Rheological properties of Deurex – modified WMA binder containing SBS

Recently, warm mixture asphalt (WMA) technologies drawn much attention for their benefits to environment and workability. Deurex is novel type of warm mixture asphalt additive, which is extracted from sugar cane. The objective of this study is to experimentally investigate the effect of Deurex on SBS modified asphalt. The Deurex was blended into SBS modified asphalt at the dosages of 2%, 3% and 4%. Physical properties tests including penetration, soft point and ductility, dynamic shear rheometer (DSR), and bending beam rheometer (BBR) tests were carried out. The test results showed that the increase in Deurex additive could significantly reduce the viscosity of SBS modified asphalt, which indicates that the Deurex can serve as an effective type of warm mixture asphalt additive. In addition, the results showed that the addition of Deurex can enhance the high temperature properties while lower the low temperature performance of SBS modified asphalt. However, as long as the Deurex dosage is not higher than 3%, the low temperature grade of WMA binder keep the same as the control binder.     

Thermolysis of AP–additive mixtures,III1

Abstract

Thermolysis of ammonium perchlorate (AP) in presence of additives such as CaCO₃ and CaO has been investigated by Ignition delay, DTA, and photomicrography techniques. The ignition delay, ignition temperature, and decomposition temperature and activation energy are found to decrease when CaO was incorporated in AP. However, CaCO₃ affected the ignition of AP at higher temperatures (622-770°K) but very little effect was observed at lower temperatures (<623°K). Thermolysis of AP seems to proceed through condensed phase reactions in presence of CaO and CaCO₃ and role of these additives in the deflagration and decomposition of AP has also been discussed.     

Predicting PVT properties of Egyptian crude oils by a modified Soave–Redlich–Kowng equation of state

The study aims to predict the physical properties of Egyptian crude oils using modified Soave–Redlich–Kowng equation of state. The modification was theoretically developed and then performed by using data of 43 black oil samples representing all active oil producing areas of Egypt. The equation enables to predict the bubble-point pressure, oil formation volume factor, gas–oil ratio, oil density, crude oil gravity, gas gravity and gas formation volume factor of black oils with average relative errors ranging from 0.01% to 10.713%.Calculation sensitivity of the proposed MSRKE is determined by testing four oil samples collected from different locations in Egypt and comparing the measured PVT properties with those calculated from MSRKE. These evaluations show an excellent agreement between the measured properties and calculated ones.The estimation of reservoir liquid and gas properties from MSRKE is often needed when detailed laboratory PVT data are not available.     

Rutting and moisture resistance evaluation of polyethylene wax–modified asphalt mixtures

One of the methods newly introduced in pavement technology to address environmental concerns and reduce total gas emission is warm mix asphalt (WMA) technology. In this study, polyethylene wax is used to produce WMA mixtures. Although this technology has several positive features, moisture and rutting resistance of WMA mixtures are always questionable. To evaluate moisture and rutting resistance of polyethylene-modified mixtures, indirect tensile strength and dynamic creep tests were used, respectively. Results indicated that polyethylene has positive effect at low compaction temperature on moisture resistance, and also has negative effect on rutting resistance.     

Quantitative characterization of polyacrylamide–shale interaction under various saline conditions

Interaction of polymer-containing injected fluids with shale is a widely studied phenomenon, but much is still unknown about the interaction of charged polyacrylamides such as anionic and cationic polyacrylamides with shale. The nature of interaction of charged polyacrylamides with shale is not well understood, especially from the perspective of assessing the potential for polyacrylamides to cause formation damage. Zeta potential and rheological measurements were made for Chattanooga and Pride Mountain shales suspended in polyacrylamide solutions with and without inorganic salts and tetramethyl ammonium chloride (TMAC). The change in zeta potential and viscosity with time was recorded. The magnitude of decrease in the absolute value of zeta potential with time is indicative of adsorption of polymer on the surface of shale and serves as a measure of the extent of polymer interaction with shale. The salts that were used in this study are potassium chloride (KCl), sodium chloride (NaCl). This study quantified the interaction of anionic and cationic polyacrylamide with different North American shales. From the experimental results, it was determined that the polyacrylamides can interact strongly with shale, particularly the cationic polyacrylamide. The objective of this study was to determine the extent of interaction of anionic and cationic polyacrylamide with each shale sample in the presence of additives such as salts.     

