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A tri-band microstrip patch antenna for aerospace communication application is presented in this paper. The antenna design is based on conventional rectangular shape with two different radiuses via hole and two rectangular slots. The patch rectangular slot dimensions are 20*4.5 mm2 and the ground slot dimensions are 22*5.5 mm2. The proposed antenna is designed to operate at L-band and S-band aerospace communication applications including mobile satellite services and satellite communication. The antenna operates at 1.805 GHz, 2.325 GHz and 3.42 GHz with -31.6 dB, -21.5 dB and -35 dB return losses respectively. The measured bandwidths of the proposed antenna are 34 MHz, 20 MHz and 100 MHz respectively. The antenna gains in 1.2 dB, 1.4 dB and 1.5 dB. The total dimension of the antenna is 44*41 mm2 uses epoxy FR-4 substrate material with 1.6 mm height and 4.3 dielectric constants. The width and length of the patch are 24 mm and 21 mm respectively. The design strategies of the antenna initiated with a conventional microstrip rectangular shape and then analysis the rectangular slot etched to the patch by varying the length and width of the slot. Different dimensions of the rectangular slot that etched to the ground with geometrical analysis is achieved. The next step by applied single via hole and examine the effect of varying the radius on the results. Final step is applied two metallic via holes with different radius (1mm and 0.4 mm) to estimate the antenna performance results. [ABSTRACT FROM AUTHOR]

The Linear elevators driven by linear motors have recently been widely used because they produce direct motion to transfer people between floors without using ropes, rollers, gears, and counterweights. However, these elevators usually suffer from the production of ripple force when traveling through floors and this makes its application to elevators limited. To minimize the impact of this ripple on the elevator performance, a smooth transition pattern based on a minimum jerk profile is proposed. The elevator cabin speed is controlled via variable frequency driver (VFD), programmed with the best V/f pattern to get the best speed curve profile in order to get a smooth start and smooth stop for the elevator cabin and constant travel speed through the elevator floors with the least jerk possible. A three-floor elevator prototype driven by a permanent magnet synchronous linear motor locally designed and manufactured to lift 25kg payload. The result showed that using the driver leads to reduce the jerk by about 88% compared the that without using the driver. The proposed model achieved convincing results in terms of system control, responsiveness, speed, and smooth and comfortable transition between floors Silos. [ABSTRACT FROM AUTHOR]

The performance of the engine oil is affected over time by the different parameters such as combustion products such as soot particles, carbon, unburned fuel, and unburned hydrocarbon (UHC). The engine oil degradation was analysed by using Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA) and Fourier Transform Spectrometry (FTIR). In this work, it is indicated that the number of primary particle (npo) increased with long time of engine operation (30 days) compared with short period of engine operation (10 days). Besides, the size of primary particle (dpo) is bigger by (33nm) from combustion of 30 days on engine operation with respect to the 10 and 20 days by 28 nm and 31 nm, respectively. The high levels of presence soot particles in the engine oil are need a higher temperature for degradation. Further, it is found that the 400 °C is the maximum temperature for weight loss in case of fresh oil, while goes to 450 °C for used oil (soot in oil). From FTIR results, the concentration of soot contamination in lubricating oil increased with long time of engine operation. [ABSTRACT FROM AUTHOR]

Synchronization is one of the main challenges at the receiver in detecting the data frame at the right time, especially in very noisy environments. The unipolar OFDM (U-OFDM) has recently been introduced as a new method in optical wireless communication to convert bipolar OFDM signals to unipolar. To increase the accuracy of timing synchronization, we present an efficient method called pre-front-end transmit (PFET) synchronization, carried out based on Schmidl's, Park's, and the negative mirror image (NMI) methods. We then propose an algorithm called the selective training sequence (STS) to achieve more reliable time synchronization, which is established by selecting a candidate row from the Hadamard matrix (HM) or Walsh matrix (WM) for use as a training sequence. Another four signals, the m-sequence and chirp signal, random signal, and U-OFDM are applied and compared. Computer simulation results show significantly superior performance to the state-of-the-art method, wherein a 2 to 6-fold enhancement is achieved in timing accuracy in comparison to the former approach depending on underwater optical channel type. Moreover, the mean square error of timing offset is also enhanced clearly. Additionally, the proposed HM and WM row-based algorithm STS is shown to give better performance in terms of timing accuracy and bit error rate among other signals. Further improvement is achieved by increasing both the correlation sequence weight W and TS power of the timing metric, with a bit error rate (BER) enhancement of about 5 dB when the weight changes from 2 to 7. [ABSTRACT FROM AUTHOR]

The impacts of argon gas pressure and current of the hardness feature of welded joints have been investigated in this paper by employing different ranges of welding gas pressures and currents. The Tungsten Inert Gas welding (TIG) of stainless steel (304) sheet has been applied to get its impact on the hardness feature of the TIG welded joints. Designed of the experiment (DOE) 'version 10' have been used to figure out the design matrix of trials depending on the used levels of the input factors. The rejoinder surface methodology (RSM) method has been adopted to get an empirical mathematical design for the highest hardness feature as a function of factors investigated. Further, the ANOVA method has been done to validate the results of the adequacy model statistically. The outcomes show that the hardness of the welded joints reaches the best level when the current the best current is 80 Amp and the best gas pressure is 13 Kgf/cm2 to give the best value of hardness, however, at a constant gas pressure value of 14 Kgf/cm2, the hardness decreased with the current value increase. Besides statistical results from ANOVA agree with the experimental results with a 0.24% error to identify the best hardness value. [ABSTRACT FROM AUTHOR]

