Tikrit Journal of Engineering Sciences

Friction Stir Welding (FSW) is a solid-state welding technique with non-fusible rotary welds. Heat is generated by the friction produced between the weld tool and the two opposite surfaces of the two welded parts and the tool works on mechanical mixing with the presence of heat, pressure, and heat generated, reaching approximately (80-90%) of the melting point of the metal to be welded. In this study, Al 1050 H14 aluminum with a thickness of (6mm) was used for the purpose of welding it by means of the friction stir welding process in a butt welding method to obtain similar welding joints. A set with a square stitching tool Made of alloy steel was used by using a milling machine, with fixed (rotational speed of 1008 rpm and linear velocity of 40mm / min), an inclination angle of (2o), and counterclockwise rotation. The efficiency of welded joints was evaluated through static mechanical tests. Tensile tests, microscopic hardness, and visual examination. The results for all welds showed that the mixing zone (NZ) consists of fine grains of equal axes compared to the base metal. When welding on one side and in one path, the microstructure of HAZ was similar to the base metal. TAMZ was a transition region between HAZ and NZ. As for welding on one side, with two paths and three paths, the structure turned into a fine crystalline structure. By increasing the number of paths per side, the welding efficiency of the welded sample increased as the best efficiency was from one side and three paths (76.215%). Through the results, the tensile strength increases with the increase in the number of paths, as the best tensile strength was obtained when conducting the welding process from one side and by three paths, which is (93.653 MPa). It is equivalent to 76.21% of the tensile strength of the base metal. The hardness value in the weld zone (NZ) is higher than the other two zones (HAZ, TMAZ) due to the occurrence of dynamic recrystallization, which results in very fine and equiaxial crystals, but the hardness value in the weld zone remains less than the hardness value of the base metal.

This paper deals with the study of drought in the Nineveh region using
the Chinese Z index (CZI) for a time scale (1 month). Historical data were
used from 1981 to 2018 for Mosul, Sinjar, and Tal Afar stations. The
return period and probability event for the moderate drought were
calculated for each month separately. The results indicated that all
stations experienced the highest drought intensity in March compared
with the other months. The average probability of moderate drought
ranged between 0-0.31 for all months, and the maximum severity of the
drought was found in December from 2004 to 2008 for all stations. In
addition, the results showed that the region's climate during the study
period was within the mild drought and humidity (closest to normal).
This paper is the first study using the Chinese Z-index (CZI) in the study
area and the Iraq region

In this paper the effect of die angle, fluid pressure and axial force on loading paths were studied. In order to reduce the cost and time for the experimental work, ANSYS program is used for implementing the Finite Element Method (FEM), to get optimized loading paths to form a tube using double – cones shape die. Three double die angles θ (116˚ 126˚, 136˚), with three different values of tube outer diametres (40, 45, 50) mm were used. The tube length L_o and thickness t_o for all samples were 80 mm and 2 mm respectively.


The most important results and conclusions that have been reached that had the highest wall thinning percentage of 26.8% with less corner filling is at tube diameter 40 mm and cone angle of (116^°) at forming pressure of 43 MPa with axial feeding 10 mm. However, the lowest wall thinning percentage was 6.9% with best corner filling at diameter 50 mm and cone were angle of (136^°) and forming pressure of 30 MPa with axial feeding 4.5 mm. Two wrinkles constituted during the initial stages of forming the tube with initial diameter of 40 mm where the ratio d⁄(t=20) (thick-walled tubes) for all die angles, while only one wrinkle is formed at the center for tubes diameter 45 and 50 mm (thin-walled tubes) . The difference in the location and number of wrinkles at the first stage of formation depends on the loading paths that has been chosen for each process, which was at the diameter 45 and 50 mm towards thin-wall cylinder deformation mode was uniaxial tension. The maximum wall thinning percentage was at the bulge apex for tube diameter 40 mm. But, the maximum wall thinning for tubes of diameters 45 and 50 mm was found at the two sides of the bulge apex .

Thermophysical Properties of Building Materials are Considered to have high importance in predicting building thermal performance, calculating thermal loads inside building, and optimizing the use of a building and insulating materials. Due to the lack of measurements of local building materials properties, designers and air- conditioning engineers have no choice but to use the published foreign data, which probably leads to inaccurate predictions of thermal loads and may give a false thermal performance. At the same time, it leads to an over-designed capacity of air- conditioning systems that lead to increased energy consumption in the building. Thus, it is clear that it was important to conduct this research to evaluate the thermal conductivity and thermal resistance of Iraqi building materials. The number of the local building materials were listed, and specimens were collected from their sites, factories, and suppliers such as bricks, stones, concrete products, gypsum, etc. Those samples were dimensioned to the specific size required when a measurement was conducted by the Hot Wire method. All measurements were carried out at room temperature. The relationship between thermal conductivity, density, moisture content, and pressure for a number of materials was Studied. A comparison between the measurements of the Iraqi building materials and results published in the ASHRAE, CIBS Guide, Australian Specifications, and Jordanian Specifications was made. However, the availability of such data is important for the climatic design of buildings, thermal load calculations for air- conditioning, and choosing the insulating materials.

The research aims to choose the paths of urban expansion by
adopting a correct scientific approach that enhances the
methodology of spatial analysis of the most appropriate sites
by studying indicators that affect the city, and since the
hierarchical analysis method is a scientific method, i.e. the twoway
comparison process, the comparison of couples is the one
who reaches the relative weights of factors or Indicators and
evaluation. Therefore, spatial decision-making usually
includes many criteria that reflect the opinions and decisions
of decision-makers, experts, interested parties and
stakeholders to determine the paths of urban expansion, and
because of these multiple opinions and decisions, all these
matters must be resolved through the adoption of a strategy of
direct integration into the environment of information systems
programs. The geographical representation of the results of the
hierarchical analysis, which was based on the weights of all
factors, i.e. the main and sub-indicators obtained from the
Expert Choice program, which worked on the integration and
integration of multi-criteria capabilities by creating an
integrated integrated unit, which proved to provide and
provide practical and scientific solutions to decision makers in
the least possible time and cost. Effort as well as its ability and
competence to provide technical support to planning decision
makers. Through what we mentioned in the study of assessing
the spatial suitability of urban expansion, we obtained the
results of the most appropriate, most and least appropriate for
the areas of determining the paths of urban expansion in the
city of Kirkuk.