DIYALA JOURNAL OF ENGINEERING SCIENCES

The electroless deposition method was used to prepare Ni-based nanocomposite coatings, this approach represents an alternate way of having coatings on the different substrates. Most of the previous literatures on this subject and work deals with a study the effect of the process conditions and, Bath composition on the microstructure at the macroscale of Ni-Al2O3composite coatings. Though, effect on the step structure of the composition of the bath and microstructure are little, the present work aims to study the effect of hard ceramic Al2O3nanoparticles at different concentrations (0.0, 0.5, 1.0, 2, 4) g/L, on the phase structure, microstructure and morphology of Al2O3nanocomposite coating, in order to enhance the mechanical, physicaland chemical properties of nanocomposite coating. In this paper, An X-Ray diffraction method, spectroscopy (EDS), energy dispersive, and scanning electron microscope (SEM) were studied in the phase structure, chemical composition and morphological nanocomposition coatings. In the present paper, is evident from EDS study that the composite coating consists of Ni and nanoparticles ofAl2O3. The micrograph study of the EDS showed that A flat and smooth surface is present in the deposited nanocomposite coating. Uniform distribution of nanoparticles of alumina within Ni-Matrix. And the XRD study showed the crystalline structure of the Ni-Al2O3nanocomposite coating

n this research, the potential improvement of some geotechnical characteristics of soft clay soil using the low Calcium fly ash was evaluated. (These characteristics include unit weight, shear strength, compaction characteristics and soil plasticity characteristics). In addition, the X-ray diffraction test was performed to measure the mineralogical changes in the soft clay soil when the low Calcium fly ash is added. The ordinary Portland cement was used to activate the fly ash. The total percent of flash and cement was10% to investigate the variation in the effectiveness of activation. The optimum moisture content that which computed by the compaction test was adopted in the rest of the experimental program. The test results revealed that the cement could be used to improve the activating of the fly ash efficiently. The maximum value of dry density was marginally affected due to activation from 1.747 to 1.738 g/cm3 along with a corresponding change in optimum water content from 17.45 to 15.5 %. The soil cohesion parameter increased from 188 to 206 kN/m2 whereas the angle of internal friction rose from about 56.7o to 59.1o. Finally, the results of the unconfined compression test reveal that the cement-activated fly ash could present better results than those obtained from a 28-days curing cement.

n the construction industry, using of traditional methods to design and perform the works with participation of different disciplines by individual method make the design of structure more pruched to errors and mistakes and increase the possibility of generate the wastes due to need sometimes to re-work. In addition to the continuous change of designs, and this needed to updating documents and plans manually to keeppace with these changes, thus wasting time and effort, so this considers "inefficient" practice. Building Information Modeling (BIM) is an innovative technology that makes the design phase and construction industry more efficient to achieve the requirements of sustainability. A case study was taken to investigate the possibility of using BIM technology and structural analysis softwares (Robot and Etabs) in the structural design stage, where a model is modeled in the Revit software, and it is exported to Robot and Etabs softwares for the purpose of analysis and design, which showed close design results between these design softwares with a slight difference in the amount of rebar, about 4% more by using the Etabs software for all the structure. All the process performed from modelling to analysis and design then extracting schemas and quantity estimation for reinforcement and concrete was done in a short time and with satisfactory results

There are challenges with cost deviation and time overruns in every project in the building sector, whether they're residential projects, infrastructure projects, or anything else. The study aims to find the most important causes of cost deviation in a construction project. The researcher depends on Root Cause Techniques. These techniques are a good choice for diagnosing the root causes of cost deviation in a construction project. Many roots cause analysis tools have emerged from the literature as generic standards for identifying root causes such as the Fishbone Diagram, ParetoChart,and the Five-Why techniques. This study diagnosed nineteen causes of cost deviation in the selected project (Dar Al-Nahrain building), These causes can be classified into three categories (planning causes, designing causes, and execution causes). According to Pareto analysis, the most important reasons for cost deviation are 10 out of nineteen causes.According to the Pareto chart above, the designing causes group (C2) and the planning cause group (C1) are responsible for 80% of the problem. As a result, focusing on these two major causes will solve 80%of the problem's project deviation in building projects. The results were filtered using the 5-Why analysis, which concluded that the project's cost deviation was due to insufficient project information, which is the root cause for the planning causes group, unclear owner requirements for the designing causes group, and changes in orders for the execution causes group