Sensors of optical fibre were developed from the experiential step to practical used in two decades age. They have been utilized in many scoters including: medical field, renewable energy, aerospace, oil and gas fields. One basic module of the optical fiber is Fiber Bragg-Grating (FBG), it can be considered as a remarkable candidate as optic fiber sensor. It should be noted that temperature and strain sensitivities must be considered, when high performance of the optimal sensor is required. Usually, error will present when such parameters are independently measured. To tackle this problem, a cascading FBG is developed in this study. Simultaneous measurement of both temperature and strain are accomplished by finding wavelength shifts of double independent components spectra for each scheme. It has shown that the obtained resolutions are (0- 100 C o) and (0 - 1500 µe) for temperature and strain, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a technique that can be used to record 256 measurements per second. Also it is measured and recorded separate parameters several times per second. This is not only facilitating the investigation of an accident or a serious incident, but also provides the opportunity to use the recorded data to predict aircraft behavior. It is believed that by analyzing the recorded data, one could identify the hazardous behavior and develop procedures to mitigate the problems before they actually occur. The flight data recording system (FDR) is an electronic device where place in the aircraft for facilitating the process of the investigation of aviation accidents and incidents also called (black box). The proposed technique is able to improve and increase the efficiency of the flight data recording system. The researchers used MATLAB/SIMULINK (program aircraft simulation) to record rapidly changing parameters with high accuracy. Therefore, the flexibility and adaptability of the proposed methodology can provide the results of high-resolution recording. [ABSTRACT FROM AUTHOR]

The effect of using blend of biolubricant oil with mineral lubricant oil on the dynamic behaviour of rotor bearing system has been investigated analytically and numerically. The using of blend of different lubricant oils in fluid film journal bearing lubrication systems can be using when their effect leads to enhancing of the dynamic performance of bearing. The finite element method has been used to modelling rotor and bearings. The results of this study clearly showed that the using of biolubricant alone as lubricant oil led to reduce the dynamic response to a significant level up to 37.3% while the blend of 90%ISO VG46 with 10%Jatropha and 70%ISO VG46 with 30%Jatropha led to reduce the dynamic response by 3.7% and 11.9% respectively. The using of different blend of the biolubricant oil with the mineral oil has no effect on the critical speed of rotor. The blend of biolubricant oil with mineral oil when used as a lubricant oil in the journal bearing led to decreasing most bearing parameters such as attitude angle, Somerfield number, oil reaction forces and oil pressure while the thickness of the lubricant oil was not changed by using different oils types. [ABSTRACT FROM AUTHOR]

Buildings have become quite complex nowadays, boosting the requirement for a strategy that lets companies identify persons for security. One of the successful solutions to the above-mentioned issue is "indoor positioning systems (IPS)". The mobile is an embedded feature of human daily life due to its capacity to communicate with the "wireless confidence (Wi-Fi)" network as a medium for positioning systems. The mobile phone has been embedded into everyday life in humans by linking to the "wireless confidence network (WI-FI)", which can be used as an instrument in positioning systems. In locations where router coverage is better spread during the inactive phase, "Acces points" are already established. For reliable readings, the data is then collected and picked. In this work A database is gathered from fourteen locations to assess the efficiency of the proposed IPS detection system. The amount of measurements from the dataset gathered is 1398 readings including the signal intensity amount that obtained from five routers. A positioning algorithm that contrasts actual training signal value with the measurements contained in the database is used in the training process. One smart classifier algorithm is adopted; the algorithm is "Numeral Virtual General Random-Access Memory (N-VGRAM)". Output values for the suggested discriminator on the basis of objective location calculation suggest that the detection precision is 98,86 % for indoor desired location detection, when the equipment has been trained at "684" RSS values. [ABSTRACT FROM AUTHOR]

This study focused on investigation of various effects of Electric Discharge Machining process parameters on process outputs. Many process inputs like working current (Ip), pulse duration time (Ton) and pulse pause time (Toff) were taken during the machining of (A2) tool steel material with CuW (copper 25% and tungsten 75%) composite material as an electrode. Here, Taguchi method L9 Orthogonal array was adopted for conducting the experiments and MINITAB 16 was adopted for analyzing the input process parameters on machining characteristics and for specifying the best process factors for maximum material removal rate, minimum electrode wear rate and minimum surface roughness. It is revealed that good inputs mixture for maximized MRR was at working current 16 A, pulse on 150 µs and pulse pause time of 20 µs, optimum inputs mixture for least Ra is current 8 A, pulse open time 50 µs and pulse pause of 30 µs and optimum inputs mixture for least EWR is at working current 8 A, pulse open time 50 µs and pulse pause of 30 µs.. The outputs of the present research reveal that suitable combination of input process factors will play an important role in machining by EDM. [ABSTRACT FROM AUTHOR]

In this paper, the encrypted speech transmission model has been assumed through orthogonal frequency division multiplexing (OFDM) over doubly selective fading channel. Two stages of security are used to enhance the security of OFDM system that are ciphering and scrambling techniques. A two dimensional (2D) logistic map is used to provide pseudo random bit generator (PRBG) and index permutation that are needed in the ciphering and the scrambling techniques, respectively. The simulation of the proposed system is programmed using MATLAB program version 2019a for 64 QAM and 256 QAM modulation and different speed velocities of 200 km/h and 500 km/h using Hybrid ciphering and scrambling techniques. The simulation results show that the speech signal over OFDM system has good intelligibility measures and robust against any attack and the signal is decrypted with little effect on the bit error rate. [ABSTRACT FROM AUTHOR]

