bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling and Controlling of position for electro-pneumatic system using Pulse-Width-Modulation (PWM) techniques and Fuzzy Logic controller
Authors: Essmat Abdul-Lateef Wisam , Alexeevich Glebov Nikolay , Hamed Farhood Naseer , Khdir Ahmed H. , Shaker Dina H.
Published: March 2020

The main objective of this paper is to design a low cost electro-pneumatic module which can be used in the industrial automation equipment’s, robotic systems and mechatronic applications. Electro-pneumatic module includes four low-cost on/off solenoid valves and double acting cylinder. A Pulse width modulation (PWM) technique was used, which enable the model to correct the control of piston position and then to enable the system to follow the required trajectories accurately in many applications. Thus, it can be a good alternative at a lower cost than the using of proportional valves in the electro-pneumatic applications. A Fuzzy logic algorithm with PD control on the model in Matlab/Simulink environment to adjust the control values was applied. The simulation results and response of model were compared with the results from a previous practical with the similar model and controller but with a proportional valve. Finally, the simulation results showed a good accuracy with the practical results.
Performance Improvement of Photovoltaic Module Using an Air-Cooling Micro Finned Heat Sink
Authors: Hasan Ibtisam A. , Faraj Sahar R. , Mohammad Israa A.
Published: March 2020

In this work, improved PV panel was fabricated by replacing the tedlar layer with aluminum alloy micro pin fin heat sink to increase the heat transfer conduction. Air flow system was designed and implemented to apply force convection on the heat sink, which named MPFHS-PV/T integrated system, to decrease the PV module temperature. The integrated system was tested on 25Jun 2019 in Baghdad climate and the results recorded as flowing: decreasing the PV module temperature by 14.65% along with electrical performance improvement by 13% for the output power and 13.32% for efficiency. The daily averages of electrical efficiency. 1102%, thermal efficiency 40.94% and overall thermal efficiency 51.9%.
The optimum thickness of paraffin wax insulator filling a double glazed window
Authors: Jalil J M , Salih S M
Published: March 2020

A numerical three-dimensional investigation is performed to estimate the optimum doping content (i.e. thickness) of the PCM filling a double glazed window. For the summer weather of Baghdad, Iraq. Finite Volume method combined with the enthalpy method is utilized to acknowledge the conduction related with phase change problems within the wax by using a constructed FORTRAN (F90) program. Based on the constructed numerical model, the transient heat transfer characteristics of the insulation were calculated and analyzed in detail. The obtained results indicate that optimum doping content of wax filling the window can be estimated, The required thickness of wax paraffin (melting point 40 °C) to keep temperature within the required range were as follows: May 2 cm, June 3 cm, July 3.5 cm, August 3.5 cm, September 3 cm and October 1.5 cm.
Palm Olein with Jatropha Curcas Oil Blend as a Renewable Bio-Fluid
Authors: Hassan Jabal Mohammed , Saad Abd Hussain , Gaddoa A. A. , Falih Kadhim Ibrahim , Samion Syahrullail , Shajar Ameer S. , Hardan Abdulwahhab A.
Published: March 2020

Many bio-fluids have been introduced to replace petroleum-based products one of which is vegetable oil which has characteristics that are friendly to the environment. Based on its characteristics, it is turning into a significant bio fluid source. Vegetable oil has a great advantage over other forms of bio-oils which is its wild availability as a renewable source. Furthermore, when used in engines, vegetable oil based lubricants have the ability to decrease hydrocarbon emissions as well as carbon dioxide. Using the pure vegetable oil with no additions and using certain blending ratios are the two methods of using vegetable oil as a bio-fluid. This paper focuses on conducting an investigation on the influence of using the normal load on the performance characteristics for the blending of two types of vegetable fluid, and making a comparison between this and a commercial mineral fluid using the four ball tribotester, palm olein with Jatropha curcas oil which were mixed in (RB60/J40) ratio. All conducted experiments were conformed to ASTM D4172. It has been noticed from the obtained results that RBD palm olein and Jatropha curcas oil Blend has the ball bearings wear scar and frication coefficient less than the commercial fluid. Based on that, it is concluded that the RB60/J40 blend is more efficient than neat RBD palm olein and commercial mineral fluid as well.
Heat Transfer Enhancement in Air Duct Flow By Micro-Channel Experimental And Numerical Investigation
Authors: Jalil Jalal M. , Aziz Ghada A. , Kadhim Amjed A.
Published: March 2020

The heating of air flow through micro-channel was studied experimentally and numerically to examine the improvement in the thermal performance achieved by micro-channel. Numerically, laminar incompressible 3D steady-state Navier Stokes equations were solved by Finite volume method. Experimentally, a rig was built to investigate the cooling of air flow through micro-channel for different velocities and electric powers heater. The micro-channels block (length = 0.1, width = 0.05, height = 0.005 m) was manufactured from copper metal with 10 rectangular micro-channels (length = 0.1, width = 0.001, height = 0.0005 m). The performance of the microchannel was evaluated through exit air temperature value. The studied parameters numerically and experimentally were air velocities inside micro-channels (1 to 20 m/s) and heater powers (1 to 5 W). The comparison between numerical and experimental results was acceptable and reached 3% as maximum. Also the results were compared with other investigator results. High heat transfer coefficients values were achieved by micro-channel, reaches maximum value of 150 W/m2K at velocity air 20 m/s and heater power 5 W.
The Effect of Mass Flow Rate on the Thermal Performance for Solar Collector with Compound Parabolic Concentrator During the Summer Season
Authors: Farge Talib Z. , Abduljabbar Owaid H , Nsaif Asst.Lec. Mina Abdulkareem
Published: March 2020