Determination of organochlorine pesticides in shrimp by gas chromatography–mass spectrometry using a modified QuEChERS approach

Pacific white shrimp (Litopenaeus vannamei) collected during dry and rainy seasons from three different states in Malaysia were analyzed for nine organochlorine pesticides (OCPs) (α-HCH, β-HCH, γ-HCH, δ-HCH, trans-chlordane, cis-chlordane, p,p′-DDE, p,p′-DDD and p,p′-DDT) using QuEChERS sample preparation method and GC–MS SIM with split/splitless injection mode. The efficiency of combination of primary and secondary amine (PSA) and octadecyl (C18) at 25 mg of PSA and 25 mg of C18 per mL of shrimp extract as the clean-up sorbent to remove matrix interferences was evaluated. By combining PSA and C18, matrix interferences such as gamma-tocopherol and cholesterol were not able to be eliminated. Good separation and high recoveries which ranged from 90 to 105% with associated RSD < 15% were obtained for all OCPs at 3–75 ng/g. No significant difference in recoveries due to seasonal variation for studied OCPs, except for α-HCH, β-HCH, δ-HCH and p,p′-DDT were obtained. The limits of detection and quantification ranged from 0.3 to 4.5 ng/g and 3 to 15 ng/g, respectively. The linearity for matrix matched standard calibrations was >0.99.     

Synthesis,characterization and comparative study of nano-Ag–TiO2 against Gram-positive and Gram-negative bacteria under fluorescent light

Currently, some of the major problems affecting the world are air pollution as well as microbial contamination. Every time we breathe, we are risking our lives by inhaling dangerous chemicals and biological contaminants that have found their way into the air. Therefore this work focuses on the antibacterial activity of Ag–TiO₂ to overcome the microbial contaminant and infectious disease. Ag–TiO₂ nanosolution were synthesized by sol–gel method and found to be an effective visible light driven photocatalyst. The nanosolutions were characterized by X-ray diffraction (XRD), transmittance electron microscopy (TEM), photoluminescence (PL) spectra, and X-ray photoelectron spectroscopy (XPS). At the concentration of 0.2–0.1 M, Ag–TiO₂ caused 100% inhibition of bacterial growth. The antibacterial efficacy of Ag–TiO₂ was evaluated with two kinds of bacteria; Gram-positive and Gram-negative. The colony count of Ag–TiO₂ against Gram-negative were evaluated with stain such as Escherichia coli, Pseudomonas aeruginosa and Shigella while for Gram-positive were investigated with Staphylococcus aureus, Bacillus subtilis, Bacillus cereus. Colony count results indicated that Ag–TiO₂ able to kill bacteria at the lowest concentration of 0.05 M that contains 0.06 mol % Ag. From the SEM and TEM observation, the survival of the Gram-positive was low and the decomposition was rapid as compared to Gram-negative bacteria.     

Microbiological,physico-chemical and organoleptic attributes of a country tomato salad and fate of Salmonella enteritidis during storage under aerobic or modified atmosphere packaging conditions at 4°C and 10°C

The effect of initial head spaces of air and 5%CO₂/95%N₂, on the microbial flora of tomato salad (Greek style) was studied at 4°C and 10°C. The microbial flora of tomatoes comprised of lactic acid bacteria, pseudomonads and yeasts. Lactic acid bacteria were the predominant organisms in all samples. The pH dropped during the storage of country salad and this was more pronounced at 10°C. The concentration of different organic acids such as lactic, acetic, formic and propionic increased in all samples stored under modified atmosphere (MA) packaging conditions at both temperatures. The spoilage of tomatoes stored under 5%CO₂/95%N₂ was delayed, as indicated by the changes in their texture, color and odor, compared with those samples stored under air. When country salad was inoculated with Salmonella enteritidis, the pathogen survived but did not grow regardless of the packaging system used at both temperatures.     

