bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced Applications of Artificial Intelligent Systems in Civil Engineering: A Review
Authors: Kate Shrikant , Swami Vidula , Doiphode Sanjay , Singh Vijay
Published: August 2021

Artificial Intelligence (AI) focuses on smart machines and their architecture and application. Solutions to complex systems need large computing resources, but AI-based technologies may provide simpler alternative solutions. As a result, the use of AI has grown in a variety of technological fields in recent years in general and has extended to civil engineering in particular. Civil engineering, on the other hand, has not yet been extensively investigated using AI techniques. To fill in the gap, this paper explores, how artificial intelligence has been used and developed in civil engineering in recent years, including Machine Learning Techniques, with the advancement of machine learning techniques in recent years, big data and deep learning developments have been successfully implemented in numerous fields of civil engineering. The research direction and challenges of artificial intelligence in civil engineering over the last few years can be learned through the work of this paper. This paper discusses the use of artificial intelligence technologies in civil engineering, including machine learning techniques, smart algorithms, big data, and deep learning.
Study on Effects of Pumice in High Performance Light Weight Concrete by Replacing Coarse Aggregates
Authors: Manoj V , Sridhar R , Ajey Kumar V G
Published: August 2021

Pumice is a rock particle that was used in this experiment’s concrete, and light weight aggregate is a type of aggregate that is lighter than natural aggregate. The major purpose of the suggested methodology is to use optimization techniques to frame a mathematical model. Structural lightweight concrete is used extensively in the construction sector, particularly in high-rise buildings. Only lightweight aggregates can be used to make it. Pumice is a solid component and a highly porous rock light in nature that can be used as an alternative to coarse aggregate (CA) in concrete and Nano Silica an alternative for cement. This lightweight aggregate, on the other hand, has a higher density than other natural and artificial lightweight aggregates. As a result, the density of concrete made with this lightweight aggregate is relatively high, falling into the semi-lightweight concrete category. According to the latest analysis, to further at the density of an lightweight concrete with high strength, Pumice was partially replaced with a coarse aggregate. In this study, pumice was substituted for CA in percentages of 0%, 20% and 30% by quantity and Nano Silica replaced in 1-3% for different mixes to predict three output parameters such as compressive strength (Mpa), split tensile strength (Mpa), flexural strength (Mpa). The addition of pumice to CA concrete decreases density while also lowering all mechanical properties, according to test results. This is because pumice has a smooth surface texture and has a lower density than CA. On the other hand, lightweight concrete containing more than 20% pumice changes into structural lightweight concrete with excellent strength. Several studies demonstrated an overall gain in strength as well as weight loss. As a result, light-weight concrete is equal to heavy-weight concrete in terms of strength.
Comparative Analysis of Various Insulation Materials for Building Envelope Components
Authors: Sugandha Rathan N , Raut Ashwin , Gnana Rahul B
Published: August 2021

Due to growing environmental and economic concerns in recent years there has been a renewed interest in building energy efficiency as building contribute a huge consumption of energy across world. Among the effective and compatible ways of energy conservation technologies available today, insulation of buildings is most relevant as it also reduces negative environmental impacts and annual energy costs. The building envelope comprises of different components which are pre-dominant in evaluating thermal performance of a building. A proper selection of insulation materials results in a low energy demand process. In any material selection procedure, the ultimatum is of addressing material properties, parameters, criteria and performance characteristics. Hence this study aims to provide a knowledge base on identified insulation materials for corresponding building components with respect to material properties and performance parameters and recommend best material. Study presents comparative analysis of insulation options available for various building components.
Parametric Comparison of Retrofitting Methods in Masonry using Finite Element Analysis
Authors: Srinithya A , Kotagi Ningappa Mallakajappa , Vinay Kumar G M , Ashwin Thammaiah K
Published: August 2021

Seismic strengthening of buildings is necessary to control the extent of damage in case of earthquakes. The concept of an equivalent diagonal strut, provision of bands and intrusion wall are studied as structural efforts to improve the seismic stability of buildings. Static analysis and free vibration analysis are performed on various configurations. ANSYS software is used for modelling and analysis, where the models are subjected to equivalent lateral loadings. The analysis is performed using the Finite Element Method (FEM). Stress contours, lateral deformations by static analysis, natural frequency by free vibration analysis and their corresponding mode shapes for each of the models are studied. The obtained results are compared with the unreinforced masonry model. Results of the analysis showed that there is the highest increase in stiffness value to 43.38 % and a decrease in the deformation to 30.25% in the model with intrusion walls when compared to the basic unreinforced model. It is found that parameters like lateral deformations and stiffness showed positive improvements by the provisions of the configurations when compared to the unreinforced structures. This paper can be further extended to implement the dynamic analysis.
Parametric study on Sheet Pile Walls in Layered Soils
Authors: Jalawadi Somanagouda S , Shivashankar R
Published: August 2021