Present study investigated the effect of the summer season, on the thermal performance (heat energy and thermal efficiency) of the solar collector with CPC without cover, by designing a proper solar collector with compound parabolic concentrator (CPC). It was implemented a solar collector with a cylindrical receiver diameter 1.5 inches and an acceptance angle of 45˚with concentration ratio of 2.613. The surface reflector was made from stainless steel an aperture area of 0.87 m2. The orientation of the solar collector at 150˚ was set as (south-east) direction and 45˚ inclined angle at Baghdad city. The experimental results showed that the performance of the solar collector was improved significantly as the water circulation mass flow rate increased. The percentage increase in the heat energy and thermal efficiency are ( 69.95 and 68.68) % resectivelly in case of the mass flow rate of 300 kg/hr with respect to 60 kg/hr.
Design and Implementation of Water Distillation System Using Solar Energy
Authors: Farge Talib Z. , Mohammed Mohammed Jawad , Ali Jassim Nuha
Published: March 2020

An investigation of the solar distillation using a solar collector with a graduated absorbed surface has been utilized in order to improve the solar still performance. The solar collector is contained on graduated absorbing surface with 25 steps. Absorbing surface made from copper plate and dye by a thermal black pigment to increase the solar absorption. The top of the solar collector is covered by a glass with 4mm of thickness. While, the other side surfaces of the solar collector are made from the transparent plastic with 6mm of thickness. Also, Aperture area of the solar collector was 0.4526 m2. Experiments had been carried out in Baghdad (33.3˚ N latitude) during May in 2019 to investigate the performance of the still. The results appeared the maximum water production that reached up to 486 ml at the time interval between 12.30 and 1.00 pm, while the total thermal solar collector efficiency was 36%. The proposed method succeeded to reduce the TDS from 679 ppm to 39 ppm. for inlet water and outlet pureed water respectively, and the volume distilled water production was 3696 ml for the time from 7.30 am to 4.00 pm.
Outdoor testing of an evacuated tube closed two phase thermosyphon solar water heater charged with Nano-fluid
Authors: Maustafa Mahdi Mahmoud , Abed Jaddoa Ameer , Falih Kadhim Ibrahem , Asmet Wisam
Published: March 2020

This paper reports the performance of two types of evacuated tube heat pipe solar water heater systems that have been experimented outdoors under the local meteorological conditions of the capital of Iraq. Tests were conducted using two systems made of the same materials but with different design specifications. To build each of the two trail system, a single evacuated tube to two phase thermosyphon is used to make the investigation of the experiments simpler. With the absence of loading conditions, experiments with the first system were conducted. Graphene water Nano-fluid (GW) was used as the working fluid in this system. The water storage tank system capacity was varied, to analyze the performance for different storage capacity. The system was operated with a flat reflector plate and without this reflector. A modified second system was built with a longer evaporator section for higher performance and with tank that enables hot water removed from it. The hot water from the storage tank was withdrawn intermittently and continuously. Graphene water (GW), Graphene acetone( GA) and distilled wate( d-W) were used as the working fluids in this second system. Energy stored at the water storage tank and overall efficiencies were calculated and found to be comparable to those obtained using natural circulation solar water heating systems. A comparison between the obtained Results and other works was made. The comparison showed that the present systems were just as good in performance. An improvement in the overall efficiency was found when operating the system under load conditions. This improved value is about 10% higher than that without load condition.
Analysis of Vector Controlled Variable Speed DFIG for Wind Turbines
Authors: Farge Talib Z. , Numan Ali H. , Hussein Ghasaq M.
Published: March 2020

Double Fed Induction Generators (DFIG) has been widely used for the past two decades in large wind farms. This paper presents control and analysis of the doubly fed induction generator (DFIG) connected to variable speed horizontal axis wind turbine (HAWT). The detailed wind turbine (WT) model, DFIG dynamic model in d-q-synchronous reference frame, power electronic converters, and controllers are presented. The reactive and active power of the DFIG can be precisely decoupled by controlling the rotor side converter (RSC). The field-oriented control (FOC) strategy and the proportional-integral (PI) controllers were used to control the RSC of the DFIG. Furthermore, a space vector pulse width modulation (SVPWM) was utilized to generate pulsing signals required to drive three phases DC-AC converter (inverter). The proposed control method of DFIG based on HAWT was verified by simulation in MATLAB-SIMULINK software. The obtained simulation results showed the capability and effectiveness of the proposed control method.
Numerical Investigation of Thermal Performance of Micro-Pin Fin with Different Arrangements
Authors: Jalil Jalal M. , Reja Ahmed H. , Hadi Amro M.
Published: March 2020

