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This research was devoted to the creation of a protection system for electric motors used in industry and transport, based on modern and traditional sensors. In the course of operation, the malfunctions of electric motors have been investigated and it was found that the accident modes occur mainly due to exceeding the permissible values of the current, voltage and temperature parameters. Modern sensors of current, voltage, and temperature have been compared and the most effective ones were selected for use in electric motors. Based on reasoning from these sensors, a protection system for a low-power electric motor has been developed in the laboratory. In addition, in the Multisim application software package, a simulation of the operation of the protection system at different voltage and current values was performed, and a circuit of the sensor control unit and the power source for powering the protection system was constructed. It has been proposed to apply such a multi-parametric complex protection system for electric motors, especially in transport.

As one of the hazardous and toxic solid wastes, spent catalysts need to be treated before the waste is discharged into the environment. One of the substances that need to be removed from the spent catalysts is the heavy metal ions and/or compounds contained therein. The method that can be applied is the extraction method using an acid solvent. In this study, the extraction process was carried out on spent catalysts samples from PT. Petrokimia Gresik. The focus of the study is on nickel extraction by varying the temperature in the range of 30–85 oC. A 1 M hydrochloric acid (HCl) solution was used as a solvent while the extraction process was 120 minutes. The experimental results show that the maximum nickel recovery of 14.70% can be achieved at a temperature of 85 oC. Kinetic studies were carried out using two kinetic models. The results of both models evaluation on the research data show that the lump model gives better results than the shrinking core model. The average error percentage of the lump model is smaller than the shrinking core model. It indicates that the extraction process was controlled by the diffusion step through the ash layer in the solid and chemical reactions simultaneously.

Equal Channel Angular Pressing (ECAP) is a promising severe plastic deformation technique that has gained significant attention for its ability to refine grain structure and enhance mechanical properties in metallic materials. This study focuses on investigating the impact of ECAP with route A and up to three passes on the mechanical properties and microstructure of 1050 aluminum. The study yielded compelling evidence of substantial enhancements in yield strength, ultimate tensile strength, and hardness. Specifically, these properties increased from 58.19 MPa, 67.06 MPa, and 23.85 HV in the annealed state to 133.02 MPa,141.21 MPa, and 38.96 HV after the third pass of the ECAP process, respectively. Furthermore, an interesting observation was made regarding the hardness ratio, which demonstrated a noticeable decrease with an increasing number of ECAP passes. This phenomenon correlated with a reduction in the size of dimples on the fracture surface. Microstructural analysis via scanning electron microscopy SEM confirms a significant reduction in grain size after ECAP passes, indicating the effectiveness of the process in inducing microstructural refinement. These findings collectively underscore the potential of ECAP with route A in enhancing the mechanical properties and microstructure of 1050 aluminum. This research contributes valuable insights into the application of ECAP with route A as a viable strategy for improving the performance of aluminum alloys.

The aim of this research is to provide bioclimatic design suggestions to improve the thermal comfort of people in hot and humid climates according to the BWh (hot desert climate) Köppen climate classification. The city of Minia is considered one of Egypt’s hot desert regions. This study considered two main variables to achieve thermal comfort according to air velocity and temperature. To select the best bioclimatic design tactic, the findings are reviewed and plotted on the Climate Consultant (CC) Bioclimatic Chart and the Mahoney Table (MT). The proposed procedures are presented as figures relating to the approaches and are examined independently. We conclude that specific bioclimatic design strategies have been applied through the extensive study presented in this paper for Minia City, which can be exported to other regions with comparable climates. These strategies are practically and effectively considered functional architectural approaches that can improve thermal comfort for people. The two tools CC and MT are compared based on 27 recommended strategies that can be achieved according to the bioclimatic parameters that were studied. They agreed with 30% as good natural ventilation, passive solar heating with a high percentage that reached 10% for each. Where there is a difference of 20 recommendations to 70%, this represents other factors or recommendations such as shading with which it is proposed in MT as well as other parameters.