The performance evaluation of wireless systems is very important with considering the parameters of a wireless channel, transmission characteristics and device structure. The research exhibits an investigation for the performance of PSK and DPSK system in wireless communications systems with various channels environments such as AWGN, Rayleigh, and Rician multipath fading. The performance is evaluated by calculating BER performance of 2PSK with Rician channels with different values of k factor=4, 6, 8, also BER performance of DPSK with Rician channels, k factor=3,8 are investigated and compared with BER performance of AWGN, Rayleigh. This research is based on Matlab programs. And we can also observe from simulation results that the multipath gain of Rician fade channel with k=8 in DPSK system has the multipath gain magnitude fluctuates over approximately a 5 dB range this variation would be further reduced by increasing the k factor. [ABSTRACT FROM AUTHOR]

Blind people face difficulty in practicing their daily life safely because they cannot know the objects surrounding them and this exposes them to many dangers. Given that the number of blind people around the world is a significant number, this research deals to build an intelligent system that helps the blind people to know the objects surrounding them in an internal environment where it is formed. The system consists of two parts, the first part is the software, which depends on the use of one of the deep learning algorithms and its name is YOLO (You Only Look Once). This algorithm was chosen because of its high speed and accuracy, and this is what this group of people needs, which the research aims to help them as much as possible. The algorithm was trained on a ready-made dataset called COCO (Common Objects in COntex) Dataset which It is used for the purposes of discovering objects and detecting faces ... etc. The other part of the system is the part of the hardware, which mainly depends on a fast and lightweight microprocessor, which is Raspberry Pi B3, in addition to the headphone and Raspberry Pi camera. After the images is taken by the Raspberry Pi Camera, these images are send to the Raspberry pi and the YOLO algorithm detect the objects in each image, and after the object is detected, it sends the output that is converted into sound via the head Phone to the person and thus can avoid the things surrounding them. [ABSTRACT FROM AUTHOR]

Solar energy is the most significant energy resource since it is pollution-free, clean, and inexhaustible. A huge number of approaches have been suggested in recent years for tracking the maximum Power and smoothing the performance of the system. In this manuscript, we submit a hybrid control scheme to ensure enduring power and achieve variable load requests in Battery based standalone photovoltaic systems. More specifically, in the submitted scheme, Model Predictive Control (MPC) is joint with Fuzzy logic to achieve the advantages of these two diverse approaches where a fuzzy approach controller is employed for the battery bidirectional DC line and a joint fuzzy-MPC scheme for the inverter (DC-AC) on the load side of the stand-alone system. The suggested controller could enhance the power reliability performance of the solar scheme. According to obtained results, the proposed topology overcomes the traditional PI model by achieving profits in the context of step-overshoot response enhancement around 0.9 % and the reduction in settling time is around 0.19 msec. [ABSTRACT FROM AUTHOR]

The requirements for high speed, high data rate and reliable communication causes the OFDM system is an attractive technique due to its wide spectrum property. The principal matter is how effectively transfer high data rate in applications that are highly significant to the military, scientific community and the industry in optical technology. In this paper, a comparative performance evaluation is conducted for LDPC coded optical OFDM based on three classical optical OFDM schemes for the underwater optical channel in the presence of turbulence noise using Rytov variance. By the simulation, the underwater channel impulse response is performed based on Monte Carlow simulation modelling of light (MMOL). The proposed systems under investigation provide clear perception for the scientific researcher and designer to deal with factors of these environments that affect the optical wireless communication and the capability of increasing the communication distance with satisfactory reliability. Simulation results showed that a good performance could be achieved under a very complicated environment at high turbulence levels. The results also reveal that IFFT/FFT size has a significant effect on system BER. High turbulence and inappropriate clipping ratios (CRs) cause a rotation in the constellation as a result of phase noise (PN) introduced by self-phase modulation (SM). The BER curves of goodput at the receiver demonstrated that coded ACO-OFDM exhibits better performance than coded DCO-OFDM which is very sensitive due to the DC-bias. Concerning the BER results, coded Unipolar OFDM (U-OFDM) slightly outperforms the other two systems with dB coding gain ranging between 0.5 → 2. [ABSTRACT FROM AUTHOR]

The fatigue life and strength of a peened component is a compromise between two opposing effects, the creation of a compressive residual stresses (CRS) resulted in increasing the life and strength, countered in part by initiation of crack which tend to reduce the life and strength. In recent years, aluminum alloys have emerged particularly in the industry, i-e in the conditions of thermal fatigue such as, crank shaft, piston, and aircraft engine due to a significant weight savings with no loss of properties. The ultrasonic impact peening (UIP) technique is widely utilized to produces plastic deformation of the surface, leading to the creation of (CRS). Fatigue S – N curve are obtained for four cases of testing As – received (AR), (AR + UIP), elevated temperature (ET) and (UIP + ET) for AA7025. It is deduced that the fatigue life and strength of AA7025 improved due to application of (UIP). However, the fatigue life and strength were increased by (UIP) as a result of generating of (CRS), Also the electrical properties were studied and it was concluded that the (UIP) reduce the above properties and it was understood that the electrical conductivity increased with increase the frequency. [ABSTRACT FROM AUTHOR]

Combined stresses as bending and axial loading is the important to check out on the design of plate due to the nature of loadings not only pure as bending or axial load. In present study, the behavior of steel plate under the effect of combined stress is investigate by experimental tests and checking out using finite elements approach by ANSYS software. The tensile tests and flexural tests for all specimens have same cross section. Different test are conducting such as tension and bending tests. The experimental data are applied in theoretical analysis by finite element to checking the failure theories on the results. Experimental test results as compared with the finite elements analysis showed closed. [ABSTRACT FROM AUTHOR]