The impact of micro-pin fins on heat transfer performance in this study is analyzed numerically. Navier-Stokes equations are solved by steady-state three dimensions turbulent forced convection. Various numbers of micro-pin fins with in-line configuration and different micro-pin fins configurations such as staggered configuration additionally to the in-line configuration are explored. In addition, comparison between micro-pin fins duct and smooth duct is studied. Results illustrate that the thermal performance was enhanced by 7.9 - 9.3% with increasing the number of micro-pin fins from 902 to 1312 and by 10.2 - 11.1% with increasing the number from 902 to 1640. Also, displays that the heat transfer performance in the staggered configuration is slightly better than the in-line configuration by 2.6 - 4.2% with the same micro-pin fins number. Moreover, the micro-pin fins duct gave an increase of 30.24% in heat transfer performance relative to the smooth duct.
Control on Temperature of Hybrid Nanofluid in Evacuated Tube Solar Collector Using Smart Curtain
Authors: Anead Hosham S. , Sultan Khalid F. , Salman Ahmed M.
Published: March 2020

This research was revealed control on temperature hybrid nanofluid in evacuated tube solar collector system, where the hybrid nanofluid utilized as working fluid in ETC for enhancement the thermal performance for heating device. The smart curtain was used for purpose shadow the evacuated tube solar collector for controlling on temperature of the hybrid nanofluid in heating or cooling conditions. In addition, Adaptive neuro fuzzy inference system (ANFIS) a way of artificial intelligence was applied to control on the shadow the evacuated solar tube collector. Where the main principle of the curtain is to control the polarization of the sun radiation, the curtain work depends on three parameters were applied in ANFIS technique, two parameters are input variable like as (temperature of hybrid nanofluids (inlet, outlet) and ambient temperature, and one output parameter represents by (distance parameter).
Innovative Design of a Ventilated Modern Greenhouse Powered by PV/T Solar System
Authors: Jadallah Abdullateef A. , Alsaadi Mohammed K. , Hafidh Zayn A.
Published: March 2020

In this paper, a modern design is proposed for ventilating and conditioning of greenhouse integrated thermal solar system in summer season in (33.3°N, 44.4 °E) Baghdad, Iraq with respect to East-West orientation. The proposed system involves photovoltaic panels and counter flow double pass (with fins). The photovoltaic solar thermal system is fixed on the roof of single span greenhouse. Experimental work was carried out during summer season. The results show the ventilation process changes the air inside temperature of the greenhouse to make it equal to the temperature required by the plants. The calculated root mean square error is 2.04 and correlation factor is 0.993 for the inside air temperature and 4.98, 0.98 respectively for the ground temperature.
MPPT Control for Grid Connected Wind Energy Conversion System Based Permanent Magnet Synchronous Generator (PMSG) and Five-Level Neutral Point Clamped Converter
Authors: Errami Youssef , Obbadi Abdellatif , Sahnoun Smail
Published: March 2020

This paper presents nonlinear control of a Wind Energy Conversion System (WECS) based Permanent Magnet Synchronous Generator (PMSG) and Five-Level Neutral Point Clamped Voltage Source Converter (5L-NPC-VSC). For WECS, the Maximum Power Point Tracking (MPPT) is a very important requirement in order to maximize the effectiveness. Therfore, MPPT approach and grid-connected control methods are discussed. On the other hand, the proposed control techniques are based on Sliding Mode Approach (SMA) and Vector Control (VC) to achieve the MPPT, to keep the dc link voltage constant and to the control active and reactive powers. The stability of the regulators is obtained using Lyapunov analysis. An extensive simulation study, using MATLAB/Simulink, is conducted on a 4-MW wind farm composed of two 2 MW PMSG based wind turbines.
Modeling and Investigation Performance of Small-Scale PMSG based HAWT with FOC
Authors: Farge Talib Z. , Numan Ali H. , Tahir Zaineb
Published: March 2020

This paper focused on modeling and simulation of small-scale horizontal axis wind turbine (HAWT) based on permanent magnetic synchronous generator (PMSG) with filed oriented control (FOC) circuit connected to 3-phase full bridge rectifier by MATLAB software. FOC system developed for generator side converter to regulate mechanical speed and electromagnetic torque at variable wind speed. Space vector pulse width modulation (SVPWM) had been implanted in FOC system to turn on six-IGBT switches and validate pure and steady-state of output voltage. Results showed optimum performance coefficient was 0.48 and tip speed ratio 8.1 at zero pitch angle, also when pitch angle increase by 5°coefficient performance decreased to 0.35. The simulated waveforms of the mechanical speed, and electromagnetic torque were contained two case, before and after applied FOC. With FOC, the results shown faster and smooth response to the faster change in wind speed.
An Experimental Investigation of Performance of Hybrid PV/T-PCM System with Control System
Authors: Hussein Hashim A. , Numan Ali H. , Aqeel Zahraa
Published: March 2020

