Journal of Engineering

Feature extraction from the surface topography is the creation of a bitmap representing the earth's surface elevations based on Digital Elevation Model, which is the base of the analyzing of topographical surfaces. The digital elevation models are mainly derived by stereo pair images (a pair of images) available from the Photogrammetry data and remote sensing, or from topographical maps, and we use a digital elevation model derived from topographical maps, and we derived a number of important properties from digital elevations model such as gradient direction and the Earth's shadow using a ArcGIS ver. 9.3 , which represent the input data to extract the hydrological characteristics such as determining the flow direction , also calculating the flow accumulation , producing the output map Stream to determine the valleys in the region and the production of Basin map to determine the basin of nutrition , the locations of the small dams can be selected using Arc GIS ver. 9.3 and its extension Arc Hydro.

Experiments were carried out to investigate natural convection heat transfer in an inclined uniformly heated circular cylinder . The effects of surface heat flux and angle of inclination on the temperature and local Nusselt number variations along the cylinder surface are discussed . The investigation covers heat flux range from 92 W/m² to 487 W/m², and angles of inclination 0° ( horizontal) , 30° , 60° and 90° (vertical) . Results show an increase in the natural convection as heat flux increases and as angle of inclination moves from vertical to horizontal position. An empirical equation of average Nusselt number as a function of Rayliegh number was deduced for each angle of inclination .

This study investigates the laminar natural convection heat transfer of air flow through a rectangular enclosure fitted with vertical partitions. The partition was oriented parallel to the two vertical isothermal walls with different temperatures, while all other surfaces of the enclosure were insulated. A test rig was designed and constructed to study the effects of Rayleigh number, aperture height ratio, partition thickness, partition position, and partition inclination on heat transfer. The experiments were conducted with air as the working fluid for Rayleigh number ranges from
5
×
10
7
to
1.3
×
10
8
and an aspect ratio of 0.5. Results showed that heat transfer is sensitive to Rayleigh number, aperture height ratio, partition position, and partition inclination, while it is independent of partition position relative to the cold wall and upper or lower walls.

The present work presents a new experimental study of the enhancement of turbulent convection heat transfer inside tubes for combined thermal and hydrodynamic entry length of one popular “turbulator” (twisted tape with width slightly less than internal tube diameter) inserted for fire tube boilers. Cylindrical combustion chamber was used to burn (1.6 to 7kg/h) fuel oil #2 to deliver hot gases with ranges of Reynolds number (10500 to 21700), and (11400 to 24150) for both empty and inserted tube respectively.A uniform wall temperature technique was used by keeping approximately constant water temperature difference (25ºC) between inlet and exit cooling water in parallel flow shell and tube heat exchanger. The test tube consisted of smooth carbon steel tube of (2400mm) long and (52mm) internal diameter. This test tube instrumented to derive local heat transfer coefficient and local flue gasses static pressure.The experimental results show that for the same fuel consumption, twisted tape insert with (H/D = 11.15) enhanced the mean Nusselt number in (75.2%), (68.8%), (49.8%), (40.3%), and (16.7%) for fuel consumption (7kg/h), (6.16kg/h), (4.5kg/h), (3.24kg/h), and (1.6kg/h) respectively.A set of empirical correlations that permit the evaluation of the mean Nusselt number (for developing and fully developed region), and average Nusselt number (for developed region) for empty and inserted tube are generated for engineering applications.

