Optimum lipid production using agro-industrial wastewater treated microalgae as biofuel substrate

Abundant wastewater discharges from palm oil industries in tropical nations being a valuable resource of biodiesel need proper exploration. Research hinted that such wastewater as economical nutrient source or substrate can support the cultivation of microalgae. In this experiment, we have tested the growth and lipid production of five different microalgal strains in palm oil mill effluent (POME). POME as a biofuel substrate is demonstrated to be lucrative for microalgae-assisted lipids production. POME is rich in macro- and micronutrients can be used as a growth medium for algal growth in order to reduce the growth medium cost and environmental pollutions. Among the five microalgal strains tested, Chlorella sorokiniana revealed optimum biomass and lipid production. The productivity was evaluated in terms of chlorophyll content, growth rate, biomass, and lipid content, which discerned to be 0.099/day, 8.0 mg/L day and 2.68 mg/mg cell dry weight (CDW). Furthermore, in this study, an optimization study was carried out to enhance the microalgae to produce high lipid content using carbon-to-nitrogen ratio and different light/dark periods. The presence of nitrogen combined glucose (with a carbon-to-nitrogen ratio 100:7) as an alternative source to carbon displayed higher lipid production of 2.68 (mg/mg CDW) by C. sorokiniana. This study confirms that 8:16 h light/dark condition at C:TN ratio of 100:7 supported to produce high lipid content of 17 mg lipid/mg CDW. The above results revealed that POME could be a suitable growth media for the alga C. sorokiniana to improve the maximum lipid yield for biofuels production.     

Comparative analysis of total proteins, amino acids, carbohydrates, fibers, lipids, macro and micro minerals contents in different types of Egyptian bread

Seven types of Egyptian bread were collected from different rural and urban areas. The chemical composition including total proteins, amino acids, carbohydrates, fibers, lipids, macro and micro minerals contents were determined. Total proteins content was higher in shamssy bread than other types of bread. Crude fat has the highest value in bread made from mixture of cereals, especially when trigonella is found, while fiber content was highest when mixture of cereals containing sorghum is used. Ash content of bread made from maize + wheat showed a higher value than other types and the differences were highly significant. Ca, Mg, Cu, and Fe were higher in bread made from sorghum + trigonella blend than other types of bread. Variations in the amino acids content of the different types of bread were found; these differences due to the origin of different cereals, the method of bread processing and the differences in the extraction rates of the flour.     

The physical and mechanical properties of polyurethanes from oleic acid polyols

Three different polyester polyols, with various oleic acid content, were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40, and Alk65, in which 28, 40, and 65 represent the percentage of oleic acid of the polyol formulations. These polyester polyols were reacted with aromatic diisocyanate [toluene diisocyanate (TDI)] to form PUR coatings. The acid value, hydroxyl value, molecular weight, and viscosity of the polyols have been determined. The reaction between the polyols and TDI was studied by Fourier Transform Infrared spectroscopy and X‐ray diffraction (XRD). The effects of varying NCO/OH ratio and oleic acid content of polyols on physical and mechanical properties of PUR films were studied. XRD results indicate that the samples are amorphous. PURs, made with Alk28, have the best mechanical properties followed by Alk40 and Alk65. The mechanical properties of the samples have increased as the NCO/OH ratio was increased from 1.2 to 1.6. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Transaction attributes and buyer-supplier relationships in AMT acquisition and implementation: the case of Malaysia

This paper explores how transaction attributes of technology affect differences in the relationship between technology buyers and suppliers. It also examines the impact on performance of different patterns of relationship between technology buyers and suppliers. Data obtained from 147 manufacturing firms in Malaysia are used to test several hypotheses, which were derived from a review of the literature on technology, transaction cost theory and buyer–supplier relationships (BSR). The research results indicate that the higher the level of technological complexity, specificity and uncertainty, the more firms are likely to engage in a closer relationship with technology suppliers. Even though the majority of firms reported improvements in their performance, results indicate that firms demonstrating a closer relationship with technology suppliers are more likely to achieve higher levels of performance than those that do not. It is also shown that with high levels of transaction attribute, implementation performance suffers more when firms have weak relationships with technology suppliers than with moderate and low levels of transaction attribute.     

Mechanical Properties and Welding Power of Friction Stirred AA2024-T35 Joints

This study is concerned with the effect of friction stir welding (FSW) parameters on the mechanical properties and the consumed welding power for AA2024-T35 joints. AA2024-T35 is friction stir welded at different welding speeds (16, 40, and 80 mm/min), rotation speed (900, 1120, and 1400 rpm), and two tool profiles (triangular and square). The welding power is measured and evaluated with two previously established models (O. Frigaad, O. Grong, and O.T. Midling, A Process Model for Friction Stir Welding of Age Hardening Aluminum Alloys, Metall. Mater. Trans. A, 2001, 32A, p 1189–1200; O.P. Heurtier, M.J. Jones, C. Desrayaud, J.H. Driver, F. Montheillet, and D. Allehaux, Mechanical and Thermal Modelling of Friction Stir Welding, J. Mater. Process. Technol., 2006, 171, p 348–357). The tool profile as well as the welding speed show significant effect on the microstructure especially at lower welding speeds. The increase of the welding speed improves the mechanical properties for both tool profiles whereas it has an insignificant effect on the welding power. The square profile produces better mechanical properties and consumed more power, at 40 mm/min, than the triangular one. Moreover, the welding speed showed a weak effect on the welding power, but the need of power increased with the increase of the rotation speed. The measured power is found to be in agreement with the computed one through a theoretical work established by Heurtier et al. (Mechanical and Thermal Modelling of Friction Stir Welding, J. Mater. Process. Technol., 2006, 171, p 348–357).     

