bluuebunny/crossref_metadata_2025_split huggingface dataset:
Punching Shear Strength Improvement of Flat Slabs using Polypropylene Fibers
Authors: Alkhudery Hayder H , Aljnabi Nabaa I 
Published: March 2021

Abstract
The punching shear failure at the region around the column is considered the most dangerous type of failure in the flat slab system, causing an instantaneous collapse of the buildings. It is a brittle failure mode that happens suddenly without any warning. Recently many techniques were introduced by researchers to avoid shear punching failure and enhance shear punching resistance of flat slab. Improving the mechanical properties of concrete is a powerful approach line using polypropylene fibers (PF) in concrete in which details are presented in this paper. Twelve slabs were made with dimensions of (1000*1000) mm, and 100mm in thickness. The flexural reinforcement was the same for all models; for the upper layer was (6ϕ6), while the lower layer was (10ϕ12) without shear reinforcement. The factors studied in this investigation involve the polypropylene fibers quantity, compressive strength value. The results showed a noticeable improvement in punching shear strength when adding (PF%=1%) by cement weight. However, the impact of polypropylene fibers was negligible when adding a ratio greater than 2%, and it was also observed that the failure changed from a brittle failure of non-polypropylene fibers models to a ductile failure in slabs containing polypropylene fibers. The failure cracks in a slab with polypropylene fibers are tiny and less in number than the NC slab. This is because fibers increase the internal bonding of the concrete material component. Also, increasing the ratio of polypropylene fibers reduced the perimeter and area of the punching shear region while the failure angle slightly increased.
Design Apollonian Gasket Antenna for Millimeter-Wave Applications
Authors: Anooz Ruaa Shallal Abbas , Hatem Ghufran M , Hasnawi Iman Hafedh Yaseen , Nemah Mohammed N 
Published: March 2021

Abstract
Fractal geometry has been widely adopted in the design of various antennas for a wide variety of communications applications. The proposed antenna design is based on fractal geometry of second iterations Apollonian Gasket. This type of fractal can produce an antenna that is miniaturized and multiband. The proposed antenna design built using the FR-4 AS substrate with 4.4 and a loss tangent of 0.002 with a thickness of 1.2 mm. The results show that the proposed antenna offers multiband that suitable for the indoor wireless environment and millimeter-wave applications with high gains and bandwidth enhancement. This antenna also gives good radiation patterns for multiband. Modeling and performance evaluation of the proposed antenna has carried out using CST Microwave Studio (CST MWS).
Optimization and Characterization of Friction Stir Spot Welding of Aluminum Alloy (AA 5754-H114) with Pure Copper Sheet
Authors: Abbass Muna Khethier , Hussein Sabah Kh , Kudair Ahmed Adnan 
Published: March 2021

Abstract
Friction stir spot welding (FSSW) was conducted to weld a sheet of an aluminum alloy (AA5754-H114) to a commercial sheet of pure copper (Cu) having (2 mm) thickness. It was performed at various tool rotating speeds (800, 1000, and 1250 rpm), times of plunging (30, 60, and 90 sec) using a tool pin geometry or profile (straight cylindrical, threaded cylindrical with the flute, and tapered cylindrical). The welding process parameters were optimized based on the Taguchi method relying upon the design of experiment (DOE). The used sheet is made of “aluminum alloy” overlapped upon copper sheets. The results manifested that the “maximum” shear forces were found at the best or optimum parameters of welding: (1000 rpm) rotational speed and (90 sec) plunging time when using the straight cylindrical pin profile. The Pareto chart of standardize influences of the tensile-shear outcomes elucidated that the time of plunging was the higher influential parameter than the other welding parameters, such as the speed of rotation and the profile of the pin.
Investigation the Quality of the Treatment Sand from Sulfite using Magnetic Water in Reactive Powder Concrete
Authors: Khreef Sabah M , Abbas Zena K 
Published: March 2021

