bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vibration caused by swing check valve closure
Authors: El-Zahaby Aly M , Zakaria Mohamed Y , El-Samadony Yasser A F , Ismail Ibrahim A 
Published: October 2019

Abstract
Check valve or non-return valve is a commonly used component in fluid control systems, the function of the check valve is to allow the fluid to flow in one direction and prevent it from flowing backward in the opposite direction. There are many types of check valve that differs in structure, material, theory of operation, applications, installations constraints, etc. The swing check valve type has many advantages like lower pressure drop, high valve flow coefficient, ease of maintenance, etc. In this paper, the swing check valve type will be investigated using a new mathematical model that avoids the inaccuracy in explicit models and time consumption of evaluating different coefficients in implicit models. The present model is validated by comparing to experimental data. Investigation of the swing check valve is carried out in order to determine the vibration produced by its closing action and closing response. Also the effect of equipping the swing check valve with a torsion spring is investigated to figure out the spring effect on the valve induced vibration.
PID vs. Backstepping Control for Cooperative Quadrotors Unmanned Aerial Vehicles
Authors: Mahfouz M. , Taiomour A. , Ashry Mahmoud M. , Elnashar G. 
Published: October 2019

Abstract
Formation reconfiguration is one of the most important tactics used in the field of cooperative Unmanned Air Vehicles. In this paper, formation reconfiguration for a team of vertical takeoff and landing quadrotors is managed by a classical approach of proportional-integral-derivative (PID) controller. PID controller is designed to regulate the attitude and the altitude for every quadrotor of a cooperative team respecting the separating span and velocity constraints. PID controller results are compared with a backstepping controller developed for the same system. The mathematical model of the propositioned system is derived initially, and then a PID controller using simplex and genetic algorithms is designed qualifying the cooperative quadrotors to track the desired trajectories. Simulation results present the assessment of PID control strategy along with backstepping control strategy in different scenarios including proposal flight mission in obstacle-free surroundings, and obstacle-laden surroundings. Noise attenuation and disturbance rejection are examined for both controllers to check the robustness of the system.
Reliability prediction of on-board subsystem satellite by Monte Carlo methodology
Authors: Zoalfakar Said H. , El Badawi Rehab E. 
Published: October 2019

Abstract
This paper presents a case study that aims to develop a hardware design for the pc to the satellite, supported fault-tree design and calculations of dependableness. The on-board pc of a satellite, inserted into the on-board management system, has functions of receiving, process and distribution of commands to the subsystems and payload of the satellite; and exploit, formatting, storage and transmission of measurement from subsystems and payload. The most necessities of associate on-board pc are high dependableness, capability of real time process, resistance to radiation, and minimizing power consumption, volume and mass. Enlarged dependableness is achieved by the fault tolerance technique that relies on adding redundancy to the system, or the utilization of elements with high price of individual dependableness. During this work, hardware redundancy techniques are thought-about. First, a pc is meant and its dependableness is calculated, for a mission of one year period. Mission dependableness goal isn’t earned during this calculation. So as to extend dependableness, two kinds of fault tolerant redundant architectures are analyzed, with their various reliabilities calculated for the identical amount of the mission.
Agile mission optimization for a constellation of earth observation satellites
Authors: Abbas A M , Meselhy K T , Moughith W S , Omer A A 
Published: October 2019

Abstract
Today’s Earth Observation Satellites (EOSs) have complicated missions with an agility capability. For this reason, a great importance for satellite mission optimization problem has been arisen. In this paper, a multi-objective equation has been formulated which contains three selected objectives (Gain, image quality and time execution). There are three constraints (Target exclusiveness, due date and transition time) which have been selected and presented by three equations. Satellite Tool Kit (STK) has been used to simulate the relation between satellites and customers’ targets. The output opportunities from STK have been saved in an excel sheet and they will be used as inputs for our problem. Genetic Algorithm (GA) has been used as one of the optimization techniques to solve this problem and it has been applied by using Matlab program and its graphical user interface. The result from solving our problem is a plan which contains selected targets numbers, satellite numbers, target’s gain, shooting time, combined angle, target’s objective function value and the total objective function value. In this paper, a case study has been presented assuming there is a constellation of four (4) satellites (Superview constellation), thirteen (13) random targets and the required output is an optimum daily plan for shooting.
Thermal behaviour of MWCNT/ammonium perchlorate particles
Authors: Yehia M , Mostafa Hosam E , Wafy Tamer Z , Abdelhafiz Mahmoud 
Published: October 2019

