Articles in This Issue
Abstract
During the last years, several researches have been studying the final disposal of tyres wastes, due to the great volume generated worldwide, as well as the difficulty for discarding the disposal sites which become a serious environmental problem. In spite of this, recycling appears as the best solution for disposing tyres residues, due to its economical and ecological advantages. This research carried out to assess the feasibility of using crumb rubber (the product of shredding used rubber tyres) as a partial sand replacement in foamed concrete, and investigates the effect of it on some properties of foamed concrete such as, density, water absorption, compressive strength, tensile strength, flexural strength and impact resistance. Crumb rubber of tyres ranging from (0.7 to 5mm) in size was used in this research. Three proportioned mixes were designed in this research, have the same cement content, water-cement ratio, and foam content. The first mix represents a typical reference formulation of foamed concrete without crumb rubber (FC). In the others mixes (FCR-1 and FCR-2), respectively, 20 and 30% of volume of sand were replaced by crumb tyres rubber waste. Tests carried out to assess the behaviour of final product. The results obtained were demonstrated decreasing in foamed concrete strength (compressive, tensile, flexural, and impact) with the increasing of crumb tyres rubber content in the mixture and rubberized foamed concrete specimens (FCR-1 and FCR-2) show a cohesive behaviour than the specimens of reference mix (FC), especially in tensile strength. Comparing with the reference mix (FC), at an age of (28 days), the decreasing of compressive strength was (20.85%) for (FCR-1) and it for (FCR-2) was (37.76%).
Abstract
The research studies the prediction of thermal characteristics for open designer shape of solar collector of flat plate of area 2.34m2, connected to water tank of 85 liter capacity . Mathematical model was represented and made the system of private accounts, transactions and through the creation of mathematical equations and solved numerically using the method of Finite Difference Method (FDM).The results of research is to obtain hot water at average temperatures up to 520C at mid-day during February month, as the water temperature is at its lowest value in this month in Baghdad city, with an average efficiency of the system up to 53.6% .This predictive study is compared with a previous measurement work and confirmed that the results match well.
Abstract
The aim of the study is to investigate the effects oils vegetable blends on the performance of single cylinder compression ignition Engine. The three types of vegetable oil appeared to affect the engine performance in a similar way and compared well with diesel fuel, this paper included prepared four samples fuels . They include (10% sunflower oil- 90% diesel blends) , (10% olive oil – 90% diesel blends), (10% corn oil- 90% diesel blends) and pure diesel . The testing achieved between different fuel simples by using the engine four stroke type (TD111) with a single-cylinder and compression ratio (21:1) . The results show that there is decreasing in parameters performance of engine with using vegetable fuel blends , the brake power decrease as (7.4% ),(5.2%) and ( 1.3%) with using the samples (10% olive oil – 90% diesel blends) , (10% sunflower oil- 90% diesel blends) , and (10% corn oil- 90%diesel blends) respectively compared with pure diesel fuel for the engine speed of 2000 r.p.m. .While at same engine speed the ηbth showed a decrease as (10.9 %),(7.5%) and ( 5.8%) with using the (10% olive oil – 90%diesel blends) , (10% sunflower oil- 90%diesel blends) , and (10% corn oil- 90%diesel blends) respectively compared with pure diesel fuel . At the same time , it can be found that bsfc also increases as (7.9% ) , (5.7%) and ( 2.4%) with using (10% olive oil – 90% diesel blends) , (10% sunflower oil- 90% diesel blends) , and (10% corn oil- 90% diesel blends)compared to pure diesel fuel . The exhaust gas temperature decrease as ( 7 0C),( 5 0C)& (3 0C) with using the samples (10% olive oil – 90% diesel blends) , (10% sunflower oil- 90% diesel blends) , and (10% corn oil- 90%diesel blends) respectively compared with pure diesel fuel for the engine speed of 2000 r.p.m. .
Abstract
Plates with interior openings are often used in both modern and classical aerospace, mechanical and civil engineering. The understanding of the effects of two cutouts on the stress concentration factor, maximum stress and deflections in perforated clamped rectangular plates, were considered. Parameters such as location, size of cutout and the aspect ratio of plates are very important in designing of structures. These factors were presently studied and solved by finite element method (ANSYS) program. The results based on numerical solution were compared with the results obtained from different analytical solution methods. One of the main objectives of this study is to demonstrate the accuracy of the analytical solution for clamped square plate. In general, the results of the square clamped plates with two cutouts come out in good agreement. The results presented here indicated that the maximum stress, deflection of perforated plates can be significantly changed by using proper cutouts locations and/or size. The results show that the rectangular plate containing two cutouts arranged along the width is stronger and stiffer than when arranged along the length at a given spacing, and the square plate is always stronger and stiffer than an equivalent rectangular plate for the same loading condition.
