Journal of Engineering and Sustainable Development (JEASD)

This study is an attempt to find out how the reinforced concrete beams with edge openings behave under the effect of shear forces. Eight simply supported reinforced concrete beams were tested under two-point loads to measure the deflections, up to a specific limit that is below collapse. After that, the samples were repaired with steel plates of the thickness of 0.5mm with dimensions (120×30mm). These plates were stuck on the concrete beams using epoxy. The repaired beam was retested, measuring deflection versus loads up the appearance of the first crack. Three of these beam samples were strengthened by steel plates stuck to the faces of their opening. The dimensions of those plates were (150×100×0.5mm). All results were compared with the results obtained from ANSYS 7.0 program. It was found that the results were acceptable and could be adopted to give a good view of the behavior of such samples.

The geographical information system permits the study of the local distribution of phenomena, activities, and the aims that can be determined in the local surrounding like points, lines, and areas, where the geographical information system treats the data related to these points, lines, and areas to make the data ready to be returned for analysis or asking about certain information by using it. The research aims to employ the abilities given by GIS to use in the field of construction of water resources maps in Iraq by transferring the paper maps into digital maps. Then extracting the layers from this map and preparing the geographic database that is appropriate. After that analysis of these data is done which permits for less effort and cost and finally increases in the production and speed and accuracy.

This paper presents the finite element method to analyze the problems of earth-retaining structures in nonlinear partially saturated soil. The finite element formulation of the incremental Biot’s theory (1941) of consolidation is presented. This formulation is extended to represent the nonlinear time-dependent behavior of earth-retaining structures in partially saturated soil. Also, the concept of the thin layer element is incorporated to simulate the behavior at the interfaces between the soil and retaining structures. The finite element method is applied to analyze the construction of real braced excavation in soft clay. The results obtained are compared to the observed field results. Good agreement is obtained and the numerical method proved how can be used for analyzing related geotechnical problems involving consolidation and support systems in nonlinear partially saturated soil.

Introducing openings in existing reinforced concrete slabs can severely weaken the slabs due to the cut-out of both concrete and reinforcing steel. There are several traditional approaches to strengthening slabs with openings; however. these approaches can be cumbersome, expensive, and may require significant usable floor area. This paper reports field tests on the use of Carbon Fiber Reinforced Polymers (CFRP) strengthening and steel fiber to restore the load capacity of the slab after having openings cut out in the positive moment region. Eight slabs (450*450*40) mm were cast to evaluate the ability of the CFRP strengthening and steel fiber to restore the load capacity of the slab, made of self-compacting concrete, after introducing the openings. Two different strengthening techniques were investigated to determine the most effective system for strengthening. The two different strengthening techniques are the use of externally bonded CFRP strips and adding steel fiber 1% by volume fraction. Test results showed that the two strengthening techniques increased the load-carrying capacities of the slabs with openings. The CFRP is more effective than the steel fiber technique. The use of CFRP enable the slabs to restore their full load capacity and increased it by 30%, also the steel fiber hence enabled the slab to restore its full capacity and increased it by 20 %.CFRP and steel fiber reduced the cracks at the inside faces of the opening and also CFRP prevents it at the inside corners.

The purpose of this research is to develop an empirical model for total delay time prediction at roundabouts as a function of influence traffic and geometric features. Four roundabouts of fifteen approaches with different characteristics are selected in Karbala City. The traffic parameters are measured using a video recording technique. Geometric elements are measured through field surveys and satellite images. A statistical approach is used to develop three delay models (linear regression models with 95% and 50% confidence levels, and polynomial regression models with 95% confidence levels). The statistical analysis indicates that both geometric and traffic variables have a significant effect on the delay time. The entry radius and circulating traffic have the greatest influence. These models have been compared with the SIDRA delay model. It is found that although SIDRA delay overestimates delay time at a high delay range, it does not have a significant difference with the field delay at 95% confidence level.

