Journal of Engineering

Engineering equipment is essential part in the construction project and usually manufactured with long lead times, large costs and special engineering requirements. Construction manager targets that equipment to be delivered in the site need date with the right quantity, appropriate cost and required quality, and this entails an efficient supplier can satisfy these targets. Selection of engineering equipment supplier is a crucial managerial process .it requires evaluation of multiple suppliers according to multiple criteria. This process is usually performed manually and based on just limited evaluation criteria, so better alternatives may be neglected. Three stages of survey comprised number of public and private companies in Iraqi construction sector were employed to identify main criteria and sub criteria for supplier selection and their priorities.The main criteria identified were quality of product, commercial aspect, delivery, reputation and position, and system quality . An effective technique in multiple criteria decision making (MCDM) as analytical hierarchy process (AHP) have been used to get importance weights of criteria based on experts judgment. Thereafter, a management software system for Evaluation and Selection of Engineering Equipment Suppliers (ESEES) has been developed based on the results obtained from AHP. This model was validated in a case study at municipality of Baghdad involved actual cases of selection pumps suppliers for infrastructure projects .According to experts, this model can improve the current process followed in the supplier selection and aid decision makers to adopt better choices in the domain of selection engineering equipment suppliers.

An experimental model is used to simulate the loss of soil lateral confinement due to excavation nearby an individual axially loaded pile. The effects of various parameters, such as the horizontal distance of excavation, depth of excavation and pile slenderness ratios are investigated. The experimental analysis results showed the effect of excavation is more remarkable as the horizontal distance of excavation becomes closer to the pile than half pile length. The effect of excavation diminishes gradually as the horizontal distance increases beyond that distance for all the investigated pile slenderness ratios and depths of excavation. The pile head deflection, settlement and bending moments along pile increase with decreasing horizontal distance between excavation face and adjacent axially loaded pile of various depths of excavation and pile slenderness ratios. The location of maximum bending moment is positioned between 1/4 and 1/2 of pile length for all horizontal distance of excavation, depth of excavation and slenderness ratios. The bending moment profiles indicate a (single curvature) for medium flexible piles and (double curvature) for very flexible piles for different horizontal distance between excavation face and adjacent axially loaded pile and various depths of excavation. In addition the theoretical approach of wood, 2004 showed good agreement especially for very flexible pile (slenderness ratio ˃45).

This paper studies the combination fluid viscous dampers in the outrigger system to add supplementary damping into the structure, which purpose to remove the dependability of the structure to lower variable intrinsic damping. It works by connecting the central core, comprising either shear walls or braced frames, to the outer perimeter columns.
The modal considered is a 36 storey square high rise reinforced concrete building. By constructing a discrete lumped mass model, and using frequency-based response function, two systems of dampers, parallel and series systems are studied. The maximum lateral load at the top of the building is calculated, and this load will be applied at every floor of the building, giving a conservative solution. For static study Equivalent Lateral Force (ELF) was conducted. MATLAB software, has been used in this study.
From analysis data, it is observed that the parallel system of dampers result lower amplitude of vibration and achieved more efficiently compared to the series system, and the horizontal displacement for each configurations by using MATLAB software is less than the analytical solution using a uniformly distributed load of 36 nodal point forces that divided the total height.

Warm asphalt mixture (WMA) and reclaimed asphalt pavement (RAP) are the most memorable sustainable materials in world of asphalt concrete pavements . This research aims to study the warm asphalt mixture for different types of filler materials such as ordinary cement and limestone dust. Beside, this research focused on the test of emulsified asphalt properties by evaluating the performance of warm asphalt mixture by Marshall Stability properties as well as moisture sensitivity. The results of this experiment provided many important points. First, The cationic emulsified asphalt is suitable with RAP aggregate for production warm asphalt mixtures .Second, The effective mixing procedure for warm asphalt mixtures consists heating the RAP aggregate at 100 Co and then mixing with emulsified asphalt. Because of heating of reclaimed asphalt pavement material can improve the dispersion as well as densification significantly. Furthermore, the warm asphalt mixtures containing filler of cement type improved the Moisture sensitivity performance by mean of increasing tensile strength ratio furthermore enhanced Marshall properties .Finally, It was indicated that optimum asphalt content (2.8%) is the best percentage found based on trail mixes ranging from (1.8 to 3.8) %