Sheet pile wall is a retaining structure. It is used to retain the deep vertical cuts made in the earth, waterfront structures, cofferdams, and bridge abutments. The geotechnical engineering advantage of sheet pile wall is that it does not consume large base width like a retaining wall. When land acquisition problem arises, sheet pile walls are preferred. Sheet pile walls are subjected to rotational failure and flexural failure in layered soil. The rotational failure can be avoided by providing adequate depth of penetration. The in-front foundation soil generates passive force against the active or driving force from backfill soil. The flexural failure is avoided by providing one or more anchors at a particular location on the sheet pile, which in return reduces the maximum bending moments, the maximum shear force developed on the sheet pile and the depth of penetration. This makes the design of anchored sheet pile walls more effective in layered soil. This paper considers soft clay and loose sand as backfill, and stiff clay and dense sand as foundation soil. The outcomes of this research are cantilever sheet pile requires more depth of penetration to avoid rotational failure. For a height of ditch 6m, single anchor is sufficient but for a height of ditch 10m, double anchor required to reduce the depth of penetration, maximum bending moment, shear force, and horizontal deflection.
A Comparative Experimental Investigation on Laced Reinforced Concrete Beam and Conventional Beam under Monotonic Loading
Authors: Sudharsan N , Grant C J Blessy , Murthi P , Poongodi K , Mahesh Kumar P
Published: August 2021

Laced Reinforced Concrete (LRC) structural elements are generally used in the defence environments where the structure encounters blast/impulsive loading. It comprises of equal number of reinforcements in both the faces of the beam with lacings as shear reinforcements bent at 450along the plane of principal bending and fastened in position by cross rod. This paper presents the performance of LRC beam by experimental investigation and compared with conventional Reinforced Concrete (RC) beam using four point flexural load testing. Experimental results indicate that the LRC beam perform well than the RC beam considering the deformation. Failure modes could not be ascertained, since the experiments were stopped due to limitations in test set-up. At this stage, the support rotation achieved by LRC beam and RC beam is found to be 4.70 and 2.430 respectively. The LRC beam is found to be more ductile than RC beam. The structural response of LRC beam and RC beam is compared and presented.
Scientific Approach of Geopolymer Concrete Composites using Marginal Materials
Authors: Mahdi Shaik Numan , Babu R Dushyanth V , Al Bakri Abdullah Mohd Mustafa
Published: August 2021

Geopolymer concrete is a sustainable composite where concrete is supplanted totally by pozzolanic cementitious materials like coal fuel ash, granulated blast furnace slag, rice husk ash, metakioline etc. with binding alkaline solutions in the matrix. Since the geopolymer doesn’t have specific code determination, a study has been made to create mix design to achieve the required workability and fresh density as per the considerable limits. Mix design procedure is proposed for flyash rice husk ash composition considering the quantity and fineness of binder, grading of aggregates. Water glass solution with Na2O = 18.79 %, SiO2 = 34.21 % and H2O = 47 % and solution of sodium hydroxide having 10M and 12M concentration were maintained constant throughout the Design. Fluid to binder ratio of 0.56, sodium silicate-to-sodium hydroxide ratio of 2.5 by mass was fixed on the basis of flowability. Measurement of Workability of geopolymer concrete was done using slump cone apparatus as per IS 1199. The cubes of 100 mm size were casted and cured under sundried condition maintaining a temperature about 40°C. From the observation it is concluded that the brick industrial rice husk ash can be utilized upto 10% in class f flyash to satisfy the Mix design criteria.
A Review of Geopolymer Composite Thermal Properties
Authors: Ali Mir Firasath , Vijayalakshmi Natrajan M M
Published: August 2021

This review paper aims to present fundamental aspects of geopolymer developments and science to emphasize their suitability for high-temperature exposure. Beginning with a comparison of the thermal properties of OPC and geopolymer, the analysis then investigates the character and occurrence of aggregates and supplementary phases. Characteristics essential for evaluating geopolymer thermal properties are thermal expansion, thermal conductivity, strength retention, explosive spalling along with microstructural characteristics such as phase stability, weight changes (dehydration/rehydration), morphology changes, and thermochemical properties were analyzed much in detail.
Effect of Water Content on Shear Strength of Black Cotton Soil
Authors: More Sachin K , Kumbhar Shridhar S , Asha P
Published: August 2021

The bearing capacity of the soil is an important factor in the process of designing foundations on soil and it depends upon shear strength parameters C and Phi. The large part of the Maharashtra state is having black cotton soil which is vulnerable because of the fluctuation in water content in it. Due to the expansion and contraction property of black cotton soil, the shear strength varies with variation of water content. This research, it is focused to find the effect of moisture content on the shear strength of black cotton soil. The undisturbed samples of black cotton soil are explored from the site from desirable depth using the drilling machine. On explored samples, various field and laboratory tests are performed to find the strength parameters of the soil at different water content. This study gives different values of shear strength in black cotton soil with variation in moisture content. From the work, it has been seen that there is increase in the shear strength in the initial stage as water content an increased, later increase in the water content causes a decrease in the shear strength of black cotton soil. It indicates that, optimum water content should be maintained in the foundation soil to avoid excess settlement of foundations in soil.
Dimensional structural mass optimization of forged steel connecting rod for aircraft piston engine
Authors: Helal M , Felemban B F , Alharthi A , Almalki S , Fathallah E , Elsherbiny A A , Eleashy H
Published: August 2021