The two dimensional steady, combined forced and natural convection in vertical channel is investigated for laminar regime. To simulate the Trombe wall channel geometry properly, horizontal inlet and exit segments have been added to the vertical channel. The vertical walls of the channel are maintained at constant but different temperature while horizontal walls are insulated. A finite difference method using up-wind differencing for the nonlinear convective terms, and central differencing for the second order derivatives, is employed to solve the governing differential equations for the mass, momentum, and energy balances. The solution is obtained for stream function, vorticity and temperature as dependent variables by iterative technique known as successive substitution with overrelaxation. The flow and temperature patterns in the channel are obtained for Reynolds numbers and Grashof number ranging from 25 to 100 and (100 to 1,000,00,) respectively. A computer program ( Fortran 90 ) is built to calculate the fraction factor and the total average Nusselt number (Nu) also the average heat transfer Q in steady state and for Aspect ratio Ar (10) and Grashof number GR (521010−), the fluid Prandtl number is fixed at (Pr=0.733) and Reynolds number Re (25-100). The results show reasonable representation to the relation between Nusselt number and friction factor with other parameters (Ar, GR and Re). Nu is increased with increasing Re and GR but it decreases with Ar increase and (Q) is increased with increasing Re ,GR and Ar. At the same time, the product friction factor(fRe) increased with (GR) and (Ar)increased and (Re )decrease. Comparison of the result with the previous work shows a good agreement

The research targets study of influence of additives on sand mold’s properties and, consequently, on that of carbon steel CK45 casts produced by three molds. Three materials were selected for addition to sand mix at weight percentages. These are sodium carbonates, glycerin and oat flour. Sand molds of studied properties were produced to get casts from such molds. The required tests were made to find the best additives with respect to properties of cast. ANSYS software is used to demonstrate the stresses distribution of each produced materials. It is shown that the mechanical properties of casts produced is improved highly with sodium carbonates and is less with oat flour and it is seem a few with glycerin additives. It can be concluded that the sodium carbonates let to get the cast produced with highly mechanical properties.

The chlorine concentration variation in Baghdad water networks was studied. The chlorine data were collected from Mayoralty of Baghdad and Ministry of Environment (MOE) for the networks for both sides of the city Karkh and Rasafa for (2008-2009). The study of these data indicates that there are no systematic testing program .Classified GIS maps showed that the areas far from the treatment plants have almost always low chlorine concentration .This indicates that the problem of the low chlorine concentration in the far areas is due to cracks of pipe along the conveyance path ,as expected. The area's most frequently have low concentration are Al-sadir,Al-Kadhimya, and Al-Amiria . It was found also that the chlorine concentrations were lowest in summer months than those in winter months.The Amiria area district (636) was selected as a case study to test the ability of using the quantitative- qualitative model in the EPANET software, to find the required onsite chlorine injection point number, locations and dose, so as to raise the chlorine concentration to the acceptable limits in the other nodes of the network. The bulk decay coefficient was found to be (-2.212)1/day and the wall coefficients were found to be between (-0.001)to(-0.9)1/day The main conclusion of this study is that the onsite injection can improve the chlorine concentration in Baghdad water supply networks. The EPANET model can be used effectively to obtain the required injection program for this purpose.

The performance grading system (superpave) has provided means to incorporate binder characteristics with pavement failure types. It’s a comprehensive system that relates climate, traffic conditions and aging with critical pavement distress. The objective of this paper is to develop an improved asphalt binder grading system for Iraq based on the principal of superpave. The country was divided into different zones according to the highest and lowest temperature ranges and traffic loading. The Performance graded binder proposed for each zone was compared with some States of USA that have same hot weather of Iraq by using Long Term Pavement Performance (LTPP v3.1) software. Iraqi asphalt samples were tested using the Superpave technology in Wisconsin University and the results were compared with those estimated using Shell pavement design software packages (BANDS 2) at different loading time and frequency. In general, the performance grade of binders produced from the three refineries in Iraq (Daurah, Basrah and Baiji) is PG 64-16. The m- value (slope of log creep stiffness versus log frequency curve at specified temperature) determined by DSR (Dynamic Shear Rheometer) and Shell software was compared.

Removal of solar brown and direct black dyes by coagulation with two aluminum based coagulants was conducted. The main objective is to examine the efficiency of these coagulants in the treatment of dye polluted water discharged from Al-Kadhymia Textile Company (Baghdad-Iraq). The performance of these coagulants was investigated through jar test by comparing dye percent removal at different wastewater pH, coagulant dose, and initial dye concentration. Results show that alum works better than PAC under acidic media (5-6) and PAC works better under basic media (7-8) in the removal of both solar brown and direct black dyes. Higher doses of PAC were required to achieve the maximum removal efficiency under optimum pH conditions for both dyes. It was observed that under optimum conditions of pH and dose values, PAC was significantly higher dye removal efficiency than alum for all dyes initial concentrations.