AbstractIn this study, the effect of using magnetized water in fine aggregate treatment has been investigated. Three mixtures of reactive powder concrete (RPC) were prepared and caste within two molds so that the compressive and flexure strength can be tested when the samples are cured by ordinary, autogenous, warm water and high-temperature cycles curing procedure. All of the three mixtures consisted of the same primary material; the difference was in the sulfite content of the fine aggregate, where the intended sand samples have diverse sulfite content. The first mixture’s sulfite content was limited within the Iraqi specifications No.45/1984, and it was equal to 0.13%, the second mix contained sand with high sulfite content of 3.54%, and in the third; the latter sand was washed with magnetizing water before mixing. The test results pointed out a severe decrease in RPC properties when the high sulfite sand was used by taking the low sulfite content mixture as a reference mix. A decrease was recorded in the compressive strength by 8.6% and 16.8% when the samples were tested at the age of 28-days and 90-days, respectively, and cured with ordinary curing procedures. Similarly, the flexure strength decreases by 7.1% and 13.5% when the samples are tested at the age of 28-days and 90-days, respectively, and cured with an ordinary curing procedure. This decrease in RPC strength could be recovered, as the third mixture’s test results indicate; when the sand was treated with magnetized water before mixing, and the sulfite content was reduced down to (0.274%) accordingly.
Vibration Effect on Natural Convection Heat Transfer in an Inclosed Cubic Cavity
Authors: Khudhair Baydaa Khalil , Salh Adel Mahmood , Ekaid Ali 
Published: March 2021

Abstract
An experimental study was performed to clarify the effect of vertical mechanical vibration on natural convection at normal gravity in the air filled cubic enclosure (L=120mm) (Pr=0.71) . In the enclosure, there were two vertical and opposing surfaces. The right wall was heated to a standardized heat flux surrounded by four other adiabatic surfaces, where the left wall cooledTc. Vibration stress was added to this heat transfer cell by vertically mounting it on the armature of electrodynamics vibratory (shaker). The experimental work was performed on a built rig which was mainly composed of a cubic enclosure cavity provided with a vibrator exciter as well as the necessary measurement instrumentation to fulfill the required investigations. At Ra= 7* 107 the frequencies shedded to the enclosure (2,4&8) Hz and at Ra=4* 108 the frequencies shedded to the enclosure (3,6&9)Hz. Three type of tests for an experimental were carried out. The first one reached to steady state and then shedded the effect of vibration to the cubic enclosure (Interrupted Vibrations), while the second shedded the vibration (Continuous Vibrations) from the start at ascending frequencies and the third shedded the vibration (Continuous Vibrations) from the start at descending frequencies. From the results of the experimental investigations two main conclusions may be raised, in the case of Rayleigh number (Ra=4*108), the gravitational thermal convection is dominant. And the motion of vibration does not enhance the transfer of heat exceptionally well. On the other side, in Rayleigh (Ra=7*), the thermal vibration convection is dominant, and the vibration greatly increased the rate of heat transfer..Also, the results show that an increase in the average Nusselt number with time as the vibrational Rayleigh number Ravib
will increase as resulting of increasing the vibration frequencies. In addition, the higher the frequency of vibration reaches, the faster the steady states is achieved. And for that, two cases of Rayleigh number, the increasing frequencies are usually higher than those of downward frequencies. Finally, the results show reasonable agreement between the theoretical and the experimental results and the present results and available previous work.
Influence of using Asymmetric Teeth Profile on Stress Concentrations in Gear Key-way
Authors: Musa Hasan Alaa , Abdullah Mohammad Qasim 
Published: March 2021

AbstractThe key is a machine element that transmits power from shafts to pulleys, gears, and vice versa. A case study shall be conducted in this paper to investigate the influence of using gears with asymmetric teeth profile on stress concentrations in gear key-way, employing the theory of elasticity represented by the stress function method. Then, the obtained results are verified by FEA. The final object is to select the best shape of the key-way that achieves the minimum stress concentration. The outputs demonstrate that stress tolerance is substantially increased as the mechanism switches from normal to irregular. It also shows that the circular key-way is the safest, more appropriate, and subjected to the minimum stress when the same force is applied. For the asymmetric gear with circular arc key-way, the percentage of improvement approaches 38%relative to the regular one of flat key-way in the numerical results, whereas, in the analytical investigation, the same percentage is almost 6 %. The percentage is also nearly 15% when going from the regular 14.5° spur gear to the 14.5°-20° asymmetric spur gear.
Evaluation of Machine Learning Models to Forecast COVID-19 Relying on Laboratory Outcomes Characteristics in Children
Authors: Mamlook Rabia Al , Al-Mawee Wassnaa , Alden Arz Y Qwam , Alsheakh H , Bzizi Hanin 
Published: March 2021