The connecting rod is an important component of the engine. It conveys the kinetic energy from the piston to the crankshaft. All cars and aircraft engines contain at least one connecting rod, which differs from one motor to another in terms of length, size and shape. Hence, it is subjected to massive alternating load. This research aims to improve the connecting rod design by reducing its mass without sacrificing durability and safety especially for aircraft applications. Therefore, a static stress analysis is carried out on forged steel connecting rod using ANSYS APDL. Geometric modelling of the connecting rod was created using ANSYS APDL. Additionally, von-Mises stress and strain, principal stresses and strains, shear stress and the deflation results of the connecting rod are investigated. The results showed a great opportunity for mass weight reduction. Thus, a dimensional structural mass optimization was performed. The optimization results were promising, which reduced the mass by 55.13% (in the tensile case) and 56.7% (in the compression case) from the initial design. Therefore, the efficiency of aircraft engine can be maximized.
Vibration analysis of composite wing with geometric and material coupling
Authors: Magdy A , Kamel M , Elshafei M A , Kassem M
Published: August 2021

Composite wing design is complicated but inevitable to enlighten modern airplanes while maintaining the required performance. Using the dynamic transfer method, this paper discusses intensively the dynamic characteristics of a cantilever composite wing with both torsion and bending coupling to represent both material and geometric coupling. The governing differential equations are obtained based upon the principle of Hamilton and are solved analytically using a harmonic oscillation assumption. For this purpose, a MATLAB code is developed and results are validated in comparison with published work. Such a comparison shows a good agreement between both results. Finally, a parametric study is carried out to show the influence of the variation of both geometric coupling and torsion bending coupling rigidity on the free vibration analysis of the composite wing. The study shows the crucial effect of both factors on the dynamic behavior of the composite wing. The current research can be considered as a base for aeroelasticians while designing composite structures.
Stress analysis of multi-layered composite cylinders subjected to various loadings
Authors: Elgohary M H , El-Geuchy M I , Abdallah H M , Sayed S S
Published: August 2021

Composite cylinders are widely used in many applications, common examples for these applications are power drive shafts, chemical storage tanks, rocket motor cases and pressure vessels used in aerospace vehicles. The structure of the composite cylinder can be represented as a cylinder composed of coaxial orthotropic layers. In this paper, an analytical method is used to calculate stresses, strains and displacements through the wall thickness of multi-layered composite cylinder made of orthotropic material. The method is based on the theory of elasticity of bodies having cylindrical anisotropy. This method permits accurate stress analysis of thin and thick-walled composite cylinders subjected to axial load, torsional load and bending moment. The analytical method is modified to incorporate internal and external pressure loads beside the prescribed load cases. A numerical example is presented for a composite cylinder subjected to internal pressure load with a tensile axial load. The resulted stresses and strains are used to validate 3-dimensional finite element model. A parametric study has been performed using the analytical method to investigate the influencing parameters on stress distribution within the cylinder thickness and the results are found to be beneficial to look into during the preliminary design phase.
A satellite-based quantum key distribution using decoy-state protocol
Authors: Sofy A M , Shalaby M Y , Dahshan H M
Published: August 2021

An ideal QKD implementation that provides the promising unconditional security using single photon laser source is not practically easy, also sending these photons over a fiber channel affects the maximum distance of link up to few hundreds of kilometers because of the receiver’s detectors losses. Therefore, the achievement of a global quantum network is not easy, and the need to use LEO satellites [1,2] for establishing quantum links makes the job easier as quantum free space link provides much less losses to the link than fiber links. Nowadays, a quantum communication link can be established by satellites through free space. in this paper, we propose an implementation [3] of a satellite-based quantum key distribution using decoy-state protocol [4], we then compare this protocol with the BB-84 protocol [3] against security and the key length of the generated shared key.
SAR image formation enhancement using effective velocity estimation method
Authors: Fouad M A , Azouz A , Mashaly A A , Abdalla A E
Published: August 2021

Synthetic Aperture Radar (SAR) presents powerful tools for grounding mapping and remote sensing applications. Effective velocity is a vital index that controls the quality of SAR image formation. An accurate calculation of effective velocity provides a particular value of azimuth frequency modulated (FM) rate. The resultant azimuth FM rate could be used to produce a focused SAR image with sharp details. In this paper, SAR image formation enhancement is proposed using two guided methods based on precise effective velocity estimation. Firstly, effective velocity is estimated based on Sentinel-1data parameters extracted from selected image raw data. Secondly, an iteration method applies output image contrast, sharpness and entropy measurements to estimate the optimum value of the effective velocity based on the initial velocities calculated in the first method. Results are compared with extracted SAR images ignoring the effect of the effective velocity, to identify the performance of the proposed methods.
Frequency analysis of SAR system design for small satellite
Authors: Douidar I , Safy M , Saleh A
Published: August 2021