The changes of hydrocarbon generation and potential in source rocks under semi-closed conditions with 50–840 bar water pressure

In order to investigate the effects of water pressure on hydrocarbon yields and potential in source rocks, carbonaceous mudstone from drilling in Liaohe Basin was pyrolyzed in simulation with constant water pressure and high-water-pressure experiments. Results demonstrate that the times of expelling hydrocarbon remarkably promote source rocks yielding liquid hydrocarbons. Increasing water pressure may increase the reaction of generating bitumen and oil, and enhance liquid hydrocarbons generation. Results of TOC, Rock-Eval, and elemental analysis in this study suggest that carbonaceous mudstone dominated by type-III kerogen remains a large number of hydrocarbon-generating potential, which may indicate that carbonaceous mudstone has a good potential to yield deep oil and natural gas. Besides, vitrinite reflectance may be the most suitable parameter to describe the maturity of source rocks.     

Epoxidation and oxidative dihydroxylation of C<Subscript>10</Subscript>–C<Subscript>13</Subscript> unsaturated bridged hydrocarbons involving hydrogen peroxide and modified forms of heteromolybdic compounds

Induced oxidation of C₁₀–C₁₃ tricyclic bridged olefins synthesized from C₅–C₈ cyclodiene hydrocarbons using hydrogen peroxide has been studied. It has been shown that phosphomolybdic heteropoly compounds supported on a finely divided carbon material and additionally modified with HBr and CoCO₃ or Gd₂O₃ exhibit high activity in this reaction. Depending on the conditions of the experiments, the main reaction products are the corresponding oxiranes and diols that retain the structure of the reactant hydrocarbons.     

Hydrotreating of vacuum gas oil on modified Ni–Mo/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalysts

The effect of the introduction of P₂O₅ into Ni–Mo/Al₂O₃ catalysts on their activity in the hydrotreating of vacuum gas oil has been studied. As the support, γ-Al₂O₃ prepared from aluminum hydroxide AlOOH powder of the TH-100 brand (Sasol) has been used. The catalytic properties of the catalysts obtained have been examined in the hydrotreating of vacuum gas oil in a continuous-flow unit under hydrogen pressure. The amounts of sulfur and polycyclic aromatic hydrocarbons, the hydrocarbon group composition, and the carbon residue of the feedstock and the hydrotreating product have been determined. The catalysts after testing have been studied using differential thermal analysis in combination with thermogravimetry (DTA–TGA); the influence of the amount of the modifier on the catalytic activity and coking of the catalysts has been shown.     

Permeability of C<Subscript>1</Subscript>–C<Subscript>3</Subscript> hydrocarbons through MDK membranes under nonisothermal conditions at lower temperatures

The presented nonisothermal technique for investigation of membrane gas separation (using MDK-1 membrane as an example) demonstrates possibilities of rapid assessment of the separation power of commercial membranes for both individual components and various mixtures in the temperature range of?20 to +40°C. The efficiency of the membrane process under these conditions (cross-flow membrane module model) for separation of propane–methane mixtures has been evaluated. It has been shown that the permeability of methane decreases with a decrease in temperature in the Arrhenius coordinates and the propane permeability increases. The separation selectivity in the mixture decreases by more than twofold in comparison with the ideal selectivity. Nevertheless, a significant improvement of separation has been observed at lower temperatures, with the recovery of the desired product and its purity being variable in a wide range depending on the practical goal. The nonisothermal technique is supposed to be useful for rapid selection of conditions (temperature, pressure, components to be separated) for efficient application of polymeric membranes for separation of hydrocarbon-containing mixtures that are close in composition to real gas sources.