Abstract
A lot of attention has been given to incorporation of carbon nanomaterials (CNMs) including carbon nanotubes (CNTs) in ammonium perchlorate (APC) based solid propellants to enhance their final performance. (CNTs) has many applications in the energetic material field due to its large surface area and surface energy. This study reports on catalysed ammonium perchlorate (APC) by multi wall carbon nanotube (MWCNT). MWCNTs were successively encapsulated with APC particles by using modified fast-crash solvent–antisolvent technique and characterized by scanning electron microscope (SEM) and Energy dispersive X-ray spectrometer (EDX). The catalytic performance of MWCNT on the thermal behaviour of ammonium perchlorate (APC) was analysed using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Interestingly, the effect of MWCNTs on the thermal decomposition of APC where the results showed that encapsulated APC with 1% MWCNT show significant decreasing in the high temperature of decomposition APC from 452.8°C to 390.1°C and MWCNTs giving an increase in total releasing heat of APC by 130 %. The results confirmed that MWCNTs are a novel catalysing agent on the thermal degradation of ammonium perchlorate which has a direct impact on the burning behaviour, performance and combustion regime of the solid rocket propellants.
Mechanical behaviour of rubber hybrid composites
Authors: Mousa Bassant Hany , El gamsy Ramadan , Abdel Latif Mohamed Hazem 
Published: October 2019

Abstract
Recently, a lot of researches are directed to recycling of waste materials such as waste tires and marble and granite dust (GM). The management of solid wastes is essential to prevent the harmful effects and hazards associated by the contamination of these wastes. Waste tire rubber particles (WTRP) are added to high density polyethylene (HDPE) matrix to increase the impact strength of HDPE, while it results in the decrease of other mechanical properties. GM is added to this mixture to modify some mechanical properties such as hardness and compressive strength, this mixture results in a novel hybrid composite. The effect of using different GM wt.% on different mechanical properties of the composite is studied. Mechanical testing such as three-point bending, Charpy impact, compression and shore D hardness is implemented according to ASTM standards and Scanning electron microscopy examination of the microstructure of WTRP-HDPE-GM hybrid composite is used to support the explanation of the results.
Firing test and evaluation of coaxial pulsed plasma thruster
Authors: Othman M A , Elzahaby Aly M , Makled Ah El-S , Khalil M 
Published: October 2019

Abstract
For many reasons, electrical propulsion systems are the most expected in space; they are suitable for researchers because they are effective, easy to design and applicable in space. One of the most important parameters that could assess the performance of the propulsion system is the problem of measuring the very low thrust of pulsed plasma thrusters (PPTs). Various test beds, including indirect designs of measuring systems such as pendulums and optical measuring systems, can measure the thrust with very high precision, but it is very complicated.
This paper presents the firing test of a new designed coaxial pulsed plasma thruster for proofing the concept and then the thrust is measured by a new simple test bed using a rod in accordance with a loading cell (0-100 gf.) which can measure thrust accurately after good calibration up to μgf. In a medium-sized vacuum chamber (VC) (10−5 bar, D= 1 m and L= 1.4 m), a coaxial PPT is designed and tested under environmental conditions in space. Four proofs of concept took place until the experiment was adjusted and six experiments were carried out to measure the thrust using the new test bed under various operating conditions. Evaluation of the system is presented too and the maximum thrust obtained is 0.68mN at the discharge voltage equals 7kV and the 12kV voltage of the spark plug initiator and the efficiency equals 10%. The steps of fabrication of the coaxial PPT and steps of measuring the thrust is presented in the paper beside the result charts of the thrust under different operating conditions.
Mobile robot position estimation using Euler-Maruyama algorithm
Authors: Abd Elfatah Mohamed G , Zaky Hany Nasry , Gharib M 
Published: October 2019

