Reducing the drag force has become one of the most important concerns in the automotive industry. This study concentrated on reducing drag through use of some external modifications of passive flow control, such as vortex generators, rear under body diffuser slices and a rear wing spoiler. The study was performed at inlet velocity (V=10,20,30,40 m/s) which correspond to an incompressible car model length Reynolds numbers (Re=2.62×105, 5.23×105, 7.85×105 and 10.46×105), respectively and we studied their effect on the drag force. We also present a theoretical study finite volume method (FVM) of solving Reynolds-averaged Navier-tokes equations (RANS) using a realizable k–epsilon (k-ε) turbulence model, conducted on a car, model KIA Pride, which is popular in Iraq and Iran. All computational analysis and modifications were carried out using the ANSYS Fluent 19 computational fluid dynamics (CFD) software and SOLIDWORKS 2018 modeller. The drag coefficient of the analysed car was found to be 0.34 and the results show that the drag can be reduced up to1.73% using vortex generators, up to 3.05% using a rear wing spoiler and up to 2.47% using rear under-body diffuser slices modifications, whereas it may be reduced up to 3.8% using all previous modifications together.

A new panel method had been developed to account for unsteady nonlinear subsonic flow. Two boundary conditions were used to solve the potential flow about complex configurations of airplanes. Dirichlet boundary condition and Neumann formulation are frequently applied to the configurations that have thick and thin surfaces respectively. Mixed boundary conditions were used in the present work to simulate the connection between thick fuselage and thin wing surfaces. The matrix of linear equations was solved every time step in a marching technique with Kelvin's theorem for the unsteady wake modeling. To make the method closer to the experimental data, a Nonlinear stripe theory which is based on a two-dimensional viscous-inviscid interaction method for each station along the wing spanwise direction and Prandtle-Glauert rule for compressibility effect were used to enhance the potential results of the method. The fast turnaround time and the ability to model arbitrary geometries is the goal of the present work. Different airplanes configurations were simulated (DLR-F4, light jet, cargo and four engine commercial airplanes). The results of pressure and forces coefficients were compared with the DLR-F4 airplane. The comparisons showed a satisfying agreement with the experimental data. The method is simple and fast as compared with other singularity methods, which may be dependent as a preliminary method to design aircrafts.

The aim of this study was to evaluate the effect of age and season on the epididymal sperm and level of testosterone in camel. A total 103 camel testes samples were collected from Al-Najaf slaughter house during a cold season (December 2012, January and February 2013) and moderatehot season (March, April and May, 2013). Testes were divided into 3 Gs according to camel age, G1 included the testes of 2-3years, G 2 (3 – 4years) and over 4 years (G 3). Blood samples were collected for determination of serum testosterone level. The sperms were obtained from the tail of epididymis from all animals groups and the results of the sperms individual motility percentage was increased at the level of (P< 0.05) significantly with age progress in both seasons. Also, sperm motility of G3 recorded a significantly higher than those of G1 and G2 in cold and moderate-hot seasons .The live percentage of G 3 animals was 90.01% in cold season with a significantly higher than those of other Gs and in both seasons. However, the live sperm percentage of G 3 during moderate-hot season was 87.82% and G 2 during moderate-hot and cold seasons were 88.58 and 88.72% respectively, showed significantly higher than those of G1 during cold and moderate-hot seasons .The concentration of sperm obtained from epididymis tail of bulls camel significantly increase with age progress in both seasons. However, the mean of the sperm concentration in cold season showed significance higher than those in moderate-hot season in animals of G 1 and 3, respectively. The abnormal morphologically sperm percentage of animals G 1 in both cold and moderate-hot seasons were significantly higher than those of G3.The testosterone levels of the young animals (under 4 years) increased gradually and reached its peak in February 2.28 ng/ml and March 2.27ng/ml. In the same trend older animal (more than 4 years) was showed 8.14 and 7.35 ng/ml, respectively. The older animals showed a significantly monthly, higher values than those of the younger animals in their testosterone level started from January up to May. In conclusions during cold months the camel over 4 years shows higher percentage of epididymal sperms parameters (live and individual motility) and sperms concentration as well as serum testosterone level.

This article aims to establish and evaluate standards for critical equipment and materials in highway projects in Iraq. Delphi technique has been used to analyze, explore, and discover the main criteria and sub-criteria that affect equipment and materials in highway construction projects in Iraq. To determine the correct response to the criteria presented in this study, a program (IBM, SPSS/V25) was used to assess the main criteria and sub-criteria using the mean score (MS) and standard deviation (SD) technique, as well as to check reliability using Cronbach's alpha factor (α). The experts' qualifications and the extent to which the person is ready to commit are both important factors in panel selection. The design of a questionnaire, which is also identified as questions or repetitions, is based on a clear identification of study objectives, a literature review, and other primary research activities. By applying the Delphi technique steps and procedures, this research reveals fifteen (15) successful criteria in equipment and materials in highway construction projects in Iraq.