Abstract
Modeling and simulation are indispensable when dealing with complex engineering systems. It makes it possible to do essential assessment before systems are built, Cantilever, which help alleviate the need for expensive experiments and it can provide support in all stages of a project from conceptual design, through commissioning and operation. This study deals with intelligent techniques modeling method for nonlinear response of uniformly loaded paddle. Two Intelligent techniques had been used (Redial Base Function Neural Network and Support Vector Machine). Firstly, the stress distributions and the vertical displacements of the designed cantilevers were simulated using (ANSYS v12.1) a nonlinear finite element program, incremental stages of the nonlinear finite element analysis were generated by using 25 schemes of built paddle Cantilevers with different thickness and uniform distributed loads. The Paddle Cantilever model has 2 NN; NN1 has 5 input nodes representing the uniform distributed load and paddle size, length, width and thickness, 8 nodes at hidden layer and one output node representing the maximum deflection response and NN2 has inputs nodes representing maximum deflection and paddle size, length, width and thickness and one output representing sensitivity (∆R/R). The result shows that of the nonlinear response based upon SVM modeling better than RBFNN on basis of time, accuracy and robustness, particularly when both has same input and output data.
Abstract
TMF (thermomechanical fatigue) damage model devoted to prediction of the high temperature fatigue lifetime of navel copper alloy (C46400) , was proposed .This model was built on the basis of the stress –number of cycles curve responsible for damage due to interaction of high temperature and fatigue. This obtained prediction compared was very favorably with the cumulative experimental TMF results.
Abstract
This research work includes production of polymer modified polystyrene concrete and studies the mechanical properties. Several proportions of raw materials were used to produce this type of concrete. This study is intended to improve the mechanical properties of light weight polystyrene concrete using styrene butadiene rubber(SBR) with rate of (5,10,15and20)% of cement weight. Compressive strength, flexural strength, impact strength and dry density tests were made on more than 150 specimen at age of 28 days. The results show that the addition of (SBR) with range of (5-20)%of cement weight is improve the flexural strength with range (3.74-18)%, and improve the impact strength with range (39-163)%. Also the results show that it is possible to produce polystyrene concrete with density (1680,1433 and 1147) kg/m3 replacing light weight Polystyrene aggregate with volume fraction (30,50 and70)%of sand.
Abstract
An experimental study was done on a solar water heater which consists of two prisms of orthogonal triangle cross-section with a 210 liters capacity . The heater was easy to make and has a low cost when comparted with other types of solar water heaters that it usually the collector separate on the water store. The study included experimental investigations , the experimental investigation was done under the Iraqi environmental conditions at Baghdad for the period in summer and winter seasons in 2006 but the calculation for only two days 15/7/2006 and 6/12/2006 . The study included testing the heater with & without loading and it tested in 13/12/2006and14/12/2006. draining hot water from storage tank at different rates . The experimental result show the ability to get hot water at 46oC at December i.e. a temperature rise at 30oC with 16oC initial temperature .
Abstract
The research deals with a study carried out on the influence of iron oxide (Fe2O3) on the characteristics of kaolin clay and the possibility of reducing iron oxide percentage in kaolin clay in the location of Ghamij in Anbar Governorate, prior to using it in industry. The raw material used in the research contained about 5.72% of iron oxide. When such a percentage of iron oxide is contained in kaolin clay, it makes it harmful in numerous industries such as paper, plastic, drugs etc….. In this research the hydro metallurgy method was used where oxalic acid was diluted with distilled water, and with the help of heat and mixing ( as assisting factor) to cause iron oxide to melt and thereafter subjected to filtration and thus the ‘Bakkag’, i.e. white kaolin which was almost free from iron oxide was obtained. The sample of kaolin raw material weighted about 25 grammas and the acid diluted in the distilled water used along periods of (2, 3) hours weighted (4,5,6,7,8,10) grammas. The findings showed that this method is very practical in ridding the kaolin samples from iron oxide; in the sample where the concentration of the acid amounted to 6 along a 3- hour period, the percentage of iron oxid reduced to 3.2% In this way much of iron oxide melted and even its red color of the raw material changed to white. The same result was obtained by using a No. 10 concentration acid was used for two hours, the percentage of iron oxid reduced to 3.18%.The construction of iron oxide reach to 45%,the loss in weight of raw material used in this research is about 14%.
Abstract
The purposes of planning for housing and solve the housing problem of the most important topics in studies of housing also it is one of the topics broad and complex, and that the planned housing in accordance with the cost and social benefit is the solution to reduce the heights fantasy of the costs of housing. Also its negative effects on the process of housing where most of Iraq's society of the middle class is needed to adequate housing with income, especially if we consider that there is a deficit of housing dramatically in Iraq. Which is estimated at more than three million housing units and offset by a significant decrease in the rates of housing construction, also which are led to the worsening problem of housing in the country, especially those with low income, so it requires the parties responsible speed up the adoption of the strategy to solve the problem of housing in the country adopt the principle of the establishment of residential low-cost through the adoption of residential buildings, multistorey (3-4) stories as characterized by the buildings of the densities of housing appropriate of effective use with economic land and reduce the costs of housing to meet the large deficit and demand residentialdemand. In order to reach the desired goal has been studied and the reality of the housing in Ramadi in the, Ta'meem, 5 km and the 7 km areas and limited the problems of constraints related with planning housing also its components as well as access to some of the experiences of countries in planning, housing and solving the housing crisis within finding the alternatives to some traditional building materials with finding teams cost whenusingthesealternatives. Also supports research field study of three residential compounds, which aims at evaluating the appropriateness of such style housing and how to achieve social benefits and meet the standards of planning and design proposed in the scheme of public housing in Iraq which have been using the method (analysis of cost - benefit) for the trade-off to choose the best alternative of residential complexes three (and low cost, Ta'meem, the 7 km), which achieves less expensive and better utility.