Entropy generation was studied for new type of heat exchanger (shell and double concentric
tubes heat exchanger). Parameters of hot oil flow rate, temperature of inlet hot oil and
pressure drop were investigated with the concept of entropy generation. The results showed
that the value of entropy generation increased with increasing the flow rate of hot oil and
when cold water flow rate was doubled from 20 to 40 l/min, these values were larger. On the
other hand, entropy generation increased with increasing the hot oil inlet temperature at a
certain flow rate of hot oil. Furthermore, at a certain hot oil inlet temperature, the entropy
generation increased with the pressure drop at different hot oil inlet flow rates. Finally, in
order to keep up with modern technology, infrared thermography camera was used in order to
measure the temperatures. The entropy generation was determined with lower values when
infrared thermography camera was used to measure the temperatures, compared with the
values obtained by using thermocouples.

The pretreatment process can be considered one of the important processes in wastewater treatment, especially coagulation process to decrease the strength of many pollutants. This paper focused on using powdered date seeds as natural coagulant in addition to chemical coagulants (alum and ferric chloride) to find the optimum dosage of each coagulant that makes efficient removal of turbidity and chemical oxygen demand (COD) from domestic wastewater as a pretreatment process, then finding the optimum combined dosages of date seeds with alum, date seeds with ferric chloride that make efficient removal for both pollutants. Concerning turbidity, the optimum dosage for date seeds, alum and ferric chloride were 40 mg/l (79%), 70 mg/l (84%) and 60 mg/l (82%) respectively. Concerning COD the optimum dosage for date seeds, alum, and ferric chloride were 40 mg/l (75%), 60 mg/l (83%) and 50 mg/l (86%). The study showed that the optimum combined dosage that made higher turbidity removal (95%) resulted from mixing 70 mg/l date seeds with 50 mg/l alum, while for higher COD removal 90% resulted from mixing 40 mg/l date sees with 70 mg/l ferric chloride.

Partial shading is one of the problems that affects the power production and the efficiency of photovoltaic module. A series of experimental work have been done of partial shading of monocrystalline PV module; 50W, Isc: 3.1A, Voc: 22V with 36 cells in series is achieved. Non-linear power output responses of the module are observed by applying various cases of partial shading (vertical and horizontal shading of solar cells in the module). Shading a single cell (corner cell) has the greatest impact on output energy. Horizontal shading or vertical shading reduced the power from 41W to 18W at constant solar radiation 1000W/m2 and steady state condition. Vertical blocking a column of cells (9 cells) in a module reduces the power from 41W to 18W (53% power reduction); while, blocking one or two cell in the row reduces the power from 41 W to 18W (53% power reduction). Shading three or four cells in the same row reduces the power from 41W to 1W or 0.006W (94% power reduction). A complete Matlab / Simulink model are achieved to simulate the effect of partial shading on power output of module. It is found that shading a single cell reduces the power from 50 W to 25 W (50%) using Matlab/Simulink model. Comparisons have been made between the I-V and P-V characteristic curves from the simulation with the practical (experimental) curves. The results showed that the percentage of error between the Simulink results and the corresponding experimental measurement are 22% without shading effect and, 32% with partial shading.

