AL-Rafidain Engineering Journal (AREJ)

This research includes a theoretical and experimental study to the effect of some designing parameters on the performance of storage solar collector and to verify its suitability in the domestic uses. Two solar collectors studies , the first collector is cylindrical with 28 cm diameter and 130 height , and the second collector is cubic with dimensions 100cm x 100cm x 8cm , each one putting in a woody frame. Ordinary window glass was used as the top transparent cover for surface facing the sun. This storage collectors can be used as storage water tank to replace the ordinary tanks commonly used in Iraqi houses.The basic parameters were investigated systematically, these included the storage tank shape of solar collector, two models were taken, the first, cylindrical tank storage collector, and the second cubical tank storage collector having equal capacity . The other parameters was studied, the effect of loading. Loading on the storage collector were carried out with three different water withdrawal patterns, continuous loading, an intermittent loading, all water withdrawal one time in the day. The results indicate that the performance of cylindrical collector was better than the cubic collector in the continuous loading and intermittent loading after 3 PM, and the performance of cubic collector was better than cylindrical collector when all water withdrawal in the day at no load conditions. To verify the experimental test results, a numerical study was carried out using Fluent program. The natural convection phenomenon in the enclosure of the storage collector was investigated based on the method of control volume. From the Fluent results and analysis of the problem, the temperature distribution throughout the day was obtained. The Fluent results agreed well with the experimental data obtained.

In this paper the behaviors of strength and deformation of short reinforced concrete column specimens wrapped with CFRP were studied through testing 48 cylindrical specimens under axial loading. The role of parameters of CFRP wrap layers and arrangement, concrete strength , main steel reinforcement , lateral reinforcement and specimen slenderness ratio was studied. Results indicated that due to wrapping with CFRP layers the state of confined concrete occurs and the properties of strength and deformation are modified considerably. The ultimate load percentage was found to vary from 123% to 280% of that of unconfined specimens. The ductility of reinforced concrete specimens was found to be increased considerably as a result of wrapping. The effect of wrapping was found to be important in the case of concrete of lower strength and poorly reinforced with both main bars and lateral reinforcements. In order to obtain higher load capacity of wrapped high strength concrete it should be reinforced highly with both types of reinforcements. In general the parameters influencing the behavior reinforced concrete confined with CFRP sheets are: number of layers, replacing layers with strips, concrete compressive strength, main bars, lateral reinforcement, and specimens slenderness ratio. An analytical model was proposed for calculating ultimate load capacity and load-strain relationship for reinforced NSC and HSC confined with CFRP sheets. The predictions were found to be accurate, and the ratio of test / calculated ultimate load was found to be 1.0043 for NSC and 1.0033 for HS

This Paper presents the effects of the Parasitic Torques in a single phase induction motor, on the Vibration and Noise that’s generated from choosing unsuitable value of running capacitor. In this research a computer program has been developed of the motor Sound. The sound signal is measured by using a sound level meter and then it is transmitted to the computer through a data acquisition card and then the signal has been analyzed. In addition to that the Vibration signal has been analyzed. Experimental results has been obtained in the Anechoic Chamber Laboratory, It has been found that the optimum value of the running capacitor for this induction motor was 23μf .This gives minimum Parasitic Torques whose frequency is twice the input source frequency, and therefore minimum noise and vibration caused by this Parasitic Torque has been obtained

A computer model was made to find drain spacing with Hooghout equation then SALTMOD was applied for water and salt balances of four different soils. Crop rotation with alfalfa in 50% of the land as continuous crop(in winter and summer) and 50% of the land wheat in winter then maize in summer season. Drain spacing can be increased than that calculated with Hooghout equation according to soil type and critical water table depth, So salinity, and water table depth were increased without exceeding root zone depth, in clay loam soil. Whereas it's increase has little effect on loamy sand soil, therefore, the best drain spacing can be chosen according to acceptable salinity in the soil . SALTMOD gives, depending on cumulative Gumbel distribution, a reasonable indication of the predicted change in soil salinity. Under the proposed conditions of irrigation and drainage after, 10 years , the root zone salinity in 80% of area irrigated with 0.5 ds/m water, was predicted to increase in summer to ,9.46, 8,7.53, 4.3 ds/m in the clay loam, loam, sandy loam, loamy sand soil respectively.

