University of Thi-Qar Journal for Engineering Sciences

Welding is a technique used for joining metal parts usually during the application of heat. There are many types of welding, including an electric arc welding this means that welding is a process in which the electric arc forms a metal work piece and an electrode, which leads to this work to heat the metals and cause them to melt, and connect them with an inert metallic gas (MIG). This study clarifies the conclusion of welding parameters such as travel speed, current and wire feeding speed to medium carbon steel through Welding. Get the greatest parameters as it gives nature to alteration of the strength and the quality of product and its impact on tensile strength, and hardness at studies the conduct of AISI 1040 steel by using the Taguchi method in this experimental procedure and analysis of variance in Minitab software and Optimization method (OptiY program / Evolutionary Algorithms). It was found that the increase in current leads to an increase in the amount of tensile strength(TS) and hardness of the material. Also, decreasing the welding speed during the welding process leads to an increase in the tensile strength and hardness of the welding area. While, the effect of the input welding wire feed values ??on the welding region, specifications are largely dependent on the welding current and welding speed values chosen

This paper studies numerically the impact of installing longitudinal fins on the performance of a DPHE. Different heights were considered for these fins and three different profiles; rectangular, triangular, and semi-circular were investigated. Fins were fixed on the internal surface of the annulus side. The numerical investigation was carried out for counter flow. The study is performed in two cases. The first one was of a constant hot water mass flow rate (mh) at (0.3) kg/s and varying values of cold water mass flow rate (mc) which was from 0.2 to 1 kg/s. The second case was of a constant cold water mass flow rate (mc) at (0.3) kg/s and changing hot water mass flow rate (mh) which was from 0.2 to 1 kg/s. Inlet temperature of hot water was 353k and for cold water was 298k. The results showed that using longitudinal fins enhances the (DPHE) thermal performance. Also, semi-circular profile gave more enhancement in the rate of heat transfer compared to other studied profiles

The pavement condition index (PCI) method provides a simple way for determining maintenance and repair (M-R) needs and priorities. The PCI procedure was developed by the U.S. Army Corps of Engineers in 1997. In this study, an attempt was made to adopt the PCI method to evaluate the pavement state and suggest suitable maintenance and repair (M-and-R) works for the 13 damaged roads. The area of the study is roads net damaged with raveling distress in Al-Hadharat Quarter in the city of Nasiriyah which located in the south of Iraq. The pavement had divided into branches which sub-divided into sections. The type and severity of pavement distress were assessed by visual inspection. The distress data used to calculate the PCI for each sample unit. Then the PCI of the whole pavement section is determined. The calculated PCI was assessed with the pavement condition rating. The results show that the PCI Rating evaluation was ranging from fair to poor roads, very poor and one case of serious, but never reached to fail case in any of the studied roads. The study shows that the (PCI) method provides a suitable measure of the present condition of the pavement. The main conclusion of the study is the ability to conduct the PCI method to diagnose pavement distresses and evaluate pavement condition in the studied area. The use of (PCI) method is efficient in the prior evaluation of road condition in order to implement suitable maintenance to the distressed pavement

In this paper analytical study has been made to investigate a hybrid refrigerant consists of different refrigerants with different mixing ratios and find out its effects on the performance of cycle and specify the best refrigerant that gives best performance and least environmental pollution. Firstly the performance of vapor compression refrigeration system has been analyzed with several different pure refrigerants( R11, R12, R13,R22,R23, R32, R41, R115, R116, R124, R125, R134a, R142a, R143a, R152a) by REFPROP software and the values of coefficient of performance (COP) and mass flow rate ( ) and work in compressor (Wc) for each pure refrigerant is calculated and by use other properties for every refrigerant it can determine the best refrigerants to make a new refrigerant that comes from mixing of two or three of pure refrigerants with best performance for example R22 and R134a with mixing ratios (25:75),(50:50),(75:25) respectively Assuming the evaporator temperature is (-10 °C) and the condenser temperature is (35 °C). The main parameters are calculated such as new refrigerant, mass flow rate and work used in compressor for various capacity in (kW). The results showed that the maximum performance recorded with R134a and the minimum value with R115 while the values of performance for their mixtures fluctuated between the maximum and minimum values for the pure refrigerants and the cause of this is due to combination of properties as boiling point temperature and critical temperature, latent heat of vaporization, specific heat of liquid and specific volume of the vapor