The piled raft is a geotechnical composite construction consisting of three elements: piles, raft and soil. In the design of piled rafts, the load shared between the piles and the raft, and the piles are used up to a load level that can be of the same order of magnitude as the bearing capacity of a comparable single pile or even greater. Therefore, the piled raft foundation allows reduction of settlements in a very economic way as compared to traditional foundation concepts. This paper presents experimental study to investigate the behavior of piled raft system in sandy soil. A small scale “prototype” model was tested in a sand box with load applied to the system through a compression machine. The settlement was measured at the center of the raft, strain gages were used to measure the strains and calculate the total load carried by piles. Four configurations of piles (2x1, 3x1, 2x2 and 3x2) were tested in the laboratory, in addition to rafts with different sizes. The effects of pile length, pile diameter, and raft thickness on the load carrying capacity of the piled raft system are included in the load-settlement presentation. It was found that the percentage of the load carried by piles to the total applied load of the groups (2x1, 3x1, 2x2, 3x2) with raft thickness of 5 mm, pile diameter of 9 mm, and pile length of 200 mm was 28% , 38% , 56% , 79% , respectively. The percent of the load carried by piles increases with the increase of number of piles.

Geotechnical engineers have always been concerned with the stabilization of slopes. For this purpose, various methods such as retaining walls, piles, and geosynthetics may be used to increase the safety factor of slopes prone to failure. The application of stone columns may also be another potential alternative for slope stabilization. Such columns have normally been used for cohesive soil improvement. Most slope analysis and design is based on deterministic approach i.e a set of single valued design parameter are adopted and a set of single valued factor of safety (FOS) is determined. Usually the FOS is selected in view of the understanding and knowledge of the material parameters, the problem geometry, the method of analysis and the consequences of failure. This results in different FOS obtained by different designers. This inherent variability characteristic dictates that slope stability problem is a probabilistic problem rather than deterministic problem. Furthermore, the FOS approach cannot quantify the probability of failure or level of risk associated with a particular design situation. The objective of this study is to integrate probabilistic approach as a rational means to incorporate uncertainty in the slope stability analysis. The study was made through a hypothetical problem which includes a sensitivity analysis. The methodology is based on Monte Carlo simulation integrated in commercially available computer program SLOPE/W. The output of the analysis is presented as the probability of failure as a measure of the likelihood of the slope failure. Results of this study have verified that the probability of failure is a better measure of slope stability as compared to the factor of safety because it provides a range of value rather than a single value

This paper presents an experimental investigation into the behavior of 24 short reinforced concrete columns with and without steel fibers. The columns had a circular section (200 mm diameter and 900 mm long). Test variables include concrete strength, spacing of spiral reinforcement, and inclusion of steel fibers. The axial stress and axial strains were obtained and used to evaluate the effects of the presence of steel fibers. It was found that the addition of steel fibers slightly improves the load carrying capacity of the tested columns whereas it significantly enhances the ductility of these specimens. Test results also indicated that for the same confinement parameter, specimens with steel fibers have higher strength enhancement compared to specimens without steel fibers. For a confinement parameter of 0.1, the strength enhancement was 1.7 for specimens with fibers while it was 1.4 for nonfibrous specimens. An empirical expression is proposed and used to predict the confined strength of columns. It was shown that the proposed formula predicts the load carrying capacity of the tested columns reasonably.

Lowering the emission, fuel economy and torque management are the essential requirements in the recent development in the automobile industry. The main engine control input that satisfies the above requirements is the throttling angle which adjusts the air mass flow rate to the engine port. Due to the uncertainty and the presence of the nonlinear components in its dynamical model, the sliding mode control theory is utilized in this work for the throttle valve angle control system to design a robust controller for this system in the presence of a nonlinear spring and Coulomb friction. A continuous sliding mode control law which consists of a saturation function, instead of a signum function, and the integral of another saturation function is used in this work. This choice for the control structure will prevent the chattering to occurs but with a certain steady state error. On the other hand, the addition of the integral term will effectively reduce the steady state error according to the choice of its parameters. The simulations result for typical references of the opening throttle angle demonstrate the effectiveness of the proposed controller, especially after the addition of a nonlinear integral term.