As outcomes and survivorship improve, total knee arthroplasty (TKA) has expanded into broader age groups. The purpose of this study is to analyze the impact of age on TKA outcomes using the National Surgical Quality Improvement Program (NSQIP) database from 2015 to 2020. Patients were categorized into young (40–49 years), middle (50–79 years), and elderly (80–89 years) groups. Findings reveal notable differences across age groups. The young cohort had the highest BMI, smoking incidence, and steroid use, while the elderly group exhibited a higher prevalence of comorbidities. Young patients experienced shorter hospital stays (p < 0.001) but longer operative times (p < 0.001), and outpatient surgery was most common in the middle age group. Multivariable regression demonstrated that the elderly group faced increased risks of pneumonia (p < 0.001), acute renal failure (p < 0.001), stroke (p < 0.001), cardiac arrest (p < 0.001), and transfusions (p < 0.001), while both young and elderly patients had higher 30-day reoperation risks (youngest cohort, 1.4% and elderly cohort 1.3% (p < 0.001)). In summary, elderly patients undergoing TKA are at the highest risk for medical complications, while young patients are more likely to undergo inpatient surgery, experience reoperations, and have longer operative times. This study underscores the importance of age-specific counseling for TKA patients and contributes valuable insights into the evolving landscape of knee replacement surgery.

Understanding mechanism of users in responding determinant variables to use mode of transport is beneficial to anticipate the effect of policy. This study aims to identify the elasticity value of travel time and travel cost of the users of private vehicles and public transportation. Using data from users of private vehicles and public transport in Bandung, Indonesia, the elasticity of travel time and travel cost was calculated based on estimated multinomial logit model (MNL) logit. The elasticity was calculated based on gasoline prices, parking fees, transfer fees, access times, travel times, and waiting times. Based on the results of the elasticity values for travel attribute, it was found that in access time and travel time, Trans Metro Bandung (TMB) Bus had the largest elasticity of -0,564 and -5,001, respectively, so TMB Bus was the most sensitive to changes in access time and travel time. In terms of waiting times and fixed costs/gasoline, conventional taxi has the highest elasticity values of -2,630 and -1,604, respectively, so conventional taxi is the most sensitive to changes in waiting time and fixed costs/gasoline.

This paper is devoted to the development of an effective system for monitoring the technical condition of the axle boxes of rolling stock. To this end, the possibility of solving problems of fault diagnostics based on the theory of fuzzy sets is considered. This allows one note such difficult-to-formalise factors as experience and intuition of a highly qualified expert specialist. It showed that an expert system-based monitoring approach allows evaluation of the technical condition of the axle boxes, characterised by internal and external operating uncertainty. It also proposed the use of parameters such as vibration and noise for comprehensive monitoring of the technical condition of axle box units together with temperature. Furthermore, the combination of these diagnostic parameters and expert system’s possibility to receive all necessary information about the condition of the most critical components of the axle boxes in real-time and analyse the changes in their operational parameters was explored. The stages of modelling an expert system in the Fuzzy Logic Toolbox package of the MATLAB computing environment are presented.

The pollutants in biogas reduce its calorific value and limit its application in machines by causing corrosion and wear in metallic parts. The commercial technologies of biogas upgrade are expensive for small digesters. Natural adsorbents present cost-effective and locally available materials for purification of biogas but the process has not been satisfactorily investigated for most materials. The current study for the first time compared upgrading of biogas by removing CO2 contaminants with clay through dry adsorption and wet carbonation processes. Natural and modified clay was characterized using X-ray fluorescence. Biogas composition was analysed using gas chromatography and digital biogas analyser. The adsorption equilibrium, kinetics isotherm and breakthrough curves of carbon dioxide removal were investigated using CAVS adsorption software. The optimum slurry temperature and clay/water ratio for CO2 uptake by carbonation process were 75 °C and 1:3 respectively. The carbonation process resulted in pH decrease from 9.2 to 6. Furthermore, activation of clay using 2 M NaOH decreased the silica to alumina (SiO2/Al2O3) ratio from 11.2 to 8.5 and enhanced the CO2 uptake by more than 5 folds. The equilibrium and the kinetics data of CO2 removal by carbonation process fitted best into Freundlich isotherm and pseudo-first order equation respectively. In addition, the breakthrough curves for column adsorption fitted best into Yan model. The highest CO2 uptake capacity for modified clay was 5.72 mmol/g. Furthermore, complete removal of hydrogen sulfide was achieved. The CO2 uptake decreased on increasing the ratio of adsorbent mass to biogas volume. However, the CO2 removal efficiency increased to maximum of 93.8% at 7 g/l ratio. Therefore, modified clay is a potential candidate for biogas purification.

