In this study, the stresses and displacement around a tunnel opening under water body in Baghdad city, middle of Iraq, during excavation and lining are discussed. For this purpose, the finite element method (FEM) was adopted as an effective approach to analyze the problem using (SIGMA/W) program. The research includes the study of the behavior of soil due to excavation of a tunnel by calculating the displacements and stresses in three positions of the tunnel (crown, wall, and invert) during the various stages of construction. The surface settlement is also studied. The finite element analyses were carried out Using (Elastic- plastic) and (linear elastic) models for the soil and the concrete liner respectively.

In this paper, a single-phase boost type ac-dc converter with power factor correction (PFC) technique is designed and implemented. A current mode control at a constant switching frequency is used as a control strategy for PFC converter. The PFC converter is a single-stage singleswitch boost converter that uses a current shaping technique to reshape the non-sinusoidal input current drawn by the bulky capacitor in the conventional rectifier. This technique should provide an input current with almost free-harmonics, comply with the IEC61000-3-2 limits, and a system operates with near unity power factor. The other function of the boost converter that should be
accomplished is to provide a regulated DC output voltage. The complete designed

For the time being, the cold-formed sections are widely used due to their simple manufacturing and construction processes. To be feasible, the strength of cold-formed columns should be determined based on their post-buckling behavior. Post-buckling relations are cumbersome and need design aids similar to those of American Iron and Steel Institute (AISI) to be applicable. These design aids have been developed to sections and materials other than those available in the local market. Therefore, this paper tries to develop a general finite element model to simulate the postbuckling behavior of cold-formed steel columns. Shell element has been used to discretize the web, flanges, and lips of the column. A linear bucking analy

The problem of non-Darcian-Bènard double diffusive magneto-Marangoni convection   is considered in a horizontal infinite two layer system. The system consists of a two-component fluid layer placed above a porous layer, saturated with the same fluid with a constant heat sources/sink in both the layers, in the presence of a vertical magnetic field.   The lower porous layer is bounded by rigid boundary, while the upper boundary of the fluid region is free with the presence of Marangoni effects.  The system of ordinary differential equations obtained after normal mode analysis is solved in a closed form for the eigenvalue and the Thermal Marangoni Number (TMN) for two cases of Thermal Boundary Combinations (TBC); th

     The water quality index was used for the evaluation of the quality of water, as well its impacts on the rotifer abundance, in the Tigris River as it passes through Mishahda City, northern Baghdad. Five sites were selected and samples were collected during October 2019 to September 2020. It was noticed that the index values in most sites have exceeded the upper limits of river waters. The values ranged from 40 (Poor) to 45 (Marginal) in all sites. While, the values were from 42 (Poor) to 65 (Fair) during different seasons. As for drinking usages, the results demonstrated poor or undrinkable (31-40) water in all sites. Meanwhile, the values ranged from 39 (Poor) to 56 (Clear) in regard to seasons. The index values

       This research aims to modify the components of stainless steel alloy by the method of surface engineering through the single diffusion coating technique in order to obtain new alloys with high efficiency in resisting harsh environmental conditions. Steam a mixture of sodium chloride ( ) and sodium sulfate ( ) at a temperature of 900 and then compare it with the base alloy. The results showed that the alloys produced in this way are very efficient. The results showed that the aluminum coating showed high efficiency in resisting oxidation and provided better protection for a longer time compared to the uncoated alloy due to the  oxide crust layer formed with high adhesion as well as the aluminum-rich phases, whether the phase

Steel–concrete–steel (SCS) structural systems have economic and structural advantages over traditional reinforced concrete; thus, they have been widely used. The performance of concrete made from recycled rubber aggregate from scrap tires has been evaluated since the early 1990s. The use of rubberized concrete in structural construction remains necessary because of its high impact resistance, increases ductility, and produces a lightweight concrete; therefore, it adds such important properties to SCS members. In this research, the use of different concrete core materials in SCS was examined. Twelve SCS specimens were subjected to push-out monotonic loading for inspecting their mechanical performance. One specimen was constructed from co

This research discusses application Artificial Neural Network (ANN) and Geographical InformationSystem (GIS) models on water quality of Diyala River using Water Quality Index (WQI). Fourteen water parameterswere used for estimating WQI: pH, Temperature, Dissolved Oxygen, Orthophosphate, Nitrate, Calcium, Magnesium,Total Hardness, Sodium, Sulphate, Chloride, Total Dissolved Solids, Electrical Conductivity and Total Alkalinity.These parameters were provided from the Water Resources Ministryfrom seven stations along the river for the period2011 to 2016. The results of WQI analysis revealed that Diyala River is good to poor at the north of Diyala provincewhile it is poor to very polluted at the south of Baghdad City. The selected parameters wer

The injection of Low Salinity Water (LSWI) as an Enhanced Oil Recovery (EOR) method has recently attracted a lot of attention. Extensive research has been conducted to investigate and identify the positive effects of LSWI on oil recovery. In order to demonstrate the impact of introducing low salinity water into a reservoir, simulations on the ECLIPSE 100 simulator are being done in this work. To simulate an actual reservoir, an easy static model was made. In order to replicate the effects of injecting low salinity water and normal salinity, or seawater, the reservoir is three-phase with oil, gas, and water. It has one injector and one producer. Five cases were suggested to investigate the effect of low salinity water injection with differen

This paper study the ability of Enterobacter cloacae for degrading crude oil in contaminated water. Six isolates of E. cloacae were isolated from hydrocarbon contaminated soil and water of different sites. The isolate E. cloacae E1 showed the highest emulsification index (E24%) reached 62% thus it was chosen for further study. Biosurfactant produced by E. cloacae E1 reduced the surface tension of the medium from 64 to 36 mN/m. pH range 6.5 – 7 and temperature range 30˚C - 35˚C were the optimal conditions for maximum degradation. After 30 days of incubation, E. cloacae E1 degraded 70.00 ± 0.40% of the crude oil. GC-MS analysis revealed that E. cloacae E1 was able to degrade aromatic compounds. This study proved that E. cloacae E1 con