Solar collectors, in general, are utilized to convert the solar energy into heat energy, where it is employed to generate electricity. The non-concentrating solar collector with a circular shape was adopted in the present study. Ambient air is heated under a translucent roof where buoyant air is drawn from outside periphery towards the collector center (tower base). The present study is aimed to predict and visualize the thermal-hydrodynamic behavior for airflow under inclined roof of the solar air collector, SAC. Three-dimensional of the SAC model using the re-normalization group, RNG, k−ε turbulence viscus model is simulated. The simulation was carried out by using ANSYS-FLUENT 14.5. The simulation

A numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber  wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for  different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the

BixSb2-xTe3 alloys with different ratios of Bi (x=0, 0.1, 0.3, 0.5, and 2) have been prepared, Thin films of these alloys were prepared using thermal evaporation method under vacuum of 10-5 Torr on glass substrates at room temperature with different deposition rate (0.16, 0.5, 0.83) nm/sec for thickness (100, 300, 500) respectively. The X–ray diffraction measurements for BixSb2-xTe3 bulk and thin films indicate the polycrystalline structure with a strong intensity of peak of plane (015) preferred orientation with additional peaks, (0015) and (1010 ) reflections planes, which is meaning that all films present a very good texture along the (015) plane axis at different intensities for each thin film for different thickness. AFM measureme

The structural properties of the CuO nanopowder oxide prepared reflux technique
without any templates or surfactant, using copper nitrate hydrate (Cu(NO)3 3H2O) in deionized
water with aqueous ammonia solution are reported. The Xrd analysis data and processing in origin
pro program used to get FWHM and integral width to study the effect of different synthesis times
was studied on the structural properties. It was found that values of crystal sizes are 17.274nm,
17.746nm, and 18.560nm, the size of nanoparticles is determined by Halder-Wagner, and 15.796
nm, 15.851nm, and 16.52nm, were calculated by Size-Strain Plot (SSP) method. The Sample was
considered to determine physical and microstructural paramete

Soil stabilization with liquid asphalt is considered as a sustainable step towards roadway construction on problematic subgrade soil, there are no requirements to import good quality materials or to implement energy consumption, but to mix the readily available soil with liquid asphalt through the cold mix technique. In this work, collapsible soil obtained from Nasiriya was mixed with asphalt emulsion, lime, and combinations of lime and asphalt emulsion (combined stabilization) and tested in the laboratory for California bearing ratio in dry and soaked conditions. Field trial sections have been prepared with the same combinations and subjected to plate bearing test. The influence of combined stabilization on the structural properties in ter

In this study, the effect of the annealing temperature on the material properties and the structural properties of cuprous oxide was studied in order to investigate how the annealing temperature affects the material properties, and the temperature varied between 200℃, 300℃, 400℃ and 500 ℃ and was unannealed. The physical properties of the cuprous oxide were measured by X-ray diffraction (XRD). The XRD patterns showed that the Cu₂O nanoparticles were highly pure, crystalline, and nano-sized. From the XRD results, we found the pure cuprite (Cu₂O) phase. The values of crystal size were discovered and calculated by the Halder-Wagner and Size-Strain Plot (SSP) methods, respectively. The crystallite size increased

Flexible pavements are subjected to three main distress types: fatigue crack, thermal crack, and permanent deformation. Under severe climate conditions, thermal cracking particularly contributes largely to a considerable scale of premature deterioration of pavement infrastructure worldwide. This challenge is especially relevant for Europe, as weather conditions vary significantly throughout the year. Hydrated lime (HL) has been recognized as an effective additive to improve the mechanical properties of asphalt concrete for pavement applications. Previous research has found that a replacement of conventional limestone dust filler using hydrated lime at 2.5% of the total weight of aggregates generated an optimum improvement in the mec

The thermal properties of four nematogenic Schiff’s bases, n-butyl-to-n-heptyl of bis (4-n-alkyloxybenzylidine)-2,3,5.6- tetramethyl-1, 4-phenylenediamine, have been studied. The transition temperatures and enthalpies of transition were examined by differential scanning calorimeter (DSC). Several correlations were carried out; those included the relations between transition temperatures, enthalpies and entropies of transition with increasing the
number of carbon atoms in the terminal alkyl chains. In addition, new regular relations were found between the ratio of the enthalpies and of the entropies,  for noematic-isotropic transition and crystal-isotropic transition ( ΔΗ_Ν-i/AH_C-I, ΔS

     During this paper, new Schiff's base derivatives [F₁-F₅] were prepared through the reaction of dapsone drug with different substituted benzaldehyde compounds. Schiff's bases were then converted into 2,3-dihyroquinazolin-4(1H)-one derivatives [F₆-F₁₀] through the reaction with 2-amino benzoic acid in ethanol. The synthesized compounds were identified by their physical properties using UV-Vis, FT-IR and ¹H-NMR analyses. The liquid crystalline properties of some prepared compounds revealed smectic and nematic phases. Using two separate bacterial species, Pseudomonas aeruginosa (Gram -ve) and Staphylococcus  aureus<