Abstract
An outbreak of the 2019 novel Coronavirus epidemic (COVID-19) has rapidly spread worldwide. The coronavirus (COVID-19) has also spread among children, but it has been less severe than in adults. The characteristics of COVID-19 laboratory findings play a significant role in clinical manifestations, diagnosis, and treatment. Since the numbers of COVID-19 cases increased, it takes more time to interpret the lab outcomes and provide an accurate diagnosis. Little information about the clinical symptoms and epidemiological of COVID-19 is known. There is a need to investigate the characteristics of laboratory findings for the clinical decision-making system using predictive algorithms. This study aims to classify and validate machine learning approaches for detecting COVID-19 in children. The five well-known machine learning approaches: the artificial neural network (ANN); random forest (RF); support vector machines (SVM); decision trees (DT) which include classification and regression trees (CART); and gradient boosted trees (GBM) were used. All these approaches have been considered in the classification, and to determine the most suitable model. The performance of each model test was by conducted using a standard 10-fold cross-validation procedure. Given these results for classification performance and prediction of accuracy, CART is the best predictive model for classifications for children with COVID-19. The results of the study illustrate that the best classification performance was achieved with CART model to provide 92.5% accuracy for binary classes (positive vs. negative) based on laboratory findings. Leukocytes, Monocytes, Potassium, and Eosinophils, were among the most important predictors which indicate that those features may play a crucial role in COVID-19. Ultimately, our model may be helpful for medical experts to predict COVID-19 and can help invalidate their primary laboratory findings of children. ML methods can be a convenient tool for providing predictions for COVID-19 laboratory findings among Children.
Using Fuzzy Inference System FIS for Identifying Motion in Digital Surveillance Systems
Authors: Abdullah Omar Muayad 
Published: March 2021

Abstract
The aim of the current study is to use the FIS Fuzzy Inference System method to determine motion in digital surveillance systems. In the analysis, there are several methods used such as segmenting, sorting, evaluating and showing the results. After capturing an online video stream with an average of 1 frame/sec, the goal of the proposed method is to translate these frames to their corresponding representation of pixels and then use these frames as inputs for the job. The output is evaluated based on these inputs. The idea is to compare the average pixel representation of the current frame boundaries (column vectors) with the corresponding column vectors in the next frame, in order to find out whether there is any motion detected by comparing the average of the calculated column vector for the ith frame with the corresponding column vector in the i+1th frame. This operation leads to extracting 8 averages and it is considered as inputs to the fuzzy inference method. There is one output that will detect whether there is any motion detected or not. By designing a set of rules and then analyzing the results, a comparison of the averages is held.
Theoretical Investigation of a Pin Fin Heat Sink Performance for Electronic Cooling using Different Alloys Materials
Authors: Nazzal I T , Salem T K , Al Doury R R J 
Published: March 2021

Abstract
Electronic cooling plays a role in removing the electronic equipment’s heat rate to prevent failure from occurring. Electronic cooling performance is based on many parameters, such as thermal characteristics and material type design. Pure aluminium, copper – aluminium, and aluminium - beryllium are selected for predicting the performance of a heat sink. It was observed that the presence of Aluminium-copper alloy raises the performance of the heat sink compared with that of the pure aluminium. In contrast, the heat sink performance using aluminium - beryllium alloy was less than that of the reference material (pure aluminium). It was found that the heat dissipated from the heat sink increases by 1.4 % with using aluminium-copper alloy instead of using pure aluminium while the heat dissipated drops by 2% with using aluminium - beryllium alloy compared with that of using pure aluminium. Further, the heat sink mass decreases with the use of the aluminium-beryllium and increases with using copper - aluminium instead of pure aluminium. Whereas the mass of the heat sink using aluminium-copper alloy is higher than that of the pure aluminium by 2.3% while the mass of the heat sink using aluminium - beryllium alloy is less than that of the pure aluminium by 2.4%.
Numerical Study of Blood Flow Through Artificial Heart Valves
Authors: Togun Hussein , Hussain Ali Abdul , Ahmed Saja , hussain Iman Abdul , Shaker Huda 
Published: March 2021

