Utilization of ethoxylated pentamine oleamide as new Gemini surfactants for corrosion inhibition effectiveness in 1 M HCl solution

This research aims to convert tetraethylene pentamine Gemini surfactants from oil to water-soluble corrosion inhibitors for applying in oil field at temperatures up to 65?°C. To achieve this aim, four new ethoxylated Gemini surfactants denoted as (T1, T2, T4 and T6) bearing different ethylene oxide units of 19, 28, 45 and 65, respectively were prepared and evaluated as corrosion inhibitors. The chemical structures of the prepared inhibitors were verified using FT-IR and ¹H NMR spectroscopic analysis. The performance of the prepared surfactants was determined using surface tension measurements and thermodynamic parameters. Weight loss and electrochemical measurements were utilized to measure their corrosion inhibition efficiencies at a temperature range of 25–65?°C. Through the obtained results, the maximum inhibition efficiency of 95.74% was obtained by T6 at 25?°C in 1?M HCl.     

Synthesis,Biological Evaluation and 2D-QSAR Study of Halophenyl Bis-Hydrazones as Antimicrobial and Antitubercular Agents

In continuation of our endeavor towards the development of potent and effective antimicrobial agents, three series of halophenyl bis-hydrazones (14a–n, 16a–d, 17a and 17b) were synthesized and evaluated for their potential antibacterial, antifungal and antimycobacterial activities. These efforts led to the identification of five molecules 14c, 14g, 16b, 17a and 17b (MIC range from 0.12 to 7.81 μg/mL) with broad antimicrobial activity against Mycobacterium tuberculosis; Aspergillus fumigates; Gram positive bacteria, Staphylococcus aureus, Streptococcus pneumonia, and Bacillis subtilis; and Gram negative bacteria, Salmonella typhimurium, Klebsiella pneumonia, and Escherichia coli. Three of the most active compounds, 16b, 17a and 17b, were also devoid of apparent cytotoxicity to lung cancer cell line A549. Amphotericin B and ciprofloxacin were used as references for antifungal and antibacterial screening, while isoniazid and pyrazinamide were used as references for antimycobacterial activity. Furthermore, three Quantitative Structure Activity Relationship (QSAR) models were built to explore the structural requirements controlling the different activities of the prepared bis-hydrazones.     

New Approach to Compare Glare and Light Characteristics of Conventional and Balloon Lighting Systems

With the increasing needs to adopt nighttime construction strategies in order to avoid disruption of traffic flow, state agencies are currently experimenting with a new class of light towers known as balloon lights. Compared to regular lighting tower, balloon lights have been reported to reduce glare significantly and to provide more uniform lighting conditions at the site. The objective of this study was to measure light and glare characteristics of two balloon lighting systems in the field. Glare and lighting characteristics of this new class of light towers were compared to a conventional lighting system. For this purpose, field measurements were made of the pavement luminance and the horizontal and vertical illuminances on a predefined experimental grid. Results of this study indicated that while being comparable in terms of wattage and luminous flux, the tested balloon light systems differed in terms of light and glare characteristics. In addition, while conventional light tower provided greater illuminance at the light source than balloon lights, the disability glare was greater for conventional light tower than balloon lights when mounted at the same height. Results of this study revealed that optimum conditions should be sought in the work zone, through which adequate lighting conditions are provided for workers while disability glare is kept below a safe threshold for drive-by motorists. Plotting the maximum veiling luminance ratio (disability glare) against the workable distance provides a simple approach to consider the two factors concurrently in the design of work zone lighting.     

The role of squalene synthetase in the inhibition of tetrahymanol biosynthesis by cholesterol inTetrahymena pyriformis

The biosynthesis of the triterpenoid alcohol tetrahymanol byTetrahymena pyriformis is rapidly inhibited by the addition of cholesterol to the growth medium. The primary site of this inhibition by cholesterol has been established to be at the level of the enzyme squalene synthetase. The protein synthesis inhibitor cycloheximide produces an identical decline in squalene synthetase activity to that of cholesterol and the half-life of the enzyme is about 50 minutes. No direct inhibition of the enzyme is observed and suggests that cholesterol inhibits the actual synthesis of the enzyme squalene synthetase. Farnesol is accumulated during in vitro incubations derived from cells grown in the presence of cholesterol or cycloheximide.     