Abstract
Mobile robots became very important and more familiar in commercial, industrial and military applications. In many unmanned vehicle applications, sensors and control systems are mounted on mobile robots to identify the surrounding environment for obstacle avoidance. This work aims to estimate the mobile robot location to compensate the time delay problem which appears in teleoperation. According to the stochastic nature of the mobile robot teleoperation, the kinematics equation of mobile robot will be converted into stochastic differential equations (SDEs). Euler-Maruyama algorithm used as it is one of the most popular numerical algorithms to approximate SDEs solution. A simulated results for the solution is produced which seem to be good comparing with mobile robot ideal path simulation.
ICI and PAPR enhancement in MIMO-OFDM system using RNS coding
Authors: Youssef M I , Emam A E , Abd elghany M 
Published: October 2019

Abstract
The Inter-Carrier-Interference (ICI) and the Peak-to-Average-Power Ratio (PAPR) of the transmitted signal are considered as bottlenecks in the utilization of Multiple-Input-Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems, which caused a significant performance degradation. In this paper Residue Numbers as a coding scheme is impeded in MIMO-OFDM systems, where the PAPR values are analysed and compared to non-RNS coding systems, and the ICI levels are measured and evaluated with respect to the conventional ICI mitigation techniques as pulse shaping, windowing and self-cancellation techniques implemented in MIMO-OFDM system. The ICI errors, Bit-Error-Rate (BER) and the Complementary Cumulative Distribution Function (CCDF) for MIMO-OFDM system with Residue Number System (RNS) coding are analysed and evaluated. The results demonstrated a performance enhancement of the transmission model over the system without RNS implementation.
Outdoor RF spectral study available from cell-phone towers in sub-urban areas for ambient RF energy harvesting
Authors: AbdelGhany Omar M , Sobih Ayman G , El-Tager Ayman M 
Published: October 2019

Abstract
In this paper, outdoor RF spectral survey results in a sub-urban area are demonstrated. this work was carried out to explore and define the ambient RF signal sources available in the populated environment so as to select the frequency bands most suitable for designing RF energy harvesting circuits. Referring to the Egyptian frequency allocation chart, the ambient RF power sources within the spectrum of 0.5 to 2.2 GHz has been detected and measured to cover the mobile downlink frequency bands (2G, 3G and 4G) and the digital TV broadcasting bands which represent the most favourable frequencies for ambient RF energy harvesting circuits which is convenient for outdoor applications that needs power supply source in the range of microwatts. According to the available parameters of the cellular network standards, the measurement results were compared with the analytical empirical path loss propagation models focusing on sub-urban areas which provide an estimation of the median path loss as a function of distance and the urban terrain classification. The models that are discussed in this paper are HATA Model, Ericsson Model and ITU-R Model. It is found that HATA model can be used to give the best predictions with minimum error for losses and received power levels. Based on the measured data,
a designer can decide the maximum distance away from a cell-phone tower that meets certain detection sensitivity. This study is useful for ambient RF energy harvesting designers.
Spray combustion characteristics of effervescent atomizer inside experimental furnace
Authors: Wilson Safwat A. , Asar Gaber M. , Elshahawy Eslam M. 
Published: October 2019