Abstract
Analysis of blood flow through artificial heart valves (Titling disc valve) with different angles of valve inclination is numerically studied. Finite volume method was adopted to solve continuity, momentum, and energy equations by using k-e model. Six different angles of inclination of valve change of (30,45,60,70,80,90) were considered with Reynolds number of laminar flow ranging 500,750,1000, and 1250 and Reynolds number of turbulent flow ranging 8000,12000,16000, and 2 0000. The results showed that the region of vortex formation before and after the artificial valve can clearly increase in recirculation zone after artificial valve has increased the Reynolds number. The maximum value of velocity was observed at the bottom side after valve was compared with top side of valve because the space of passage flow is larger than other side for all cases. The counter of velocity for turbulent range showed that the recirculation region is clearer and bigger after the valve was compared with laminar range. The best performance of artificial valve (Titling disc valve) was with greater opening angle of valve (90) compared with other cases. Generally, unsymmetrical blood flow for range opening angles valve were found to be (30,45,60,70,80,) while opening angle valve (90) for the blood flow was symmetrical and that demonstrated good performance for valve at angle (90). There can be seen a focus pressure of artificial valve (Titling disc valve) on one side in counter pressure and this may have harmful effect on aortas walls and lead to unnecessary aorta fatigue. The novelty of the present paper is to obtain new results for specific angle of valve since most papers focused on the standard angle.
The Effect of Variable Engine Parameters on Performance and Emissions of DI Diesel Engine Running on Diesel-Biodiesel Blended with Nano Additives
Authors: Jumaa Hussein , Mashkour Mahmoud A 
Published: March 2021

Abstract
An experimental investigation was conducted to study the effect of variable engine parameters like injection timing and compression ratio on performance and emission characteristics of single cylinder four stroke Ricardo E6/US diesel engine at a constant speed (1800rpm) running on diesel fuel biodiesel blends with nano additive. By transesterification process, the biodiesel was produced from waste cooking oil. The mixture percentage consisted of diesel fuel (B5, B10, B15, and B20) vol%, iron oxide nanoparticle (Fe2O3), particle size of 20 nm and different weight fractions (10ppm, 30ppm, 50ppm, 70ppm, and 100ppm) wt%. The injection timing was regulated for (20°, 30°, 38°, and 40°) bTDC, while compression ratio was (16:1, 17:1, 18:1 and 20:1). The design of experiments (DOE) approach of Taguchi method was employed to predict the optimum parameter settings for engine performance like biodiesel blend (B20), nano additive (100ppm), injection timing (38° bTDC), and compression ratio (17). The experimental results showed that the addition of nano additive to biofuel gives increased brake thermal efficiency (BTE) by 15.05% and reduced brake specific fuel consumption (BSFC) by 10.73%. Furthermore, the exhaust emissions like CO, HC, and smoke density reduced by 62.5%, 63.01%, 28.9%, respectively, but NOx, PM increased by 16.19%, 15.30%, respectively, compared to diesel fuel.
Contaminant Removal from Virtual Operation Room
Authors: Rasheed Wakkas Ali , Al-wahid Wisam A Abd , Alturaihi Muna 
Published: March 2021

