Articles in This Issue
Abstract
The studying of the distribution of wetting patterns in soils having a stratified profile is of great importance due to the presence of this type of profile in abundance in agricultural lands, including greenhouses. Therefore, there was a need to develop a numerical program that predicts the dimensions of the wet area of the subsurface drip irrigation system under different operating conditions for purpose design and manage these systems properly to avoid water losses resulting from evaporation or deep penetration. The present study aims to develop a two-dimension model simulates the wetting pattern in stratified soils using (HYDRUS-2D) software and study the effect of soil hydraulic properties and different operating conditions on the progress of the wetness pattern and the interference pattern between two wetting fronts. Laboratory experiments were carried out for the system of subsurface drip irrigation in stratified soils that consisted of three layers (silty clay loam soil, loamy sand soil, and sand soil) arranged from bottom to up. Three different emitter flow rates 0.5, 1, and 2 l/h were tested, as well as three different initial moisture contents for each soil layer were considered. The interference pattern between two wetting fronts of two emitters with different spacing between emitters 30, 40, and 50 cm was studied. A numerical model was developed to guess the horizontal and vertical dimensions of the wetting zone for the single emitter and the pattern of interference between the two wetting fronts of two emitters. The predicted values obtained from the numerical model were compared with those obtained from laboratory experiments. Statistical analysis of the obtained data showed that the developed numerical model has a good ability to guess the dimensions of the wet pattern of the single and the two emitters and there were good agreements between the predicted and the experiments results and minimum values of RMSE ranged between 0. 5 and 3.6 were achieved.
Abstract
This study assessed the temporal and spatial water quality variability to reveal the characteristics of the Shatt Al-Arab River, Basrah, Iraq. A total of 14 water quality parameters (water temperature (T), pH, electrical conductivity (EC), Alkanets (Alk), total dissolved solids (TDS), turbidity (Tur), total hardness (TH), calcium (Ca), magnesium (Mg), chloride (Cl), sulphate (SO4), total suspended solids (TSS), sodium (Na), and potassium (k)) were analyzed Use of multivariate statistical methods in a total of three stations for the period 2016-2017. In this study was use a statistical approach to determine the water quality using the Pearson Correlation Index (PCI), Principal component analysis (PCA), and Factor Analysis (FA) were used to analyze the data. Main water pollutant sources were wastewater from agricultural drainage and industrial wastewater. Significant relationships recorded between the investigated parameters based on the results of PCI, at the 0.01 and 0.05 significance levels. Per the FA results, 77.1 % of the total variance explained by two factors.
Abstract
The present research is devoted to solve the problem of high energy consumption by air conditioners in summer. In order to eliminate domestic electricity for cooling purposes and rely directly on solar energy isolated from the grid connection and increases the performance of the solar panel by using front water spray cooling system for the panel, and by using Adruino as controller to control the cooling system. The experimental system setup arranged in Iraq at Al-taje site during the summer season at a room. The proposed system consists of an array of photovoltaic, battery used to store power, PWM charge controller, and DC air cooler, Adruino. During the examination of the system, The enhancement of the solar panel has a positive effect on long-term batteries and improves the battery life by which the charge and discharge when combined with a direct photovoltaic air conditioning system without refrigeration. Excess power generated from the PV panels is storage in the batteries, which make the system is the most familiar with Iraq's summer conditions
Abstract
Deep beams with rectangular cross-sections are widely used in concrete structures. In the present study, reinforced concrete rectangular deep beams cast with self-compacted concrete (SCC) which contains recycled concrete as coarse aggregate (RCA) were tested under directly and indirectly loading conditions. In the experimental work, fifteen deep beams were investigated, the first parameter considered in this study was the shear span to effective depth (a/d) ratio. The other variable is the replacement ratio by which the normal coarse aggregate is replaced by RCA. The beams were cast without the use of shear reinforcement. During the tests, the response of the beams including the cracking load, the ultimate load, concrete strain, and mid-span deflection were recorded. Test results indicate that the presence of RCA caused a reduction in the values of cracking and ultimate loads. For instance, the cracking load was reduced by 9%, 23%, and 50% and the ultimate load was reduced by 2% , 23%, and 25% as RCA replacement increased by 25%, 50%, and 75% respectively for a/d ratio equals 1.0. Further, by increasing the a/d ratio, the ultimate load was decreased due to the lower contribution of arch action shear transfer in the beam with a higher (a/d) ratio.