Abstract
The spray combustion characteristics of “inside-out” effervescent atomizer at low injection pressure have been investigated in the present study. The atomizer is mounted on experimental furnace cooled by separate segments water jacket the plain orifice atomizer is powered by diesel fuel and air as atomizing gas. The study shows the influence of A/F ratio, atomizing gas to liquid mass ratio (GLR), injection pressure, and exit orifice diameter on flame temperature distribution inside the furnace. cooling water heat flux, stack temperature, and combustion efficiency. The air to fuel mass ratio (A/F) varies from 20 to 50 Kgair/Kgfuel, and operating pressure varies from 0.5 to 2 bar. The results show that the increasing on A/F ratio decreases the flame length, and exhaust gas temperature, while the combustion efficiency increases. It was found also that, when using A/F ratios higher than 30 the combustion efficiency becomes greater than 90%. Where, the increasing on operating pressure increases the flame maximum temperature and heat transfer to cooling water. Moreover, increasing the combustion efficiency. The results could enrich our knowledge of effervescent spray combustion characteristics and achieving higher combustion efficiency with low pollutant emissions.
Investigation the effectiveness of using heat pipe on the temperature uniformity distribution over the SC equipment panel
Authors: Abdou M , Elzahaby Aly M , Khalil M 
Published: October 2019

Abstract
The heat pipe is a thermal device which allows an efficient transport of thermal energy. In this paper parametric study has been achieved to investigate the importance of using heat pipes about the uniformity of the temperature distribution over the equipment panel of the spacecraft (SC), which is a part of a real thermal control subsystem. Heat pipe analytical solution is used as a guide for design and geometrical parameters selection. The design of SC equipment panel radiator and a parametric study of the heat pipe are obtained numerically using Thermal desk top program (TDT). The space environment and the spacecraft operational conditions have been simulated by TDT program. Heat pipe prevents the hot spots which can be occurred due to the different equipment heat dissipation. The selected heat pipe design approach incorporates a conservative reliability philosophy and provides maximum operational flexibility.
Performance analysis for aerial-towing system
Authors: Khalil Mostafa 
Published: October 2019

Abstract
The dynamics of open chain systems have been widely investigated as a result of its increased applications such as aerial towing system, submerged towed cable applications, robot manipulators, and bio-mechanical applications. In this study, a practical engineering system, Mine Clearing Line Charge MICLIC system is taken as an example for an open chain system with accelerated end and varying number of segments. To validate the proposed model, a comparison between two different finite segment methods namely Kane’s method and Riccati transfer matrix method of linear multibody system (Riccati-MS-TMM) have been performed for a large open chain system. Results show that computational speed of Riccati-MS-TMM outperforms Kane’s method due to its huge matrix size to be solved. Then, using a predefined rocket motor total impulse, a parametric study has been performed on MICLIC system to illustrate the impact of different rocket motor thrust profiles on the resulted flight performance including the missile range, flight time, maximum tension applied on the rocket towing bridle, and the missile stability.
Flight dynamic model for low earth orbit satellites
Authors: Alshamy Hossam M. I. , Makled Ah. El-S. , Elhalwagy Y , Hendy Hossam 
Published: October 2019

Abstract
Low Earth Orbit satellite(LEO) missions have potentially attractive features such as low launch cost, and wide remote sensing applications.
There are three vital missions during the satellites life time including orbit transfer from the parking to the operating orbit, maintaining the operating orbit and de-orbiting mission to a disposal orbit at the end of the satellite lifetime according to the standard disposal orbit law. The mathematical model has been implemented to study various LEO mission orbits including the three vital missions.
The mathematical model evaluates the required performance parameters, velocity budget, number of manoeuvers, duration and consumed propellant mass for each mission.
The mathematical algorithm is carried out using Matlab/Simulink, the complete mathematical flight dynamic model has been verified through comparisons with the generated mission scenarios from Satellite Tool kit (STK), the graphical user interface is designed to display the model.
The carried out algorithm can be applied in satellite mission design to help predicting the parameters for each mission to minimize the risks and intensive tests. it can be considered as powerful tool to design and analysis LEO satellite missions.
Optimization Analysis of Minimum Flat Curve Radius of High Speed Maglev Line with Design Speed of 500 km/h
Authors: Jiang Fujie , Sun Xiangdong , Li Huibai , Huang Jingyu , Li Dongshuai 
Published: October 2019