The aim of this research is to investigate the effect of silica fume addition on the behavior of soil subgrades which has inadequate natural stability. Natural silty-clay soil and silty-clayey soil-silica fume mixtures were compacted at the optimum moisture content and subjected to various laboratory tests. The test results showed a significant improvement in swelling pressure and compressive strength of composite samples with silica fume. The swelling pressure decreased by 87% with increasing silica fume contents from 5% to 15% for all samples and the compressive strength of clay samples increased by 4% with increasing silica fume contents from 5% to 10% and after that, it decreased. It is observed that the permeability of soil increased with increasing silica fume content. The coefficient of permeability increased by 100% with increasing silica fume content to 15%. Also, the results show that the silica fume decreases the development of cracks on the surface of compacted clay samples by reducing crack width by 75%. The investigation showed that silica fume is a valuable material to modify the properties of soil subgrade to make them suitable for construction.

The observations and digital interpreted results of four simply supported composite reinforced concrete T-beams with steel channels tested up to failure under four-point loading conditions simulating approximately the central 1-m uniformly distributed load, are reported and discussed. Three of those beams were provided with headed studs. The variables were the headed stud shank length relative to the flange width of the steel channel and the breadth of the T-section beam, in addition to the existence or absence of shear connectors. The first beam was destitute of headed studs; while the three other beams were provided with headed studs of moderate length (equal to the steel channel flange width), 30% longer length, and 30% shorter length, beam. The beam with headed studs of moderated lengths has revealed substantial preeminence-of diverse numerical values in the respects of flexural stiffness, ductility and ultimate resistance, relative-slip constraint, and integrity characteristics for which mechanically-based argumentation is set forth. In spite of the concrete confinement in the zone of the steel channel, drastic drops in levels of the integrity and the ultimate bending resistance occurred when shear connectors were eliminated.

Twelve self compacted concrete (SCC) T-section beams were design and tested to determine the effect of using SCC on the shear behavior under two concentrated loads. All beams have the same longitudinal steel ratio of (0.018823) and gross section area of (20000) mm2. The tested beams were divided into two groups- with and without stirrups. The first group consists of three beams without stirrup and with different values of compressive strength (f'c).While the second group consists of nine beams with stirrups. It were divided into three series according to the compressive strength (f'c ) each series have three beams with different value of clear span to effective depth ratio (ln/d). It was found that The ultimate shear strength predicated from ACI 318M-08 is conservative prediction than the experimental values, The clear span to the effective depth ratio (ln/d) has a significant influences on the ultimate shear strength, The ultimate shear strength of SCC T-beams with stirrups increased about 28.57%.10.714%and 10.169%; when the compressive strength (f'c ) increased from (29.36 to 49.2 MPa), the ultimate shear strength of SCC T-beams without stirrups increased about 55.55%; when the compressive strength (f'c ) increased from (29.36 to 49.2 MPa).

One of the most important and major problems that face the controllable devices for industrial applications, and solid-state switches for pulsed power applications, is the high rate of current and voltage changes during the switching transients of the device. This problem can be overcome by suitable circuitry connected across the device which is well known as a Snubber Circuit. In this paper, a proposed numerical solution using the Fourth Order Runge-Kutta numerical method is applied to evaluate the values of the snubber circuit parameters to maintain the effect of current and voltage rate of changes, during device turn–ON, at levels that the device can withstand. Comparison with other design procedures showed good agreement with reasonable results for the circuit parameters to validate the proposed method.

Neural networks are facing many problems when they employ a backpropagation algorithm. These problems are characterized by long training time and trapping the network into local minima. For these reasons the trend, in recent years, started toward the application of the genetic algorithm because of its ability to discover wide and complex search spaces. In the present work, a number of comparisons between BP and GA have been carried out. The results regarding training speed and performance, show that GA is more suitable than BP for training neural networks (ANN). with respect to the results obtained, a novel approach for designing a multiplayer artificial neural network system has been introduced and implemented. The new system uses GA for updating and modification of the architecture and weight coefficients of the neural network.

