bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Fabrication of 3-Axes Mini CNC Milling Machine
Authors: Ali Saad Mahmood , Mohsin Haider
Published: March 2021

The main aims of the current work are to explore the theoretical and technical procedures for design, fabricate, assembly, and testing of the electromechanical subsystems for developing a high precision cost-effective mini three-axis vertical CNC milling machine with an easy interface, high speed, less power consumption, safety and durable for rapid prototyping machining, small parts and engraving small features in the electrical and medical industry. The new Mach3mill G-Code CAD/CAM software package runs on a PC and turns it into a very powerful and economical machine controller. The 3Axis CNC driver board type Kit TB6560 was used as a micro-stepping drive for the smooth drive of the selected stepper motors. The fabricated prototype CNC milling machine with an easy interface that can interpret standard G-M codes. The fabricated machine router was tested and calibrated to determine its accuracy in different position modes for surface flatness, axes perpendicularity, and several geometric accuracies such as positioning, straightness under specific tool paths, and feed rate. The results misalignment lay around +0,01 and -0,01 mm. This means that the fabricated prototype machine movements contain 0.13° tilting on X-axis and 0.22° tilting on Y-axis. After comparison and making the required improvements in both electrical and mechanical design, the machine is in a position to milling a complex contour on soft metals with considerable accuracy and speed.
Design and Implementation of Tracking a user’s Behavior in a Smart Home
Authors: Abbas Ammar Farooq , Abdullah Mahmood Zaki
Published: March 2021

A smart home is automated structures with control contraptions and presented area; it comes with advanced sensing and automation systems to supply the inhabitants with monitoring and management no matter if they are in the home or outside. In light of the developments that are taking place in the smart home, machine learning, and the needs of the home, which makes the appropriate decisions based on the user’s behavior of the smart home, and the use of development in technology to facilitate the general requirements of people. Modern smart home systems tend to be standalone solutions that focus on lifestyle needs using a smart control system, such as lighting and temperature control. Ubiquitous home expects the emergence where sophisticated (Ambient intelligent) systems monitor and learn user’s behavior and lifestyles and enable the home to predict and respond to all the needs and activities of home occupants. During perception, residents perform their daily routine while the in-house embedded sensors transmit and store the readings in a database. By doing so, the intelligent agent uses these readings to generate knowledge, such as patterns and trends. Thus, it can predict based on the built knowledge to enable the smart home to identify and automate the action that meets the occupants’ aims.
Najaf Zero Energy House, Suggestions for Design & Construction
Authors: Hussain Tahseen Ali , Hachim Dhafer Manea , Salih Salah M
Published: March 2021

As a result of intensive efforts in preserving the environment and reducing the use of fossil fuels, the idea of zero energy houses has spread in recent decades. The zero-energy house is a house that depends almost entirely on natural sources to provide the needed energy which is not polluting the environment. This idea has been adopted in many countries and states, where each region has a unique design for the zero-energy houses based on the environmental, social, economic, and geographical conditions of that area. In this research, it will be presented firstly a set of proposals to be taken in the design and construction of the zero energy house in the Najaf area in the middle of Iraq. Eight steps were prposed to design and build the Najaf Zero Energy House(NZEH). Some of these steps is the selection of location (site) and design of the house in terms of configuration and direction as well as the criteria for the design of the interior spaces, then the selection of energy systems and the management of water sources, down to the selection of lighting equipment, covering materials and colorants. From the research conclusions, the passive cooling and ventilation due to the climatic conditions characterized by Iraq in general and Najaf, in particular, should be emphasized. It was also concluded that the social traditions and customs greatly influence the architectural design and the choice of the necessary components of this house.
Experimental Study of A LiCl-H2O Bubble Pump Solar Absorption Cooling System
Authors: Hashim Noora A , Kassim Muna S
Published: March 2021