Abstract
Most bacterial contaminants found in operation rooms come from patient’s exhale or from wounds after surgery that make colony forming units. Thus, yearly, a lot people suffer from infections acquired during surgical procedures. Removing pollutants from operation room by investigating the influence of different locations and types of entry and exit grills is the subject of the present work. Equations of fluid flow including the continuity, momentum, energy equations and species equation have been numerically solved by using the FLUENT ANSYS v.14 for virtual symmetric operation room taken in this paper. Turbulent flow of mixture material species is applied in the model of operation room. Standard K-epsilon was used for simulating turbulent flow pattern. The present study aims to find a proper arrangement of inlet and exhaust locations to reduce the unfavorable factors in operation room such us, contamination, humidity, temperature and also air velocity. These factors were achieved according to modification in inlet and exhaust grills arrangement and then simulated through FLUENT software program. Six different arrangements of supply and exhaust were studied to determine case of best health and comfort demands. Case no 5, using local exhaust ventilation, shows good improvement in removing contaminants. However, case no 6 which uses both local exhaust ventilation and like air curtain air supply, shows the optimum removal of contaminants, because it shows lower contamination mass fraction. Meanwhile, the worst contaminant removal were in case 2 and case 1, where source of contaminant exists in low movement zone (dead zones) or region of separation of streamlines. The results showed, using both local exhaust ventilation and like air curtain air supply as in case (6) maintains an average temperature of 21.3 °C, the least amount of particles mass fraction of contaminants 6.36E-08 and moisture content of 0.009.
Preparation and Characterization of Activated Carbon with (ZnCl2 - Activated) from (PET) Bottle Waste for Removal of Metal ions (Cu+2) in Aqueous Solution
Authors: Alwaan Ismaeel M , Jaleel Mohammed A K 
Published: March 2021

Abstract
The power of activated carbon resides from polyethylene terephthalate (PET) by chemical and physical activation to adsorption of metal ions (Cu+2) on certain conditions, such as (Concentration of metal ion in the solution, and contact time). Its chiefly objective is to reduce the poisonousness by the metal mentioned above and reducing the surrounding contamination resulting from the bottle waste after throwing them. In this work, activated carbons were prepared from bottle waste by carburizing and activation methods. The Carburizing temperature were 500°C and 900°C under Argon gas with flow rate (150 cm3 min−1). activating agents (ZnCl2) were utilized. The isotherm models of Langmiuir and Freundlich were studied and Langmuir isotherm model was more appropriate when Carburizing temperature was 900°C, in contrast to carbonization in 500°C were studied the Freundlich isotherm model was best. Pseudo-first-order, Pseudo-seconds order kinetics also studied. The pseudo-seconds-order was more suitable to describe the adsorption properties for (Cu +2) when Carburizing temperature was 900°C. In general, the (PET) west activated with ZnCl2 and temperature of 900°C was best adsorption from activated with temperature of 500°C.
The Procedure of Experimental Work and Finite Element Simulation to Produce Spline Shape Multi-Stage Deep-Drawing Operation
Authors: Mukhirmesh Kadhim H , Jawad Waleed K 
Published: March 2021

AbstractThis research deals with a multi-stage deep-drawing operation. The research aim is to produce spline shapes using two methods (direct and indirect) for three-stages based on experimental work and FE model procedure. The direct method was performed to produce spline shapes from the blank for the first stage, while the second and third stages from shapes of the first and second stages, respectively. The indirect method was performed to produce spline shapes from the cylindrical shapes of three-stages. The multi-stage deep-drawing was completed to perform the experimental procedure required to produce a spline shape with inner dimensions of major axis D = 41.5,33.3,28.8, and miner axis d = 34,27.2,23.6 mm for the first, second, and third stages, respectively. Flat circular blanks (diameter Db= 80 mm and thickness t = 0.7mm) of low carbon steel (1 008 - AI S I) used in this research. FE analysis based on the ANSYS workbench program was used to model the multi-stage deep-drawing operation. The comparisons between results showed that the direct method was successful with the first stage, while it was failed with the second and third stages. For the three-stages, the maximum drawing force required to produce spline shape by the direct method is greater than the maximum drawing force required to produce spline shape by the indirect method. The maximum drawing force values equal to 41.650 kN, 33.175 kN, 33.11 kN for the first, second, and third stages, respectively, Also, for the three-stages, it was observed that it is possible to produce a complete spline shape without defects in the indirect method when comparing with the direct method.