AL-Rafidain Engineering Journal (AREJ)

The aim of the present research was to study the effect of friction stir welding parameters such as ( tool rotation and tool travel speeds) on the impact energy of (6.1 mm) thick weldments of aluminum alloys (2024-T351,7075-T651). Which are used in aircraft industries andare poorly weldable by fusion welding such as (TIG,MIG and Laser) welding .Friction stir welding welds were carried out on a traditional milling machine .Tow tool rotation speeds (900 and 1120 rpm) and three travelspeeds (28,40 and 56 mm/min) were selected for the friction stir welding of each alloy. The resistance of the weldments has been investigated using the impact test with standard V-notched specimens at room temperature.Finally a comparison has been made between welds impact energy and base metal impact energy. It has been observed that the impact energy increased at the friction stir welding of both alloyscompared with the base metal for most cases. The impact energy of the (2024-T351) Al alloy reduced with increasing the rotation speed of the tool at the same travel speed , while rotation and travel speeds have a little effect on the impact value of (7075-T651) Alalloy and the results are very close to each other.

The present work describes the structural analysis performed on a preloaded bolted joint configuration. The joint modeled was comprised of two L-shaped structures connected together using a single bolt. Each L-shaped structure involved a vertical flat segment (or shell wall) welded to a horizontal segment (or flange) and the structural shape under Uniaxial tension load , loaded at upper end and fixed support from other end, Steel bolted joint has been used. Experimental investigation was carried out on bolted joint to determine the influence of several factors on the bolted-joint response. The factors considered included bolt preloaded , washer-surface size, washer material(steel or brass) . Joint response is reported in terms of displacements, gap opening, and surface strains or stress by using strain gages technique to measure and to distribute strains on joint surface. The experimental results were compared with analytical results by using finite element structure analysis technique (F.E) i.e. using (ANSYS) program. Results have been presented that the maximum principle stresses by FEM analysis are less than actual stresses (≤10%). the strength of bolted joint increase by using hard steel washer 30mm . The standard preload 75% from proof strength for bolt material is the optimum value . Most of the factors studied were determined to have minimal effect; however, the washer surface size affected the response significantly.

Researches have been conducted on corrosion, its effect on the metal used, and the factors affecting the corrosion resistance and methods of protection. In most of these researches ferrous and non-ferrous metal were tested in different water media. In this work , the corrosion of gray cast iron, In drinking water (normal and magnetic), was studied using two methods.
In the first method, the samples were immersed in water (normal and magnetic) for a different periods of time. In the second method the same number of samples were immersed in the water (normal and magnetic) for half an hour and dried for half an hour under the lab condition during the same above periods. A device was designed and manufactured for the immersion and drying purposes. The results showed that the corrosion rate of cast iron by the magnetic water is less than that by normal drinking water for both methods.

Le Corbusier and Kahn are two of the most distinguished architects who had employed natural lighting on the expressive dimension of Architecture. Despite the general impression given by previous literature about the resemblance between the two architects regarding natural lighting in Architecture, this research focuses on the problem of the inadequacy of the knowledge about the two architects variance regarding the expressive properties of natural lighting in their works and adopts defining this variance as its objective. The research adopts the approach of light zones and employs the relevant computer program for representing and analyzing natural lighting. And through a comparative study for two cases, the conclusions about the variance between the two architects, regarding defined variables representing a group of natural lighting properties, related to the expressive dimension of architecture, are introduced.

Buildings in Islamic architecture are characterized in general, in employing written inscriptions in many aspects of the building; as the external elements (facades, entrances, minarets, domes ...) as well as the internal elements of the building (mihrabs, minbars, columns, walls and ceilings of the Interior…).
Employing written inscriptions has many characteristics which can be classified into two groups: the first are related to the architectural aspects, as position within the building, method of execution, building materials, the second group are related to aspects of Fine Art for the calligraphy as type of font, size and proportion ...Both characteristics contributed to enhancing the various functions provided by this writings as defining the building, and its creator, or its symbolic significance of meaning according to building type or inscriptions' position or theme.
The research aims to detect and identify design characteristics of employing inscriptions within the architecture of the Congregational mosques and Multifunctional complexes (Which include the addition of a school or Mausoleum, or both at the mosque) which are related architectural aspects, and to show dissimilarity of those characteristics depending on the local styles within Islamic architecture, in order to come up with recommendations to help implementing this knowledge in future designs of contemporary Islamic architecture.