Modification of parameters in mechanochemical synthesis to obtain - and -molybdenum disilicide

In this paper, molybdenum disilicide <alpha>- and <beta>-phases can be successfully synthesized during mechanical alloying (MA). Also, this method promote a self-propagating reaction (MSR) at balls to powder ratio (BPR) 10:1, shorter milling time with speed (400 rpm) without subsequent heat treatment that was considerably lower energy than that used in conventional methods. Two different molar ratios of Mo:3Si and Mo:4Si were prepared in addition to the stoichiometric powder mixture Mo:2Si intermittent sampling was done from 4 h to 20 h. Increasing Si content clearly delayed the MSR and the reactants were gradually converted to both <alpha>- and <beta>-MoSi2 phases over a relatively long time. Samples were characterized by using X-ray diffraction (XRD)/scanning electron microscopy (SEM) analyses and grain size calculated based on the conventional Scherrer method. XRD patterns of stoichiometric powder samples milled with BPR 10:1 indicated the rapid formation of <alpha>- and <beta>-MoSi2 even after 4 h milling. Samples milled with higher BPR lost their crystallinity after milling for 16 h. SEM images in general showed considerable lowering in average particle size with milled samples. Crystallite size was found to decrease with milling time and with increasing BPR.     

Co-solvent ethanolysis of chicken waste: Optimization of parameters and characterization of biodiesel

Fatty acid ethyl ester (FAEE) was developed from chicken waste. A blend of chicken fat and waste chicken oil was used as a feedstock for FAEE preparation via alkali-catalyzed transesterification with ethanol assisted by a co-solvent. Hexane was used as the co-solvent. The influences of alkali catalyst type and concentration, ethanol/blend molar ratio, hexane/ethanol volume ratio, temperature, time, and type of co-solvent on the yield of FAEE were investigated. The best yield of FAEE (96.94%~96.78% w/w ester content) was obtained at 0.75% KOH w/w, 8:1 ethanol/blend molar ratio, 1.5:1 hexane/ethanol volume ratio, 60°C temperature, and 60 min of reaction. The fuel properties of FAEE produced as well as its blends with petro diesel were within the range of those prescribed by ASTM D 6751 standards, indicating its suitability as fuel for combustion engines. It was concluded that the presence of co-solvent increased the yield of FAEE and enhanced its properties compared to FAEE produced via non-solvent processes. The process was found to follow first-order kinetics, and the activation energy was found to be 13.31 kJ/mol.     

Poly(vinyl alcohol)‐Based Film Potentially Suitable for Antimicrobial Packaging Applications

This work aimed at developing a thin and water‐resistant food‐grade poly(vinyl alcohol) (PVOH)‐based matrix able to swell when in contact with high moisture content food products without rupturing to release antimicrobial agents onto the food surface. This film was prepared by blending PVOH and 7.20% (wt/wt of PVOH) of poly(ethylene glycol) (PEG) with citric acid as crosslinking agent. The film‐forming solution was then casted onto a flat surface and the obtained film was 60 μm in thickness and showed a good transparency (close to T = 100%) in the visible region (400 to 700 nm). After immersion in water for 72 h at room temperature, the crosslinked matrix loses only 19.2% of its original weight (the percentage includes the amount of unreacted crosslinking agent, antimicrobial in itself). Water content, degree of swelling, and crosslinking density of the film prove that the presence of PEG diminishes the hydrophilic behavior of the material. Also the mechanical properties of the wet and dry film were assessed. Alongside this, 2.5% (wt/wt of dry film) of grapefruit seed extract (GSE), an antimicrobial agent, was added to the film‐forming solution just before casting and the ability of the plastic matrix to release the additive was then evaluated in vitro against 2 GSE‐susceptible microorganisms, Salmonella enteritidis and Listeria innocua. The results indicate that the developed matrix may be a promising food‐grade material for the incorporation of active substances.