Characterization of stabilized porous magnetite core–shell nanogel composites based on crosslinked acrylamide/sodium acrylate copolymers

Stabilized and dispersed superparamagnetic porous nanogels based on sodium acrylate (AA‐Na) and acrylamide (AM) in a surfactant‐free aqueous system were synthesized via solution polymerization at room temperature. The formation of magnetite nanoparticles was confirmed and their properties characterized using Fourier transform infrared spectroscopy. Extensive characterization of the magnetic polymer particles using transmission electron microscopy (TEM), dynamic light scattering and zeta potential measurements revealed that Fe₃O₄ nanoparticles were incorporated into the shells of poly(AM/AA‐Na). The average particle size was 5–8 nm as determined from TEM. AM/AA‐Na nanoparticles with a diameter of about 11 nm were effectively assembled onto the negatively charged surface of the as‐synthesized Fe₃O₄ nanoparticles via electrostatic interaction. Crosslinked magnetite nanocomposites were prepared by in situ development of surface‐modified magnetite nanoparticles in an AM/AA‐Na hydrogel. Scanning electron microscopy was used to study the surface morphology of the prepared composites. The morphology, phase composition and crystallinity of the prepared nanocomposites were characterized. Atomic force microscopy and argon adsorption–desorption measurements of Fe₃O₄.AM/AA indicated that the architecture of the polymer network can be a hollow porous sphere or a solid phase, depending on the AA‐Na content. © 2013 Society of Chemical Industry     

GEOCHEMICAL CHARACTERIZATION OF POTENTIAL JURASSIC/CRETACEOUS SOURCE ROCKS IN THE SHUSHAN BASIN, NORTHERN WESTERN DESERT, EGYPT

Some 180 core and cuttings samples of shales and limestones from the Middle Jurassic – Late Cretaceous succession (Khatatba, Masajid, Alam El-Bueib, Alamein, Kharita, Bahariya and Abu Roash Formations) were collected from wells Ja 27–2, Tarek-1 and Jb 26–1 in the central, structurally-low part of the Shushan Basin and from well Lotus-1 in the structurally-elevated western part of the basin. All samples were screened for total organic carbon (TOC) content. Selected samples were then analyzed by Rock-Eval pyrolysis, and extracted for biomarker analyses. Visual kerogen analysis and vitrinite reflectance measurements were also undertaken and oil - source rock correlations were attempted. The results indicate that the thermal maturity of the samples can be correlated closely with burial depth. Samples from the central part of the basin are more mature than those from the west. Samples from the central part of the basin (except those from the Albian Kharita Formation) have reached thermal maturities sufficient to generate and expel crude oils. Extracts from the Middle Jurasic Khatatba and Early Cretaceous Alam El-Bueib Formations can be correlated with a crude oil sample from well Ja 27–2.
In well Lotus-1 in the west of the basin, four distinct organic facies can be recognized in the Jurassic-Cretaceous interval. One of the facies ("facies 4") has a sufficiently high TOC content to act as a source rock. Thermal maturities range from immature to peak oil generation, and the top of the oil window occurs at approximately 8000 ft.     

In-Vivo Evaluation of Different Types of Commercial Aspirin Tablets

In-vivo evaluation of four different types of aspirin tablets namely effervescent, soluble, buffered and aluminium derivative of aspirin was assessed in six healthy subjects. The bioavailability parameters of the studied aspirin types were calculated. Effervescent aspirin showed the best results, while buffered aspirin showed the worst.

The pharmacokinetic parameters of the six subjects for the different types of aspirin tablets were also computed. Out of all the different types of aspirin tablets studied, effervescent aspirin exhibited the highest absorption rate constant, while aluminium derivative of aspirin showed the lowest absorption rate constant. Sex was found to greatly affect the absorption of aspirin from the different types of tablets studied, where in all cases male subjects gave higher absorption rate constants and greater bioavail ability parameters than females.     

Hydration of granulated slag-alite in the presence of quartz

The aim of the present work was to study the effect of quartz on the hydration characteristics of hydrothermally hardened granulated slag-alite pastes. The pastes, of water: solid ratio 0.20, were moulded at a pressure of 50 kg cm^–2 and autoclaved at 10 atm for 0.5, 2, 6, 12 and 24 h. Compressive strengths of the hardened product were determined, and the kinetics of reaction were studied by the quantitative determination of free lime and combined water contents. The phases formed after autoclaving were determined using XRD techniques. The reaction mechanism of the system under investigation was discussed and correlated to the strength of the hardened product. It can be concluded that the addition of quartz to slag-alite mixture increases the strength of the final product. The strength obtained for samples with high alite content are higher than that of low-alite content. Finally, the addition of quartz assists the formation of tobermorite in the hardened specimens.     

Ascorbate enhances iron uptake into intestinal cells through formation of a FeCl3–ascorbate complex

It has been well documented that ascorbate enhances iron uptake, with a proposed mechanism based on reduction to the more absorbable ferrous form. We have performed a study on the effects of ascorbate on ferric iron uptake in the human epithelial Caco-2 cell-line. Ascorbate increased uptake in a concentration-dependent manner with a significant difference between iron uptake and reduction. Uptake kinetics are characteristic of a non-essential activator and the formation of an Fe³⁺–ascorbate complex. This investigation provides evidence that ascorbate enhances the apical uptake of ferric iron into Caco-2 cells through the formation of a Fe³⁺–ascorbate complex.