An experimental test rig is constructed and designed according to the results obtained from a thermodynamics model solves by EES software assuming a constant generator, condenser, absorber, and evaporator temperatures to study a bubble pump’s performance solar absorption cooling system. The whole system consists of a parabolic trough solar collector, a generator, a condenser, an absorber, an evaporator, and a cooling water system. The used PTC area is designed according to the quantity of thermal energy required to operate the bubble pump cooling system and the minimum solar radiation incident at Kufa city (Najaf/Iraq), which lies on (32°N and 44°E). A modification is added to the collector receiver to ensure water exposure to solar energy for a longer time. The weather features that affected system performance like the solar radiation incident and the ambient temperature are measured for each test. The maximum recorded receiver temperature is 122 °C without water flow, and it is reached to 90.5°C as a maximum in case of water flow through the receiver. The water in the storage tank is reached to 89 C as a maximum. The collector thermal efficiency reaches its maximum value of 69.2 % for a water flow rate of 0.3315 kg/s, while the maximum efficiency at 0.189 kg/s is 68.3%. The maximum recorded generator temperature is 87°C, and at the same test, a minimum evaporator temperature of 17°C is obtained at an ambient temperature of 46.8 °C.
The Interrelationship between the Methods used to Determine the Workability of Concrete
Authors: Salman Mohammed Mosleh , Zghair Luma Abdul Ghani , Jumaa Nada Hadi
Published: March 2021

Workability is one of the factors that affect concrete strength and durability in addition to the cost of labor and the appearance of the final product. It is a vital feature of the concrete that must be measured properly to ensure the quality of concrete. This paper presents a method for predicting equations for workability of concrete and correlation between the workability tests by using Pearson correlation coefficient. The results show that the developed model is accurate and it can be used for prediction of the workability parameters with a high degree of accuracy. Based on statistical analysis, the correlation was significant at the 0.01 level (2-tailed) between the workability of concrete tests. Regression equation relating compacting factor and slump was based on nonlinear general equations (C= 0.5371S^0.1204) and also nonlinear equations were found between Vebe and slump tests (V = 8.0689e−0.0175x).
Punching Shear Strength Improvement of Flat Slabs using Polypropylene Fibers
Authors: Alkhudery Hayder H , Aljnabi Nabaa I
Published: March 2021

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

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

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

In 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

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

The 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

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

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

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

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

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

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

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

This 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.
Effect of Symmetric and Asymmetric Rolling Processes on The Microstructure and Mechanical Properties of AZ31B Magnesium Alloy
Authors: Hisab Hussein Ali , Hussein Emad A , Latif Nawal E A B , Ismail Azal R
Published: March 2021

Microstructure progression, in addition to excellent plasticity possessions of AZ31B-alloy procedure using four paths in asymmetric through various reductions, was studied to facilitate develops the deprived plasticity of alloy. The procedure was used for alloy of about 78μm grain size, with a prim thickness of 5mm. It was formed by using different ratios,1:1,1:1.4,1:1.8and1:2.2.The thinning were 20%,25%,30%, 35% to reduce thickness to 4.00mm, 3.750 3.500 And 3.2500 repetitively. The rolling method was completed by using equal rollers diameter at a constant temperature of 473 K and devoid of lubricating after heating the rollers to 373K; the method was finished through four routes. Path (U.D.), pattern “way was kept” stable and unmoved connecting continual passes; whereas pattern was turned 180o to direction connecting continual passes during path (R.D.); pattern (N.D.) was turned throughout 180° concerning the standard direction to the continual passes; pattern (H.Y.) was turned 180o to the rolling direction primary in addition to, subsequently turned 90° concerning the standard direction connecting continual undulating passes. A traditional rolling process was done under identical situations to evaluate the outcome; microhardness test was also completed. Visual microscopy was used to study of rolling parameters on the microstructure of the rolled pieces. The outcome of inspection explained to the alteration of the microstructure had been pretentious employing path, ratio and decrease area. At low proportion, large numbers of mirror image creation become visible, as reduction raises dynamical recrystallization happening on the identical twin and shear bands were encouraged. In contrast raised proportion caused a raise within the quantity of recrystallized grains furthermore improved the microstructure. Very fine grains construction had been improved while the alloy was rolled using H.Y. path at a proportion of (1: 1.8) and 25% decrease. Excellent plasticity possessions of patterns devoid of annealing were experienced in stress at 673.00 K along with next to room temperature at primary strain selection from 1 × 10−3 s−1 to 2.2×10−3 s−1.
Influence of Alloying Elements on Cyclic Oxidation Behavior of (Cu/Al) Alloys
Authors: Aslan Noor Sabah , Rajih Abdalwahid K , Haleem Ali Hubi
Published: March 2021

