Journal of Techniques

The critical buckling load of column for different cross section shapes is analyzed. The constant cross sectional area of all shapes is assumed constant. The theoretical equation of buckling load is compared with the finite element model using ANSYS11 program. A good resultsare obtained as comparing with the theoretical. The results indicate that the critical buckling load depends on the shape and dimensions of column section. It is observed that the higher values of critical buckling load are found in the U- section while the Z- section gave lower values. Increasing the thickness of cross section resulted in decreasingthe critical buckling load. Approximately, it has been observed that the increasing the width of column section resulted in increasing the critical buckling load.

The purpose of the present paper isto identify theinfluences ofMetal inert gas joiningmethod on the behavior of AA 6061 -T6 joints’ regarding corrosion. Many experiments have been performed to test the rate of the corrosion of this alloy. Metal inert gas (MIG) welding processhas been performedonplates having a thicknessof 6mm to producemultiple buttwelding connectionswithmeasurements of (100 *50* 6)mm,withmarginalangle of single and twofold V of 70⁰byfiller metal having symbol ER- 4043 and Argon as a protecting gas. The connected pieces are examined byX-ray radiography.
The welded joints were treated by heat, the joints heated for half an hour in the stove to 150 C° then cooled in the air to releasethe connecting stresses.Numeroussampleswere providedfor the corrosion examination inmeasurements of (15*15*3) mm agreeing to ASTM G71-31 from the weld joint and the base metal, then the microstructure was examined. The corrosion test was achieved by potentiostatic polarization measurements in 3.5%NaCl seawater at various temperatures (25, 50, 75°C). It was found that the corrosion rate for the base metal decreases as the media temperature increasesbecause the increasing temperature prevents the oxygen from dissolving in the water and accelerates the chemical reaction between the metal and the oxygen forming aprotective layer. Besides, the results of the corrosion rate for the weld joints showed a noticeable decrease for the same reason and for the change in the microstructure during the welding.

Theinfluence ofshot peening onbending strength using MIG welding joint aluminum alloys 2024-T351 was studied. The paper implements many series of experimental techniques to figure the bendingstrength of all specimens , by performance hardness, shot peen, remaining stress and bending examinations for un-joint and joinedsamples.
(MIG) process has implemented onsheets of "8mm thickness" to getbutt joiningconnections with measurement of (200 *100* 8) mm with joining readying angle in formsingle and double V of 75⁰and flatjoinby "ER- 4043(Al-Si5)"as a "groutmetal"and "argon" as protected gas. The juncturesareexamined by"X-ray radiography"and exceptedtheimperfect joint, then Welding joint exposed to heat treatment to removed joiningresidual stress.
Hardness was measured using Vickers test and the specimens microstructure were examined, finally bending testimplemented on the samples which fabricated into typicalexaminationsample dimensionagreeing to the ASTM (E 190-92) of welded and un welded joints, and then ejaculation by steel ball in diameter 1.25 mm for 10 min to show the influence of shot peening on weld bending
The Results of bendingqualities for MIGweld connected showdecay when comparing it with theunwedded joints and chiefly along the HAZ .but unweddedsamples were fiascoes nigh the middle line of the sample shot peening contributed in improvement of bending process for all specimens. Ansysprogram was used to conduct stress analysis operations.

Represent airports with its intricate tangle requirements integrated cities as it comprises interference planning and design, as well, they are one of the most widely used spatial spaces by several nationalities and rumored to be used by airlines belonging to different countries, Also, the increase in the number of aircraft and increasing its flights and the remarkable increase in air traffic between the different countries of the world during the past two decades a significant impact on the complexity of the problem of planning and design required for many of the airports, and necessary that the sites are viable airports and specifications and operational planning and enjoys strategic locationsoccupies qualify for this important position and that the process depends on the locating of a series of planning criteria and determinants of which take into account the factors affecting the choice of location appropriate for airport,Aim of the research is to verify the efficiency of the spatial location of the Middle Euphrates Airport(Proposed project implemented in the holy city of Karbala) and evaluate factors influencing the

This paper investigate the effect of tilt angle on heat transfer through (12.5*12.5*100 cm) packed duct experimentally. The duct was at a vertical position ,heated at constant heat flux varying from (0.2 to 0.5 kW/m2) and the tests were done for Reynolds number (8010 to 18400). The porous duct were packed by ( 12 piece) of commercial galvanized steel wire mesh and arranged courrgeatly in (V end) shape (zig-zag) at the center line axial with pad porosity (Ɛ=0.99).
The results showed that Nusselt number was increasing with increasing heat flux and Reynolds number. Average Nusselt number obtained in this work at vertical duct was increased up to ( 150% ) when compared to empty duct and up to ( 40% ) when compared to horizontal duct at the same tested condition. This results indicated that heat transfer in vertical duct is enhanced than horizontal duct.

The present study was conducted for Cr+3 removal which is one of the most toxic wastewater pollutants onto zero-valent iron. In this system, the toxins are removed from in situ site by an arrival of the wastewater through a permeable sorbent packed columns filter occupied with a special sorbent solid .However, the filter resources should be carefully chosen. A chain of batch tests were handled with synthetic wastewater. The contact time mixing of sorbate and sorbent (0-240) min, initial Cr+3 concentration (50-250) mg/L, pH (3-6), zero-valent iron dosage (10-100) g/ L, and achieve the speed of agitation (50-250) rpm, have been studied the effect of these parameters in batch tests and the outcomes displayed that the optimum values for the efficiency of removal of Cr+3 (=93%) were 90 min, 50 mg/L,4, 50 g/L and 200 rpm respectively. As well as the results showed that the model Langmuir in representation of adsorption data is the best fitting compared with model of Freundlich under the same circumstances. Mathematical model which is established on ''finite element'' technique was handled to simulate the carrying of Cr+3 under equilibrium situation. The data based on predicted and experimental showed that the permeable sorbent filter acting the role of potential in the limitation of the sorbate plume movement and a respectable matching between these data were obtained with RMSE ''root mean squared error'' no more than 0.152.