A hyperboloid solar concentrator (HSC) was designed with a truncation angle side to the entrance aperture by simulation in the Zemax Optical Design software. The (HSC) has a wide exposure range to solar radiation due to the relatively large entrance aperture. The design consists of an entrance aperture facing the sun to obtain the largest possible amount of solar radiation, and a small exit aperture compared to the entrance aperture whose mission is to receive solar radiation after it enters the entrance aperture and reflects it from the inner reflective walls of the (HSC). In the exit aperture, there is a detector to measure the number of rays incident on it, which is a measure of the optical efficiency of the sample. A hybrid sample has been designed with an angular truncation at the front of it. This feature contributes to a greater absorption of solar radiation for greater efficiency. The results showed a slight change in the value of optical efficiency when changing the truncation angle, and the values of optical efficiency were superior to designs that had a small concentration ratio, and optical efficiency increased with increasing the concentrator length.
After the twenty – first century become necessary for us motorcade era in educational a chevements by searching for the best strategies and teaching methods and techniques artotalbagesh resorting to the strategy
Did not use in use in the teaching of the foreseeable material general by voice and teaching perspective for the student of the class fourth science
In particular ,so the researcher asking the question follows:
Can the peer education strategy to have an impact in perspective drawing skill development ?
From here it demonstrated the importance of current research know the impact of p
... Show MoreA new Schiff base [I] was prepared by refluxing Amoxicillin trihydrate and 4-Hydroxy- 3,5-dimethoxybenzaldehyde in aqueous methanol solution using glacial acetic acid as a catalyst. The new 1,3-oxazepine derivative [II] was obtained by Diels- Alder reaction of Schiff base [I] with phthalic anhydride in dry benzene. The reaction of Schiff base [I] with thioglycolic acid in dry benzene led to the formation of thiazolidin-4-one derivative [III]. While the imidazolidin-4-one [IV] derivative was produced by reacting the mentioned Schiff base [I] with glycine and triethylamine in ethanol for 9 hrs. Tetrazole derivative [V] was synthesized by refluxing Schiff base [I] with sodium azide in dimethylformamid DMF. The structure of synthesized compound
... Show MoreAims: The aim of this study was to evaluate the value and accuracy of longitudinal strain in detection of coronary artery disease compared to coronary angiography. Results: The left ventricular longitudinal strain-speckle tracking showed evidence of stenosis of left anterior descending artery, circumflex artery and right coronary artery in (86.1%), (76.4%), and (84.7%) respectively. For the stenosis in left anterior descending artery, the current study showed that the longitudinal strain was a good predictor for presence of significant stenosis with a sensitivity of (93.8%), specificity (75%) and accuracy (91.7%) compared with coronary angiography. For the stenosis in right coronary artery, the left ventricular longitudinal strain had
... Show MoreA new ligand [N-(3-acetylphenylcarbamothioyl)-4-methoxybenzamide](MAA) was synthesized by reaction of 4-methoxybenzoylisothiocyanate with 3-aminoacetophenone,The ligand was characterized by elemental microanalysis C.H.N.S, FT-IR, UV-Vis and 1H,13CNMR spectra, some transition metals complexes of this ligand were prepared and characterized by FT-IR, UV-Vis spectra, conductivity measurements, magnetic susceptibility and atomic absorption, From obtained results the molecular formula of all prepared complexes were [M(MAA)2(H2O)2]Cl2 (M+2 =Mn, Co, Ni, Cu, Zn, Cd and Hg),the proposed geometrical structure for all complexes were octahedral
Highway embankments stability during its service period represents an important factor for the safety of highway users and vehicles. Consequently, the cost of construction of these embankments should be adequate to maintain the safety and durability during this period through proper estimation of the loading on asphalt pavement, slope stability, horizontal and vertical deformation, etc. Slope stability of the embankment mainly depends on the shear strength of the soil layers materials; this shear strength is affected by the water table level through the contribution of the capillary water. Negative pore water pressure above the water table level evolves matric suction in the unsaturated zone above water table; this matric suction increases
... Show MoreThis study was aimed to reduce the amount of the sprayed solution lost during trees spraying. At the same time, the concentration of the sprayed solution on the target (tree or bush) must be ensured and to find the best combination of treatments. Two factors controls the spraying process: (i) spraying speed (1.2 km/h, 2.4 km/h, 3.6 km/h), and (ii) the type of sensor. The test results showed a significant loss reduction percentage. It reached (6.05%, 5.39% and 2.05%) at the speed (1.2 km/h, 2.4 km/h, 3.6 km/h), respectively. It was noticed that when the speed becomes higher the loss becomes less accordingly. The interaction between the 3.6 km/h speed and the type of Ultrasonic sensor led to a decrease in the percentage of the spray
... Show MoreIn this paper, SiO2 nanoparticles thin films were synthesised at different PH values of solution by sol gel method at fixed temperature (25oC) and molar ratio (R =H2O/precursor) of (Tetra Ethyl Ortho Silicate) TEOS as precursor at (R=1). The structure and optical properties of the thin films have been investigated. All thin films were tested by using X-RAY diffraction. All X-RAY spectrum can be indexed as monoclinic structure with strong crystalline (110) plane. The morphological properties of the prepared films were studied by SEM. The results indicate that all films are in nano scale and the particle size around (19-62) nm .The size of silica particles increases with increasing PH value of solution where both the rate of hydrolysis and
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