Nanofluids are playing an important role in industry and multiple solar applications as an excellent heat carrier. In this study, a nanofluid consisting of an additive, multi walls carbon nanotube (MWCNT), is examined to the base fluid consisting of a mixture of water and ethylene glycol (EG) at a ratio of 75% to 25%, respectively. MWCNTs were added in four different volume ratios (0.1, 0.5, 1 and 2%). To obtain a good mixing of the nanoparticles with water/EG, ultrasonic shaking was used. The produced samples were examined and analyzed for their thermophysical properties in addition to their stability. The high thermal conductivity of MWCNT caused a significant increase in the thermal conductivity of the resulted nanofluids, which reached 140% compared to water. The effect of adding MWCNT on the density of the nanofluid was limited and did not exceed 0.075% when adding 2% of it. The viscosity of the nanofluid is affected by the addition of MWCNT, as the suspension viscosity reached 2.8% for adding 2% of the nanoparticles. The stability of the prepared nanofluids was measured using zeta potential. The results of this examination showed that the studied nanofluids have high stability. The nanofluids with 0,1% and 0,5% were the most stable. While the nanofluid with 2% MWCNT was the least stable, yet its stability was high, reaching 48 mV. This stability was confirmed by the camera images. [ABSTRACT FROM AUTHOR]

This paper is the evaluation of the performance of the FEMM software in comparison with the performance of the ANSYS/Emag software, where the magnetorheological (MR) valve needs magnetic designs and that the calculation by traditional methods is not easy, so need finite element modeling and analysis (FEM). As the ANSYS/Emag software is certified in most researches magnetorheological (MR) valves, in this paper, the magnetic designs of three papers were relied upon in which the ANSYS/Emag software for magnetic analysis was used. By using FEMM software for the same MR valve magnetic designs, the results of the magnetic density and magnetic flux density satisfactory and close to the ANSYS/Emag software depending on the same dimensions, metals, and the number of coils turns of the original design. The FEMM software is characterized by flexibility and ease of use, due to its specialization in calculating magnetic designs, and less complex than other software. (Some figures in this article may appear in color only in the online version). [ABSTRACT FROM AUTHOR]

The object of the work carried out in this article is a numerical study of the aerodynamic flow around a UAV propeller. The flow is assumed to be three-dimensional, turbulent, stationary, and incompressible. The design process started with the selection of the appropriate airfoils for the new propeller by part of the numerical calculation of a two-dimensional flow around three different airfoils at Reynolds number Re=3.106, Comparison of the results allowed the selection of the NACA 4412 profile as the appropriate profile for our propeller design. Particular attention is paid to the velocity and pressure fields in the area around the airfoils, and to the pressure coefficients and the lift force on the surface of the airfoils. Followed by the creation of the 3D design of the propeller by changing the angle of attack, chord, and blade roughness. The numerical simulation of the turbulent flow produced by the rotation of the propeller is carried out using the commercial calculation code ANSYS. [ABSTRACT FROM AUTHOR]

The mechanical effects in the boiler of steam power plants are a very complex problem and dangerous because of unstable pressure in the upper drum boiler. This work deals with an experimental investigation of the drum water level system in (Al-Quds power plant) in Baghdad / Iraq to explain the dynamic behavior of the system under a given operating condition. Mathematical equations of the boiler model are solved. The rapid elevation in the heat input (mass flow rate of fuel) has a dynamic effect on the riser tubes properties in the natural water circulation tube in a steam power plant's boiler. These are typically calculated under increasing heat input by ratio 10% and 20% for upper drum parameters. The outcomes represented that the rapid rise in the fuel flow rate leads to increase rates of evaporation and consequently caused a high elevation in the quality and this causes tube overheating. The temperature of the riser rising above the saturation temperatures slightly because of the steam temperature altitude and the dynamic influence resulting from a sharp rise in the thermal flux. [ABSTRACT FROM AUTHOR]

The shape memory wires are used as actuators for many applications. The purpose of this paper is to build a measurement device that could calculate the properties of bending shape memory wire actuators to find their activation temperature and generated force. The measurement device is build using the thermosensor and load cell, and it is controlled using LabVIEW. The device can test the bending shape-memory wires for (30,60, and 90 Degree). It is found that the diameter of the wire is the significant parameter that affects the generated force, while the folding angle did not affect the results. The activation temperatures for all wires are determined to be between (50-79 OC). The bending shape memory wire is the potential solution for self-folding robot applications. [ABSTRACT FROM AUTHOR]

The enlargement in the cost of electrical energy and relevant development in both material technology and operating cost, promoted the designers to improve the performance of the induction motors. In this paper presents the modeling and analysis of a three-phase induction motor with different depth dimensions of the rotor rods using the two-dimensional finite element method. The research deals with the effect of rotor rods depth on motor performances. The prototype contains the basic dimensions of the stator and rotor according to the basic design, as the motor works on a 380-volt source with a frequency of 50 Hz and an effective power of 2200 watts. The rotor rods depth was changed at rates starting from -25% up to +75%, analyzing the motor performance for each change state, and comparing the effect of the rods depth on the motor performance in terms of efficiency, power, power factor, torque, stator current and starting current to get the optimal depth of bars achieves the highest performance. The ability of ANSYS to solve Maxwell's equations was exploited in a comprehensive results analysis. The ability of the ANSYS program to solve Maxwell's equations was exploited in conducting a comprehensive analysis of the results. [ABSTRACT FROM AUTHOR]