In this paper we investigated experimental performance of designed hybrid PV/T with phase change material (PCM) of paraffin wax type based thermal storage material. Paraffin wax embedded with aluminum matrix foam to enhancement the physical properties. Designed hybrid system consists of three main parts, glass to glass PV module, thermal collector and, control system. Thermal results indicated the optimum layer thickness of PCM was 3cm because discharge time of thermal energy storage was longer of 6 hours. Also, optimum temperature of difference air, absorber plate, glass to glass PV module and, paraffin wax were 8.6°C, 80°C, 44°C and, 55°C at air speed of 0.8m/s, respectively.
Improving the Performance of the Pump Station in Pipe Line Transportation System Using PLC Controller and Remote Monitoring
Authors: Hussein Hashim A. , Aleeby Abdzahraa J. , Mahdi Zahraa M.
Published: March 2020

In industries, analysis and control of pressure and flow rate control is very difficult, this leads to factory closings and heavy maintenance through PLC and SCADA implementation. Automatic control plays an important role in the continuous operation of the system. In this project, the actual pump performance is tested in terms of pressure, efficiency, and flow rate of the pump for the operating system using a pipeline by crossing pressure in the pipeline with a length of 2 m by connecting pressure sensing equipment. The global control unit SIMATIC S7-1214 as the main decision-making unit that uses this data to make the required decisions. Thus the operation and stopping of the pump as it asks the details related to all other correct information to SCADA to monitor and control the parameters in the pipeline system of the oil pumping station. Then it performs continuous supervision of oil pump station pipeline in order to allow solving any problem and thereby regulating the control system in the structure consists of three layers. These include the first layer of field devices second remote terminal units, and third domain controllers. The signals are sent from the devices via the transmitters to the dedicated PLC boards in the second layer. The central level of SCADA contains a high-speed computer to supervise or operate the station remotely in order to display information through the LABVIEW screens that was showed the final results of pressure and flow rate by operating the system with a voltage rated by Plus With Modulation at a value of 2.73 V for both light and heavy crude oil. It was showed that the pressure value is 0.22bar and the value of the flow rate is 0.25 L/M for heavy oil. While the light is 0.23bar for pressure and the flow rate is 0.652L/M. In addition, to conducting several experiments that show that an increase in the value of the voltage obtained using heavy oil by a value of 3.77 V the pressure value becomes 0.35 bar the flow rate is at 4.78L/M, while light oil has shown the results are that the rated voltage value is 3.77 V, the pressure value is 0.33bar, and the flow rate value through the tube becomes 5.17 L/M. Thus, the greatest value of the voltage 3.77 V, The result when the flow rate through the pipeline increases rapidly, and the pressure decreases, the pipeline passes through the pipeline faster
Influence of Cryogenic Temperature (CT) on Tensile Properties and Fatigue Behavior of 2024-Al2O3 Nanocomposites
Authors: Abdulridah M N , Assi A D , Al-Alkawi H J
Published: March 2020

The stir casting process used to manufacture the AL/Al2O3. AA2024 with matrix material alumina Al2O3at different weight percentage ratio 0.3, 0.5, 0.7 and 0.9%. Were fabricated by using cryogenic temperature (CT). It was observed that the maximum enhancement is occurred at nanocomposite containing 0.9% Al2O3which shows improvement percentage of 9.9%, 14.63% and 14.28% for ultimate strength, yield stress and Brinell hardness respectively and the ductility is reduced by 34.57% compared to 0% by weight AA2024. It clearly shows that all the mechanical properties are improved by increasing weight percentage of Al2O3but the best properties are obtained at 0.9% Al2O3nanocomposite. The fatigue S-N curve tests were done for all the specimens having average of roughness between 0.2 to 0.5Mm.The fatigue endurance limit of the 0.9% wt. Al2O3composite into two cases without (CT) and with (CT) is taken at 107 cycles. The fatigue limit at 107cycles increases from 83 MPa for without (CT) to 89.6 MPa with (CT) resulted in 7.95% fatigue limit improvement.
Characterization of Ni-Ti-Ag Shape Memory Alloy
Authors: Salman Khansaa D. , Saud Laith J. , Shihab Suad A.
Published: March 2020

In this paper, specimens of Ni-Ti shape memory alloy incorporating different percentages of Ag nanoparticles are constructed and three of its properties are studied which are density, porosity, and electrical conductivity. The specimens are constructed using powder technology. The construction process involved three main steps; mixing, compacting, and sintering. Before conducting the tests necessary to reveal the alloy properties mentioned above which represent the focus of this work, the constructed ternary Ni-Ti-Ag alloy specimens were first tested to check some of its characteristics and prove that the constructed alloy is a shape memory alloy. These tests included the Differential Scanning Calorimeter (DSC) test, the X-Ray Diffraction (XRD) test, the Scanning Electro-Microscopy (SEM) test, and the Shape Memory Effect (SME) test. The results of these tests reflected the homogeneous distribution of the Ag nanoparticles in the Ni-Ti matrix and indicated the formation of the austenite (Ti2Ni) and martensitie (Ti 002) phases, and that the alloy has a very good SME (89.9% for the 10 wt.% percentage of Ag nanoparticles). Next to this step, porosity test and electrical resistance test were carried out. The results and related calculations for these tests showed that increasing the weight percentage of Ag nanoparticles decreases the porosity and increases the density as well as the electrical conductivity.
Experimental study to increase the strength of the adhesive bond by increasing the surface area arrangement
Authors: Ameen K. A. , Al-Dulaimi M J , Abdulaziz Abrahem Hussain , Hasan H A
Published: March 2020

