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Benzene contamination has been reported in some food groups. This study aims to identify high-risk foods groups to assess exposure to benzene.

Benzene is a hazardous volatile organic compound commonly used in the production of chemicals, detergents, paints and plastics. In addition, benzene is present in food and beverages.

Citrus juice-based beverages are usually more contaminated with benzene than other beverages. Benzene was also detected in carbonated beverages, fruit juices, pickles, lime juices, mayonnaise and salad dressing. Smoked and canned products have higher content of benzene. Aromas that are used in food contained benzene. Food packaging is one of the sources of benzene contamination of food. One of the reasons for its formation in food staff is due to the reaction of vitamin C (or similar acid) with benzoate, which is mainly used as a preservative in various foods.

Foods contaminated with benzene were determined. Moreover, mechanisms of its formation and some preventive measures were discussed.

This review determined the amount of benzene in foods, mechanism of formation and suggestion for prevention of benzene contamination in food.

The purpose of this paper is to present a study of corrosion inhibition of carbon steel in hydrochloric acid by some benzene nitriles using the quantum chemistry calculation.

The molecular structure and inhibition mechanism, and the relationship between inhibition efficiency of some benzene nitriles on carbon steel in the hydrochloric acid, were studied from a microcosmic viewpoint using the quantum chemistry calculation.

The calculation results showed that the inhibition efficiency of benzene nitriles on carbon steel in hydrochloric acid could be expressed by σ_N and E_LUMO, and the greater σ_N absolute value and the lesser the value of E_LUMO, then the greater the efficiency of the inhibitor. The regression equation for benzene nitriles is: η=2.665056−0.4447122E_LUMO−10.92817σ_N r=0.9953128.

The paper offers insights into the application of the quantum chemistry calculation.

SOLVENT DEWAXING OF LUBRICATING oils found its first commercial application in 1927 when Indian Refining Company started its original acetone‐benzene dewaxing operation. Since that time, solvent dewaxing has wholly superseded the classical cold pressing methods in new installations. Of 171,165 bbls/doz. lube oil produced in the United States in 1951, some 60% was of the solvent extraction type and 40% of the older conventional type. By 1954, solvent extraction's share had risen to an estimated 75% of all dewaxing operations.

The purpose of this paper is to predict the aquatic toxicity (LC50) of 92 substituted benzenes derivatives in Pimephales promelas.

Quantitative structure-activity relationship analysis was performed on a series of 92 substituted benzenes derivatives using multiple linear regression (MLR), artificial neural network (ANN) and support vector machines (SVM) methods, which correlate aquatic toxicity (LC50) values of these chemicals to their structural descriptors. At first, the entire data set was split according to Kennard and Stone algorithm into a training set (74 chemicals) and a test set (18 chemical) for statistical external validation.

Models with six descriptors were developed using as independent variables theoretical descriptors derived from Dragon software when applying genetic algorithm – variable subset selection procedure.

The values of Q2 and RMSE in internal validation for MLR, SVM, and ANN model were: (0.8829; 0.225), (0.8882; 0.222); (0.8980; 0.214), respectively and also for external validation were: (0.9538; 0.141); (0.947; 0.146); (0.9564; 0.146). The statistical parameters obtained for the three approaches are very similar, which confirm that our six parameters model is stable, robust and significant.

To prepare surfactants and use as pour point depressants for a waxy gas oil.

Some anionic surfactants (Calcium O, P.dioctyl benzene sulphonate and calcium hexadecyl benzene sulphonate) were prepared in the laboratory. The physicochemical characteristics were investigated. The adsorption behavior of these surfactants at air/solution and oil/solution interfaces were investigated by measuring the surface tension and interfacial tension as functions of concentration.

The surface parameters and free energies of micellization and adsorption confirm the decreasing and improving of pour point by prepared surfactants. It is found that there is a good relation between surface properties especially interfacial tension of the prepared surfactants and their efficiency in depressing the pour point. Also, the results indicating that anionic surfactants can be improved pour point of waxy gas oil.

Addresses long‐standing problem in the petroleum industry.

Revisions of the 1963 editions of BS 135, BS 458 and BS 805 have just been issued as one volume, entitled BS 135, 458 and 805 Benzene, xylenes and toluenes. The main feature, apart from the new single volume arrangment, is the reduction in the numbers of grades for each product from 5, 7 and 5 respectively, to 1, 3 and 3. The assembly of the revisions into one volume, with common appendices will be more convenient for most users.