Fast switching in SMPS generates a large amount of Electromagnetic Interference (EMI). The EMI consists of mainly common mode and differential mode noises. In the present work, conducted EMI is studied and a procedure for designing an AC power line filter is proposed. As an application of this design procedure, conducted EMI noise measurement and filter design of a boost AC-DC converter with PFC has been achieved while successfully satisfying the CISPR22/EN55022 limit in the frequency range from 150KHz to 30MHz, which confirms the validity of the design procedure.

Most of the early research on content-based image retrieval (CBIR) has been focused on developing effective global features. While these researches establish the basis of CBIR, the retrieval performance is still far from users’ expectations. The main reason is acknowledged to be the gap between low-level features and high-level concepts. To narrow down this semantic gap, an additive technique has been widely used: region-based features to represent the focus of the user’s perceptions of image content. The primary intent of this paper is to develop a system for efficiently retrieving similar images on the basis of their visual content from large image repositories. Studies on the benefit of various computational features in the description of visual contents of an image and on the grouping of features leading to successful retrieval results are the basis for the development of an image indexing and retrieval algorithm in this paper. This research presents an elegant and efficient system for content-based indexing and retrieval of images. The global and region features are extracted from the images and are used in indexing the same. Tree data structures are used in indexing the extracted region features. The proposed system makes use of the following image processing techniques: color space conversion, quantization, denoising, edge detection, and segmentation.

A smart antenna system can automatically change the directionality of its radiation patterns in response to its signal environment. This can dramatically increase the performance characteristics (such as capacity) of a wireless system. Among the most sophisticated utilization of smart antenna technology is SDMA, this technology increases the number of users that can access an existing wireless phone system by exploiting the spatial characteristics of the channel itself through the highly developed implementation of an intelligent antenna system's capabilities for receiving and transmitting. The cellular system must evolve to provide the required coverage and capacity, increasing the capacity of a cellular system using adaptive base station antennas by finding the optimum tradeoff between SDMA and interference rejection approaches. Measurements presented in the Matlab application have implications for increasing capacity and coverage area through the use of a smart antenna with SDMA when we compare the results with Omni antenna under the same number of channels, area, and the number of cells per cluster.

The Multiple-Valued Logic (MVL) is one of the keys to building processors in the future because the use of the MVL in control and uP will reduce the number of instructions that are necessary to solve problems and it increases the parallelism. The MVL will increase the speed of the systems and reduce the required memory size and reduce the connections. This paper proposed a new theory to extend the binary logic as operations in a new space called Convert-Coded-Collect space (CCCi). The CCCi space is a closed space that has i integer values, it is used to convert the input to the output in three phases called the convert phase, coding phase, and collect phase respectively. The CCCispace carries out with any integer number of MVLs that depend on the value of i. This paper will discuss two cases of the CCCi space, the first two values (i=2) that are called CCC2; it will prove that CCC2 is more efficient than the Boolean algebra. The other case for this space is CCC4 which has 4 values MVL. This theory is a useful MVL so it has simple functions with a package of advantages. This paper will discuss an example to design a logic multiplier under Boolean logic, under CCC2 space, and under CCC4space to show the advantages of the new theory.

The material of fiber and its length affect its characteristics such as chromatic dispersion D(λ) and bit error rate (BER). So in this paper two types of glasses, the fused silica (SiO2) and fused Germania (GeO2) were considered to study these effects and find which fiber is better to use in optical communications for wavelengths in the range (1-2) µm. Chromatic dispersion comes from combining two dispersions (waveguide dispersion and material dispersion). To solve the material dispersion, the Sellmeier formula was used. The numerical results and the figures shown in this paper were obtained by using Matlab software 2008. As a result of this paper, the GeO2 fiber is better than SiO2 fiber in communications because it has higher BER and less D(λ), and the fiber length is inversely proportional to the BER.