This research represents an experimental and numerical tensile study to investigate the effect of adding epoxy and both sides of two specimens on the shear stress at which the failure of the bond occurs. Also, the effect of the of epoxy bond arrangements on the toughness and the area of contact were investigated. Fifteen specimens in three arrangement s are used for the tensile test. In the first arrangement (case 1) the epoxy bond is placed in between the steel specimens. In the second arrangement (case 2), the epoxy bond is placed between the steel specimens and it extended 5 cm outward from both sides. In the third arrangement, the epoxy bond is placed between the steel specimens and it extended 10 cm outward from both sides. These arrangements used to increase the contact area of the bond. The single Lap – Simple bond type is used for this study. The experimental and numerical results show a god agreement. The arrangement of the epoxy bond is found to have a strong impact on the mechanical behavior. The shear stress increase by 500 % in case of arrangement 3.
Evaluation the Sensitivity of Bone Natural Frequency as a Diagnosis Tool to Identify Bones Integrity
Authors: Hassan Shaker S , Al Juboori Ameen M
Published: March 2020

This study explain the reason behind the low sensitivity of the natural frequency for the changes in bone health. The mechanical properties of the bone were reduced by placing the bone in boiling water for 2 hours and the mass of the bone was reduced by placing the bone in diluted acidic medium for 24 hours. The natural frequency of the bone samples (10 samples) was calculated in three cases (fresh, after boiling, and after acidic treatment). The natural frequency was calculated theoretically by using finite element analysis based upon CT-Scan DICOME images and experimentally by using impulse test. The difference between the results in the two methods was less than 15%. The boiling process caused a reduction in the natural frequency while the acidic treatment caused an increase in the natural frequency compared with the natural frequency of the fresh condition. The mutual influence of these two component cannot be separated. This mutual influence will reduce the sensitivity of the natural frequency as diagnosis factor for the changes in the health condition of the bone.
Compression strength, dielectric and magnetic properties of new aluminium matrix hybrid nanocomposites
Authors: Aljawad Hussain A. , Alalkawi H. J. M. , Adel Aziz Ghada
Published: March 2020

Nanocomposites are materials fabricated from two or more materials with different mechanical and electrical properties. Combining these materials produces a new designed material with new and better properties compared to the individual components. In recent years nanocomposites have been developed and employed almost in all industries. The current study deals with fabricating a hybrid nanocomposite ( when there are a minimum of three materials, the composite is called as hybrid composite). Pure aluminium as the base matrix. Iron oxide Fe2O3 (alpha) and aluminium oxide Al2O3 (alpha alumina). Fe2O3 weight percentage (wt.%) is varied (1.5, 2.5 and 5 % by weight) and the wt % of Al2O3 is held constant (2 wt.%). The new designed nanocomposite was produced using Powder Metallurgy (P/M) method. This method has been widely used for fabricating aluminium matrix nanocomposites (AMNCs), due to it is low costs and gives high accuracy as well as the ease of using. The matrix used was aluminium powder with an average particle size of (60µm) with 99.6% purity and Fe2O3 (99% purity and 30 nm particle size) and Al2O3 with (99.5% purity and 14-20 nm particle size ). The experimental results revealed that the microstructure images of composites showed uniformly distributed of Fe2O3 and Al2O3 in aluminium matrix. The maximum compressive strength is 152 MPa in nanocomposite containing (1.5 Fe2O3 + 2 Al2O3) wt.%. The improvement percentage was recorded to be 30% for CS. The real and imaginary components of relative permittivity decrease with increase of frequency. The hysteresis curve of nanocomposites showed that the magnetic properties were improved for all the nanocomposites but the better response of magnetic properties was found with the nanocomposite of (1.5% Fe2O3 + 2% Al2O3) content.
Thin-plate stress analysis solved by combining FEM functions and approximations of class C0
Authors: Abdulaziz Abrahem Hussain , Obeid Hassoun Enaam , Salman Hind D. , Serazutdinov M. N
Published: March 2020

The method for constructing functions with finite support is used, which combines the properties of FEM functions and approximations in the form of series with unknown coefficients. To illustrate the properties of the approximating function constructed, we present the results of the solution of the 2D theory of elasticity for a thin plate, shown on figure 1,b. The thickness of the plate is h. One facet of the plate (at x = −a) is fixed and the other one (at x = − a) unfixed; the remaining two are under shear stresses τ and an evenly distributed load θ. The solution of the problem of determining the stress and strain in the plate can be obtained from the steady-state condition of the Lagrange functional by using the functions of class C0 of the high-degree approximation for scientific calculations. The calculations show that the obtained solution has high accuracy, even in cases when the length of the rectangular domain is considerably greater than its width.
The effect of crack length on the fracture parameters of an edge crack parallel to the material variation in a rectangular FGM plate
Authors: Khazal Mehbes Haider , Ibraheem Khalaf Hassanein , Ahmed Nasser Ameen
Published: March 2020