Tests on fibrocement discs were carried out to measure tensile stress- strain relationship including testing wide ranges of matrix strength. Equations were proposed for calculating tensile strength based on the present test results and other results in the literature. A trilinear idealized model was proposed for calculating tensile stress – strain response of Ferro cement. The model was found to be accurate especially for higher strength Ferro cement. Later an analysis was carried out for calculating the load-deflection relationship of Ferro cement beams based on moment – curvature relationship and bending theory of elastic beam. The analysis which based on the proposed tensile model was found to be accurate for Ferro cement beams and slab strips provided that the span / depth ratio less than 22

Organic content measures (COD, BOD, and TOC) has been tested for different types of waters, municipal wastewater, treatment plant influent and effluent, synthetic wastewater and river water samples. The correlation between each two parameters has been studied. The results revealed that the relationship between BOD and COD is not always invariant and its changing depending on the type and the state of the samples (raw, treated or ..etc.). TOC also had changing relationship with COD, however, the TOC,COD relationship was best than the BOD relationship with the other two parameters. The separation between the data and homogenizing them gave best correlation. Finally , equations describing the relation between the three parameters has been edited and they can be used to estimate the absent test in accepted accuracy in similar samples to which have been studied in this work. The equations represent Mosul city wastewater samples were: (BOD=0.461COD-23.46), (TOC=0.455COD+7.938), and (TOC=0.625BOD+24.87) with R2= 0.511, 0.824 and 0.648 respectively. More equations are included in this work.

Self-compacting concrete (SCC) is a special type of concrete that can flow through intricate geometrical configurations under its own mass without external or internal vibration or segregation. The objectives of the research work were to evaluate the effects of filler types (silica fume and limestone dust) and high- range water- reducing agent, (HRWRA, superplastizier-type Sikament -163) on the workability and splitting tensile strength of SCC. The experimental results showed the using silica fume and limestone dust in Self-compacting concrete led to a considerable improvement in splitting tensile strength. As the percentage of limestone powder and silica fume increases, the workability properties of SCC slightly decreased with increases in splitting tensile strength. The workability properties of SCC for all the replacements satisfy the recommended values given by specifications

In the present research Thirty raw water samples were collected from kharazi wadi for further treatment , Those samples represent a mixture of (municipal ,irrigation and storm) sewage discharged directly to Tigris river north Mosul city .The Jar test technique was conducted to measure the variation of the main important characteristics of irrigation water . The treatment was carried out using bentonite clay as a coagulant compared with the treatment by sedimentation only. The results showed that the bentonite clay was more effective in removing :BOD, EC, TSS, Coliform bacteria and phytoplanktonic algae and max% removal recorded were (%51.43,%14.54) (%1.43,%0.95) (%72.22,%68.52) (%70.45,%47.20) (%53.33,%14.70) respectively ,The result indicated also that the reclamation of Kharazi Wady sewage was according to WHO standard for irrigation pwposes.

The main objective of this paper is to determine the effect of silica fume on the compressive strength of concrete under two types of loading, monotonic and repeated compressive loads. Mixes were carried out by replacing cement with different percentages of silica fume of (0, 5,10,15,20) % by wt. of cement with a constant water-binder ratios 0.25. Tests on standard cylinders (300*150) mm for the different ratios of silica fume were carried out to study the behavior of concrete under monotonic and repeated loads, the load was applied for many cycles up to failure with rate of loading (0.3) N/mm2/sec. The results indicated that the addition of silica fume improves the properties of concrete giving high compressive strength, high stress and strain, stresses carried by the concrete increased by (46.3,68.8,63.1,57.5)% also the strain increased by (58.5,97.8,52.8,22)% for silica fume percentages (5,10,15,20)% for monotonic loading, and stresses increased by (44.4,68.5,63.7,56.5)% and strain increased by (45.8,68.4,51.5,26.3)% for the same percentages under repeated loads. Compressive strength, dissipated energy, and modulus of elasticity also increased with increasing silica fume percentage.

This investigation was conducted to assess the efficacy of the glass, hay and polypropylene fibers for enhancing the unconfined compressive and tensile strengths of clayey soil stabilized with lime. Lime was mixed with the clayey soil in different proportions. Based on the optimum value obtained for lime (according to the unconfined compressive strength values), the compressive and tensile strength characteristics, stress – strain and load – deflection behaviors of lime stabilized samples mixed with different percents of glass, hay and polypropylene fibers were investigated. Fibers were added to the soil at range of (0.5 – 1.5 %). All stabilized samples were cured for 7 days at 250 C.Results indicate that the inclusion of fibers does not meaningfully improve the compressive strength, but significantly enhances the tensile strength, stress – strain and load – deflection behaviors. Also, it was found that the stress – strain and load deflection curves can be utilized to evaluate the performance of a fiber – reinforced stabilized soil for geotechnical and pavement applications.