This investigation aims to study the mechanical properties and microstructural analysis of aluminium matrix incorporated with different amount of Fe3O4 at (2, 4, 6, 8 and 10) wt.% with constant amount of Ni at 2wt.%. Al/ Fe3O4 +Ni hybrid nanocomposites specimens were prepared using powder metallurgy technique. Aluminium matrix nanocomposites (AMNCs) are considered as an important alloy due to their properties such as high strength, wear strength and light weight which enable them to use in many applications such as automotive, electronics and aerospace. There are many examinations have been carried out for the specimens of this work such as Field Emission Scanning Electro Microscope (FESEM) and X-Ray Diffraction (XRD) analysis to estimate the microstructure and phases of the prepared nanocomposites. Mechanical tests also carried out such as micro hardness test, compressive test and wear test to evaluate the mechanical properties of the hybrid nanocomposites. The results of this work show that Fe3O4 and Ni nanoparticles have been homogeneously dispersed in Al matrix by FESEM and XRD analysis. While the mechanical tests show that improving the compressive strength at 8wt.% by 55.36%, the highest micro hardness at 10% by 111.1% and also improving wear rate. [ABSTRACT FROM AUTHOR]

Wastewater containing heavy metal ions from industrial activities is one of the most critical issues that affects negatively on the environment. The present work is to study cobalt (II) ion removal using activated carbon from synthetic solution in a batch reactor. Effects of the initial cobalt ion concentration (10-70 mg/L), pH (3-13), and adsorbent dose (0.1-0.4) were studied at room temperature while isotherms and kinetic of adsorption were studied in linear forms. The results showed that These results indicated that activated carbon has a good ability to remove cobalt ions from wastewater and flowed the Freundlich isotherm and pseudo-second order kinetic equation. optimal values of the pH, an adsorbent dose and initial concentration were 9.2, 0.2, and 63.15 respectively. [ABSTRACT FROM AUTHOR]

Underground cables collapse as an electrical treeing due to high-degradation phenomenon is one of the main elements of underground cables failures. In this research, Crosslink polyethylene (XLPE) electric tree features that includes zirconia nanoparticles ZrO2 was reported. The XLPE concentrations of nanoparticles ranged from 1wt.% and 3 wt.%. In this research. The electrode needle plane and the distance between electrodes was 3 mm. A digital camera and stereo microscope system have been used to track the electric tree pattern and the progress of XLPE; Results revealed that XLPE's tree initiation (TIV) voltage increased with increase concentration of nanoparticles. The tree growth expanding length and breakdown time (BDT) are also improving in comparison to unfilled XLPE. Potential explanations for improving tree growth and starting voltage as well as increasing the BDT of electrical tree by inserting nanoparticles are explained. [ABSTRACT FROM AUTHOR]

In this paper, the effects of nanoparticles Fe3O4+Ni on the mechanical behavior of epoxy resins are studied. Morphological structure of preparing specimens has been investigated via Field Emission scanning electron microscopy FESEM and X-ray diffraction spectra XRD. Mechanical testing includes of tensile, bending and hardness was performed on the specimens at room temperature according to ASTM standards. The study dealing with manufacturing of specimens composed of an epoxy resins as a matrix material embedded by different weight percentages of magnetite Fe3O4 that varies from 0 wt.% to 15 wt.% and constant weight percentage 2wt% of nickel Ni nanoparticles as a reinforcing material. The specimens were prepared using the casting method by combining the epoxy with the additive reinforcement materials Fe3O4+Ni and the mixture was slowly mixed in a sonication bath for 10 minutes, then the mixture was poured into silicon molds. Micro-structural analysis demonstrates that the Fe3O4 and Ni nanoparticles were homogeneously dispersed in the polymer matrix. The results of this work exhibit an enhancement the mechanical properties of the epoxy nanocomposites. Increasing the weight percentages of Fe3O4 nanoparticles with constant weight of Ni nanoparticles increased the mechanical properties. The preferred weight level at 15 wt.% Fe3O4+2 wt. % Ni except for bending strength the preferred weight at 12 wt.%. The tensile strength, young modulus and hardness, increased by 68.66%, 39.59% and 25.75%, respectively, bending strength increased by 140% and the bending modulus increased by 400% compared with the pure epoxy resin. [ABSTRACT FROM AUTHOR]

The Poly methyl methacrylate (PMMA) powders are used to preparing the bio-composite coatings by electrostatic spray coating on 316L stainless steel with dimensions of (2×2×1 mm) was used as substrates. Different weight percentages dry powders were mixed to form a composite mixture consisted of Al2O3and TiO2 with of PMMA matrix material, the ceramic powders additives were studied in four groups, namely, A (2 % wt Al2O3and 3% wt TiO2) with 95% wt PMMA), B (4 % wt Al2O3and 6% wt TiO2) with 90% wt PMMA), C (6 % wt Al2O3and 9% wt TiO2) with 85% wt PMMA) and D (8% wt Al2O3and 12% wt TiO2) with 80% wt PMMA). The samples of all groups were cured at (140 C°) for (2 hr). The coating morphology from SEM was characterized and analyzed for bio-composite coating with examined FTIR and DSC. The results show improving the performance of coating base-PMMA by depositing a ceramic material on the surface of the 316L SS implant. The results in DSC test showed that the maximum value of glass transition temperature was obtained in the coated composite materials for (Group C) specimen and no exhibited significant other endothermic appears for the DSC scan range. While the results in FTIR test showed no other new peak or peak shifts appear for all coated composite specimens were observed and these give good indication of improving the state of miscibility for all groups specimens. [ABSTRACT FROM AUTHOR]

