Tikrit Journal of Engineering Sciences

In this study a cylindrical liner was produced by horizontal centrifugal casting process. The liner was composed from aluminum alloy (A380) matrix reinforced with alumina particles (Al2O3) with grain size of (63−125)μ and volume percent of 10,15 and 20%. The die was rotated at different speeds and its temperature was remained constant at (350)ºC.
In this present study it was concluded that any increase in temperature difference between pouring and die temperature will reduce the surface defects. This study reveals that increasing the rotational speed refines the grain size but cause the alumina particles to be concentrated at the outer surface. Finally it was found that the addition of alumina particles increases both hardness and wear resistance of the alloy.

Present research includes the study of theoretical and experimental behavior of hollow ferrocement beams, by using solid waste of empty plastic bottles and empty metal can. Solid reinforced concrete and reinforced cement mortar for the purposes of comparison between behavior of hollow ferrocement beams and solid beams were casted. The results showed the possibility and efficiently of producing lightweight hollow beams using solid waste. The hollow ferrocement beam have a good flexural strength resistance, toughness, and high ductility as use wired mesh converts a sudden failure to a gradual failure and distributes cracks along the beam. The results also show the possibility of the production of hollow ferrocement beams without rebar, where using of wire mesh only increasing the economic and easily produce these lightweight beams. The study proved that the ferrocement hollow beam fail under the load higher than the design load.

This paper presents an analytical and deductive study at software and hardware level for a symmetric multiprocessors system. Basic influential factors in the performance as cache memory size, processors number, and coherence protocols of cache memories are defined and compared, and a different simulations and evaluations of multiple experimental values of these parameters have been carried out also. In order to speed up the parallel processing and to improve the performance for realizing the execution in real time, harmonious values of these factors are obtained as experimental results.

The great difficulty in controlling the value of the continuous voltage and the inability to use electrical transformers because of constant produce flux by the direct current(DC) with time, therefore must be find other ways to control the continuous voltage value. The best methods used for this purpose are power electronics circuit, these circuits is buck converter, as a result of the output voltage becomes lower than from the input voltage. the renewable energies need to converter circuits to enable consumers to use and the circuit which represent the heart of the hybrid system (the sun /wind).
This research addresses use modern methods in the control of buck converter used with the hybrid systems (solar energy / wind) as well as mathematically represented using the equations and computer simulation program and the famous (proteas (ISIS professional)) .

The effect of sinusoidal corrugated upper surface for enclosure on the heat transfer by natural convection from two heat sources placed on the bottom surface of the enclosure has been studied. The two heat sources constant and high temperature, length of each heat source (10%) from the total length of bottom surface, the distances that do not contain heat source on the bottom surface thermally insulated, temperature of verticals walls and upper surface low and constant. corrugating upper surface was change the dimensional corrugation amplitude between (0.1-0.3), for number of corrugations (3), the dimensional distances between the two heat sources were change between (0.2-0.8), the Rayleigh numbers ranged between (103 ≤ Ra ≤ 105), the fluid inside the enclosure was air Prandtl number for it (0.7). were analyzed flow and temperature fields inside the enclosure numerically by solving Navier Stokes and Energy Equations, have been used Cartesian velocity components and pressure on a collocated grid are used as dependent variables in the momentum equations which discretized by finite volume method, body fitted coordinates are used to represent the geometry shape of the problem accurately, were grid generated technique based on elliptic partial differential equations, SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The results showed the increase in the magnitude of dimensional distance between two heat sources lead to increased average Nusselt number for all values of Rayleigh numbers (103 ≤ Ra ≤ 105), as are the highest value of the average Nusselt number at dimensional distance (0.8)and less value at the dimensional distance (0.2), the dimensional distance (0.6) is a special case when the Rayleigh number equal (105) as at least average Nusselt number from the remaining values of the two dimensional distances (0.2) and (0.4), as the average Nusselt number increases with increasing dimensional corrugation amplitude for the number of corrugations (N=3) for dimensional distance (0.8), as well as comparing numerical results showed good agreement with published results.

The information technology revolution is the most important attribute of our era under the technological competition in all fields of specialties and branches of knowledge. Using computer within stages of designing and directing the architectural works have had a great influence in entering new capabilities in architecture engineering through what in named (The Virtual Reality) which simulate all circumstances and probabilities in designing to live with a tangible experience completely which lacks nothing but to be a real experience. Also an urgent need has appeared for developing methods and means to evaluate architectural works in order to convoy the technology development that escorted the designing and establishing evenly, the matter which opened the way for using new technical means and tools that contribute in a great degree to identify specific characteristics of the architectural works through which it makes possible for giving a logical evaluation for these facilities to access the benefit of these characteristics in identifying many aspects relevant to the architectural works.
Relying on what is said above, the technique of classification of pictures is one of the new technological methods that uses developed programming languages to access results that are convincing and reliable in analysis. It is possible to deal with architectural result pictures as study samples according to a specific technique to attain the identification of the shape of characteristics of these facilities after it was restricted on visual observations to identify these characteristics, and that mislaid many important things in comparisons and controlling the select samples size. The )Image – j( program is used which has high ability and efficiency in the image
processing. This study is trying to deal with this important side of architectural work evaluation,
which opens new prospects in the architectural evaluation process.