Congregational Mosques Classification is an important issue for Islamic Architecture studies which introduced many different classifications.This paperaims to introduce a new classification of the congregational mosques using the pattern recognition digital technique. The cases selected for the study covers most of the period and space of the Islamic for a more objective and accurate classification. Thepaper takes up an unsupervised texture image classification algorithm which uses a competitive neural network. The classification is done by assigning data to one of the fixed number of possible classes then classifying image segments into a given number of classes using segments features by using Kohonen competitive neural network and through a process of self-organization, configures the output units, representing the selected congregational mosques, into a spatial mapincluding the resulted classificationtypes.The conclusions support some knownstatements and contradict others within Islamic Architecture Theory, so certain modifications are needed according to the concluded statements after corroborating them in future studies.

Asphalt concrete consists of coarse aggregates, fine aggregates, filler, and asphalt cement(used as a binder)mixed together in proportions according to a specified specifications.
Mineral filler is the inert material passing the No.200 sieve , occupies the void space between coarse aggregates particles and pores within the aggregates particles .There were many types of local waste materials that can be used successfully used as a mineral filler in hot asphalt concrete mixtures instead of ordinary portland cement and limestone powder.
The main objective of this research is to investigate experimentally the effect of using different types of fillers, and content, on hot asphalt concrete mixtures. Several specimens of hot asphalt mixtures were prepared according to (SORB/R9) using the obtained Optimum Asphalt Content (O.A.C.) with three percentages of the fillers of ordinary portland cement, lime stone powder, and waste glass powder at 4%, 6% and 8% by weight of total aggregates, respectively.
The results of Marshall tests on mix design of hot asphalt concrete mixtures, for the wearing course were concluded that, using the waste glass powder as a filler, with its optimum content of 8% (by the weight of total aggregates), leading to produce asphalt concrete mixtures with higher Marshall Stability, lower Flow, and lower voids in total mix comparing with ordinary portland cement and lime stone powder fillers.

This study presents an experimental and numerical investigation of the performance of a forced draft counter flow cooling tower with two kinds of wire mesh packing. The packing used in this study is wire mesh with small square holes (WMSSHSP) and expanded wire mesh with diamond holes (EWMDHSP) configurations. In the numerical investigation, the two dimensional CFD model with finite volume scheme has utilized the standard ( ) turbulence model to computes the air properties, while one-dimensional model is used to get the water properties. From the results it is concluded that the (EWMDHSP) enhance the performance of the cooling tower. That is due to the pressure drop in the (WMSSHSP) is higher than that for the (EWMDHSP) because air resistance of the former pack is higher than the latter pack. The agreement seems to be acceptable between the numerical and the experimental results.

This research was carried out by adding several reinforcement materials to the epoxy type (Henkel/pattex) then the shear strength was measured. It was noticed from experimental results that there is a significant improvement achieved by adding the reinforcement materials. Also the change of the percentage of the reinforcement materials was studied and its effect on the shear strength was considered. The reinforcement materials include iron filing, silicon carbide as weight percentages 10%, 20% and 30%. Also steel mesh, polymers mesh and fiber glass was used. The cling was carried out on standard specimens including galvanized steel, aluminum and brass. The results obtained shows that the shear strength was significantly improved by adding the reinforcement materials .The results were affected by the type of reinforcement materials and type of metals being glued. The maximum improvement obtained with brass/brass specimen using mixture of epoxy with 10% iron filing as a weight percentage.

The bio-restoration project of the mercurial career of Guenicha zone operating in the region of Azzaba must not only take into account the potential of the site but also its integration into the surrounding landscape. To achieve this result we performed a qualitative estimation of the potentialities of the site to understand better the structuring of the space and these various affectations. We took into account the current occupation of grounds to locate the precious elements, the curiosities susceptible to remain constant in the landscape and to highlight sectors or zones of an exceptional fragility which we call "sensitive sectors or zone" where any intervention can influence the visual atmosphere of the landscape. The zoning allowed us to reveal two landscaped bulks represented by the plain of Azzaba and the career of Guenicha. At first time we identified their components. To increase the visibility of the site, we shall create the dominances which characterize them and we arrange the transitions between them. In the last we will link the study area with the surrounding landscape by offering the most sensible choice of a pardon to restore the soil and also achieve the integration with the surrounding landscape.