PID controller tuned by intelligent optimization method has been employed in this research using genetic Algorithm (GA) for vehicle suspension system vibration (VSSV). Modelling and control VSSV one of the main problems that still facing the researchers in automotive applications. A new modelling of VSSV by autoregressive with exogenous-genetic algorithm (ARX-GA) has been utilized, in addition to control the system by PID-GA and electromechanical actuator. To validate both of modelling and control techniques, integrate square error method (ISEM) has performed. The results showed that the proposed method (ARX-GA) was succeed to model the system where the value of ISEM was 0.00219, on the other hand, PID-GA controlled on VSSV vibration performed well, where the lowest ISEM was 0.593 and the controller suppressed the vibration up to 86.23 at Kp, Ki and Kd equal to 2.4348, 1.9667 and 0.5316 respectively. [ABSTRACT FROM AUTHOR]

In the current study, stir casting process was used to fabricate AA7049-Al2O3 nano particulate composite containing 6 wt% Al2O3. The characterization work was conducted by scanning electron microscope (SEM). The hardness mechanical properties and fatigue behavior of AA7049-6 wt% Al2O3 composite were investigated by Brinell hardness test, tensile test and rotating bending fatigue test respectively at room temperature (RT). The (SEM) revealed uniform distribution of Al2O3 into matrix. It was observed that the Brinell hardness number (BHN), tensile properties and fatigue behavior of 6 wt% Al2O3 nanocomposite improved in compare to the base metal. The maximum improvement percentage for nanocomposite were enhanced by 5.3%, 4.81% and 8.92% for BHN, ultimate tensile strength (UTS) and yield stress (YS) respectively compared to the unreinforced matrix. Ductility decreased with reduction percentage of 16.6%. The fatigue strength of nanocomposite showed 3.31% improvement compared to the unreinforced matrix. Corrosion of the composite at 3.5% NaCl solution for 60 days is also reported and it was observed that the corroded reinforced matrix still better in fatigue strength and life compared with the base metal. [ABSTRACT FROM AUTHOR]

During the repeated braking, it will generate high amount of heat on the braking disc and braking pads. The value of the generated heat depends on many factors such as the vehicle speed, materials properties, disc brake construction, as well as the number of braking cycles. The aim of this paper is to investigate the effect of repeated braking on the temperature distribution of the braking pads and disc. It was performed the experimental approach under the laboratory conditions without air flow. It was found that the temperatures of disc and pads increase significantly with each new cycle of braking. It was found that magnitude of the friction coefficient has great influence to reduce the braking distance. The obtained experimental results can be applied in the design and manufacture the brake system of the automotive vehicles based on the safety factor of passengers. In the other words, keep the heat generation within the limit. [ABSTRACT FROM AUTHOR]

The ballistic protection became an important issue in military tactics, it is concerned with how soldiers can possess high mobility and comfortable feeling together with high protection. In nature, there are many example of great armor systems that may serve as a source of inspiration for engineers to design a new generation of armors. Armadillos, Crocodiles, Fish, and many other species of animals possess the best balance between the high flexibility, strength, and low weight. All of these parameters protect the animals from predators without any adverse effect on the locomotion of these animals. This article attempted to use the biomimetic design to combine the characteristics of modern ballistic protection inspired by the biological structure of the animal's carapace. The hexagonal shape and overlap pattern of scales used to construct a special type of tiles in this armor, hence, the experimental and numerical work have focused on the performance of the structure design of the armor. The results of the study verified the ability of the system to convert between the flexibility and rigidity via the self-lock technique, furthermore, many characteristics concerning with the capability to withstand under the multi-hit condition, the high energy distribution between the tiles, and the capacity to prevent the behind armor blunt trauma have done in this work. [ABSTRACT FROM AUTHOR]

The objective of this research is studying the influence of sodium carbonate particles on tensile strength properties, hardness shore (D) , impact strength and fracture toughness properties of unsaturated polyester resin reinforced with carbon / chopped glass fiber. The sodium carbonate particles (3%,5%,7% w.f) with (5% w.f) carbon / chopped glass fiber are adding in the unsaturated polyester resin as filler. Specimens were fabricated by hand lay-up technique of pouring unsaturated polyester resin with particles and fiber. The mean particle size analyzers of sodium carbonate (0.71µm).Applications of this study are "Automobile system ,water and fule storge tanks, vessles and industrial supports". The results showed that the impact strength, ultimate tensile strength, fracture toughness and hardness shore D properties enhanced with an increase weight fraction of sodium carbonate particles. The samples reinforced with carbon fiber have better mechanical properties than samples reinforced by chopped glass fiber. [ABSTRACT FROM AUTHOR]

The basic function of the gas turbine blades is to rotate the shaft connected to the generator motor. In electricity generation station, because the materials used in manufacturing must resist harsh working conditions, gas turbine blades are subject to high vibration, pressure and temperature. In this paper, the maximum pressure and deformation are caused by the effect of centrifugal force on the gas turbine blades. And to determine the natural frequencies of vibration, which are caused by the rotation speed about 3000 r.p.m under high-temperature conditions. The finite element method (FEM) was used to determine the natural frequency of turbine blade material (GTD-111) applied in the South Baghdad Power Station in Iraq, Baghdad. This paper deals with the structural analysis of gas turbine blades. Analysis was performed to find out the mechanical stresses and radial elongation to which the gas turbine rotor blade is subjected. A solid turbine blade model is constructed using the SOLIDWORKS2018 software. The turbine blade is analyzed for its structural performance due to the loading conditions using ANSYS 19 software to study the stress variation on the GTD-111 alloy gas turbine blades. The results shows that under static load and the stress and strain on the blade, the amplitude of the blade vibration will change at the higher frequencies of 581.42 Hz and 935.84 Hz because the root of the blade is placed on the disk-like cantilever (girder fixed at only one end). [ABSTRACT FROM AUTHOR]