This study is conducted to extend the effective life of Cu/Al alloy. The used samples were (Cu/9.5%Al),(Cu/9.5%Al/5%Ni),(Cu/9.5%Al/5%Ni/0.9%Mn),(Cu/%9.5Al/5%Ni/4.5%Fe), (Cu/9.5%Al/5%Ni/0.9%Mn/4.5%Fe),(Cu/9.5%Al/5%Ni/0.9%Mn/4.5%Fe/0,1%Y),(Cu/9.5%Al/5% Ni/0.9%Mn/4.5%Fe/0.2%Ge) by using powder metallurgy these samples were prepared, the cyclic oxidation test was conducted in the presence of air in a programmable furnace (typeVBF-1200X-H8-USA) at 250°C and 800°C for 50 hours at 5-hours cycle. It was represented by the weight-gain of all examined samples that the oxidation rate increased as the temperature increased. It appears that cracking or spalling of oxides was at high temperatures such it found the weight gain of the base alloy (Cu/9.5%Al) was (12.09*10−3g/cm2)at 250°C otherwise, it was (5.98*10−2 g/cm2) at 800°C for the same alloy. This is attributable to the expected behavior of oxides when stressed. The addition of Ni, Mn, & Fe to (Cu/9.5%Al) caused a relative increase in resistance to cyclic oxidation, while the addition 0.1% Y to (Cu/9.5%Al/5%Ni/0.9Mn/4.5%Fe) caused the lowest oxidation rate as compared with other alloys, it showed that the reduction in weight gain (165.13%) relative to(Cu/9.5%Al) the highest weight gain at 250°C, and it was (285.22%) relative to (Cu/9.5%Al/5%Ni) which has highest weight gain at 800 °C. Both alloying elements Y and Ge represented a major change in cyclic oxidation resistance.
Stability analysis of Alfvén eigenmodes in China Fusion Engineering Test Reactor fully non-inductive and hybrid mode scenarios
Authors: YANG Wenjun , LI Guoqiang , GONG Xueyu , GAO Xiang , LI Xiaoe
Published: March 2021

In this paper, NOVA/NOVA-K codes are used to investigate the stability of Alfvén eigenmodes (AEs) in the China Fusion Engineering Test Reactor (CFETR). Firstly, the stability of AEs excited by energetic alpha particles is investigated. For the fully non-inductive scenario, it is found that all AEs are stable, and the least stable toroidal mode number is

n
=
8
.

However, for the hybrid mode scenario, it is found that many AEs are unstable, and the least stable toroidal mode numbers are

n
=
7
,

8
.

Secondly, the effect of energetic alpha-particle parameters and beam ions on AE stability is also presented. The threshold of the least stable AE is about

β

crit
,
α

=
1.12
%
,

less than the value of alpha-particle beta (

β

α

=
1.34
%

). The result demonstrates that the AEs excited by alpha particles are weakly unstable. The effect of the beam ions on AE stability is found to be very weak in CFETR.
COVID-19 infection and attributable mortality in UK care homes: cohort study using active surveillance and electronic records (March–June 2020)
Authors: Dutey-Magni Peter F , Williams Haydn , Jhass Arnoupe , Rait Greta , Lorencatto Fabiana , Hemingway Harry , Hayward Andrew , Shallcross Laura
Published: March 2021

Background

epidemiological data on COVID-19 infection in care homes are scarce. We analysed data from a large provider of long-term care for older people to investigate infection and mortality during the first wave of the pandemic.

Methods

cohort study of 179 UK care homes with 9,339 residents and 11,604 staff. We used manager-reported daily tallies to estimate the incidence of suspected and confirmed infection and mortality in staff and residents. Individual-level electronic health records from 8,713 residents were used to model risk factors for confirmed infection, mortality and estimate attributable mortality.

Results

2,075/9,339 residents developed COVID-19 symptoms (22.2% [95% confidence interval: 21.4%; 23.1%]), while 951 residents (10.2% [9.6%; 10.8%]) and 585 staff (5.0% [4.7%; 5.5%]) had laboratory-confirmed infections. The incidence of confirmed infection was 152.6 [143.1; 162.6] and 62.3 [57.3; 67.5] per 100,000 person-days in residents and staff, respectively. Sixty-eight percent (121/179) of care homes had at least one COVID-19 infection or COVID-19-related death. Lower staffing ratios and higher occupancy rates were independent risk factors for infection.

Out of 607 residents with confirmed infection, 217 died (case fatality rate: 35.7% [31.9%; 39.7%]). Mortality in residents with no direct evidence of infection was twofold higher in care homes with outbreaks versus those without (adjusted hazard ratio: 2.2 [1.8; 2.6]).

