Articles in This Issue
Abstract
The presented work investigates the effect of addition admixture (cement kiln dust) to concrete as a partial replacement of cement weight. Cement kiln dust was added by (10,30,50)% of cement weight.Four mixes were selected, three of them contain cement kiln dust (CKD) and one reference mix without any admixture for ages (7,28,90) days. Compressive strength ,flexural strength, ultra-sound velocity (UPV), slump, splitting tensile strength and static modulus of elasticity were tested.The test results indicated that the use of (CKD) led to significant decreasing in concrete strength in general and this decreasing increases with the increasing of (CKD), for example at 28 day the compressive strength of reference concrete (A) was 35 MPa, while the compressive strength of (B,C,D) contain (10,30,50)%CKD were (28,25,22) MPa respectively.
Abstract
The aerodynamic characteristics of forward swept wing were studied theoretically and experimentally .In the present work, theoretically a computer program was constructed to predict the pressure distribution about surface of the wing using three dimensional Low Order Subsonic Panel method. The aerodynamic coefficients of the wing were calculated from the pressure distribution which gained from tangential velocities Experimentally ,test were carried out by designing and manufacturing a wing model with special arrangement for pressure tapping, suitable for low wind tunnel testing. The entire wing was rotated rotate about an axis in the plane of symmetry and normal to the chord to produce different sweep and incidence angles for wing, by using rotating mechanism. Wind tunnel test was carried out at (Uپ‡=33.23m/s) for different swept angles and angles of attack.Comparisons were made between the predicted and experimental results. It is good and gave reasonable closeness. It was clear from the present investigation that the lift and drag characteristics for the forward swept wing are less in values compared with the swept back wing, therefore a forward swept wing can fly at higher speed corresponding to a pressure distribution associated for lower speed.
Abstract
Natural convection heat transfer in two-dimensional region formed by constant heat flux horizontal flat tube concentrically located in cooled horizontal cylinder studied numerically. The model solved using the FLUENT CFD package. The numerical simulations covered a range of hydraulic radius ratio (5, 7.5, and 10) at orientation angles from (0o up to 90o). The results showed that the average Nusselt number increases with hydraulic radius ratio, orientation angles and Rayleigh number. As well as enhancement ratio for Nusselt number at orientation angle 90o and hydraulic radius ratio 7.5 equal 24.87%. Both the fluid flow and heat transfer characteristics for different cases are illustrated velocity vectors and temperature contours that obtained from the CFD code. The results for the average Nusselt numbers are compared with previous works and show good agreement.
Abstract
The increase in traffic volumes at intersections is one of the important problems that makes difficulties in the traffic movement then leads to traffic congestion in these facilities.The objective of the present study is improvement the traffic operation of the selected intersection (Al-Zeoat intersection) in Al-Ramadi city by analysis and evaluation this intersection and using accepted solutions to improve the traffic operation of Al-Zeoat intersection under local exist conditions and present a best proposal to enhance the performance at the intersection.To achieve these objectives, the traffic volumes data collection and geometric layout for Al-Zeoat intersection that required for the traffic and geometrical analysis were gathered manually, while SIDRA traffic program is used for the requirements of traffic analysis process.
Abstract
In recent years, the elastomer forming technique has found acceptance on the shop floor and is used increasingly as a pressure- transmitting medium for various metal-forming operations. This is due mainly to the introduction of a new range of materials and of new concepts in tooling, which have served to kindle industrial interest in the process. The purpose of this paper is to study the sheet formability with compressible die (natural rubber). The forming was occurred using hemi-spherical punch and rubber die. Experimental tests were used to know the mechanical properties for rubber and sheet materials which were brass and aluminum. After that several forming processes were prepared with a 58 mm diameter steel ball as a punch to form 0.5 thickness brass and aluminum dishes with different diameters (15-40 mm). Force-stroke history was plotted through forming to find the stiffness of formed plate with rubber die and later to compare this parameter for different diameters. Wrinkling and springback were pointed for the formed dishes. It was found that the stiffness of the formed dish increases with diameter until reaching to the diameter at which wrinkling will takes place (about 33 mm for aluminum and 28mm for brass), and then the stiffness will decreases with diameter above this value. It was found that the springback ratio (ratio of final high to the stroke) was increased with diameter until wrinkling takes place, and this ratio is greater for aluminum than that for brass. The results show that it is able to use natural rubber as a die for sheet metal forming with limitation of using small sheet thickness
Abstract
Fire clay are directly into kaolin with different weight percent. Density, shrinkage , water adsorption properties were studies at )1000C0 (and )1200C0 ( . All samples pressed under (10 tan) . The results showed that the fire clay increase density , at the same time decrease the shrinkage and water adsorption .