Composite material is commonly used in most industries: it became a basic substance for generating electric energy in many industries, aircraft , automobile and air turbine Composite material is a big family and it is classified into many kinds like fiber glass which has been frequently used in production, therefore many researches and tests have been made by taking samples and making tensile compression, impact and fatigue test as well as determining the numbers of layers which are the best fiber tensioned resistant, this will be discussed in this research, chapter one is an introduction to composite material and identification of fiber glass and its uses and properties, as well as making a comparison between its strength and the strength of steel, while chapter two, presents the researches, conclusions of previous researchers in the same field, the chapter three includes theories and equations which are used to know the size and thickness of fiber glass, the chapter four is a tensile test that has been made for some samples, the chapter five includes the results of this test, and the future advices for making this test or other tests for fiber glass and other composite materials discussed also.

Steam power plants are responsible for the production of most electricity in the world. A small increase in the thermal efficiency of the plant means a large saving in fuel consumption. Therefore every effort is made to improve the efficiency of the cycle on which steam power plants operate. One of the major elements that increase the efficiency of the power plants is the feedwater heater. The study has been carried out to investigate the causes of tube failure of the high-pressure feedwater heaters in an electric power station. Specimens of the failed tubes were examined and photographs of the microstructure of the tube material were taken. Mechanical properties and the chemical composition of the tube material were also examined. A comparison between the failed tube and the new tube was made. The results of the laboratory test showed that the main reason for the tube failure is the OD (outside diameter) erosion. This effect is very clear, especially in desuperheating zone.

Warm water is circulated through the soil medium in order to maintain the plant root zone above the same critical temperature. In power plants rejecting heat from steam through the condenser, the waste heat could be a suitable resource for soil heating. This work presents theoretical and numerical models. Two methods are applied with water temperature (20°C, 30°C, and 50°C) to give the temperature distribution in the soil around buried pipes carrying hot water. The Models used to calculate the required heated land area using the heat from power plants of Daura Steam Power Plant where the discharge 85000m3/hr at Tw = 20°C which is cover the land area (44.7Km2) with piping of (4cm) diameter and length of (10714m). The theoretical results are compared with experimental published work (Johnsion 1976) and showed good agreements.

Natural convection heat transfer with two-dimensional in a rectangular enclo¬sure is examined numerically. The enclosure object with a heated left side wall, while the right side was cold, and the top and bottom walls were adiabatic. The theoretical study involved the numerical solution of the Navier-Stokes and energy equations by using the finite difference method. The stream function– formulation was used in the mathematical model. The numerical solution is capable of calculating the velocity, stream function, vorticity, and temperature fields of the computational domain. A computer program in (FORTRAN 90) was used to carry out the numerical solution. The problem has been analyzed and the non-dimensional governing equations are solved using the finite difference method. The enclosure is assumed to be filled with air with a Prandtl number of 0.71. The problem is analyzed for different values of the Rayleigh number in the range from 103 to 105, aspect ratio parameter (AR: 1, 3, and 5). It is found that for small Ra, the heat transfer is dominated by conduction and begins to be dominated by convection with increasing Ra, and the Nusselt number Nu decreases with increasing AR due to decreasing the volume of the enclosure. In order to validate the numerical model, the results of variation local Nusselt number and relation between average Nusselt number and Ra number, are compared with previous works. For square enclosure filled with air (Pr=0.72). There is an agreement in results and found excellent agreement which validates the present computational model.

The compare Cr (VI) adsorption characteristics removed from artificial wastewater by using decolorized cooking tea waste (CTW) and commercial activated carbon (AC) were examined. Adsorption experiments were carried out in a batch process and various experimental parameters such as the effect of pH, rpm, temperature, adsorbent dosage, contact time, and initial chromium ion concentration on percentage removal have been studied. The adsorption process was found for two adsorbents to be highly pH-dependent. The maximum removal took place at pH 2. A significant fraction of the total Cr (VI) uptake was achieved within 180 min and an initial concentration of 50 mg/L. The maximum efficiency of chromium removal was 99.5% and 99.4% for CTW and AC, respectively, and the maximum adsorption capacity of chromium ions by using AC and CTW were 42.42, 42.46 mg/g respectively. Studies showed that the Freundlich adsorption model was better fitted with the results than Langmuir with R2 equal to 0.991 and 0.974 for AC and CTW, respectively. The chromium uptake by the CTW and AC was best described by the pseudo-second-order rate model. This investigation verifies the possibility of using CTW as a low-cost material for the removal of chromium from an aqueous solution compared with AC.