Great interest is given in recent years to the small satellites as their main advantages are the low development cost and the reduced deployment time, which give attention to develop payloads that can be mounted on the platform of these satellite. the platform of small satellites imposes constraints on the sensor design to fit in the size, mass and power limitations, which leads to necessary trade-offs between the design parameters of the sensor. The selection of the operating frequency is dependent mainly on the mission requirements as each frequency band gives different information about the scene and has different penetration capabilities. However, the SAR sensors used on small satellites come with limitations, so other parameters should be considered during the design. After going through the SAR design process, a frequency analysis is presented at L, C and X bands, which is used to evaluate the effect on the size of the antenna (length and width) and the average power consumption that suit the constraints of small satellite.
Updating land use and land cover classes of Blue Nile basin using landsat-8 images
Authors: Shobary A S , Elsharkawy A , El-Hanafy H E M , Moussa O M
Published: August 2021

Land Use and Land Cover are considered as a main input layer for the estimation of surface runoff along with the soil maps, rainfall data, DEM. The main purpose of this research paper is to update the Land Cover and Land Use of the Blue Nile basin that can be used for further processing to estimate the surface runoff of the Blue Nile basin. Recent satellite images of Landsat 8, dated May and June, 2020, were used with less than 10% clouds covering the full scene of the study area. Six land cover classes were targeted namely; water, urban, barren land, forest, grass and agricultural crops. Supervised (maximum likelihood) classification method was used and accuracy assessment with the help of google earth as ground truth was performed. With the aid of 30-m DEM, the Blue Nile basin was divided into fourteen sub-watersheds. Classification scheme was applied to each of the fourteen sub-watersheds and the classification results were introduced as a percentage of the total area of each sub-watershed. Moreover, confusion matrices were formed for the sub-watersheds.
Hybrid fusion using Gram Schmidt and Curvelet transforms for satellite images
Authors: Hammad M , Ghoniemy T , Mahmoud T , Amein A
Published: August 2021

Optical satellites generally provide high-resolution panchromatic but low-resolution multispectral images which provide structural details of features and spectral information respectively. Nowadays, fusion of the two types of resolutions, to have complementary information, becomes increasingly essential for many applications such as microscopic, astronomical and satellite imagery. In this paper, a novel hybrid pixel-level image fusion method is proposed for benefiting from both panchromatic (PAN) and multispectral (MUL) images. The proposed method integrates Gram Schmidt (GS) and curvelet transforms (CVT), by the aid of local energy and maximum fusion rules, for reducing individual method limitations and achieving both better spectral consistency and spatial details preservation. After a pre-processing stage, orthonormal bases are obtained for low spatial resolution images by using GS transform. Then, high-resolution and low-resolution images are fused using CVT by the aid of histogram matching. Finally, the fused image is obtained by applying both curvelet and GS inverse transforms. The performance of the proposed method is evaluated using publicly available Pleiades benchmark-datasets. Consequently, the spectral and spatial qualities of the fused images are assessed subjectively as well as objectively using different quality metrics. Moreover, the proposed method is compared with state-of-the-art fusion techniques and results show the robustness of the proposed method that has the best result in spatial and spectral evaluation metrics such as, Quality with No Reference (QNR), Peak Signal to Noise Ratio (PSNR), Standard Deviation (SD), Entropy (ENT) and Spectral Correlation Coefficient (SCC) metrics.
Output power boosting of a photovoltaic panel based on various back pipe structures: a computational study
Authors: Bayoumi A , Abdo G M , Emara A A
Published: August 2021

The efficiency of photovoltaic panels (PV) drops due to the rise in temperature, which leads to a decrease in the PV output power. A PV/Thermal system is therefore used as a solution to increase the output power from the PV panels. Comsol Multiphysics software program, a simulator-based Finite Element Method (FEM) tool, and Matlab program simulations are used to perform this electro-thermal model. The simulation process for different back pipes follows a serpentine, and a new shape of pipes called (square shapes) which are attached under the PV module. These shapes were specifically chosen for higher conversion efficiency and increase the heat transfer of the system. Additionally, a comparison between electrical parameters and heat transfer characteristics of water and CuO/water nanofluid in a PV cooling system has been studied. The new shape leads to improve the photovoltaic (PV) module parameters, such as short circuit current ISC, open-circuit voltage VOC, and maximum power Pmax for a new shape more than the serpentine shape. These parameters are calculated under Air Mass 1.5 G (AM1.5G) with 1000 W/m2 of irradiance which is considered the average irradiance at the MENA (The Middle East and North Africa) region throughout the year. The results exhibit the PV module’s total enhancement by using the new shape with CuO nano-fluid about 24.7 %.
Numerical investigation of four photovoltaic/thermal integrated structures from energetic point of view
Authors: El-Hamid M Abd , Moustafa S , Wei G
Published: August 2021

