A new technique is presented by which lateral outflows of material , from an oblique impact collision between wax projectile and a rigid surface , are collected to form a high speed single jet. This jet has been shown to be capable of producing cavities in semi-infinite target of wax in a manner similar to that produced in a hypervelocity impact situation. The produced jet capability of penetration is found to be maximum at higher velocities of impact , lower values of standoff and with projectiles having angle of obliquity in the range (â=20-25o). A preliminary theoretical model is also presented in an attempt to describe the process of jet creation and jet characteristics. The present technique is proved to be promising in simulating penetration of semi-infinite targets by the impact of high speed jet .
The study of springs Abu-Aljeer natural asphalt at proven of al-anbar (Iraq), to find a mean of exploiting the asphalt springs as alternative energy resource, Included two stages The first: Separation the components of asphalt in two ways the first is column chromatography and second represented by extraction- chromatography. The results of separation were 10.20% Asphltene, 89.18% Maltene which separated lately to (Paraffinic 45.23%, Aromatic 28. 39% and Resin 21.66%). The second: Trying to improve the asphalt specifications by using natural materials that are available locally (limestone) with (5, 15, 25, 35%), which have given good results. Rheological properties have been tested, in such average that (virgin Softening was 430C, became 560C, Penetration was 110 dropped 39 and viscosity was 11355 turnedy other 47231cent-Stok, mm2Sec), and flash point ( 1790 C became 200 0C), Fractionated parts of asphalt were characterized by (UV), (FT-IR) spectra. This study also clarified paraffin compounds which represent the main part material and the colloidal state is in Gel phase.
Addition of 40% of Phosphogypsum ( Pg ) and Cement Klin dust ( CKD) to Asphalt has given encouraging results including penetration , softening , Flash point an fire point identical to the accepted properties of industrial asphalt. Chlorination of Natural Asphalt at 1.5 hr the same additive of 40% in the presence of Fe2O3 as catalyst have affered optimizing rhealogy and thermal properties. The FT-IR and UV identifications have indicated the existence of clear groups as aresult of chlorination and additives. The microscopic study for floor samples have shown the good atomic distribution to floor asphalt .Generalty results on the modified natural asphalt ( Heet- Abo- Aljeer ) have proved the capability of using it in paving instead of Industrial asphalt .
The Cooper-Harper rating of aircraft handling qualities has been adopted as a standard for measuring the performance of aircraft. In the present work, the tail plane design for satisfying longitudinal handling qualities has been investigated with different tail design for two flight conditions based on the Shomber and Gertsen method. Tail plane design is considered as the tail/wing area ratio. Parameters most affecting on the aircraft stability derivative is the tail/wing area ratio. The longitudinal handling qualities criteria were introduced in the mathematical contributions of stability derivative. This design technique has been applied to the Paris Jet; MS 760 Morane-Sualnier aircraft. The results show that when the tail/wing area ratio increases the aircraft stability derivative increases, the damping ratio and the natural frequency increases and the aircraft stability is improved. Three regions of flight conditions had been presented which are satisfactory, acceptable and unacceptable. The optimum tail/wing area ratio satisfying the longitudinal handling qualities and stability is (0.025KeywordsLongitudinal Handling---Stability---Tail Design
The studying of the distribution of wetting patterns in soils having a stratified profile is of great importance due to the presence of this type of profile in abundance in agricultural lands, including greenhouses. Therefore, there was a need to develop a numerical program that predicts the dimensions of the wet area of the subsurface drip irrigation system under different operating conditions for purpose design and manage these systems properly to avoid water losses resulting from evaporation or deep penetration. The present study aims to develop a two-dimension model simulates the wetting pattern in stratified soils using (HYDRUS-2D) software and study the effect of soil hydraulic properties and different operating conditions on the progress of the wetness pattern and the interference pattern between two wetting fronts. Laboratory experiments were carried out for the system of subsurface drip irrigation in stratified soils that consisted of three layers (silty clay loam soil, loamy sand soil, and sand soil) arranged from bottom to up. Three different emitter flow rates 0.5, 1, and 2 l/h were tested, as well as three different initial moisture contents for each soil layer were considered. The interference pattern between two wetting fronts of two emitters with different spacing between emitters 30, 40, and 50 cm was studied. A numerical model was developed to guess the horizontal and vertical dimensions of the wetting zone for the single emitter and the pattern of interference between the two wetting fronts of two emitters. The predicted values obtained from the numerical model were compared with those obtained from laboratory experiments. Statistical analysis of the obtained data showed that the developed numerical model has a good ability to guess the dimensions of the wet pattern of the single and the two emitters and there were good agreements between the predicted and the experiments results and minimum values of RMSE ranged between 0. 5 and 3.6 were achieved.