Abstract
Traffic accidents and traffic delay have a negative impact on the mobility traffic flow due to their huge costs on the transport system. Thus one of the main primary aims for transport policy makers are reducing the negative effect of traffic accidents and traffic delay on the road network. In this study, fixed and random parameters Tobit models have been developed to model the accident rates from 20 intersections in Al-Karakh district in Baghdad City, Iraq. The safety significant of logarithm of annual average daily traffic, the percentage of heavy vehicles and the delay time for both major and minordirections for each intersection on the accident rates were evaluated. The main finding of this study shows that delay has an important effect on traffic accident rates of intersections. Regarding to the effect of other factors on traffic Accident rates, the result of the model shows that the logarithm of annual average daily flow, the percentage of heavy vehicles for both major and minor directions of the intersection are positively associated with more accident rates.
Abstract
The quality of the built environment could highly impact our state of wellbeing, by affecting our stress and exposure within the building environment. Scientific studies linked stress to depression, diabetes, obesity, and cardiac disease. Hospitals considered as stressful places due to their inconvenient experiences. The theory of Salutogenic design aims to reduce stress through the implementation of an interdisciplinary design study to enhance the sense of coherence ( SOC) for any individual to be able to adapt himself to the overall life challenges. Salutogenic defines several factors which can affect an individual’s state of well-being in any space. This research limited on two of these design factors (daylight, colour) within three selected hospital through a critical methodology using a sample questionnaire of 15 questions headed to 90 from all three hospitals. the second part of the methodology using a Light-meter device for calculating the amount of Lux in actual hospital conditions, the third part of research methodology is a simulation program (Ecotect) to have an adequate daylight calculation in the wards of all three hospitals as well as the lighting distribution with (daylight factor) to evaluate the efficiency of wards in Erbil city. The last part of the study is by a field investigation by the researcher for the implementation of Salutogenic Colours. through a critical methodology approach.The research results shows that wards of three hospitals has a poor natural daylight to penetrate the building, and hospitals depends mainly on artificial light which causes uncomfortability and inconsitnecy in treatment process. Patients prefrences are twords new colours such as turquoise, palepink, and blue rather than the tradtional colours used in Erbil governmental hospitals. using light meter as assessment tool to compare between the Ecotec Lux measurement and the actual condition of lighting in hospital. The evaluation of three Wards within hospitals shows clearly the un sufficiency of natural lighting which leads to needing of artificial daylight. And might delay the process of recovery. Ecotect calculates the most suitable design condition in any city and finds other suitable orientations for buildings.
Abstract
The field of image processing has several applications in our daily life. The image quality can be affected by a wide variety of deformations during image acquisition, transmission, compression, etc. Image compression is one of the applications where the quality of the image plays an important role since it can be used to evaluate the performance of various image compression techniques. Many image quality assessment metrics have been proposed. This paper proposes a new metric to assess the quality of compressed images. The principle idea of this metric is to estimate the amount of lost information during image compression process using three components: error magnitude, error location and error distribution. We denote this metric as MLD, which combines the objective assessment (error magnitude) and the subjective assessment (error location and error distribution). First, the metric is used to estimate the quality of compressed images using the JPEG algorithm as this is a standard lossy image compression technique. Then, the metric is used to estimate the quality of compressed images using other compression techniques. The results illustrate that the proposed quality metric is correlated with the subjective assessment better than other well-known objective quality metrics such as SSIM, MSE and PSNR. Moreover, using the proposed metric the JPEG2000 algorithm produces better quality results as compared to the JPEG algorithm especially for higher compression ratios
Abstract
Hydraulic actuators are one of the most viable choices due to their high power-to-weight ratio,low cost, robustness, fast response and great power supply. The present work focuses onbuilding an elevator prototype model simulates real hydraulic elevator. This model consists ofhydraulic parts (double-acting hydraulic cylinders, pump, valves, pipeline and filter) andelectronic parts (PLC, push-bottoms, relays and encoder). It is built with three floors in about300 cm height (total with the cylinder) to elevate a 30 kg payload and controlled by a PLCcontroller of (DELTA DVP-ES32) with 16 inputs and 16 outputs. The PLC receives input signals asorders from the operator as well as sensors and encoders. The PLC is programmed with WPSOFT2.46 Ladder diagram software to basically calling the elevator cabin through three locations andenabling its arrival at the desired floor. The cabin descent is achieved by using a proportionalcontrol valve which is controlled by the PLC. The cabin door is automatically opened and closedby DC motors. It is observed that, the application of this partnership between the PLC and theproportional valve in the build model helped to achieve excellent results in terms of systemcontrol and its efficiency, response, and smoothness.