The aim of this work is oriented to increase film cooling effectiveness value through numerical investigations for flow of Mach number not more than 0.3 around vane surface, to find the effects of inclination and compounds angles of round holes in staggered rows on adiabatic film cooling effectiveness of vane suction side. Multi cylindrical film cooling hole cases were studied with pitch ratio P/d =2 and 3, local blowing ratios M=0.382, 0.77 and 1.14, inclination angles =30° and 45°, compound angles β= 0°, 15°, 30° and 45° and local momentum ratios I= 0.084, 0.34 and 0.756 for better cooling process.
A numerical technique, using ANSYS-FLUENT version 14.5, was used to solve governing partial differential equations of mass, momentum (Navier Stokes equations) and energy conservations in three dimensions with a turbulence model that involves the solution of the four transport equations. Based on the results of the numerical solution, the best film cooling configuration, blowing ratio, with the range of actual engine flow conditions, dimensions and vane geometry; density ratio 1.74 , temperature ratio 0.57 and blowing ratio M=0.382, 0.77 and 1.14 was obtained. The best case for inclination angle =30°, P/d=2 was at M=1.14 and β=0° for the total average effectiveness along 60L/d of surface suction side was 0.616, while the best case for inclination angle =45°, P/d=2 was at M=0.382 and β=30° for the total average effectiveness along 60L/d of surface suction side was 0.516.
In addition, comparisons were performed with available other work, where the experimental total average effectiveness results of Dees et al., 2011 were in good agreements with the numerical results of current work with a maximum deviation of 9.9% at I=0.34 and 3.6% at I=0.75.

In this paper, an analytical solution describing the deflection of a cracked beam repaired with piezoelectric patch is introduced. The solution is derived using perturbation method. A novel analytical model to calculate the proper dimensions of piezoelectric patches used to repair cracked beams is also introduced. This model shows that the thickness of the piezoelectric patch depends mainly on the thickness of the cracked beam, the electro-mechanical properties of the patch material, the applied load and the crack location. Furthermore, the model shows that the length of the piezoelectric patches depends on the thickness of the patch as well as it depends on the length of the cracked beam and the crack depth. The additional flexibility of the beam caused by crack is modeled depending on a dimensionless parameter identified from finite elements method. Different piezoelectric patches were designed and investigated using analytical and finite elements models. The results show that increasing the patch thickness enhances the beam resistance to crack and load effects, while increasing the length of the piezoelectric patch reduces the magnitude of the voltage required to repair the cracked beam.

This study aims to assess the accuracy of digital elevation model (DEM) created with
utilization of handheld Global Positioning System (GPS) and comparing with Advanced
Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model
(ASTER GDEM), version 2. It is known that the quality of the DEM is affected by both of
accuracy of elevation at each pixel (absolute accuracy) and accuracy of presented morphology
(relative accuracy). The University of Baghdad, Al Jadriya campus was selected as a study area
to create and analysis the resulting DEM. Additionally, Geographic Information System (GIS)
was used to visualize, analyses and interpolate GPS track points (elevation data) of the study
area. In this research, three additional DEMs were created using 60%, 30% and 15% of the all
GPS track points to deduce the effect of the number of the included points on the accuracy of the
resulting DEM. The study findings show a high resolution for the resulting DEM less than 5m
when taking into consideration all GPS tracking points that observed in this research. Moreover,
the resulting DEM has relative accuracy better than absolute accuracy and reaches to around 2m.
By comparing with ground control points (reference points), the quality of handheld GPS DEM
shows considerable improvement better than ASTER GDEM. Thus, this study indicates to
improve the accuracy level of handheld GPS DEM by about 40% with increasing the observed
number of GPS track points to twice.

Drilling fluid loss during drilling operation is undesirable, expensive and potentially hazardous problem.
Nasiriyah oil field is one of the Iraqi oil field that suffer from lost circulation problem. It is known that Dammam, um-Radoma, Tayarat, Shiranish and Hartha are the detecting layers of loss circulation problem. Different type of loss circulation materials (LCMs) ranging from granular, flakes and fibrous were used previously to treat this problem.
This study presents the application of rice as a lost circulation material that used to mitigate and stop the loss problem when partial or total losses occurred.
The experimental work included preparing drilling fluid, which is selected to be water based mud. Amount of loss for rock samples was measured where the percentage of losses of drilling mud were 46.52% and 96.66% as well as the percentage of improvement in curing of lost circulation were calculated after rice adding. Rice materials addition was done by tow stages: a) Adding 24 Ib/bbl of fine rice and 1 Ib/bbl of course rice gave improvement in curing from 30.67% to 100%. b) Adding 24 Ib/bbl of fine rice and 6 Ib/bbl of course rice gave an improvement in curing equal to 92.12%.