In this study, the extended element free Galerkin method (XEFG) is used for crack analysis an edge crack parallel to the material variation in a rectangular functionally graded material (FGM) plate under traction loading. For the first time, the effective parameters of XEFGM are employed such as the sub-triangulation term for numerical integration, suitable influence domain, and enrichment functions for discontinues locations in the fracture analysis of different crack positions of an edge cracked FGM plate. In addition, the incompatible formulation is adopted to extract the stress intensity factors (SIFs). Good data and results are observed about the relationship between the crack lengths and SIFs with good verification during changing XEFG parameters. There is good agreement and stability in the results of SIFs through the sizes of J-integral rJ equal to 0.4 -0.8. In addition, the acceptance results for the size of the support domain are bound between dmax=1.52 to 2.
Simulation of the analytical solution of lasing output power for Yb
3+: YAG thin disk laser regime in a fundamental mode operation
Authors: Mahdi Salih Raed , Shihab Ahmed Mudhir
Published: March 2020

A theoretical model is established to derivation equation of output Laser power for multi-pass pumping for a quasi-three level thin-disk laser, A numerical solution of this equation for Yb3+:YAG thin-disk laser, which pumped at wavelength (940 nm) and lasing emission at wavelength (1030 nm), regime in fundamental transverse mode (M2=0.95) at room temperature were performed by calculated the variation of (Nt),(d),(Mp),(R2),(T) and (Pp) on the output Laser power and find the typical value of these parameters are used to obtain high output Laser power.
Characterization the wear behavior of Al-Ti alloy having different Ti ratios prepared by powder metallurgy
Authors: Ghadhanfer Hikmat Nadia , Mohammed Mahdi Sahib , Yaseen Taha Dalmn
Published: March 2020

In this study, the Al-Ti alloy was fabricated by powder metallurgy method using three different Ti ratios (10wt%; 15wt%; and 20wt%Ti); and the wear behavior of these three alloys was investigated. The mixtures of powders were compacted at 146 MPa and sintered for 5 hours at 550- ˚C under vacuumed atmosphere. The samples were characterized using X-Ray Diffraction test (XRD), Scanning Electron Microscope test (SEM), microhardness and density tests. The tests of wear were achieved by employing a pin on disk machine under constant normal load 15N for four different sliding times 5, 10, 15, and 20 minutes. The results illustrate that the density and microhardness of Al-Ti alloy were increased as the Ti content increased. Also, it was observed that Al-Ti alloy with 20wt%Ti had the highest wear resistance and lowest weight loss.
Stability Control Investigation of a Self-Balancing Platform on the Robot Smart Car Using Navigation Parameters
Authors: Adel Aziz Ghada
Published: March 2020

A self-balancing platform is constructed on a robot smart car, and its navigation parameters are investigated by running the car outdoors on a straight surface with structured bumps of 3and 5 mm in height. A ball-and-socket joint are supported at the centre of the platform, which is to be freely rotated with the lateral and longitudinal movement of the platform and in each axis, is controlled by three servomotors. Which move according to the recorded data movements from a gyro-accelerometer sensor which controlled by an Arduino UNO. The SimMechanics Matlab simulation helps to give the initial values of all parameters and the additional unexpected signals due to the influence of bumps on the vibration signals, with the proportional-integral-derivative (PID) controller, used to control the relationship of the rapid simulation of the robot smart car and mathematical model between platform and car shock absorber system with respect to the servomotor’s rotation angle. These bump is more effective on the pitch and roll angle values when compared to other parameters, with more than 815 degrees and error up to 35 degrees due to vibration signals, and the time required for stabilization increases due to the bump height and the navigation parameters, roll angle from 2 to 6 in mean change value 2, yaw angle from 43 to 59 in mean change value 8 and pitch angle from 1 to 2 in mean change value 0.5, which indicates that yaw, roll and pitch angle have variation changing in Mission Planner software
Effect of Y/Zn ratio on microstructure and properties of as-extruded Mg-Y-Zn alloys
Authors: Liu Baosheng , Yang Jiaao , Wang Zehui , Fang Daqing
Published: March 2020

In this work, four Mg-Y-Zn alloys with specific Y/Zn (wt%) ratio have been prepared. The effects of Y/Zn (wt%) on the microstructure of extruded Mg-Y-Zn alloy were investigated by SEM and TEM. The mechanical properties and corrosion behavior of extruded Mg-Y-Zn alloy were also studied by tensile test, electrochemical and immersion measurements. The corrosion mechanism was studied by SEM observation of the surface morphology of the samples after immersion corrosion. The result indicates that the as-extruded Mg-6Y-3Zn alloy consists of α-Mg, W phase and long-period stacking ordered structure (LPSO) phases. Two types of LPSO structure (18 R and 14 H) appear in the as-extruded alloys. The volume fraction of LSPO increases with the increase of Y and Zn atoms witht the same Y/Zn mass ratio. Mg-9Y-3Zn alloy has the best comprehensive mechanical properties. Its yield strength, ultimate tensile strength and elongation are 230 MPa, 327mpa and 23% respectively, because the volume fraction of LSPO phase in the alloy is the highest. In addition, the higher volume fraction of LPSO is beneficial to enhance the corrosion resistance of Mg-9Y-3Zn alloy.
Law as a Branch of Morality: The Unity of Practice and Principle
Authors: Allan T R S
Published: March 2020