The paper presents the transverse vibration of an open edge crack graded Rayleigh beam with axial motion. The vibration equation was obtained relying on Hamilton's precept and resolved by the approach of Galerkin's. The power-law is adopted to represent the gradient of properties of the material composing the beam along the direction of the thickness. Cracks were modeled as rotational massless spring. The effects of axial velocity, material property change index, location, and depth of cracking on the vibration characteristics are observed. Also, the corresponding mode shapes are found for cracked moving graded Rayleigh beam with simply supported, and fixed-fixed end supports. The results clear up that the natural frequencies drop due to the rise in the axial velocity, the crack depth, and the material property index

Recent advances in materials engineering have given rise to a new class of materials known as active materials. These materials when used appropriately can aid in development of smart structural systems. This research presents the smart composite beam study in experimental and numerical by ANSYS V.15. In the present research, shape memory alloy NiTinol wire as fiber was used with a linear low density polyethylene (LLDPE) as host matrix. Nitinol wire high temperature is about 80°C±10°C full annealed, (2 mm) with a straight shape, black color, it consists of (Ni-55%, H-0.001%, O-0.05%, N-0.001%, C-0.05%, Ti-Balance). The model consists of four NiTinol wires, each one with 180 mm length and 2 mm diameter, the distance between them is about 10 mm. In the experiment, the model was subjected to a bending load with speed 500 mm/min and displacement 30 mm. After unloading, the composite backed upward (spring-back) by a displacement about 13 mm and stopped. But, the spring back in finite element modeling was about 12.5 mm, the error percentage between the experimental and finite elements results is about 3.8%. Recovery stress is sufficient to return the composite beam to the original shape and position. The factors play the important role in the recovery composite beam are recovery stress, rigidity of host matrix, interfacial bonded force, pre-strain and activation temperature. The temperatures distribution is same on the surface of smart composite beam model in the middle line in both cases, finite elements modeling and experimental work. The pre-strain 4% is enough to recover the composite model after activation. The chosen polymeric host is very significant, because through activation of NiTinol wire, the host material becomes flexible.

A composite material is a material that consists of a matrix (base phase) and a stiffener (reinforcement) that combined together to build up a structural unit. Reinforcement material form may be fibers, flakes or as a particle. In the current paper, unsaturated polyester resin (UP) was used as a base material, Sisal fibers (SF), glass fibers (GF) and Silica dioxide (SiO2) particles were performed as a reinforcing material. Three composite types were prepared: (C1) UP only, (C2) UP reinforced with 15% SF and 15% GF, and (C3) UP reinforced with 15% SF and 15% SiO2 to investigate the effect of reinforcement type on some mechanical properties such as elastic modulus, compressive strength, hardness and impact toughness with various temperatures.

The experimental results showed that the mechanical properties of composite materials were improved by using reinforcement with fibers and nanoparticles. The high values of elasticity, hardness and toughness were obtained with the specimen C2 composite. While the highest values of compressive strength were obtained with the specimen C3.

On the other hand, the modulus of elasticity, compressive strength and hardness were decreased with increasing of temperature values with various percentages. Other clockwise, the toughness values were increased

Today, lean philosophy is widely used in many manufacturing and service systems to reduce or eliminate waste and defects for improving system quality. Recently, Lean Engineering Education (LEE) is a new concept lean philosophy and widely used in education system. Engineering education is so important field where practical and theoretical study have a strong impact to increase students' knowledge and improve their skills. This study will illustrate how can be successfully used Lean tools on the engineering education system by identifying defects that have a negative influence on the final quality of the theoretical and practical studies. E- questionnaire by google form is prepared to collect data about quality of engineering education elements from students point view where it was conducted in mechanical engineering department and included 82 students. Six engineering education elements that have a strong impact on the quality of the theoretical and practical studies are used, namely; lecturer, students, curriculum, assessment process, scientific method and scientific equipment and tools. Lean tools, namely; pareto analysis, fishbone analysis have been used to clarify the defects types and causes of the critical defect in the engineering education that have a big influence on the quality of both studies. weights method is used also to compare between the theoretical and practical studies to identify which one is less quality than another quality scale was used that based on triple Likert scale to identify the quality level; namely bad, acceptable and good. The results showed that both the theoretical and practical study in the mechanical engineering department have the same acceptable level of quality and the scientific equipment and tools have largest defect in the practical study and the unavailable enough number of laboratory devices is considered a critical cause of scientific equipment and tool defects but in the theoretical study , the assessment process has largest defects with critical causes result from unclear the assessment questions during examinations

