The laminar fluid flow of water through the annulus duct was investigated numerically by ANSYS fluent version 15.0 with height (2.5, 5, 7.5) cm and constant length (L=60cm). With constant heat flux applied to the outer duct. The heat flux at the range (500,1000,1500,2000) w/m2 and Reynolds number values were ≤ 2300. The problem was 2-D investigated. Results revealed that Nusselt number decrease and the wall temperature increase with the increase of heat flux. Also, the average Nusselt number increase as Re increases. And as the height of the annulus increase, the values of the temperature and the local and average Nusselt number increase.

In this work, PAni nanofibers (NFs) are successfully synthesized via hydrothermal method. The structural, surface morphological, optical, electrical and H2S gas sensing properties have been investigated for PAni thin films deposited by spin coating technique. The XRD pattern reveals crystalline nature of PAni NFs with crystallite size of 9.2 nm. The SEM image of Polyaniline clearly indicates that the polymer possesses nanofiber like structure. The optical properties show that the optical energy gap follows allowed direct electronic transition calculated using Tauc’s equation. Intense hotoluminescence (PL) peaks at 309, 340 and 605 nm are observed. The electrical properties such as D.C. conductivity and Hall effect have been studied wher

Random throwing of industrial waste has a significant impact on the environment unless it takes into account the conditions of engineered destroying and/or re-used. Taking the advantage of re-using waste materials in engineering projects represents a well-planned project in order to resolve a lot of engineering problems for some difficult soils. The objective of this study was to evaluate the capability and effects of Rubber Shreds (RS) from scrap torn belts towards improving the shear strength of soft clay. A direct shear tests were conducted on soft clay-RS mixture. The following parameters were investigated to study the influence of RS content, water content, normal stress, and dilation ratio. From experimental test results it was fou

In this paper, we derived an estimator of reliability function for Laplace distribution with two parameters using Bayes method with square error loss function, Jeffery’s formula and conditional probability random variable of observation. The main objective of this study is to find the efficiency of the derived Bayesian estimator compared to the maximum likelihood of this function and moment method using simulation technique by Monte Carlo method under different Laplace distribution parameters and sample sizes. The consequences have shown that Bayes estimator has been more efficient than the maximum likelihood estimator and moment estimator in all samples sizes

This research aimed to examine the effect of concentration of dyes stuff, contact time, temperature and ratio of adsorbent weight in (gm) to volume of solution in (ml) on the percentage removal. Two dyes were used; direct blue 6 and direct yellow and the adsorbent was the maize cob. Batch experiments were performed by contacting different weights of adsorbent with 50 ml of solution of desired concentration with continuous stirring at various temperatures. The percentage of removal was calculated and the maximum percentage of removal was 80%. And as the concentration of solution, contact time, temperature and the ratio of adsorbent to volume of solution increase the percentage of removal increase.

ABSTRACT

Critical buckling temperature of angle-ply laminated plate is developed using a higher-order displacement field. This displacement field used by Mantari et al based on a constant ‘‘m’’, which is determined to give results closest to the three dimensions elasticity (3-D) theory. Equations of motion based on higher-order theory angle ply plates are derived through Hamilton^, s principle, and solved using Navier-type solution to obtain critical buckling temperature for simply supported laminated plates. Changing (α₂/ α₁) ratios, number of layers, aspect ratios, E₁/E₂ ratios for thick and thin plates and their effect on thermal

In this work, a novel biocatalytic process for the production of 7-methylxanthines from theobromine, an economic feedstock has been developed. Bench scale production of 7-methlxanthine has been demonstrated. The biocatalytic process used in this work operates at 30 ^OC and atmospheric pressure, and is environmentally friendly. The biocatalyst was E. coli BL21(DE3) engineered with ndmB/D genes combinations. These modifications enabled specific N₇- demethylation of theobromine to 7-methylxanthine. This production process consists of uniform fermentation conditions with a specific metabolically engineered strain, uniform induction of specific enzymes for 7-methylxanthine production, uniform recovery an

Industrial wastewater containing nickel, lead, and copper can be produced by many industries. The reverse osmosis (RO) membrane technologies are very efficient for the treatment of industrial wastewater containing nickel, lead, and copper ions to reduce water consumption and preserving the environment. Synthetic industrial wastewater samples containing Ni(II), Pb(II), and Cu(II) ions at various concentrations (50 to 200 ppm), pressures (1 to 4 bar), temperatures (10 to 40 ^oC), pH (2 to 5.5), and flow rates (10 to 40 L/hr), were prepared and subjected to treatment by RO system in the laboratory. The results showed that high removal efficiency of the heavy metals could be achieved by RO process (98.5%, 97.5% and 96% for Ni(II),