The article explores Dworkin’s suggestion that law and morality comprise a unified normative domain, considering similar suggestions by Greenberg and Hershovitz. It defends an interpretative approach to law, akin to Dworkin’s, against the view that the law’s content is determined by direct appeal to political morality at large, subject only to the effect of action by law-making institutions. Legal practice and political principle are in important ways interdependent, each capable of illuminating and clarifying the other. As an approximation of justice, grounded in practice, the law consists fundamentally in the moral principles that, in the final analysis, constitute the political community. The law’s content is an interpretative question, dependent on a grasp of practice that gives determinate shape to abstract concepts of equality and justice.
Cryolipolysis: Clinical Best Practices and Other Nonclinical Considerations
Authors: Few Julius , Saltz Renato , Beaty Mark , Kelly Michael , Movassaghi Kiya , Marcus Keith A , Sieber David , Burns A Jay , Sangha Sara
Published: March 2020

Cryolipolysis is a nonsurgical body contouring procedure that involves cooling of fat cells to induce lipolysis while sparing surrounding structures. Plastic surgery practices are increasingly incorporating noninvasive aesthetic procedures (eg, cryolipolysis, fillers, radiofrequency, ultrasound) to offer their patients a wider range of aesthetic treatment options. Here, we report insights from 8 plastic surgeons with regard to cryolipolysis best practices from a clinical perspective and the impact of integrating this noninvasive body contouring procedure into a plastic surgery practice. The authors prefer cryolipolysis over liposuction for patients who are not amenable to surgery or those who desire to avoid downtime, also taking into consideration body mass index, skin laxity, comorbidities, and risk of contour irregularities. Patient counseling is critical for setting realistic expectations regarding outcomes and should focus on the efficacy of cryolipolysis, individual variability in results, potential side effects, time course of treatment response, and the need for multiple treatment cycles. Strategies for reaching new patients and expanding services among current cryolipolysis patients are discussed.
Estimation of dynamic SNP-heritability with Bayesian Gaussian process models
Authors: Arjas Arttu , Hauptmann Andreas , Sillanpää Mikko J
Published: March 2020

Motivation

Improved DNA technology has made it practical to estimate single-nucleotide polymorphism (SNP)-heritability among distantly related individuals with unknown relationships. For growth- and development-related traits, it is meaningful to base SNP-heritability estimation on longitudinal data due to the time-dependency of the process. However, only few statistical methods have been developed so far for estimating dynamic SNP-heritability and quantifying its full uncertainty.

Results

We introduce a completely tuning-free Bayesian Gaussian process (GP)-based approach for estimating dynamic variance components and heritability as their function. For parameter estimation, we use a modern Markov Chain Monte Carlo method which allows full uncertainty quantification. Several datasets are analysed and our results clearly illustrate that the 95% credible intervals of the proposed joint estimation method (which ‘borrows strength’ from adjacent time points) are significantly narrower than of a two-stage baseline method that first estimates the variance components at each time point independently and then performs smoothing. We compare the method with a random regression model using MTG2 and BLUPF90 software and quantitative measures indicate superior performance of our method. Results are presented for simulated and real data with up to 1000 time points. Finally, we demonstrate scalability of the proposed method for simulated data with tens of thousands of individuals.

Availability and implementation

The C++ implementation dynBGP and simulated data are available in GitHub: https://github.com/aarjas/dynBGP. The programmes can be run in R. Real datasets are available in QTL archive: https://phenome.jax.org/centers/QTLA.

Supplementary information

Supplementary data are available at Bioinformatics online.
Dynamic QoS-Aware Cloud Service Selection Using Best-Worst Method and Timeslot Weighted Satisfaction Scores
Authors: Nawaz Falak , Janjua Naeem Khalid
Published: March 2020

The number of cloud services has dramatically increased over the past few years. Consequently, finding a service with the most suitable quality of service (QoS) criteria matching the user’s requirements is becoming a challenging task. Although various decision-making methods have been proposed to help users to find their required cloud services, some uncertainties such as dynamic QoS variations hamper the users from employing such methods. Additionally, the current approaches use either static or average QoS values for cloud service selection and do not consider dynamic QoS variations. In this paper, we overcome this drawback by developing a broker-based approach for cloud service selection. In this approach, we use recently monitored QoS values to find a timeslot weighted satisfaction score that represents how well a service satisfies the user’s QoS requirements. The timeslot weighted satisfaction score is then used in Best-Worst Method, which is a multi-criteria decision-making method, to rank the available cloud services. The proposed approach is validated using Amazon’s Elastic Compute Cloud (EC2) cloud services performance data. The results show that the proposed approach leads to the selection of more suitable cloud services and is also efficient in terms of performance compared to the existing analytic hierarchy process-based cloud service selection approaches.
Spatial variation in egg polymorphism among cuckoo hosts across 4 continents
Authors: Yang Canchao , Si Xingfeng , Liang Wei , Møller Anders Pape
Published: March 2020