Photovoltaic/Thermal (PV/T) module is considered to be one of the most recent technologies which offers harness and production of both electric and thermal energy. In the current study an energetic analysis is carried out to compare between four different configurations which are: the single pass single glazed (PV/T-I), the single pass double glazed with air gap (PV/T-II), the single pass double glazed with argon gap (PV/T-III) and the double pass double glazed (PV/T-IV) hybrid photovoltaic/Thermal air collector systems. A 3 dimensional numerical model is built up and validated with both the numerical and experimental results coming from the literature. The numerical simulations have been accomplished to investigate the energetic performance with a detailed thermal and electrical study taking in account an inlet coolant temperature the same as the ambient temperature for a coolant (air) mass flow rate equals to 0.025 kg/s of a typical day in August from 9:00 to 17:00 under the ambient conditions of Beijing, China. The results show that the single pass single glazed configuration has the highest electrical efficiency, whereas the double pass configuration has the greatest thermal and energy efficiencies among the proposed configurations. The average daily energy efficiencies are 53.14%, 75.92%, 77.63% and 82.19% for the (PV/T-I), (PV/T-II), (PV/T-III) and (PV/T-IV) configurations, respectively.
Comparison of dust and high-temperature effects on mono and poly photovoltaic panels
Authors: Elshazly E , El-Rehim A Abd , El-Mahallawi I
Published: August 2021

Solar Photovoltaic Panels are considered as one of the most powerful alternative renewable and sustainable energy sources. However, a major challenge is the effect of dust accumulation on the photovoltaic panels in natural outdoor environment as it reduces the transmissivity of the light on the surface of the solar panels. For many small communities, the decision of implementing mono or polycrystalline PVs should consider economic aspects. This study is a case study that is held at The British University in Egypt at El Sherouk city to study the effect of different parameters such as dust accumulation, water cooling and coating on the performance of both mono- and poly-crystalline panels at El-Sherouk City. The effects of high temperature and dust accumulation on different solar panels placed in natural outdoor conditions at El-Sherouk City are studied and the electrical performance of the solar panels is represented by measuring several characteristic parameters of dusty and cooled PV panels compared to cleaned and non-cooled panels. The effect of the tilt angle on the accumulation of dust on the surface of the solar panels is, also, studied. The mono-crystalline solar panels are installed at tilt angles 0°, 15°, 30°, 45°, and 60° for one month without cleaning, by any method. The results shows that the power reduction percentage is 17%,20%,25%,27% and 30% for tilt angles 60°,45°,30°,15° and 0°; respectively. Tilt angles 15° and 30° show to be optimal for the installation of the PV solar system, as they produce the highest amount of output power. It is found from the study that the accumulation of dust on the surface of different types of solar panels can reduce the efficiency by 30%. While the high temperature can reduce the efficiency by up to 10 %.
Parametric optimization of non-prismatic micro-plates to reduce stiffening and curling initiated during fabrication
Authors: Bakeer B , Elsabbagh A , Hedaya M
Published: August 2021

Microelectromechanical devices such as accelerometers, gyroscopes, pressure sensors, and radiofrequency (RF) switches are widely used in aerospace applications. Reduction of stiffening and curling initiated during fabrication of these devices is one of the challenging issues in MEMS design. Reducing response time is also favorable in some applications such as RF MEMS switches. This paper aims at reducing stiffening, curling, and increasing the natural frequency for three well-known designs of micro-plates with fixed-fixed supports. To achieve these objectives, a parametric size optimization is carried out. For comparison purposes, same volume is set as a constraint for all three designs. Compared to conventional rectangular micro-plate, a reduction of 34% in stiffening in design 2, and 44% in curling in design 3. Design 1 showed the maximum fundamental natural frequency. Thus, it is predicted to have the lowest switching time. Moreover, design 2 showed the maximum critical buckling temperature, extending the operation range of the device. The effect of changing micro-plate material is also studied in this paper.
Factors affecting Failure mode and load of rubber polyester composite joint
Authors: Mousa B H , Azab N A , Bassioni G , Abdellatif M H
Published: August 2021

The joining of rubber polyester composite is affected by design and geometry parameters. These parameters affect the failure load of the composite joint and the failure mode. Catastrophic failure modes should be avoided, and the optimum parameters are selected to achieve a progressive failure that could be observed. Geometry parameters such as the edge distance and the center distance between holes are tested under tensile loading to get the optimum values. Design parameters such as tightening torque of bolt and washer size are also tested under tensile loading, and their effect on the failure load is obtained and studied. The failure modes are investigated under the digital microscope in each case. It is found that the failure load increases by increasing the edge distance, the tightening torque, and decreasing the center distance between holes. The optimum washer size is varied according to the used tightening torque. The optimum obtained failure mode in tests is a mixed - mode of bearing and net tension modes.
An investigation of plasma sprayed nickel-based and pure aluminum coatings on austenitic stainless steel AISI 304
Authors: Hamed K. , El-Mahallawy N. , Mokhtar M.O.A.
Published: August 2021