Installation of perforated sieve plates into a bubble column has the effect of introducing structure into an otherwise chaotic hydrodynamic behavior. In this study, we studied the effect of tray plates spacing and geometry on the overall gas holdup and liquid phase residence time distribution (RTD). The measurement carried out in bubble columns with diameter 10 cm and 20 cm with air-water system. Partition sieve plates with open areas of 15 and 30% and the tray spacing equal the column diameter (10, 20 cm) and twice the column diameters (20, 40 cm) were used in the studies. The overall gas holdup is measured experimentally by bed expansion technique and the liquid phase backmixing has been studied by measuring liquid phase RTD and analysed using one parameter dispersion model. The experimental results show that the increase in the tray spacing reduces the overall gas holdup and increase liquid phase dispersion. Also by comparing the liquid phase dispersion coefficient values with that in the conventional bubble column, it has been observed that there is reduction in the backmixing by 45-11% for tray spacing of 10 cm and 20 cm respectively in the 10 cm bubble column diameter. Correlations have been used for the estimation of the overall gas holdup and liquid phase dispersion coefficient in multistage bubble column.

An accurate correlation for calculating the saturated specific volume of gases is obtained by nonlinear regression based on experimental data collected after a thorough survey of the literature. This equation can be used to calculate saturated specific volume of gases independently, it is also to be of great significance in building the equation of state for hydrocarbons in the gas region. The average deviation between the results obtained by this equation and experimental data is about 6% for 201 data points. For a better understanding of the equation, the saturated specific volume curves observed and predicted are compared.

A modified softened strut-and-tie model (MSST) for determining the shear strength of reinforced concrete deep beams is proposed in this paper. It is a simplified analytical model and several improvements have been made. The method is based on Mohr Coulomb's failure criterion. The concrete softening effect and the stress distribution factor, k, based on force and moment equilibrium are satisfied. To validate the proposed method, the obtained results are compared with those available in the literature. The results indicate that the proposed method MSST is capable to predict the shear strength of a variety of deep beams with acceptable accuracy.

Is the maintenance of the buildings gamaipossalib management are Important issues which should receive the attention and the development efforts. The research included an areal state study of maintenance management in AL Mustansiriya University buildings to propose a suitable maintenance management system and the analysis of the four factors of the management system, which are (planning, organizing, directing, and controlling)and discussed the concept of the modern maintenance definition, classification. The field survey included preparing the questionnaire list, conducting the statical analysis for its axes, and discussing the results. Many conclusions and recommendations have been deduced related to the applications of maintenance management in AL-Mustansiriy University buildings and a suitable maintenance management system.

Serpentinite ore is one of the Iraqi ores in the Benjwen city in the north of Iraq, it contains (33.62%) Magnesium and (35.62%) Silica, and (6.1%) magnetite, and its specific gravity was (0.760). The photographic film by the (XRD) shows that the mineral ore was Olivine, Cresotyle, Anthersite, and Magnetite, so from that the research idea arose in concentrate of the magnesium from the Iraqi serpentinite ore to invest it locally and with economic way by using concentrated sulfuric acid for solving the magnesium in the ore in the form of magnesium Sulfate after separating the magnetite by wet magnetic separation and after that solved by the sulfuric acid and by different temperatures, and concentrated acids and times from the results that the best temperature of the pulp is in the boiling temperature(100) oC and in 40% concentrate of sulfuric acid and the solvent time is two hour and solid-liquid 1:3 so the grade of magnesium was 91.5% and the recovery was 93.6%.