Al-Al2O3 and SiC metal matrix composites (MMCs) samples with different volume fractions up to 20% were produced by high-pressure torsion (HPT) using 10 GPa for 30 revolutions of Al-Al2O3, and SiC and powder metallurgy (PM). The effect of the processing method of micro-size Al MMCs on the density, microstructure evolution, mechanical properties, and tensile fracture mode was thoroughly investigated. HPT processing produces fully dense samples relative to those produced using powder metallurgy (PM). The HPT of the Al MMCs reduces the Al matrix grain size and fragmentation of the reinforcement particles. The Al matrix average grain size decreased to 0.39, 0.23, and 0.2 µm after the HPT processing of Al, Al-20% Al2O3, and SiC samples. Moreover, Al2O3 and SiC particle sizes decreased from 31.7 and 25.5 µm to 0.15 and 0.13 µm with a 99.5% decrease. The production of ultrafine grain (UFG) composite samples effectively improves the microhardness and tensile strength of the Al and Al MMCs by 31–88% and 10–110% over those of the PM-processed samples. The good bonding between the Al matrix and reinforcement particles noted in the HPTed Al MMCs increases the strength relative to the PM samples. The tensile fracture surface morphology results confirm the tensile properties results.

The motivation for the current study was to improve the wear and frictional properties of Al, Al–Al2O3, and SiC MMCs through HPT processing. The wear test using a tungsten carbide (WC) ball was carried out for different PM and HPT-processed Al and MMC samples. The effect of the sample processing methods on the wear rate, friction, and wear surface morphology was thoroughly investigated. The high hardness after Al grain refinement and reinforcement fragmentation through the HPT processing of the samples increased the wear resistance by 16–81% over that of the PM samples. The average coefficient values and variation ranges were reduced after HPT processing. The Al and Al MMC processing methods affected the wear mechanism and surface morphologies, as proven by the microscopic observations and analyses of the worn surfaces of the samples and WC balls.

In this paper, the signal flow graph technique and Mason gain formula are applied for extracting small signal model and transfer functions from control to output and from input to output. In order to investigate a rather complex system, a four quadrant dc-dc Luo converter known as a second generation and high order power electronic converter is chosen for modeling and analyzing purposes. This converter has received the least attention and its dynamic modeling and analysis is not reported in literature. To get rid of complex equations in modeling high order converters, signal flow graph method is applied to manipulate the equations. Hence, the small signal models for two converters in different states are derived in detail and the obtained models are used to achieve the frequency responses and do stability analysis. The whole paper shows that using the proposed method, derivation of small signal models for all states and frequency domain analysis can be easily carried out in detail. Keywords: Frequency response, Four quadrant Luo converter, Mason gain formula, Modeling, Signal flow graph

The influence of the number of passes and the tube materials on the microstructural evolution, mechanical properties, and wear behavior of Cu and brass tubes after parallel tubular channel angular pressing (PTCAP) was investigated. The grain size decreased to final grain sizes of 138.6 nm and 142.7 nm, after PTCAP of the Cu and brass tubes was conducted in up to 4 and 2 passes, respectively. PTCAP contributes to obtaining an ultra-fine grain (UFG) microstructure, with a mixture of different grain sizes that conferred high hardness. The present results indicate the superior wear resistance of Cu and brass PTCAP tubes, relative to Cu and brass samples that were previously deformed by different severe plastic deformation (SPD) processes. The wear mechanism of the Cu tubes changed from delamination and cracks with a high degree of adhesive wear before PTCAP into a combination of adhesive and abrasive wear, with a decrease in the presence of oxygen content after the PTCAP procedure. The wear mechanism also changed from a combination of adhesive and abrasive mechanisms into abrasive ones with the absence of oxygen after the PTCAP of brass tubes.

Commercial Al-brass tube was successfully processed by Parallel Tubular Channel Angular Pressing (PTCAP) in 2 passes under an imposed strain of 1.49 per pass. The effect of the number of PTCAP passes on the microstructure and the mechanical properties (hardness, tensile, and wear mass loss) of the Al-brass tubes was fully investigated. The average grain size of the as-received tube decreased to 1.28 μm after up to two passes of PTCAP with a mixture of ultrafine grain (UFG) and coarse grain (CG). The annealed tubes’ tensile strength and Vickers hardness increased by 237.65% and 175.6%, respectively, after two passes. In addition, a ductile fracture occurred with a clear necking. The fracture surface morphology indicated an apparent decrease in dimple size after PTCAP processing, combined with a decrease in ductility. Moreover, the wear mass loss decreased with increasing number of PTCAP passes due to the decrease in the grain size, and the increase of the hardness of the tubes was enhanced after PTCAP processing.