The aim of this paper is to solve the load flow for Power System Connection (IEEE 6 Bus System), and find the power losses in the transmission lines and the total power losses for 10 MVA base power rating and 33 KV rated voltage. This can be achieved with the aids of simulation by using a software programme called PSAT, which is compatible with MATLAB. In addition, to improve the efficiency of the system a 2 MW wind turbine has to be installed on the system, but due to the fact that the wind turbine has changeable output power and this leads to variation in the voltages and currents in the transmission system. Therefore, we will examine the effect of the 2 MW wind turbine at different busbars and find out where is the optimal location for the turbine, which results in low system losses and optimum voltage. The next section is to apply a PV generator with variable output on different busbars and find the best position that we can obtain less power losses and optimum voltage regulation. The final section is to apply 0.5 PV generators at different buses at the same time and compare the result with the case obtained from applying 2 MW PV generators

Although wavelets are powerful as a tool in image processing it has three serious drawbacks: shift sensitivity, poor directionality and lack of phase information. Wavelets suitable for dealing with objects with point singularities; it can only capture limited directional information due to its poor orientation selectivity. Through decomposing the image into a series of high-pass and low-pass filter bands, the wavelet transform extracts directional information that capture vertical, horizontal, and diagonal activity. However, in noisy images, these three linear directions are limiting and might not capture enough directional information, like medical CT scans, which do not have strong vertical, horizontal, or diagonal directional elements.

Ridgelet transform improves Multiresolution Analysis MRA segmentation; however, they capture structural information of an image based on multiple radial directions in the frequency domain. Line singularities in ridgelet transform provides better edge detection than its wavelet counterpart. One limitation to use ridgelet in image segmentation is that ridgelet is most effective in detecting linear radial structures, which are not dominant in images. The curvelet transform is a recent extension of ridgelet transform that overcome ridgelet weaknesses. Curvelet is proven to be particularly effective at detecting image activity along curves instead of radial directions which are the most comprising objects of images. However, the fact that at sufficiently fine scales, a curved edge is almost straight, and so to capture curved edges, one ought to be able to deploy ridgelets in a localized manner, at sufficiently fine scales.

In this paper, a new method is used combining the Window Shrink threshold and Bayes Shrink threshold based on Curvelet transform to enhance removing Additive Weight Gaussian Noise AWGN noise from image. It has better PSNR than the traditional Curvelet that uses each threshold alone, and the images gotten by this method is better and outperform that of the traditional curvelet and wavelet methods and the results reported here are promising

Real time monitoring with IOT is developed in the industry of health care , this can enable the doctors and specialist to diagnosis the patient status in quick, smart and efficient methods. Although, there is a lot of research and studies are designed methods for observing the ECG signal remotely, there are no proposed methods for classifying these signals with monitoring, and therefore , to design complete health care system, classification techniques should be used to classify the extracted signal. In this paper , We have proposed ECG monitoring and classification system. The proposed system is extracted ECG signal based on AD8232 sensor with the ardunino nodeMcu, analog to digital converter and its communication is used to convert the signal to more precision , then the extracted signal is transmitted to cloud to be used at anywhere by using cloud, the signal is pre-processed to remove the noise and QRS complex is detected to determine the other characteristics of the signal such as heart rate, also to determine one cycle of ECG signal, later the signal is classified by using proposed convolution neural network model to detect the signal status. The extracted ECG signal is transmitted in real time to cloud (Ubidots cloud is used) through ESP8266 over to the cloud using WiFi based on MQTT publishing method. The experimental results are performed on different signals and the different stage of de-noising and QRS detection are applied and different pooling layers are used in the proposed CNN model. The results show that the proposed classification model is achieved accuracy (94.94%) with ( 94.56%), (94.56% ) and ( 5.06) for sensitivity, specificity and error rate (ERR) respectively

In this research a numerical simulation of the micro-jet system used to cool an electronic chip was performed, as it was of type multijet, the basic idea of how the impingement cooling method works on the micro jet cooling array was provided by these simulations that consisted of a variety of parameters: Reynolds number (500-3000), diameter of jets (150-750) µm, number of jets (11,13,15,19,21), and distance between jets and target (450,337.5,225,168.75,112.5) µm. Shear stress transport (SST) K-? model was used because it's able to predict the laminar to turbulent transition according to previous research. The input heat flux =36421 w/m² and area of plat (28700×28700) µm². The result shows the performance was improved when the jet diameter was increased, as the highest value of the Nu was obtained at (d = 600µm) and the losses were reduced. Also, the performance improved when the number of jets was increased.