The analysis of the reservoir-dam-foundation coupled system is much more complicated than that of the structure alone because of the difference between the characteristics of the foundation and concrete dam. The small hydraulic structure may be built in seismically active regions, where ground movement would impose earth pressures. The safety of these structures should be investigated quite critically by logical and precise methods. Rawanduz dam subjected to EL-Centro earthquake-S00E component excitation was chosen as a typical case of study. The static and dynamic stability of the Rawanduz dam had been analyzed and evaluated. A 2-D Finite Element model employed using ANSYS software to simulated dam response. The water was modeled as an additive mass according to the theory of Westergaard on the back of the dam while leaving the rest of the reservoir inactive. The dam body is presumed homogeneous, elastic, and isotropic properties for mass material. The soil was assumed to be flexible and analyzed as a nonlinear material. When assessing the stability of the structure under the influence of the seepage loads, the structure was founded safe because the exit gradient value was equal to (0.25), which was less than the critical value of the exit gradient (1/6). Results showed that the principal stresses at the heel and toe of the dam were founded important to study the stability. The static and dynamic analysis findings indicate that the stress values are very low, hence satisfy the normal criteria for protection factors relating to the tensile and compressive strength of the concrete

Research problem: when the pandemic emerges and the threatens people's lives;social distance becomes one of the most important requirements to ensure the public safety. The social distance reaches the learning pillars, the instructor and the student, that’s why the new methods should be appeared, to solve the learning problem especially when the all-tradition always cannot meet the pandemic safety criteria which requires social distance. The architectural studies especially the undergraduate have different learning courses; theoretical, practical and studio learning classes. That’s why the research problem is the“need the future learning method for the future and during the pandemic.The research aims to find a method of learning that takes into account the current conditions in light of the Corona pandemic, suitable for lecturers and students.Research methodology:The research will usethe theoretical analytic for the learning methods to find the research concepts which will build the new learning method concept.The research relied on the descriptive approach in analyzing the results of the questionnaire by comparing the learning approaches for the purpose of reaching varied learning. The questionnaire was analyzed using SPSS to reach the results.The main conclusions are varied learning gives flexibility to students and instructors in temporal and spatial dimensions, allowing students and instructors to interact better, and a system that can be applied in critical times that requires the integration of a face-to-face learning system with various electronic learning

Construction project delay is a global phenomenon. The delay risk being regarded as a main challenge that is tackled via the firms of construction. It possessed an inverse effect upon the performance of the project resulting in cost overruns and productivity reduction. In Iraq, most construction projects surpassed their prearranged time and were delayed, resulting in a loss of productivity and income. The objective of this paper was to predict the cost and delay of construction projects to illustrate their risks effects by using of artificial neural networks with the particle swarm optimization method (ANN-PSO). Thereby, risk factors were identified and analysed using Probability and Impact Analysis which were embraced as the model inputs. In comparison, the outputs for the models were represented by the ratio of the contractor's profit to project costs and the delay in construction projects. An ANN model was additionally evolved with a backpropagation (BP) optimization method to assess the exhibition of the ANN-PSO model. To evaluate the accuracy of the results of the ANN-PSO model, coefficient of correlation (R), determination coefficient (R2), and root mean squared error (RMSE) wasutilized as performance evaluation of the models. The ANN-PSO model showed a significant performance in the delay prediction. The performance evaluation for the cost and delay prediction were (R=0.929, R2=0.863, RMSE=0.044), and (R=0.998, R2=0.996, RMSE=0.094), respectively. The model of ANN-PSO has a virtuous performance in the delay prediction better than the cost. However, the ANN-BP model showed better performance than ANN-PSO in term of cost prediction

The objectives of this study are to evaluate the use of geothermal energy combined with conventional air-conditioner (A/C) and its contribution to reducing dependence on electrical energy. Assessment of geothermal sources in Diyala governorate. This experiment includes installing a combined system in the test room. The indoor and outdoor temperatures and relative humidity were calculated, as well as the calculation of borehole temperature, in addition to theenergy efficiency ratio(EER)andcoefficient of performance(COP)of the systems. The amount of electricity consumption in kWh was calculated. The most important findings in this experiment are: (1) Thetemperature of the well at a depth of (6m) is almost constant throughout the year, about 24°C. (2) Usingthe geothermal system alone in the test-room reduces the average indoor temperature by 8°Cwithin one day. (3) Iraq can benefit from the important geothermal energy and its sources;however, its use is still very limited and limited to scientific research only. (4) The experiment proved that the EER and COP of the geothermal system, the combined system and the window-type air-conditioner are 18.9, 9.8, 9.4, 5.54, 1.9 and 1.52 respectively

