflatoxin-Inhalt geprüft. Während der ersten drei Tage wurden das Wachstum und die Aflatoxin-Biosynthese durch Nisin etwas gehemmt, nach längere Incubation jedoch gefördert.