Generally fossil based fuels are used in internal combustion engines as an energy source. Excessive use of fossil based fuels diminishes present reserves and increases the air pollution in urban areas. This enhances the importance of the effective use of present reserves and/or to develop new alternative fuels, which are environment friendly. Use of alternative fuel is a way of emission control. The term “Alternative Gaseous Fuels” relates to a wide range of fuels that are in the gaseous state at ambient conditions, whether when used on their own or as components of mixtures with other fuels. In this study, a single cylinder diesel engine was modified to use LPG in dual fuel mode to study the performance, emission, and combustion characteristics. The primary fuel, liquefied petroleum gas (LPG), was mixed with air, compressed, and ignited by a small pilot spray of diesel. Dual fuel engine showed a reduction in oxides of nitrogen in the entire load range. The brake thermal efficiency improved by 3% in dual fuel mode, especially at low load, and also reduced the hydrocarbon, carbon monoxide, and CO2 emissions.

A Photo Dynamic Therapy (PDT) is a technique which is used with Laser to treat many of cancer tissues. This paper deals with the relatively new therapeutic technique (PDT) with pulsed Nd:glass Laser which was applied to human soft tissues (Ovary and Kidney tissues), and to the hard tissues (freshly extracted human teeth), with power density of 280 watt/mm2 and exposure time 330 usec. Different dyes (Blue, methylene, eosin, and orange) were applied to the area before irradiation to study the effect of the pigments on the laser interaction with biological tissues. The zone of treatment (Z-necrosis) with aid of MATLAB was determined. The relationship of zone of treatment with exposure time, accumulated damage and fraction of oxidative radicals was obtained.

The aim of the present research is to study the dissolution and transport process of benzene as a light nonaqueous phase liquid (LNAPL) in saturated porous media. Unidirectional flow at water velocities ranged from 0.90 to 3.60 cm/hr was adopted to study this process in a three dimensional saturated sand tank (100 cm×40 cm×35 cm). This tank represents a laboratory-scale aquifer. The aquifer was constructed by packing homogeneous sand in the rectangular tank. The experimental results were used to characterize the dissolution behavior of an entrapped nonaqueous phase benzene source in a three dimensional aquifer model. The time invariant average mass transfer coefficient was determined at each interstitial velocity, the values of this coefficient were ranged from 0.016 to 0.061 cm/hr. It was increased proportionally with velocity toward a limiting value. The results show that the concentration of the LNAPL reduces as the distance increased in x and/or z direction from the source of pollution. In most cases the benzene concentration declines with velocity more than 2.34 cm/hr at downstream of the LNAPL pool.

The research aims to apply the novel forward osmosis (FO) process to recover pure water from contaminated water. Phenol was used as organic substance in the feed solution, while sodium chloride salt was used as draw solution. Membranes used in the FO process is the cellulose triacetate (CTA) and polyamide (thin film composite (TFC)) membrane. Reverse osmosis process was used to treatment the draw solution, the exterior from the forward osmosis process. In the FO process the active layer of the membrane faces the feed solution and the porous support layer faces the draw solution and this will show the effect of dilutive internal concentration polarization and concentrative external concentration polarization. In the FO process was a run-time for five hours, and the concentration of phenol 100 and 1000 mg/l, and for the NaCl the concentration was 10000 and 30000 mg/l. It was found that recovery percent increases with increasing time, while water flux through membrane decreases with increasing time. Also, it was found that recovery and water flux increases with increasing draw solution concentration, on the contrary, water flux and the percentage of recovery decreases with increasing the concentration of phenol (feed solution). Increase in draw solute (NaCl) concentration has more effect on the water flux in FO process compared with increase in the concentration of phenol. Outlet phenol concentration increases with time, while the outlet salt concentration decreases with increasing the time. The results showed that the cellulose triacetate membrane gave the highest recovery ratio from the thin film composite membrane. The highest recovery was reached in five hours is 51.33%, while using CTA membrane recovery rate increase, by 23% compared with TFC membrane. The value of the resistance to solute diffusion within the membrane porous support layer is 36.83 h/m. Reverse osmosis is perfect method for removal of dissolved salts from water, thus its suitable process for reducing the content of NaCl in draw solution; therefore the sodium chloride rejection percentage was 91.6 – 96 % for polyamide membrane (TFC). Within two hours of work of the reverse osmosis system the recovery percentage of pure water is 58%.