In this paper, capacity analysis for mobile WiMAX working in distributed subcarrier permutation modes is investigated mathematically depending on the physical layer simulation results. These simulation results of physical layer dispose exact values for the number of best burst profiles that candidate to carry Medium Access Control (MAC) payload in a proposed ITU-R mixed user channel. The complete simulation model for physical and MAC layers has been made using OPNET 14.5 to validate the analytical results of the obtained capacity. This approach for capacity analysis based on simulation results is proposed to overcome the lack of interests by other researches in the significant influence of the physical layer constraints on the MAC layer capacity calculations. As well as in this paper, a proposed ITU-R mixed user channel is performed to suit the high mobility users involved under distributed subcarrier permutation modes. Moreover, this paper focused on the exact overhead calculations by taking into account all the significant overhead parameters in the MAC layer frame structure that affects the overall system capacity.

It is known that PID controller is used in every facet of industrial automation. The application of PID controller span from small industry to high technology industry. The aim of this paper is to design a position controller of a robot arm by selection of a PID parameters using genetic algorithm. The model of a robot arm is considered a third order system. And this paper compares two kinds of tuning methods of parameter for PID controller. One is the controller design by the genetic algorithm, second is the controller design by the Ziegler and Nichols method. It was found that the proposed PID parameters adjustment by the genetic algorithm is better than the Ziegler & Nichols’ method. The proposed method could be applied to the higher order system also.

Elimination of load harmonics can be achieved by either filtration of selected harmonics or the use of pulse-width modulation PWM technique. Many PWM techniques are developed, but the most commonly used in industrial applications is the SPWM technique where the distortion factor DF (one of the most important performance parameters of the quality and efficiency of a lot of the electronic devices) is significantly reduced. In this paper, the SPWM technique for harmonic elimination (HE) is implemented using 8051 microcontroller and the well known MATLAB software. The result is tested on a prototype inverter which was designed since 1998. This method is based on the analysis of Fourier series and Fourier coefficients of the required SPWM output voltage waveform.
In this paper, the odd function technique with three and five pulses per half cycle to generate the required SPWM control signals is achieved. The basic flow chart of the control program, samples of the experimental results as well as an appendix illustrating the complete source code programs (INV1) and (INV2) in an assembly language of 8051 microcontroller are given.

This paper proposes a prototype system for road traffic monitoring purposes using Wireless sensor networks (WSN) which consists of relatively inexpensive sensor nodes capable of sensing and wireless communication. A Web server is embedded into WSN nodes to provide a flexible remote monitoring based on web browser. WSN nodes and Embedded Web Server (EWS) have been implemented using UBICOM IP2022 network processor. The reference design includes complete source code written in C-language. The web pages which are required for the web server have been developed using HTML together with CGI scripts by implementing them as C functions within the web server. A practical implementation of the system has been tested and its operation is validated through simulation using OPNET 11.5. The simulation results have declared that the wireless LAN IEEE.802.11b is very suitable for the system’s environment and the utilization of EWS’ CPU is 55%. This means that EWS can afford the network load without dropping. The results also indicates that the average throughput, delay, and response times are in the reasonable rang.

Nineveh province in Iraq has experienced a process of land cover conversion and vegetation loss especially in last decades. It is important to get accurate information on vegetation loss and changes in areas that are used for agriculture. Among the most effective methods to study and get information about this phenomenon is remote sensing technology.
Since classical approaches lack of accuracy, artificial intelligence has been introduced to strengthen feature detection which leads to better classification. This paper uses ant colony algorithm to study and classify part of Nineveh province land into six classes. These are Agriculture land/flood plane, Water, Outcrop, Origin of early sand sheet, Desertable area, and Sand dunes. The variation in these six classes from 1987 to 2009 is shown. Results show that agriculture region and flood plain decreased from around 31% in 1987 to 11.2% of total area in 2009 while origin of early sand sheet and desertable area increased from 42.7% to around 49%. Beside that sand dune appears in 2009 to form about 26.47% of total area under study.