Abstract
Firstly, based on the traditional circuit design method, the theoretical calculation value of the minimum radius of the flat curve under the design speed of 500 km/h is calculated in this paper; Through the analysis of the structural characteristics of the TR08 high-speed maglev train and the degree of freedom of each component, a 129-DOF high-speed maglev vehicle-line dynamics model is established by using the multi-body dynamics software SIMPACK; And using the modle to simulate and analyze the influence of the radius of the flat curve on the dynamic performance of the vehicle. Finally, according to the simulation results, the theoretical calculation of the minimum radius of the flat curve is optimized and adjusted, and the minimum radius recommended value of the flat curve that satisfies the dynamic evaluation index is obtained. After the simulation optimization, the unbalanced lateral acceleration and the vertical acceleration dynamic response of the vehicle passing through the designed curve section are significantly reduced, and the ride comfort of the passengers is good.
Finite Element Analysis of Residual Stress in Welded Joints of T91 Steel
Authors: Wang Zhi-ling 
Published: October 2019

Abstract
The pressure equipment is the key equipment in the petrochemical industry, natural gas chemical industry and coal chemical industry. Without safe and reliable pressure equipment, advanced process industry cannot be realized. It is important of the quality assurance of pressure vessel in order to prevent the failure of pressure vessel, especially some rupture accidents. One of the key reasons for quality assurance of pressure vessel is the treatment of residual stress in welded joint. In this paper, the working stress and welding residual stress of the thick plate of pressure equipment material and the welding joint of pressure equipment have been measured and analyzed successively by means of actual stress measurement and finite element simulation analysis. The influencing factors of welding stress are introduced, and the control of residual stress is analyzed and some suggestions are put forward in this paper.
Sliding Mode Variable Structure Control Strategy Applied on Position Servo System of EMA
Authors: Wang D Y , Gao S J , Yan M , Zheng S C 
Published: October 2019

Abstract
This paper introduces the basic elements of Electronic-Mechanical Actuator (EMA), and gives the equations. The mathematical model-state equations is established based on the basic equations, and the sliding mode variable structure control strategy, based on the reaching law is applied to control the position servo of EMA. We design a position-speed integrated sliding mode variable structure controller. The models of EMA machinery, electrical motor and controller are established in AMESim and Matlab, and joint simulation is carried out. Finally, this control strategy is compared with the three loop PID control strategy, and the experiment is carried out. The result shows that the sliding mode variable structure control strategy based on reaching law used to control EMA can improve the frequency response and control accuracy of the system, can also improve the dynamic performance of the position servo system.
Investigation on Polymer Composite Materials Wear Reinforced by Microparticles of Jatropha Curcas L. Waste
Authors: Müller Miroslav , Valašek Petr , Tichý Martin , Ruggiero Alessandro , D’Amato Roberto 
Published: October 2019

Abstract
The subject of the paper is a research on the wear resistance by friction against loosely fixed abrasive particles on a polymer composite material reinforced by waste microparticles from a pressing process of Jatropha curcas L. seeds with concentration from 5 to 20 wt.%. The seed pressing waste was used in form of Whole seeds cake (WSC), Seed shells (SS) and Seed kernels cake (SKC). The waste, which is difficult to further utilize for its inability to use as feed, arises at the pressing process of Jatropha Curcas L. seeds. A matrix of composite materials was epoxy-based. The wear tests were performed by the device Tester T-07 according to GOST 23.208-79. An addition of the filler significantly increased the wear resistance by friction against a rubber wheel with loosely fixed abrasive particles of sand. The wear resistance was increased up of 69% to 82% at tested polymer composite systems against matrix (resin). Composites materials with the filler Whole seeds cake (WSC) achieved the best results.