Presently, a wide range of polyurethane adhesives can be obtained using different kinds of polyols and isocyanates. However, the applied temperature of the polyurethane adhesive is not more than 80°C. The film of polyurethane adhesive will be softened and deformed when its applied temperature is more than 100°C. Thus, the mechanical property of the polyurethane adhesive is decreased clearly, which limits its further application. The purpose of the study is to improve the heat resistance of polyols, especially polyester polyols and its resultant polyurethane adhesives.

The more rigid benzene ring is introduced into the polyester polyols to improve the heat resistance of its resultant polyurethane adhesive.

The more rigid benzene ring has ben introduced into the polyester polyols and the heat resistance of its resultant polyurethane adhesive is improved.

The polyester polyols with more rigid benzene ring have been prepared successfully by the vacuum melting method when diethylene glycol, neopentyl glycol, 1,6-hexanediol, ethanediol, isophthalic acid, terephthalic acid, sebacic acid and adipic acid are used as raw materials and tetra-isopropyl titanate is adopted as the catalyst.

This study aims to evaluate the effects of volatile organic compounds (VOCs) on the indoor and outdoor air quality in Kuwait due to vehicular traffic.

About 700 VOCs samples were collected from randomly selected residences within Kuwait. For simplicity, the study was divided into three areas: area A between the first and third ring roads, area B between the third and fifth ring roads and area C between the fifth and sixth ring roads. Hazardous Air Pollutants on Site (HAPSITE), a portable Gas Chromatograph/Mass Spectrometer (GC/MS), was used to gather air samples inside and outside of the residences selected in the study area for a period of three months during 2008.

Median indoor air quality levels in the study area were similar to the outdoor levels. Indoor/outdoor ratios varied from 0.5 to 8 for most compounds, suggesting that the indoor air quality was less than the outdoor air quality. It was found that none of the indoor VOC concentrations measured exceeded the upper limits of the indoor air quality set by the Kuwait Environmental Protection Agency (KEPA), with the exception of only one residence where the benzene concentration was observed to be in excess of 17 per cent of the KEPA limit. Moreover, the indoor air quality for the study areas was found to be in accordance with level 1 set by KEPA, indicative of very good air quality.

This is the first study conducted in Kuwait to collect VOCs samples and to explore the air quality inside and outside of residential buildings.

In this study, the conditions of obtaining neutral calcium sulfonate which is added to engine oils as a detergent‐dispersant was studied. For this purpose, post‐dodecyl benzene sulfonic acid, obtained from post‐dodecyl benzene which remains as the bottom product during the production of dodecyl benzene sulfonate was used as the initial substance. Additionally, the reactor to be used in the production of neutral calcium sulfonate was designed and the amounts of spindle‐oil, toluene, raw sulfonic acid solution and Ca(OH)₂ used during neutralization were determined.

The purpose of this paper is the design and investigation of novel acrylated epoxidized soybean oil-based photocurable systems as candidate materials for optical 3D printing.

Aromatic dithiols, benzene-1,3-dithiol or benzene-1,4-dithiol, were used as cross-linking agents of acrylated epoxidized soybean oil in these systems. Kinetics of photocross-linking was investigated by real-time photorheometry using two different photoinitiators, 2, 2-dimethoxy-2-phenylacetophenone or 2-hydroxy-2-methylpropiophenone, in different quantities. The effect of the initial composition on the rate of photocross-linking, mechanical, thermal properties and swelling of obtained polymers was investigated.

The rate of photocross-linking was higher, more cross-links and shorter polymer chains between cross-linking points of the network were formed when benzene-1,4-dithiol and 2, 2-dimethoxy-2-phenylacetophenone were used in compositions. The higher yield of insoluble fraction, glass transition temperatures and values of compressive modulus were obtained when benzene-1,3-dithiol and 2, 2-dimethoxy-2-phenylacetophenone were used in compositions.

This is the first study of acrylated epoxidized soybean oil-based thiol-ene system by real-time photorheometry. The designed novel photocurable systems based on acrylated epoxidized soybean oil and benzenedithiols are promising renewable photoresins for rapid optical 3D printing on demand.