Al-hawija district considered one of the most important agriculture regions in Iraq; it contains two big irrigation projects: Hawija irrigation project, and Kirkuk irrigation project, this research aims to study the use of wind electricity generation and irrigating agriculture areas in this region.
This study showed that the wind velocity, in general, has a low speed which is not appropriate to generate electricity unless its velocity not less than 3.5 m/s at a height of 10 m and it is suitable to amount towers reach 50 m in height. The wind velocity increased in summer then slowdown in winter. June, July, and August recorded the highest in wind velocity, the study showed that wind velocity was appropriate to pump water from the wells that have little to medium depth.

This research represents a practical study of the reality of fine aggregate quarries scattered across Salahalddin province, which includes the cities of Tikrit, Samarra, Balad, Dujail, AL-Dour, Tuz, Baiji and Shirqat suffering mostly from the failure of gradient and the percentage of total sulfate content (one or both).
The results showed that all the quarries in the province did not meet the requirements of Iraqi standards in the gradient except quarries of Tuz and Shirqat, while all of them except quarries of Daur and Balad has been successed when tested for percentage of total sulfate content. The problem of sieve analysis has been solved through a simple calculation and process which can be applied in the workplace easily and it has proved validity in practice. The work was by mixing Tikrit sand with Baiji sand by proportion of (1:1.08) ,Samarra sand with AL-Dour sand by proportion of (1:2.34), the corresponding proportion for mixing Balad sand with Dujail sand is (1:1.45).This process leads to the formation of a new sand mixture which has been achieved the requirements of Iraqi standard specifications No.45 of 1984 year for gradient and percentage of total sulfate content.
This research contributed in solving the problem of the adoption of most projects in the province on Tuz quarries only by the ability of using the produced sand of all quarries in the province. This process lead to reduce the cost of the produced sand compared with Tuz sand by ratios ranged between 32% to 48%.

Promoting power system performance is regarded as one of the essential issues for a sustainable customer service, alongside with the expansion of the inductive loads and population increase. The study aims to improve and promot power system performance by using series capacitors and phase – shifting transformers. The capacitors and transformers are used separately in the system, then they are used together in two separate lines for two load cases: the base load and the increasing the base load 25%. The system power flow has been examined by utilizing Matlab version 7.6. The study shows that the efficiency of both series capacitors and phase – shifting transformers in improving line loadability, whether used together or separately. The highest rate for improving line loadability was 53.15% when using series capacitor in the line 1 – 5. As for the transformer, the highest rate was 53.25% in the line 11–5. The study has also shown that adding series capacitor and phase–shifting transformer simultaneously to the system is more efficient in promoting and improving system performance than adding them separately. The current stud

Vibration in cars is undesirable because it causes discomfort to passengers, and can also lead to fatigue and failure of some parts of the vehicle. Therefore, the study and analysis of comments movements cart embedded in ever to research vehicles since the invention. And associated vibration cart passenger comfort, safety and stability of the vehicle. The researchers analyzed several vibration of vehicles by looking at different models, such as quarter wagon model ,and Half Car Model and full vehicle model with different types of excitement experienced by the vehicle and intended here excitement is a set of external forces arising from the terrain. This research includes a half vehicle linear model , written for four degrees of freedom plus one (4 +1 DOF) after addition degree of freedom which is driver / passenger seat system becomes a five degrees of freedom, also the vehicle body is assumed as a rigid body and taking into account the Bounce and Pitch. The system governing equations of motion are formulated by using the finite element method (FEM). A Fortran language computer program has been established for this purpose and used in the process covering (Simulation) and stand on the performance evaluation and analysis riding cart at the design stage and stand on the impact driver way through a study on the subject and the quality of the driver's seat, Two criterion of standards of comfort has been used, such as standard rate of absorbed energy (Average Absorbed Power) to be the norm over the driver comfort or not. And the comfort factor which is the vertical acceleration root mean square is used as an indication for the ride comfort. In factthe driver is the most important link in the process of using vehicles because the decision-maker and dominant direct the movement of vehicle.

The field and laboratory works of present study are focused on determination of the composition and generation rates of Residential solid wastes. The residential solid waste generation rate was found to be 0.496 kg/capita/day. Food waste comprises the highest percentage among other component about 76.688% from total weight of the solid waste.
The study also examined the weekly and seasonal variation of residential solid waste generation rate. It was clearly obvious. the maximum generation rate was recorded on Fridays of summer 0.519 kg/capita/day. Thus. the total daily amount of Residential solid waste which will be received at landfill will be 424.541 ton/day.

In this study, 68 wells were selected from different locations for the area located between Tigris river and Lower Zab river, and its suburbs south of Makhmor Mount. A series of chemical and physical tests were carried out for the groundwater of each well, where the calcium , total hardness (T.H)., total dissolved soled (T.D.S)., Electrical conductivity (EC), pH, Turbidity, Alkaline were examined..
Results were compared and evaluated with the limits permitted by the Iraqi standards for drinking water and with the specifications of industrial and agricultural consumption. The results showed the disqualification of most of these wells for drinking purposes because the high content of salt and high hardness, where exceed the limits of Iraqi standards for drinking water except one well. Also, the results show that 36 wells were suitable for irrigation and agriculture with taking precautions to proportion of salts, while 32 wells were not well within the specifications of irrigation water. The industrial consumption has been found that all wells were not identical to the specifications used in the food industry.