Atmospheric Plasma Spray (APS) is one of the most leading industrial techniques for protective coating, by improving the performance of parts in the thermal barrier, and wear resistance. Ni-Al alloys are very effective players in the field of design of protective coatings. Accordingly, mixed Al, Ni/Al, and Ni5Al powders were applied on 304stainless steel substrate to develop plasma sprayed coatings. The effect of different compositions on microstructure, microhardness, and porosity was measured. The microstructures of the as-deposited films were characterized utilizing X-ray diffraction (XRD), scanning electron microscopy (SEM), and microhardness measurements. The results showed the formation of two intermetallic compounds, namely: NiAl and Ni3Al. The existence of NiAl is inevitable in all samples, despite the amount of Ni-based alloys in mixtures, or even the atomic percentage of nickel, where the appearance of Ni3Al depends only on increasing the amount of the Ni-based alloy to 50 % percent in mixtures. As regards the steel substrate, the microhardness of the interdiffusion zone of the substrate has been significantly enhanced. Results have shown that the microhardness of the different tested coatings is increased directly with the increment of Ni-based percentage in the coating mixture. The average porosity of the plasma sprayed coatings has proven to be within the normal range.
Studying the distribution of hardness values in friction drilled 7075 Al-alloy sheets at different conditions
Authors: Hamzawy N , Khedr M , Mahmoud T S , Ei-Mahallawi I , Khalifa T A
Published: August 2021

The thickness of sheet metal parts can be locally increased by friction drilling technology via forming of a hole with a bush by a special drilling tool. Here, a 7075 Al-alloy was drilled by friction using tool cone angles with values of 40, 45 and 50° under different feed rates (100, 200 and 315 mm/min) and rotational speeds (1000, 1250 and 1600 rpm). The present study investigates the hardness distribution in the thermally-formed bush and in the heat-affected zone around the bush. It was found that the hardness of the bush was slightly increased with increasing of the tool cone angle and reduction of the tool rotational speed. However, the hardness of the thermally-induced bush showed values lower than the parent metal. The hardness near the drilling surface was approximately 65±10 HV, while it recorded hardness values of 75±10 HV at 5 mm away from the drilling surface. In addition, the microstructure of the friction drilled specimens showed a very fine structure in the drilling zone due to crushing of the original structure during the friction drilling process.
Low thermal emissivity coating based on aluminium / acrylic composite coatings
Authors: Ateia E E , Metwaly M A , Tantawy H R
Published: August 2021

Low emissivity coatings were synthesized by using fine flake Aluminium (Al) powder as a filler within acrylic resin to from the desired composite coatings. In the current work, ball milling was applied to prepare Al with different shapes and sizes. The technical parameters of prepared Al powders with respect to the initial raw Al are characterized by scanning electron microscope (SEM), X-Ray diffraction (XRD), and Energy Dispersive X-Ray Analysis (EDX). Moreover, parameters that affect the emissivity of the coating was investigated; such as coating thickness, particle size, spin coating, ball milling time and the content of coated Al powder. The thermal signature is highly affected by the variation in Al content (5%, 20%, 25%, 35%, 40% and 60%) at different temperatures (50°C, 70°C, 90°C). The results indicate that the perfect percentage for the filler (Al) in the matrix within the range (35 wt. - 40 wt. %) and Al fine flake powder particle, which gives the lowest infrared emissivity of 0.385 μm and 0.412 μm for (3-5) μm, (8-12) μm, respectively.
Enhancement of carbon fiber/epoxy composite electrical, optical and thermal properties by using different types of nano-additives
Authors: Bassiouny L , Samir T , Abdallah S , Ashour H , Anwar A
Published: August 2021

Environmental space threats are becoming more critical as they affect the optical, thermal, and electrical properties of the reinforced fiber polymeric-based materials in spacecraft. Three different Nano-particles Alumina (Al2,O3), Multiwall Carbon Nanotubes (MWCNT), and Reduced Graphene Oxide (RGO) were added to the epoxy matrix and then reinforced by bidirectional carbon fiber plain to form carbon fiber/epoxy by hand lay-up using autoclave curing technique to make three different reinforced materials. In this paper, the electrical, optical, and thermal properties of the carbon fiber/Epoxy Nanocomposite were studied.

Fourier transform infrared (FTIR) was performed to evaluate the structural changes in the newly synthesized materials. The optical, thermal, and electrical properties were tested by UV-visible Spectroscopy, Photo-acoustic spectroscopy (PA), and Keithley 2635A respectively. The results showed an enhancement in the electrical, optical, and thermal properties of the epoxy matrix after the addition of Nano-particles.