The design optimization approach is presented in this paper to minimize the number of poles and other dimensions like an air gap, Dia. Yoke, Z-length (Deep of Model) by studying all private equations of design to increase the performance for a radial Active Magnetic Bearing based on Genetic Algorithm method and using ANSYS Maxwell (Version 17.1) program of electro-magnetic. The best air gap value is found at about 0.85 mm. The next steps for conducting an optimal design evaluation of the bearing are explained, with and without loads with different rotational speeds. It's found that when the external load increases, as well as the rotational speed, the torque decreases. [ABSTRACT FROM AUTHOR]

Polymer nanocomposite of polystyrene reinforced with a multiwall carbon nanotube at different weight percentages (0,100,140,200) ppm. were prepared via the electrospinning technique to produce nanocomposite thin textiles. Structural properties and bonds between MWCNT and polystyrene nanofibers were studied via "Fourier transform infrared spectroscopy" (FTIR) analysis. Morphology, tribology, porosity, and roughness of thin films by Atomic force microscopy (AFM) were tested. Energy band gap measured using ultraviolet spectroscopy test, the morphology of manufactured films have been conducted with Scanning electron microscopy (SEM). Results proved that the solution's viscosity decreased with increasing the MWCNTS ratios, the surface tension slightly increased with increasing the ratio of MWCNTS in the polymeric solutions, FTIR test proved there is no chemical reaction between MWCNTS and the polystyrene Furthermore, the transmittance of polystyrene was higher than the polymeric nanocomposite, FESEM test showed the average diameter of fibers reduced in relation to the ratio increasing of MWCNT also the alignment improved significantly, and the average surface roughness increased with increasing the MWCNTS concentration. finally, the prepared films converted to hydrophobic at higher percentages of MWCNTS, the bandgap measurements showed that the best sample is PS/140 ppm MWCNTS. [ABSTRACT FROM AUTHOR]

Biodiesel is a very potential fuel to replace diesel fuel. Waste cooking vegetable oil (WCVO) can be used as raw material for making biodiesel. One method of making biodiesel is by using microwave irradiation. Microwave heating is more advantageous than conventional heating. This study aims to determine the effect of power supply in the production of biodiesel from (WCVO) at optimum reaction time and oil-to-methanol molar ratio. Transesterification of waste cooking oil takes place in a microwave oven by variations in microwave power (160, 320, 480, 640, and 800 Watt) at reaction time of 4 min, oil-to-methanol molar ratio as 1:6. Also, methanol and ethanol are used to compare between them. The optimum condition that have found was 480 watt power supply and maximum biodiesel yield is 82%. Also the methyl ester has same physical properties of ethyl ester with slightly increasing in biodiesel yield as 84% with ethanol. [ABSTRACT FROM AUTHOR]

The present research aims to show the benefit of using egg-shell-composite material for enhancing mechanical and acoustical properties, as well as to reducing cooling/heating need in building. Brick wall model was selected for thermal performance calculations. The suggested composite materials included two types of egg-shell particles (normal egg-shell particles and toasted egg-shell particles). In addition, hollow plastic panels have been selected as conventional packaging materials when performing calculations and comparison with the proposing materials. The outcomes of present work show that the proposed materials offer superior mechanical properties than the conventional packaging materials. Moreover, it shows capability of reducing noise level by about 3.4 % higher than hollow plastic panels. In addition, the results indicated that hollow plastic panels offer better thermal performance than the proposing materials because of its low thermal conductivity. [ABSTRACT FROM AUTHOR]

The present study investigated the modified kinematically admissible velocity field of three-dimensional upper bound theory analysis to determine the distribution of the extrusion powers during the extrusion of the hexagonal bar from the circular cross-section by adopting the inclination angle of the multi-sector of the extrusion die. The study takes into consideration the factors affecting the extrusion process such as the friction factor, the angle of inclination of the die, and the reduction of area. The study adopted the upper bound theory in determining the kinematically velocity field and powers consist of total the extrusion power required of the extrusion process. The results showed increasing the friction factor from (0.1) to (0.8) leads to an increase in the extrusion energy with a ratio (62.72%) while increasing the reduction of the area from (25%) to (40%) leads to an increase in the forming energy by (4.81%), and increasing the discontinuity power at (3.47%) while decreasing the frictional power dissipation by (1.19%). [ABSTRACT FROM AUTHOR]

This work has been focused on the study of the effect of vibration and noise generated on the engraving machine through operating in a range of various speeds of the stepper motor. The method that's used is to reduce the vibration and noise is by changing the design of the structure and changing the settings of the stepper motor and changing the thickness of the acrylic and changing the legs material of the machine Also these effects are affecting the accuracy of the engraved surface of the product. finally results are the velocity responses of the vibration in the y-direction of (p-p) are greater than that of the in x-direction. the maximum vibration values are at the acceleration rate of (100 mm/s2) and in the direction of the Y axis, while the vibration values are (350 mm/s2) in the direction of the X axis when the machine is operating at (R.M.S) condition. the lowest critical velocity is (200mm/s2) at acceleration, which means that the increase in acceleration values leads to this velocity moving towards the highest frequency value. [ABSTRACT FROM AUTHOR]