Forming of aluminum sheets at warm forming temperatures has been investigated as an alternative manufacturing process for improving formability compared with forming at room temperature. However, the forming technology should be developed to increase the application field, especially in the predication of formability and the failure in order to design the process and die outcomes. The results obtained during this study showed that the formability of annealed Al-alloy (Al-2024-O) is increased by increasing temperature. Its formability is significantly improved compared with the precipitation hardened alloy (Al-2024-T3). The possibility of forming (Al-2024-T3) sheet metal at moderate temperatures, with acceptable formability and higher strength for structural parts is much better if compared to the annealed condition (Al-2024-O)

Natural convection in a porous medium saturated with supercritical carbon dioxide (CO2) whichis bounded by square cavity is studied numerically by solving the governing Darcy equation using finite-differences method.The side walls of cavity were assumed to be isotherm with fixed temperature difference of 0.0152K, while the upper and lower sides are assumed to be thermally insulated, the aspect ratio is chosen to be one, with cavity height of 0.01 m, the Darcy number adopted is , usually these values lead to very small modified Rayleigh number. Despite all of this, the state of supercritical takes the fluid (CO2) to a huge changes in its properties ( ) which allow to transfer a relatively large amount of heat between the hot and cold sides of the cavity with a very small temperature difference with maximum Nusselt number over 13 . The results of this study show clearly these concepts. The state of carbon dioxide in supercritical region is specified by reduced pressure and reduced temperature , the reduced temperature and pressure have been varied as

In this study, austenitic stainless steel AISI 316L has been selected to investigate the effect of aging time and temperature on tensile strength using (ABI) technique. Heat treatment consisted of aging at temperature of 400 oC, 600 oC and 800 oC and socking time for 0.5, 1.5, 10, 24 and 72 hrs.For microstructure examination, an optical microscope were used. The results showed that with increasing the aging time at 400 oC and 600 oC the tensile strength will increase but this approach inverted at 800 oC. These results could be attributed to some metallurgical transformation that occurs during heat treatment like changing in grain size, carbide and nitride precipitation along the grain boundaries, and secondary austenite

The conventional methods - used for - measuring brake, friction, and indicated power are based on brake - off dynamometers which use hydraulic or electrical dynamometers .The mentioned above methods use the measured torque to calculate the related power.The present method and instrument are characterized by measuring the amount of pressure opposed by a compressor joined to the engine and a reservoir for a compressed air, thus; the engine speed decelerates with the increasing pressure . For a specified pressure and engine speed, power could be calculated.In addition, friction power in the engine could be estimated by measuring the consumed current and effective voltage on an electrical driving motor when the diesel engine at run – off situation; no fuel supply. The whole present dynamometer had been designed and performed by the researcher as explained.

There are mainly two kinds of network processor: coprocessors-centric model, and core-centric model. In the coprocessors-centric, the data-plane is handled by coprocessors. The core processes most of the data-plane packets yet offloading some tasks to coprocessors in the core-centric model. The IXP is one of Intel network processor series which is a core-centric model. They are optimized for home, small-to-medium enterprise, and networked embedded applications.This work aims to design a module of IXP425 performing VPN. The processing time for each stage is available in the datasheet of the IXP425. The Markov chain and Omnet++ has been adopted in this work to explore the system parameters and bottlenecks focusing on the buffer length and how to be optimized for each stage. Single process programming is considered in the IXP425 operation.

In this paper,we introduce a new model, of long-period fiber grating, by taking the value of ambient refractive index greater than the refractive cladding index, where the difference between them must equal(≈0.2).The results show the change in power attenuation coefficient, where it increases with the increase in refractive ambient index. The power attenuation coefficient shift shows a dramatic change of a sharp increase from 0.00dB to ≈ 0.03788dB and 0.00dB to ≈ 0.04675dB and 0.00dB to ≈ 0.06875 dB. Here this model is used as sensor for shifting in input signal (15nm, 5nm).

BistaticTracking Radar (BTR) is an advanced mode of conventional BistaticRadar (BR) which is used for target detection. The principle of working of BTR system is same as that for Mono Static Tracking Radar (MTR), with the difference that the transmitter is apart from the receiver,and they operate separately and independently. In this paper,the associated equations that control the BTR system operation, was derived in a simple manner. These equations determine the receiver and transmitter antenna positions to keep their lines of sight meet at the target, beside the assurance of tracking the target during maneuvering. The operation of the system was explained and the simulation program was made to characterize the operation of the system by using the derived equations in this paper

Quality of service (QoS) is a corner stone in recent Internet applications. One of the requirements of achieving QoS in routers is scheduling algorithms. Priority Queuing (PQ) is the simplest most used scheduling algorithm. This algorithm may cause starvation in less priority queues. Time Expired (TE) algorithm is a refine of PQ which discards packets that would reach the receiver out of time. Thus improving throughput and delay for less priority queues with the discard of retarded usefulpackets in time sensitive – loss tolerant Internet applications. A simulation study using OPNET Modeler is carried out. The results show a 20% improvement in throughput of less priority applications. The delay performance is improved for all applications by a factor of 4% to 42%