The optical test showed that the neat epoxy and epoxy/Nano-particles absorption spectra were in the infrared range. The thermal test indicated that the three thermal parameters diffusivity, effusivity, and conductivity showed the best enhancement after the addition of MWCNTs. The electrical test pointed out that after the addition of Nano-particles, neat epoxy changed from an insulating material to a semi-conductive material.
Investigation of foamcrete mechanical and physical properties
Authors: Youssef T , Elsayed Y , Elsayed T A , Lawaty S M
Published: August 2021

Engineered Material Arresting Systems (EMAS) serve as a substitutional alternative/solution to airport runways when the Runway Safety Area (RSA) does not meet international Federal Aviation Administration (FAA) standards. The length of the runway can be shortened if an EMAS is installed on both ends of the runway. This paper provides experimental test results on foamcrete material used for such an important safety application. The objective of the paper is to present the required and measured properties of foamed concrete (density, compressive strength and water absorption) and results of an evaluation of a first phase of testing. In this study, a total of fourty eight mixes were conducted; yielding a range of densities, compressive strength(s) and water absorption characteristics that are: 554 to 1528 kg/m3, 1.1 to 21 MPa and 7.4 to 28.3 %, respectively. It is demonstrated herein – though the Analysis of Means statistical method – that foam volume is predominantly the main factor affecting the observed output characteristics. This is followed by Sand/Filler and Filler/Cement that yield marginal effect compare to the former foam volume ingredient.
Enhancing the propulsion characteristics of rockets by adding the energetic Nitro-hydroxyl-terminated polybutadiene (NHTPB) in the propellant compositions
Authors: Azazy A , Saleh A , Aly W F , Elbeih A , Hussein A K , Elshenawy T , Abdelhafiz M , Wafy T Z , Zaki M. G. , Ahmed H S
Published: August 2021

Replacing the inert binder by an energetic one could increase the specific impulse of the propellants and enhance the propulsion characteristics of rockets. In this study, Nitro-b
hydroxyl-terminated polybutadiene (NHTPB) was prepared by a simple method. The prepared NHTPB in addition to HTPB binder were characterized. FTIR spectra of both HTBP and NHTPB was determined and compared. The thermal behavior of the prepared NHTPB was studied using DSC technique at heating rate 5 degree/min. A composite propellant based on AP/NHTPB was prepared and the specific impulse was measured for AP/NHTPB using two inch motor. It was concluded that the energetic nitro-hydroxyl-terminated polybutadiene has a clear max. exothermic peak at 203 °C with heat release of 323 J/g. By comparing the results, the prepared propellant AP/NHTPB has specific impulse higher than the traditional AP/HTPB propellant. NHTPB is a promising binder for the application of rocket propellants and needs more tests for its approval.
Acoustic threat detection and direction finding system
Authors: Abdallah A , Tork H
Published: August 2021

In this paper, an acoustic threat detection system is investigated as preliminary study of one of the anti-terrorism systems. The proposed system is a prototype of acoustic threats detection, classification, and direction finding system. For this purpose, an experiment is performed to test the capability of a proposed warning system to perform the task accurately. The direction of the sound source is determined by means of two microphones. The angle to the acoustic threat is calculated based on time difference of arrival (TDOA). The limitations of the system are discussed and some possible solutions are introduced to improve the performance of the system.
Tactics Overview for Implementing High-Performance Computing on Embedded Platforms
Authors: Elshazly A , Elliethy A , Elshafey M A
Published: August 2021

Future space missions will rely on novel high-performance computing to support advanced intelligent on-board algorithms with substantial workloads that mandates firm real-time and power constraints requirements. Consequently, these advanced algorithms require significantly faster processing beyond the conventional space-grade central processing unit capabilities. Moreover, they require careful selection of the target embedded platform from a diverse set of available architectures along with several implementation tactics to map the algorithms to the target architecture to fully unlock its capabilities. In this paper, we present a study of different architectures and embedded computing platforms for the satellite on-board computers. Moreover, we present a comprehensive overview of recent implementation tactics such as source code mapping and transformations. Additionally, we highlight some optimization techniques such as partitioning and co-designing using hardware accelerators. Finally, we discuss several implementation analysis methodologies to derive optimized code implementations. The top ranked YOLO-v3, as a deep learning based object detection algorithm, is selected as a case study model to be optimized using OpenVINO toolkit. The experimental results show an improvement ratios up to 73%, 41%, and 34% in terms of frames per second, CPU utilization, and cache memory, respectively. The study presented in this paper aims to guide the researchers in the field of high performance embedded computing in terms of different hardware architectures along with several implementation tactics.
Modelling and simulation of two axes gimbal fuzzy PI stabilization system in the presence of feedback sensors noise
Authors: Fathi A , Kamel A M , Elfarouk A O , Elhalwagy Y
Published: August 2021

The missile guidance in terminal phase is an optimization problem as the miss distance should be minimized. The optimization of missile miss distance is highly affected by the missile seeker performance. Design of gimbal control system suffers always from feedback sensors noise which leads to system instability. In this paper, a promising design of the fuzzy PID controller for a missile seeker gimbal is proposed considering the feedback sensor noise with practical gyro transfer function calculated based on real experimental measurements utilizing MATLB system identification toolbox. Also, the mathematical model of two stabilized axes gimbal. Stabilization is achieved considering the missile motion parameters such as rates, torques and coupling between yaw and roll channels. A Matlab simulation is carried out for evaluating the proposed system modelling and to test the robustness of the fuzzy PID controller in the presence of feedback sensor noise. A comparative analysis with PI based controller is conducted to evaluate the performance of the proposed controller which presents sufficient enhancement to the missile gimbal stability parameters.
Performance comparison among popular implementations of H.264 encoders
Authors: El-Arsh H Y , Elliethy A S , Abdelaziz A M , Aly H A
Published: August 2021