Abstract
The movement of water in the soil are affected by many factors including: the soil structure and texture, the flow rate , the volume of application water ,application method (continuous or intermittent), initial water content of the soil, and temperature of water and soil. The bulk density of surface soil or sub surface soil will be changed due to tillage or compaction operations , so the research aims to study the effect of bulk density on the advance of the wetting front under trickle irrigation. The experiment Included 9 tests for monitoring the advance of the wetting front with time, during the water application phase and water redistribution phase, using three cases of provider soil densities virtual amount of 1.35 and 1.45 and 1.55 g / cm 3, using three flow rates 0.675, 1.350, 2.700 cm 3 / min / cm. The study showed that the horizontal advance increases and the vertical advance decreases with the increase in bulk density, although the decrease in the vertical advance is greater than the increase in the horizontal advance with the increase in bulk density of soil profile during the water application phase. The study also demonstrated that the percentage of change both the horizontal advance and the vertical advance through water redistribution phase relative to the value of each of them at the end of the water application phase are 27.2% and 35.1% respectively, and there is no effect to change the bulk density of the soil profile on these ratios. The study clarified that the percentage of change both the horizontal advance and the vertical advance through the water redistribution phase relative to the value of each of them at the end of water application phase increases with the decrease in the flow rate. And the degree of increase in the vertical advance roughly constant, while there is decrease by the increase in the horizontal advance with the increase in flow rate the water redistribution phase.
Abstract
High performance thermal insulators industries is recognized as one of most significant industries worldwide. This, of course, due to its basic role in industries requiring elevated temperatures. Concerning this target, a former study was performed in production of a thermal insulator containing locally available kaolin taking into consideration the effect of ignition temperature and grain size on the general specifications of the insulator. The low alumina content in kaolin samples , as shown by analysis, has resulted in lowering both the softening and melting points. It is planned in this research to study the effect of soaking time and added alumina on improving physical, thermal and mechanical properties of kaolin sample. Certainly, better properties of sample will result in better performance towards thermal insulation and to be more effective in resisting elevated temperature without affecting other properties.
Abstract
This search includes analysis of Fallujah water network that are fed from the old drinking water treatment station in Fallujah , which provides citizens in residential areas (AL-Jolan District, AL- Mu'tasim district, AL-Andalus district) by drinking water by using a program (EPANET) in the hydraulic network analysis .It was found their are lack in the required amount of water which estimated by about 20% due to oldness of the station and the lack of expansion by estimation the population growth the city. After input required the data in the analysis in got the results, it was noted that the three areas were getting the amount of required water, but the speed of water in the pipe network was very low and below the allowable limits (less than 1 m / s), this means that the design of the network has not takes into account the economic side and health status. The results were compared with the situated case and found a lack of water amount reaching the people as a result of trespasses and interruptions which occurring in the network, as well as the head pressure which reach the supply points fall within the permissible limits where ranging between (38-48 m) but the use of water pumps in homes lead to decrease the head pressure whenever the node far away from the drinking water station.
Abstract
To create an architecture with a local identity, expresses its environment convenient with contemporary time, we need to examine the architectural traditions of the region and get interest from the results which produced by old architects to be suited with natural and social circumstances. Confusing ideas and non related modern architectural products in addition to the incorrect following to the modern movements, led to lose the local identity and to harden distinguish among different environments (general problem) then there's no closeness with those products and feeling estrangement from them because they forced to our Arabic environment, by copying known architectural compositions here & there in regions with civil and social values different entirely from the west. Generally some of new architects (practically) , and specifically our student (academically) concern with western Architecture more than Islamic Arabic architecture history (specific problem) then the research problem is :there is non _clarity of means which might be a common base and guide for our new Architects & students to create a local architecture harmonize with society & environment , therefore the main objective of the research is: to come out with clear image about these means & fix them in our student minds in architectural schools (for both of academically & practically fields ) Accordingly we have to return to our traditions and investigate their properties and use them in such a way suitable with needs of time and progressive technology. That doesn't mean we have to metaphor formal and external language but we have to analyses the traditions and derive the distinguished sides and using them in modern way to create new modern architecture with local identity.