This research examines the potential of using cement kiln dust (CKD) as a blended cement material to study the effects of this partial replacement on the most important properties of cement paste, mortar and concrete. The levels of replacement of cement by an equal amount of the (CKD) dust were (5, 10, 15, 20, 25, 30)% by weight. A reference cement paste, mortar and concrete mix were also prepared for comparison. The tested properties included the initial setting time of each cement paste and the compressive and tensile strengths of mortars and concrete. Water curing was used for all specimens and the strength tests were carried out at (3, 7, 28) days. Results of experimental data reveal that (CKD) can be effectively used as a partial cement material. The initial setting time of the cement paste is decreased with the increase of (CKD) content due to the high amount of lime and alkalis in (CKD). Besides, the compressive and tensile strengths of the blended cement and concrete specimens were also found to be comparable to the strengths of the reference mixes at all levels of replacement. Generally, it was indicated that the compressive strength decreased with the increase of (CKD) content. The (10)% replacement level had the best results in the compressive strengths of mortars and concretes at all ages in comparison to the reference mixes, also this level of substitution had a significant effect on the tensile strength of the mortars and concretes at early ages. It was noted that (15)% (CKD) replacement maintained the higher tensile strength of mortars at (7, 28) days, whereas a (25)% (CKD) had a similar effect but at (3, 28) days

In this research, four experimental plants have been constructed and operated in order to study the impact of using the anaerobic selectors on the behavior and efficiency of the extended aeration activated sludge system. The study program was divided into three stages. In the first stage, the experimental plants were run on the hydraulic retention time of the aerobic reactor equals to (32) hours, whereas, the hydraulic retention times in the biological aerobic reactors for the second and the third stages were (24 and 18) hours respectively. The results of the study revealed that; adding the anaerobic selectors improves the properties of the aerobic biological treatment in terms of removing soluble organic materials (CODs) and the efficiency of removing phosphor (PO4). The results also showed that,the organic and phosphorus removal efficiency increases with increasing the hydraulic retention time of the anaerobic selector. In contrast the values of the sludge volume index (SVI) decreases with this increasing. Higher removal efficiencies were recorded in the experimental stations that include anaerobic selector, which operates on a hydraulic retention time of (120 min) followed by the plant with the selector of (60 min) detention time and in the last place the plant that include selector, which operates on a hydraulic retention time of (30 min).

This research includes performance of using crushed glass as a filtration media with sand depending on the variation in turbidity levels in the raw water (5, 10, 25, 50, 75, 100 and 200) turbidity unit, type of the filter , type of filtration and the depth of the filter (25, 35 and 55 cm.) within filtration rate (8) m/hr. A total of (9) different configuration filters with different types and different depths of the filtration media, (6) of them are single-media and (3) are dual media which ranged between (25 and 55) cm and the number of the samples was (196) of the water resulting from the filters. The results showed that the glass media has the capability to remove turbidity and provide quality effluents conform to international and Iraqi specifications (less than 5 NTU).Effluent turbidity well below (1 NTU) is also achieved. In addition to that, the best results were obtained of removing turbidity when using the crushed glass as a filtration media in the dual filters as upper layer and with a removal percentage that reached (98.4%). For the single filters, the study showed the superiority of the glass filter over the sand filter in terms of turbidity removal at the preliminary levels in raw water in which turbidity is less than (25 NTU). While the sand filter was superior over the glass one in turbidity levels which exceed (25 NTU).

The study aims to develop computer model that simulates how a specimen by which to know the impact of Application uniformity on the soil surface and the lack of operating time for the sprinkler on the efficiency , adequacy ,useful application uniformity of each irrigation and productivity. The model building adopted on the principle of water balance in the field and has been applied to sesame summer crop by using available field data for the water distribution under sprinkler system. The model also adopted the climate data and the type of crop and soil. The study show that useful uniformity coefficient more than uniformity on the soil surface and the value of the efficiency and adequacy and useful uniformity vary from one irrigation to another and start to decline with the stability of the root zone irrigation after irrigation, and the results show that productivity depends on the efficiency , adequacy and useful uniformity that are affected in turn byuniformity and the time of application. the water use efficiency increased by increasing the application uniformity and decreasing the sprinkler operating time.