Demolition and construction waste are among the topics that focus by many researchers. The methods of reuse of waste materials must reduce the economic and environmental pressure of their presence in various regions. Before 2014, the city of Mosul contained relatively small quantities of demolition and construction debris, especially concrete rubble, asphalt materials, and bricks (they formed approximately 80% of the construction and demolition debris). These materials increased very greatly after the liberation operations and the widespread destruction of large parts of the city and became a great problem in the reconstruction operations. There is no clear plan yet in the city to deal with this debris, and it is disposed of by moving them to another place or burying them randomly when rebuilding the destroyed parts. This study shows to deal with demolition and construction debris in Mosul after liberation and during reconstruction operations. Also, many sources and data dealing with the re-use of demolition and construction debris in the field of geotechnical engineering for operations to improve the engineering properties of soils are presented. Many papers show the possibility of using construction and demolition waste as an alternative base or sub-base materials, fill for embankments, or increase durability and reduce the swelling and plasticity of clay. The study concludes that the researches and data can be used to deal with the rubble of demolition and construction in Mosul in a way that enables to benefit from it economically and environmentally.

The strengthening and rehabilitation of reinforced concrete structures is an important issue all over the world. Fiber-reinforced composites (FRC) are mainly used for the strength and rehabilitation of concrete members. However, its use is limited due to its high price and environmental effects and its adoption of epoxy as an adhesive, where epoxy is considered inefficient at high temperatures and loses most of its properties. The solution to this problem leads to the use of low-cost locally availablegeopolymer adhesive paste, with the possibility of adding fibers to improve the mechanical properties. This paper presents the experimental results of the circular RC columns confined by carbon fiber reinforced geopolymer adhesive (CFRGA) with fibers at geopolymer adhesive (GPA). Variables included; Geopolymer adhesive with or without fibers and type of fiber added to GPA (micro steel fibers, carbon fibers, and polypropylene fibers) with the volumetric ratio of (2%, 0.4%, 0.2%), respectively. The results where it was found that confinement by carbon fiber reinforced fibrous geopolymer adhesive improved the columns compressive strength estimated by (215%) and the axial strain improved by (268%). When adding (micro steel fibers, carbon fibers, and polypropylene fibers) to the adhesive led to an improvement in the strength of about (16.1%, 8.4%, and 7.96%) respectively, compared with the confined RC column without fibers at (GPA). Finally, confinements by carbon fiber reinforced geopolymer adhesive are more suitable for use in strengthening and rehabilitation of RC columns in areas with a hot climate.

Chemical stabilization is one of the most alternative methods using on soil stabilization with various materials. In recent decades geopolymer has been attention from engineers and experts geotechnical to use it for improvement of soil, because of considered eco-friendly and cost-effective. This paper aims to investigate the influence of used MK-based Geopolymer in geotechnical engineering and to enhance the properties of soil. Where the MK is considered eco-friendly material and cost-effective compared to other materials. Different percentages of Metakaolin-based Geopolymer were used, which are 8, 10, 12, and 14%. It can be concluded that the peak value of strength illustrated when used MK of 10% with curing time 14 days. In addition, Scanning Electron Microscope (SEM) results show the clay particles covered by cementations compounds due to the reaction of the Geopolymer with clay which led to the production of binder particles.

In recent years, new methods have developed utilizing steel plates instead of deformed steel bar reinforcement in the concrete beams. This paper presents the utilization of a new proposed approach for replacingthe main flexural reinforcement concrete beams bysteel checker plates of (6mm) thickness. Four reinforced concrete beams were cast and tested under two-point load. All beams had the same cross-sectional area of reinforcement and the dimensions of 210 cm in length, 35 cm in height and 25cm in width. Theresult show there wasa reduction in crackload, yield load, and ultimate load of steel plate ascompared to steel bar, Whereasincreasedwith increasingcross-sectional area of the steel. Once,the increment in crack load and yield loadof steel plate were 25.5% and 16,67% more than steel barwhereas the same increment was found in ultimate load for both steel bar and steel plate. The measured crack load and ductility for steel plate was 16.7% more than steel bar when increasing cross-sectional area of steel.The deflection past of failure for steel plate has a considerable deflection before failure than steel bar. Finally, the observations show cracks have been much wider and less in range for all steel plate samples in comparison with the steel bar