This paper numerically investigated the square microchannel heat exchanger (MCHE) at hydraulic diameter 20 ?m and the diluted water 1:1 potassium chloride (KCl) solution as a working fluid at ionic concentration M with using silicon microchannel. A comparison has been made between parallel and counter flow with two methods of driven flow of liquid through MCHE (pressure driven flow PDF and electroosmotic flow EOF) with using two values of zeta potential (-75, -200 mv) to investigate the effect of zeta potential on performance of parallel and counter flow. In this paper solved a three dimensional Poisson-Boltzmann equations and Navier-stoke equations with electric field which applied on electrolyte solution have been solved using the finite volume scheme. The results showed that, the total pressure drop increased at combined EOF/PDF compared with pure pressure driven and it clear in parallel flow more than counter flow. Heat transfer rate for counter flow is higher in parallel flow. That the increasing in zeta potential of surface charge caused an increase effect of EDL due to increase in Helmholtz-Smolochowski velocity

This paper discusses the fabrication techniques and the fabrication technique of single electron transistor (SET). The SET differs from the conventional CMOS in the sense that it has the ability to control an electron movement so that single electron can be transport at a time, meaning that one by one electron along the channel. This is due to its stunning technique that has the ability of controlling the electron tunneling. The SET represents a promising technology as it offers several unique advantages, example, small size, high operating frequency, and low power consumption. Several SET of fabrication technologies were reviewed in this paper, including quantum dot, carbon nanotube, graphene, and zinc oxide.

In this paper, it presents a detailed analysis of the use of the parabolic solar cooker in cooking and boiling water. Three models of parabolic solar cookers were manufactured with aperture diameter (96 cm, 120 cm, and 140 cm) made using satellite dishes of the same diameters and using glossy aluminum foil as a reflector sun ray after being cut into strips 10 cm wide and glued to the inner surface of the dish. A metal tin can (3L) was used as an absorbent receiver instead of a cooking pot. Experiments were conducted to boil water from the roof of the house in Nasiriyah City located in southern Iraq. Through this study, the optical efficiency of the three types of parabolic solar cookers with diameters (96,120, and 140 cm) was calculated, as they were (69,66%), (66.5, 66.35%), and (67.4,66.7%) respectively. The amount of heat gained for the three cookers, respectively (670.665, 556.394W), (1142.6, 1074.83 Watt), and (1535.38, 1460 Watt). The heat loss from the receiver, respectively (68.6, 70.53 W), (118.16, 140.385 W), and (112.69, 96.576 W). The collector efficiency of the three cookers (58.77, 53.32%), (56.16, 53.3%), and (60, 60%), and the cooking power of these cookers (475,875, 264.375 W), (413.8, 434.13 W). ), (740.25, 691.44 W). Many tests were conducted on the specified location at the weather in Iraq during the winter season. The results of the experiments showed that the parameters of the solar cooker mentioned above mainly depend on the diameter of the concentrator dish, the quality of the reflector used, the cooking time, and the closing to midday. While the high ambient air speed leads to a decrease in the pot temperature by increasing the heat loses to the surrounding air through convection, thus greatly affected the solar cooker parameters, especially the collector efficiency and cooking power, as well as the accuracy of directing the dish towards the sun, and determining the focus accurately affected on the parameters of the solar cooker too

Due to the importance of survey work and positioning in any construction project, the opportunity of using new technology is vital to observe high accurate information. Differential Global Positioning Systems (DGPS) represents of most recent innovation in positioning systems. This tool used two types of methods to reduce the error, firstly the gather information from geographic position systems satellites (GPS) comparing it with real fixed ground locations. DGPS can not only improve project accuracy but it can reduce the total survey work in terms of time and cost considerably. However, the high initial cost to buy this kind of equipment prevents many public and private organizations in Iraq from start using this new technology. This research will aim to give real evidence of how accurate DGPS can be. This aim has been achieved via implementing DGPS in a real project and show the real results and compared with standards errors derived from using common survey tools such as Total Station and GPS.

In this paper, a comparison was presented between the use of two parabolic solar concentrators to boil water with the same aperture diameter (96 cm) with two different reflectors, one made of aluminum foil and the other one made of mirror pieces. The two concentrators were made using a satellite dish of the same diameter. When using aluminum foil as a reflector, it was cut into strips with a width of 10 cm and glued to the inner surface of the dish. As for the mirror pieces, they were cut into pieces (5 * 5cm) and glued to the surface of the dish. A metal tin can with a volumetric capacity (1 liter) was used as a thermal receiver. Experiments were conducted to boil water from the roof of the house in Nasiriyah, southern Iraq. During these experiments, the optical efficiency of the parabolic solar concentrator, the amount of heat loss from the heat receiver by radiation and convection, the collector efficiency of the solar concentrator were calculated.