Although egg color polymorphism has evolved as an effective defensive adaptation to brood parasitism, spatial variations in egg color polymorphism remain poorly characterized. Here, we investigated egg polymorphism in 647 host species (68 families and 231 genera) parasitized by 41 species of Old Word cuckoos (1 family and 11 genera) across Asia, Europe, Africa, and Australia. The diversity of parasitic cuckoos differs among continents, reflecting the continent-specific intensities of parasitic selection pressure on hosts. Therefore, host egg polymorphism is expected to evolve more frequently on continents with higher cuckoo diversity. We identified egg polymorphism in 24.1% of all host species and 47.6% of all host families. The common cuckoo Cuculus canorus utilized 184 hosts (28.4% of all host species). Hosts of the common cuckoo and of Chrysococcyx species were more likely to have polymorphic eggs than hosts parasitized by other cuckoos. Both the number of host species and the host families targeted by the cuckoo species were positively correlated with the frequency of host egg polymorphism. Most host species and most hosts exhibiting egg color polymorphism were located in Asia and Africa. Host egg polymorphism was observed less frequently in Australia and Europe. Our results also suggested that egg polymorphism tends to occur more frequently in hosts that are utilized by several cuckoo species or by generalist cuckoo species. We suggest that selection pressure on hosts from a given continent increases proportionally to the number of cuckoo species, and that this selection pressure may, in turn, favor the evolution of host egg polymorphism.
Identifying the Implementation Conditions Associated With Positive Outcomes in a Successful Nursing Facility Demonstration Project
Authors: Hickman Susan E , Miech Edward J , Stump Timothy E , Fowler Nicole R , Unroe Kathleen T
Published: March 2020

Background and Objectives

To identify the implementation barriers, facilitators, and conditions associated with successful outcomes from a clinical demonstration project to reduce potentially avoidable hospitalizations of long-stay nursing facility residents in 19 Indiana nursing homes.

Research Design and Methods

Optimizing Patient Transfers, Impacting Medical quality, Improving Symptoms—Transforming Institutional Care (OPTIMISTIC) is a multicomponent intervention that includes enhanced geriatric care, transition support, and palliative care. The configurational analysis was used to analyze descriptive and quantitative data collected during the project. The primary outcome was reductions in hospitalizations per 1,000 eligible resident days.

Results

Analysis of barriers, facilitators, and conditions for success yielded a model with 2 solution pathways associated with a 10% reduction in potentially avoidable hospitalizations per 1,000 resident days: (a) lower baseline hospitalization rates and investment of senior management; or (b) turnover by the director of nursing during the observation period. Conditions for success were similar for a 20% reduction, with the addition of increased resident acuity.

Discussion and Implications

Key conditions for successful implementation of the OPTIMISTIC intervention include strong investment by senior leadership and an environment in which baseline hospitalization rates leave ample room for improvement. Turnover in the position of director of nursing also linked to successful implementation; this switch in leadership may represent an opportunity for culture change by bringing in new perspectives and viewpoints. These findings help define the conditions for the successful implementation of the OPTIMISTIC model and have implications for the successful implementation of interventions in the nursing facility more generally.
Old abuses in new markets? Dealing with excessive pricing by a two-sided platform
Authors: Ayata Zeynep
Published: March 2020

Exploitative abuses, especially excessive pricing, have been one of the most debated forms of abuse of dominant position. Unlike exclusionary abuses, they have been prohibited only under certain jurisdictions and on rather rare occasions. In Europe there have been few recent decisions and investigations that have reiterated existing approaches and tests for establishing excessive pricing. The Turkish Competition Authority’s Sahibinden.com decision has come at such a time where the discussion on excessive pricing has been somewhat revived. However, this decision stands out as it is the first one where a competition authority has found prices to be excessive and therefore abusive in the context of a two-sided platform. Competition in platform markets display unique dynamics that may be very different from what may be observed in traditional markets especially in terms of pricing strategies. This article aims to demonstrate, through the Turkish Competition Authority’s recent decision, the difficulties in applying existing tests and criteria on excessive pricing to a two-sided platform. A thorough analysis of this decision demonstrates that competition enforcement in what may be called ‘new’ platform markets necessitates new approaches or adjustments of existing ones.
Factors influencing digital review of pathology test results in an inpatient setting: a cross-sectional study
Authors: Challen Robert , Tsaneva-Atanasova Krasimira , Edwards Tom , Gompels Luke , Dayer Mark , Pitt Martin , Danon Leon
Published: March 2020

Background

Delay or failure to view test results in a hospital setting can lead to delayed diagnosis, risk of patient harm, and represents inefficiency. Factors influencing this were investigated to identify how timeliness and completeness of test review could be improved through an evidence-based redesign of the use of clinical test review software.

Methods

A cross-section of all abnormal hematology and biochemistry results which were published on a digital test review platform over a 3-year period were investigated. The time it took for clinicians to view these results, and the results that were not viewed within 30 days, were analyzed relative to time of the week, the detailed type of test, and an indicator of patient record data quality.

Results

The majority of results were viewed within 90 min, and 93.9% of these results viewed on the digital platform within 30 days. There was significant variation in results review throughout the week, shown to be due to an interplay between technical and clinical workflow factors. Routine results were less likely to be reviewed, as were those with patient record data quality issues.

Conclusion

The evidence suggests that test result review would be improved by stream-lining access to the result platform, differentiating between urgent and routine results, improving handover of responsibility for result review, and improving search for temporary patient records. Altering the timing of phlebotomy rounds and a review of the appropriateness of routine test requests at the weekend may also improve result review rates.