Resource allocation and leveling are of the top challenges in project management, due to the complexity of projects. This research aims to develop an optimization model for resource smoothing, so that. The proposed model is formulated using C++ program for resource smoothing. The project management software MS-Projects is adopted hereto perform resource leveling to facilitate achieving the optimal solution. The proposed model utilizes a system that depends on Genetic Algorithms (GAs) procedure built in C++ program to find the optimum solution. This research reach concludes that it is possible to smooth resources using Genetic Algorithms program and compares then with MS-Project when the GA results are better than MS-Project. Three case studies have been applied in this research and the application results come identical with research objectives, to form the conclusion. Then comes the recommendations regarding adopting and using the research results in construction planning and project management. Further suggestions related to the research subject are proposed for future works.

In this study, structures damage identification method based on changes in the dynamic charac-teristics (frequencies) of the structure are examined, stiffness as well as mass matrices of the curved (in and out-of-plane vibration) beam elements is formulated using Hamilton's principle. Each node of both of them possesses seven degrees of freedom including the warping degree of freedom. The curved beam element had been derived based on the Kang and Yoo’s thin-walled curved beam the-ory in 1994. A computer program was developing to carry out free vibration analyses of the curved beam as well as straight beam. Comparing with the frequencies for other researchers using the gen-eral purpose program MATLAB. Fuzzy logic system (FLS) applied in two stages to calculate the damage extent and location in simply in and out-of- plane curved beam, the damage deduce by re-duction in stiffness for three levels (20%, 40%, 60%). At the first stage the output faults of the fuzzy system represented by four levels of damage in curved beam (undamaged, slight, moderate, and severe), and at second stage indicate damage location at element with two defuzzification me-thods (centroid and middle of maximum). The results show that the frequency difference method is efficient to indicate and quantify damage with accuracy about (99.5%) for slight and moderate damage about (100%) for severe damage. Consequently fuzzy logic performs well for detecting, locating and quantifying damage in curved beam.

Root-finding is an oldest classical problem, which is still an important research topic, due to its impact on computational algebra and geometry. In communications systems, when the impulse response of the channel is minimum phase the state of equalization algorithm is reduced and the spectral efficiency will improved. To make the channel impulse response minimum phase the prefilter which is called minimum phase filter is used, the adaptation of the minimum phase filter need root finding algorithm. In this paper, the VHDL implementation of the root finding algorithm introduced by Clark and Hau is introduced. VHDL program is used in the work, to find the roots of two channels and make them minimum phase, the obtained output results are similar in accuracy to the past work results, which is built by using MATLAB program. Using VHDL is necessary in FPGAs for building hardware of the root finding algorithm in lower cost and time. MATLAB program is used only for displaying the input and output discrete signals of tested channels.

This research study experimentally the effect of air flow rate on humidification process parameters. Experimental data are obtained from air conditioning study unit T110D. Results obtained from experimental test, calculations and psychometrics software are discussed. The effect of air flow rate on steam humidification process parameters as a part of air-conditioning processes can be explained according to obtained results. Results of the steam humidification processes (1,2) with and without preheating with 5A and 7.5A shows decreasing in dry bulb temperature, humidity ratio, and heat add to moist air with increasing air flow rate, but humidification load, and total energy of moist air increase with increasing air flow rate in the testing tunnel. The steam humidification process (1) with dehumidifying coil shows increase in dry bulb temperature, humidity ratio, humidification load, and heat add to moist air with increasing air flow rate in the testing tunnel, but the total energy decrease as air flow rate increase. These obtained results can be beneficial for controlling comfort air-conditioning processes in buildings.