The main objective of this study is to evaluate the influence of prior immersion of samples from aluminum alloy 6061, which have treated with (shot-peening them before and after corrosion) in 3.5% NaCl solution up to 120 days. The effects of shot -peening (SP) on the surface roughness, and the fatigue properties under the rotating bending at R=- 1of the aluminum alloy 6061 have been conducted. SP as a surface treatment leads to plastic deformations in the surface areas, which occur in the development of residual stresses and variations in the surface topography. Treated samples with (SP) before corrosion found the fatigue life decreased significantly at a rate lower than in the case of the (SP) after corrosion of the same Al alloy. The fatigue endurance limit of (SP) specimens after corroded decreased by 10% in comparison with samples treated with (SP) without corrosion while the fatigue endurance limit of shot-peened before corrosion improved by 6% compared to the case of after immersing inadequate solution. [ABSTRACT FROM AUTHOR]

In the presented study, the major objective is reducing the viscosity and enhancing the flow related to heavy crude oil via pipelines using dual treatment as electrical field and dilution. The investigation of experimental variables' interaction effects on the objective function using optimization technique has been achieved. In this experiment, at first, the dilution's impact (without using electric field) is studied on the Iraqi crude oil's viscosity. Toluene was used as a diluent in different concentrations (0, 5, 10, 15, and 20wt.%). The results show that the viscosity is decreased exponentially with increases in the concentration of diluent from 0 to 15 wt.%. The lower value of viscosity is about 25.14cSt and it is achieved by adding 15wt. % of the diluent. Thus, the maximum viscosity reduction is about 20.7% when adding 15 wt.% of Toluene. Second, the effect of the electric field (without dilution) has been studied,. The results showed that the lower value of viscosity 20.41 cSt is obtained when applied electric field equal to 36.67(v/cm). Therefore, the maximum viscosity reduction is about 35.6%. Lastly, the effect of dual treatment (dilution and electric field) has been studied according to factorial design. Fourteen experiment have been performed; the lower viscosity is about 17.395cSt obtained at 16.5 wt.% toluene and 36.67 (v / cm) of the electric field , which means that the best viscosity reduction obtained from this experiment amounted to about 45.126%. [ABSTRACT FROM AUTHOR]

This paper presents a Vector Control (VC) strategy for a Doubly Fed Induction Generator based Wind Energy Conversion System (DFIG-WECS). In this constitution, the Rotor Side Converter (RSC) is responsible for implementing Maximum Power Point (MPP) whereas the Grid Side Converter (GSC) is responsible for regulating reactive and real power flow to the electrical and it is used to regulate the dc bus voltage and the ac side power-factor. The proposed strategy does not require any wind speed measurement. To verify the performance of the presented control approach, simulations are performed with MATLAB/Simulink. A complete simulation model is developed under varying wind speeds and system responses of open loop control are compared with those of closed loop control for different grid voltage conditions. [ABSTRACT FROM AUTHOR]

This paper presents a design procedure and manufacturing of a small hybrid solar-wind turbine type Savonius vertical axis wind turbine (VAWT) compensated with PV panel. The design of Savonius wind turbine (SWT) depend on modified blade shape model according to site condition in Baghdad city with wind speed 3 m/s. The sizing of photovoltaic (PV) system depends on required load (400 W) for lighting. PV panel tilt angle optimized according to Baghdad city location at (latitude 33°20′). Mathematical models were programmed by MATLAB to predict the solar energy incident on the surface all day of the year at angles from (0-90o). The monthly optimum tilt angle can vary significantly during the year between 18o at summer to 65o at winter seasons. The wind turbine can provide 10%-25% from total clean energy especially at cloudy or dusty days with received low solar radiation. [ABSTRACT FROM AUTHOR]

Brain cooling methods play an important role in saving the lives of patients with different types of head trauma, accidents, and other kinds of injuries. Nevertheless defining the suitable temperature is challenging due to notable variations amongst individuals and variations over time in patients. Therefore, specific brain temperature control is challenging in manual techniques. The main objectives of this paper are to build a Microcontroller Based Brain Hypothermia System, which is used to reduce the temperature of the brain within a few hours after a stroke and, therefore, can decrease brain damage and risk of death. The thermoelectric was cooled using water circulation, to make the proposed system able to provide long operational time along with maintaining the cooling rate of the system. The designed water-cooling system kept the system cooling rate at maximum throughout the time required for the system to operate which is between 8 to 72 hours. [ABSTRACT FROM AUTHOR]

The paper deal with best twist angle and optimum HAWT blades chord to determine the best performance using different HAWT blades cross-section. BEM theory, L/D max theory and algorithm theory used to analysis performance equation. Self f.90 program and CFD code as used to calculate the results. Three different cross section was used unsymmetrical airfoil (NACA 4412), symmetrical airfoil (NACA 0012) and supercritical airfoil (Eppler -417). Scientific thought of using different cross-section was to change the force distribution on blade to performance best L/D max. Optimization result figure 16 % increase in cp coefficient for NACA 0012 cross-section and 10.3 % for Eppler 417 and 9.5 % for NACA 4412 cross-section. All the result was plotted and tabulated for all optimization results. [ABSTRACT FROM AUTHOR]

Recently, a clear tendency has emerged for the Omani government to spread the culture of reliance on renewable energies in the production of electricity in the country. One of the most important aspects of this trend is that the Omani government has installed PV systems connected to the national grid in some schools across the country. The current study aimed at assessing and practically measuring the performance of the photovoltaic power plant installed in one of these schools (Asma Bint Al-Hareth School in Sohar, Oman) over a whole year. This system has a maximum power of 150 kW. The practical measurements for a whole year of the station's output showed that the system losses varied from low values to high values. The results showed that a clear variation occurs in the outputs of the system as a result of changing seasons and weather. The practical results demonstrated the suitability of Oman's environmental conditions for the deployment and operation of such stations connected to the grid. [ABSTRACT FROM AUTHOR]