University of Thi-Qar Journal for Engineering Sciences

The method for localization of isolated direct contour lines based on form-factor is proposed in this paper. The essence of this method consists in comparison to unit of value of form-factor –the relations of the size of the contour line (distance between end points) to its length (number of the forming contour pixels). It is found that the proposed method provides a gain in speed of allocating direct contour lines in 4 times in comparison with the method of LSD (Line Segment Detector) and in 14.8 times in comparison with the method based on the Hough transform.The effective method of normalization of the contour line on thickness on the basis of the analysis of orientation of the connected pixels is proposed in this paper. This method is specially developed for deleting excess pixels of a dedicated line.Also developed algorithm of normalization of contour lines on thickness promotes the best calculation of a form-factor.

Pile foundation is widely subjected to both vertical and lateral loads. The available design procedure assumes that the effect of these two loads is independent of each other and hence the pile design is carried out separately for vertical and lateral loads. The traditional methods for analysis of piles according to sub-grade reaction methods also do not consider the effect of interaction between the different load directions. The effect of combination vertical loads and lateral on pile performance that installed in cohesionlesssoils is considered in this paper through three-dimensional finite element analyses. In the numerical model, the pile was treated as a linear elastic material and the soil was idealized using the Mohr-Coloumb constitutive model. The results from the analysis of single piles under combined vertical and lateral loads are studied in this paper. The influences of related parameters such as shear strength (angle of internal friction and dilatation angle) of soil in term of loose and dense sands and pile/soil interface friction coefficient have also been studied in this work.The results have shown that the combination vertical load and lateral has a significant effect on the pile performance that installed in cohesionless soil.

This work involves studying the effect of heat treatment on the fatigue stress of friction stir welded joint of 6061T6 aluminum alloy. The microstructure,micro hardness , tensile and fatigue test of the welds and base alloy were examined before and after heat treatment which includes solution heat treatment at 500ºC and artificial aging at 190ºC for 2, 4, and 8 hrs.The friction stir welding was carried out by using CNC milling machine at constant tool rotational speed of (1000 rpm) and welding speed of (20mm/min),the fatigue test is investigated for all specimens to obtain the S-N curve. The results show that the heat treatment decreased fatigue strength for all elements comparing with base metal, while ageing at 2 hrs gives the best fatigue strength due to participated phases.

Film cooling process is one of the most important external cooling methods used for gas turbine blades. In the present study the effectiveness of multi –row film cooling process on flat plate was estimated. Three rows of film cooling were considered with three configurations which are: simple injection angle with uniform cooling holes distribution, compound injection angle with uniform cooling holes distribution and staggered distribution for film cooling holes with simple injection angle. The simulation of the three cases were performed for different Reynolds number under real operating conditions. Gambit –Fluent package was used for the numerical simulation. Three dimensional incompressible turbulent flow with k –Ɛ model for turbulence was used for the simulation. The results show that, the staggered distribution for the film cooling holes gives the best for effectiveness the cooled surface.

The aim goal of this research was to study the effect of using the waste-iron which product from milling processes on the mechanical properties of concrete. The tests performed to evaluate waste-iron concrete are compressive strength, splitting tensile strength and flexural strength tests. Sixty cubes of concrete for the compressive strength, sixty cylinders of concrete for the tensile strength, and Sixty prisms of concrete for the flexural strength tests with different volume fractions of waste-iron (1%, 2%, 3% and 4%) were prepared. The specimens were tested at 7, 14 and 28 days age. The results show that the concrete mixes with waste-iron have a higher compressive strength, tensile strength and flexural strength than the plain concrete mixes. Concrete containing volume fractions 3% ratio of waste-iron has the maximum value of compressive strength, tensile strength and flexural strength. The primary effect for adding the waste-iron to the concrete is to improve the post-cracking behavior.

This research aims to study the effect of laser surface treatment on wear resistance of different aluminum alloys (5086H32,6061-T).The specimens were hardened by using pulse Nd:YAG laser with wave length 1064 nm and pulse duration 100 ns with constant energy 1J and spot size1–5mm .Wear behavior of the specimens as –received and specimens treated by laser being studied by using pin-on-disc technique under dry sliding wear conditions at different applied loads and different sliding speeds.This study shows that the wear rate increases by increasing values of applied loads and decreases with increasing sliding speed, and wear rate for 6061-T6 alloy is less than 5086-H32 alloy. Also the results show that the micro hardness decreases by increasing hardening depth and the micro hardness values for 6061-T6 alloy more than 5086-H32 alloy at the same depth.

The effect of water –gas shift equilibrium on adiabatic flame temperature for Alkanes family fuels was studied.The calculations of adiabatic flame temperatures were carried out by developing a program by using visual basic 6 language, based on a general algorithm meant to compute the equilibrium composition of products for any fuel–oxidizer gaseous mixture. The algorithm is based on the thermodynamic principles. Ten compounds were considered as products: the fuel (CnH2n+2), CO2, CO, H2O, N2, O2, CH4, C2H6, C3H8, C4H10, H2,their heat were capacities expressed as function of temperature with the form: Cp=ao+a1T+a2T2+a3T3. Two methods with and without water –gas shift equilibrium were used to analysis the products gases. The results showed, adiabatic flame temperature calculated with water –gas shift equilibrium greater than that calculated without water –gas shift equilibrium.