Abstract
The present study was concerned with the analysis, simulation of the air flow pat-terns and thermal comfort levels in the University of Anbar at conferences hall (Ibn Al Haitham hall). The study was performed in a hot - dry season. The pur-pose of the present work was to investigate the level of thermal comfort and the influence of the air flow on the flow patterns at the conferences hall. It has been assumed that the total number of occupying audiences in the hall was approxi-mately 100 persons. The present work simulated and analyzed four hypothetical cases, namely: in the first case, the hall was assumed as an empty place, whereas the other three cases were performed by redistribution for the three units of air conditioning, the hall was assumed as a filled place with persons in September 2019. The study was accomplished using simulation techniques, a CFD code (FLUENT 6.2) v.17, which is commercially available. The CFD modelling tech-niques were applied to solve the continuity, momentum and the energy conserva-tion equations in addition to the Turbulence k-є (RNG) model equations for a tur-bulence closure model. Thermal comfort was assessed by finding the values of predicted mean vote (PMV), predicted percentage of dissatisfied (PPD), and ASHRAE standard-55. In conclusion, the second case was the superior in compar-ison to these other cases. It was noted that the PMV value was 0.17, whereas the PPD value was 6.79 at the breathing level.
Abstract
The goal of the current investigation is to construct an artificial neural network (ANN) to estimate the ultimate capacity of the composite columns consisting of a rectangular steel tube filled with concrete (RSTFC) under concentric loads. The experimental results of (222) samples collected from previous researches were used in constructing the proposed network. Totally (45) specimens were randomly chosen for network testing while the remaining (177) speci-mens were used to train the network. The information used to create the ANN model is ar-ranged into (6) variables represents the different dimensions and properties of the RSTFC col-umns. Based on the input information, a formulated network was used to estimate the columns' ultimate capacity. Results obtained from the formulated network, available laboratory tests, and Eurocode 4 and AISC equations were compared. The network values were closer to the laboratory values than the calculated values according to the specifications of the mentioned codes. It has been shown that the formulated ANN model has a high ability to estimate the RCFST ultimate capacity under concentric loads
Abstract
Friction welding method is one of the most efficient and effective techniques for joining similar and dissimilar materials. The AISI 304 austenitic stainless-steel is a most common type of austenitic stainless steel which is used in various practical applications like automotive, food manufacturing, chemical applications, etc. Therefore, the impact strength and microstructure behavior of friction welded AISI 304 austenitic stainless-steel joints were investigated. The specimens were divided into two groups, the surface of the first group was flat while the interface of the second group was designed by fabricating a pin and hole. The effect of different forging pressure (192.4, 240.5, 288.6 and 384.8 MPa) on impact toughness and microstructure behavior of AISI 304 were examined using Charpy impact tester and optical microscope, respectively. The minimum impact strength was observed at 240.5 MPa for flat interface samples whereas, the maximum impact strength value (0.5675 J/mm2) was at 388.6 MPa forging pressure for pin interface samples. In addition, the ductile mode in pin type for all cases while both, brittle and ductile mode in the flat joint was noticed. Finally, it was concluded that the impact strength improved with designing a pin and hole shape at the joint interface.
Abstract
The research aims evaluates the water consumption and future demand by using the WEAP program. Five scenarios have been adopted, which is the reference scenario that showed the results of increase in water demand from (100) million cubic meters in 2015 to (397) MCM in 2035 with a water deficit in 2035 to (38) MCM. Modern irrigation methods reduce the water deficit from (38-2.9) MCM. While the use of underground water reduced the deficit from (38-26) MCM. As for the wastewater reuse scenario, the deficit decreased from (38-35) MCM. Reducing the per capita share did not reduce the water deficit.
Abstract
Recently, the investigations studies of simulating flow over spillways have increased using numerical models. Due to its important structure in the dams to pass flood wave to the downstream safely. Researches finding have shown that CFD (Computational fluid dynamics) models as the numerical method are a perfect alternative for laboratory tests. Performance analysis of the CFD platforms Ansys Fluent-2D and Flow-3D are presented, focus on finding the variations between the numerical results of the two programs to simulate the flow over ogee spillway. The present study treats the turbulence using RNG k-ε of RANS approach, and also use the Volume of Fluid (VOF) algorithm to track the water-air interaction. The Fluent-2D and Flow-3D accuracy are assessed by comparing representative flows variables (velocity; free surface profiles; pressure; and the turbulent kinetic energy). The results of both codes have been also compared with experimental data. The results of the analysis show an excellent agreement between the two platforms data, which could assist in the future by using both programs to calibrate each other, rather than traditionally relying on laboratory calibration models.
Abstract
A steam boiler is a metal vessel in which a particular liquid is heated to steam. Steam is used in the production of energy in several areas as most boilers convert water to steam used in heating buildings and others. Steam boilers are exposed to corrosion and sediment as a result of salts dissolved in water, which may lead to increased temperature inside the boiler and thus the boiler explosion. The research included finding a suitable way to solve the problem of sedi-ment and corrosion by adding suitable chemicals to get rid of the dissolved salts inside the water and maintain steam boiler. To control this problem, the control system is designed to control the amount of salts in the water in the steam boiler using PLC.