Conclusions

findings suggest many deaths occurred in people who were infected with COVID-19, but not tested. Higher occupancy and lower staffing levels were independently associated with risks of infection. Protecting staff and residents from infection requires regular testing for COVID-19 and fundamental changes to staffing and care home occupancy.
Widespread convergence in stream fishes
Authors: Bower Luke M , Saenz David E , Winemiller Kirk O
Published: March 2021

Convergent evolution, the evolution of similar phenotypes among distantly related lineages, is often attributed to adaptation in response to similar selective pressures. Here, we assess the prevalence and degree of convergence in functional traits of stream fishes at the microhabitat scale in five zoogeographical regions across the world. We categorized species by microhabitat, water velocity and preference for substrate complexity and calculated the prevalence of convergence, degree of convergence and functional diversity for each category. Among species occupying similar microhabitats of small, low-gradient streams, 34% had combinations of convergent traits. Convergence occurred at higher rates than expected by chance alone, implying that adaptation to similar environmental conditions often resulted in similar evolutionary patterns along multiple niche dimensions. Two of the microhabitat groupings had significantly convergent species represented in all zoogeographical regions. Fishes occupying microhabitats with high water velocity and low structural complexity generally occupied a restricted morphospace and exhibited greater prevalence and higher degrees of convergence. This suggests that water velocity and habitat structural complexity interact, selecting a restricted distribution of trait distributions and higher degrees of convergence in stream fish assemblages. Furthermore, these results suggest that microhabitat features in streams select for fish trait distributions in a fairly predictable and deterministic manner worldwide.
Neurotensin: a neuropeptide induced by hCG in the human and rat ovary during the periovulatory period
Authors: Al-Alem Linah , Puttabyatappa Muraly , Shrestha Ketan , Choi Yohan , Rosewell Kathy , Brännström Mats , Akin James , Jo Misung , Duffy Diane M , Curry Thomas E
Published: March 2021

Neurotensin (NTS) is a tridecapeptide that was first characterized as a neurotransmitter in neuronal cells. The present study examined ovarian NTS expression across the periovulatory period in the human and the rat. Women were recruited into this study and monitored by transvaginal ultrasound. The dominant follicle was surgically excised prior to the luteinizing hormone (LH) surge (preovulatory phase) or women were given 250 μg human chorionic gonadotropin (hCG) and dominant follicles collected 12–18 h after hCG (early ovulatory), 18–34 h (late ovulatory), and 44–70 h (postovulatory). NTS mRNA was massively induced during the early and late ovulatory stage in granulosa cells (GCs) (15 000 fold) and theca cells (700 fold). In the rat, hCG also induced Nts mRNA expression in intact ovaries and isolated GCs. In cultured granulosa-luteal cells (GLCs) from IVF patients, NTS expression was induced 6 h after hCG treatment, whereas in cultured rat GCs, NTS increased 4 h after hCG treatment. Cells treated with hCG signaling pathway inhibitors revealed that NTS expression is partially regulated in the human and rat GC by the epidermal-like growth factor pathway. Human GLC, and rat GCs also showed that Nts was regulated by the protein kinase A (PKA) pathway along with input from the phosphotidylinositol 3- kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways. The predominat NTS receptor present in human and rat GCs was SORT1, whereas NTSR1 and NTSR2 expression was very low. Based on NTS actions in other systems, we speculate that NTS may regulate crucial aspects of ovulation such as vascular permeability, inflammation, and cell migration.
‘Covid-19 has caused a dramatic change to prison life’. Analysing the impacts of the Covid-19 pandemic on the pains of imprisonment in the Scottish Prison Estate
Authors: Maycock Matthew
Published: March 2021

The purpose of this paper is to provide insights into the impact of COVID-19 in the Scottish Prison Estate. During the 2020 lockdown in prison in response to the COVID-19 pandemic, all face-to-face research was paused. In response to this methodological challenge, a participatory correspondence methodology was designed, enabling project participants to influence the direction of this project through suggesting research questions. The main project findings relate to the analysis of ways in which the COVID-19 enhanced the pains of imprisonment for participants, exploring the challenges that the participants faced in relation to communication, feelings of heightened isolation and detachment from family, friends and the normal rhythms of life in prison. Analysis of the letters received as part of this study provides unique insights into the ways in which the COVID-19 pandemic in custody has added an additional layer or enhancement to pre-pandemic pains of imprisonment, increasing the ‘tightness’ ‘depth’ and ‘weight’ of participants time in custody.
CD4 T cells mediate brain inflammation and neurodegeneration in a mouse model of Parkinson's disease
Authors: Williams Gregory P , Schonhoff Aubrey M , Jurkuvenaite Asta , Gallups Nicole J , Standaert David G , Harms Ashley S
Published: March 2021