Rock engineers widely use the uniaxial compressive strength (UCS) of rocks in designing surface and underground structures. The procedure for measuring this rock strength has been standardized by both the International Society for Rock Mechanics (ISRM) and American Society for Testing and Materials (ASTM), Akram and Bakar(2007). In this paper, an experimental study was performed to correlate of Point Load Index ( Is(50)) and Pulse Wave Velocity (Vp) to the Unconfined Compressive Strength (UCS) of Rocks. The effect of several parameters was studied. Point load test, Unconfined Compressive Strength (UCS) and Pulse Wave Velocity (Vp) were used for testing several rock samples with different diameters. The predicted empirical correlations based on various test results indicate that the UCS could be obtained directly from measured (Vp), and then the Index Is(50) can be calculated by back substitution.

Date stones were used as precursor for the preparation of activated carbons by chemical activation with ferric chloride and zinc chloride. The effects of operating conditions represented by the activation time, activation temperature, and impregnation ratio on the yield and adsorption capacity towards methylene blue (MB) of prepared activated carbon by ferric chloride activation (FAC) and zinc chloride activation (ZAC) were studied. For FAC, an optimum conditions of 1.25 h activation time, 700 ̊C activation temperature, and 1.5 impregnation ratio gave 185.15 mg/g MB uptake and 47.08 % yield, while for ZAC, 240.77 mg/g MB uptake and 40.46 % yield were obtained at the optimum conditions of 1.25 h activation time, 500 ̊C activation temperature, and 2 impregnation ratio. The equilibrium data for MB adsorption on prepared activated carbons at optimum conditions were well represented by the Langmuir isotherm model, giving maximum MB uptake of 304.51 and 387.54 mg/g for FAC and ZAC, respectively. Also, the results showed that the surface area and iodine number of activated carbon prepared by activation with ferric chloride at optimum conditions were 780.06 m2/g and 761.40 mg/g, respectively. While 1045.61 m2/g surface area and 1008.86 mg/g iodine number were obtained for ZAC prepared at optimum conditions.

This paper provides the result of an investigation to use of crushed clay brick as aggregates in producing concrete. Eight different crushed clay brick aggregate concretes were used in this investigation. Compressive strength, splitting tensile strength and pulse velocity of crushed clay brick aggregates concrete were determined and compare to natural aggregate concrete. The compressive strength of crushed clay brick aggregates concretes were always lower than the compressive strength of natural aggregates concrete regardless the age of concrete, but the crushed clay brick aggregates concrete showed better performance as the age of concrete increases and average reduction in compressive strength were 33.5% at the age of 7 days but it becomes only 20% at the age of 56 days compared to natural aggregates concrete. The splitting tensile strength of crushed clay brick aggregates concrete were always lower than natural aggregate concrete, the reduction in splitting tensile strength of crushed clay brick aggregates concrete is ranging between 11 and 26% with an average reduction of about 18.5% compared to natural aggregates concrete. The pulse velocity of crushed clay brick aggregates concrete were also lower than natural aggregates concrete, the reduction in pulse velocity of crashed clay brick aggregates concrete is ranging between 6 and 22% with an average reduction of about 14% compared to natural aggregates concrete.

This work presents the simulation of a Low density Parity Check (LDPC) coding scheme with multiuserMulti-Carrier Code Division Multiple Access (MC-CDMA) system over Additive White Gaussian Noise (AWGN) channel and multipath fading channels. The decoding technique used in the simulation was iterative decoding since it gives maximum efficiency with ten iterations. Modulation schemes that used are Phase Shift Keying (BPSK, QPSK and 16 PSK), along with the Orthogonal Frequency Division Multiplexing (OFDM). A 12 pilot carrier were used in the estimator to compensate channel effect. The channel model used is Long Term Evolution (LTE) channel with Technical Specification TS 25.101v2.10 and 5 MHz bandwidth including the channels of indoor to outdoor/ pedestrian channel and Vehicular channel.