Remote sensing videos captured by Unmanned Aerial Vehicle (UAV) air-born high-resolution cameras require an efficient compression scheme that preserves the details of the visual contents of the videos while reducing the total size of the data to be managed in real-time. This paper presents a detailed comparison between different open-source implementations for the H.264 video compression scheme. While the high-resolution videos allow analysts to extract more descriptive interpretations and draw more conclusive results, the increase in the consequent data size consumes more storage, resulting in more channel bandwidth, more power, and encounters an extra delay in transmission time. An efficient implementation of video compression can alleviate these large data size effects. In this paper, we analyze and compare the JM-encoder, the X264, the FFmpeg, and Cisco’s OpenH264 open-source implementations in terms of compression efficiency, video quality, and computational load. Moreover, we present the rate-distortion curves in terms of PSNR as a quality metric against the bit-rate for a combination of 20 videos with various resolutions and dynamic contents. Albeit H.64 is superseded by H.265, till now H.264 is used in more than 65% of video coding applications. For example, YouTube only allows H.264 for live streaming.
Modelling and transient response study of hydraulic servo actuator
Authors: Ibrahim E E , Elnady T , Saleh I , Hassan S
Published: August 2021

This paper presents a mathematical model of electro hydraulic servo system (EHS) using two-stage electrohydraulic servovalve (EHSV), by the aim of Matlab-simulink-simscape multibody to predict the flow characteristics (pressure/flow rate) with changing the parametric configuration of (EHSV), these parameters could be used to estimate the error at different operating conditions. It includes establishing mathematical model, controller model and validating the performance of the (EHSV) by experimental result of published work using the data of servovalve labelled B.31.210.12.1000.U2V (mechanical feedback) manufactured by PPT - Trstenik. The effect of changing servovalve orifice diameter (0.25, 0.30, and 0.35) mm, show that increasing the orifice diameter of the servovalve leads to increase the transient time but decrease the system overshoot. The pressure behaviour is plotted and shows that increasing the orifice diameter leads to increasing the pressure inside the system as to reach the relieve pressure.
Formation configuration of unmanned cooperative quadrotors via PID tuning approaches
Authors: Mahfouz M , Taiomour A , Ashry M M , Elnashar G
Published: August 2021

Formation configuration is one of the major intrinsic strategies used in cooperative Unmanned Air Vehicles field. In this paper, Backstepping-PID control technique for cooperative quadrotors unmanned aerial vehicles are developed to solve the formation problem. The proposed controller is divided into couple of parts working together. Backstepping controller is used to stabilize the position control as a higher controller. Simultaneously, PID controller receives the desired position to stabilize the attitude control as a lower controller to track the desired planning trajectories. The main contribution of this paper is using Fraction Order Approach, and Local Optimal Approach to refine the PID lower controller gains. The tunning of the PID gains through the proposed PID tuning approaches guarantee the stabilization of the attitude control for all the team members. Simulation results present the success of the proposed PID tuning approaches in solving the formation problem for cooperative unmanned quadrotors tracking a desired path. Moreover, the simulation results present the ability of the proposed approaches to handle disturbance rejection and noise attenuation while preserving the stability of the system.
Impact of nozzle profile on ballistic performance and structural loads
Authors: Saleh M , Saleh S , Zayed A , Ahmed M Y M
Published: August 2021

A nozzle is a device that is designed to regulate the direction and characteristics of the combustion gas products of jet engines. So, the nozzle performance has a significant impact on the mission achievement. This paper is concerned with the internal ballistics of the nozzle aiming to estimate pressure and thermal loads on its walls. Computational fluid dynamics is applied to analyse the effect of changing nozzle internal profile on the resulting thrust, flow energy losses, and nozzle wall structure. Area ratios at the inlet, critical, and exit sections are considered as constraints for the examined design. Two different sets with 4 different profiles for each are investigated. The results show thrust, entropy losses across the nozzle and the static pressure and temperature at nozzle wall. Bell shape profiles produce better performance compared to other profiles. Changing the internal profile of the nozzle causes significant change in pressure and temperature loads acting on nozzle wall structure.
Parametric study of solid propellant slotted grain
Authors: El-Naggar M , Belal H , Abdalla H M
Published: August 2021

One of the goals in solid rocket motor design is to have as large volumetric loading as possible keeping the basic requirements unaffected. Slotted grain can achieve this goal as it has the advantages of sliver-free and no stress-concentration regions that occur in other internal burning grains as star grain and wagon wheel grain. It has the disadvantage of exposing the motor wall to hot gases. In this paper, the geometry of slotted grain is discussed and the effect of design parameters (e.g., number of slots, dimensions of the slot, etc.) of slotted grain on grain burn back is explained. Also, a comparison between results and experimental data is performed.