α-Synuclein, a key pathological component of Parkinson's disease, has been implicated in the activation of the innate and adaptive immune system. This immune activation includes microgliosis, increased inflammatory cytokines, and the infiltration of T cells into the CNS. More recently, peripherally circulating CD4 and CD8 T cells derived from individuals with Parkinson’s disease have been shown to produce Th1/Th2 cytokines in response to α-synuclein, suggesting there may be a chronic memory T cell response present in Parkinson’s disease. To understand the potential effects of these α-syn associated T cell responses we used an α-synuclein overexpression mouse model, T cell-deficient mice, and a combination of immunohistochemistry and flow cytometry. In this study, we found that α-synuclein overexpression in the midbrain of mice leads to the upregulation of the major histocompatibility complex II (MHCII) protein on CNS myeloid cells as well as the infiltration of IFNγ producing CD4 and CD8 T cells into the CNS. Interestingly, genetic deletion of TCRβ or CD4, as well as the use of the immunosuppressive drug fingolimod, were able to reduce the CNS myeloid MHCII response to α-synuclein. Furthermore, we observed that CD4-deficient mice were protected from the dopaminergic cell loss observed due to α-syn overexpression. These results suggest that T cell responses associated with α-synuclein pathology may be damaging to key areas of the CNS in Parkinson’s disease and that targeting these T cell responses could be an avenue for disease modifying treatments.
Checkpoint inhibitor therapy-associated acute kidney injury: time to move on to evidence-based recommendations
Authors: Perazella Mark A , Sprangers Ben
Published: March 2021

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment since their introduction ∼15 years ago. However, these monoclonal antibodies are associated with immune-related adverse events that can also affect the kidney, resulting in acute kidney injury (AKI), which is most commonly due to acute tubulointerstitial nephritis (ATIN). Limited data are available on the true occurrence of ICI-associated AKI. Furthermore, evidence to guide the optimal management of ICI-associated AKI in clinical practice is lacking. In this issue, Oleas et al. report a single-center study of patients with nonhematologic malignancies who received ICI treatment during a 14-month period, experienced AKI and underwent a kidney biopsy at the Vall d’Hebron University Hospital. Importantly, they demonstrate that only a minority of ICI-associated AKI patients was referred to the nephrology service and kidney biopsy was only performed in 6.4% of patients. Although the authors add to our knowledge about ICI-associated AKI, their article also highlights the need for the development of noninvasive diagnostic markers for ICI-associated ATIN, the establishment of treatment protocols for ICI-associated ATIN and recommendations for optimal ICI rechallenge in patients with previous ICI-associated AKI.
Has COVID-19 changed the workload for primary care physicians? The case of Spain
Authors: Fernández-Aguilar Carmen , Casado-Aranda Luis-Alberto , Farrés Fernández Miquel , Minué Lorenzo Sergio
Published: March 2021

Background

The COVID-19 pandemic has led to a massive over-exertion of doctors, multiplying their work intensity, overload and stress. Yet no studies have been conducted on the changes in primary care physician overload during the pandemic.

Objective

To address this research gap, the aim of this article is to document the subjective dimensions of physicians’ work during the peak of the pandemic for comparison with a pre-COVID-19 situation. In addition, the relationship between workload and the individual characteristics of the physician or the percentage of tele-assistance is examined.

Methods

This study performs a subjective measurement procedure for the analysis of work overload through the NASA-TLX questionnaire, with a total of 102 records from 16 doctors from a Primary Health Centers of the Granada-Metropolitan Health district (Andalusia, Spain).

Results

The results reflect a significantly higher workload during COVID-19 in relation to a previous situation (66.1% versus 48.6% before COVID-19). All the dimensions of the NASA-TLX test suffered an increase during the COVID-19, this increase being higher in the physical, temporal and frustration levels. Interestingly, the findings reflect the higher the percentage of telematic consultations, the lower workload.

Conclusions

Work overload and the emotional state of health workers is one of the many repercussions of the COVID-19 pandemic. The results derived from this study may be useful in formulating policies and practices related to the workforce development, funding streams to prepare for the next wave of COVID-19 infections as well as for future public health emergencies.