This paper reports a fundamental investigation consisting of systematic trials into the response of Ti6Al4V alloy to high-speed machining using carbide inserts. It is a useful extension to work previously published, and aims at assessing the impact of the process parameters, depth of cut, cutting speed and feed rate in addition to cutting length, and their interrelations, on observed crater and flank wear and roughness of the machined surface. The results showed that abrasion was the most important flank wear mechanism at high speed. It also showed that increased cutting length accelerated crater wear more than exhibited flank wear and had considerable effect on surface roughness. In particular, crater wear increased by over 150% (on average), and flank wear increased by 40% (on average) when increasing cutting length from 40 to 120 mm. However, cutting the same length increased surface roughness by 50%, which helps explain how progression of tool wear leads to deteriorated surface quality. ANOVA was used to perform statistical analyses of the measured data and revealed that cutting length and depth of cut had the greatest effect on both crater and flank wear of the cutting tool. These results confirm that high-speed machining of Ti6Al4V alloy is a reliable process, with cutting speed identified as having a relatively small influence on the tool wear and resultant roughness of the machined surface relative to other parameters.

In this paper, an experimental investigation into the machinability of AISI 316 alloy during finishing end milling operation under different cooling conditions and with varying process parameters is presented. Three environmental-friendly cooling strategies were utilized, namely, dry, minimal quantity lubrication (MQL) and MQL with nanoparticles (Al2O3), and the variable process parameters were cutting speed and feed rate. Power consumption and surface quality were utilized as the machining responses to characterize the process performance. Surface quality was examined by evaluating the final surface roughness and surface integrity of the machined surface. The results revealed a reduction in power consumption when MQL and MQL + Al2O3 strategies were applied compared to the dry case by averages of 4.7% and 8.6%, respectively. Besides, a considerable reduction in the surface roughness was noticed with average values of 40% and 44% for MQL and MQL + Al2O3 strategies, respectively, when compared to the dry condition. At the same time, the reduction in generated surface roughness obtained by using MQL + Al2O3 condition was marginal (5.9%) compared with using MQL condition. Moreover, the results showed that the improvement obtained in the surface quality when using MQL and MQL + Al2O3 coolants increased at higher cutting speed and feed rate, and thus, higher productivity can be achieved without deteriorating final surface quality, compared to dry conditions. From scanning electron microscope (SEM) analysis, debris, furrows, plastic deformation irregular friction marks, and bores were found in the surface texture when machining under dry conditions. A slight smoother surface with a nano-polishing effect was found in the case of MQL + Al2O3 compared to the MQL and dry cooling strategies. This proves the effectiveness of lubricant with nanoparticles in reducing the friction and thermal damages on the machined surface as the friction marks were still observed when machining with MQL comparable with the case of MQL + Al2O3.

This article presents the results of an experimental investigation into the machinability of Ti6Al4V alloy during hard turning, including both conventional and high-speed machining, using polycrystalline diamond (PCD) inserts. A central composite design of experiment procedure was followed to examine the effects of variable process parameters; feed rate, cutting speed and depth of cut (each at five levels) and their interaction effects on surface roughness and cutting temperature as process responses. The results revealed that cutting temperature increased with increasing cutting speed and decreasing feed rate in both conventional and high-speed machining. It was found that high-speed machining showed an average increase in cutting temperature of 65% compared with conventional machining. Nevertheless, high-speed machining showed better performance in terms of lower surface roughness despite using higher feed rates compared to conventional machining. High-speed machining of Ti6Al4V showed an improvement in surface roughness of 11% compared with conventional machining, with a 207% increase in metal removal rate (MRR) which offered the opportunity to increase productivity. Finally, an inverse relationship was verified between generated cutting temperature and surface roughness. This was attributed mainly to the high cutting temperature generated, softening, and decreasing strength of the material in the vicinity of the cutting zone which in turn enabled smoother machining and reduced surface roughness.

Several techniques for improving performance of reinforced concrete (RC) beam-column (BC) connections have been developed in last two decades, but these techniques have been criticized for being labourintensive and susceptible to premature de-bonding. To overcome these shortcomings, a novel technique utilising embedded steel bars has been developed in this study for strengthening seismically deficient RC BC connections. This technique involves drilling holes within the joint core. After the drilled holes are cleaned, they are partially filled with epoxy. Finally, steel bars are inserted in the epoxy-filled holes. Two exterior BC connections were constructed and loaded under displacement-controlled cyclic loading. The first specimen was a control specimen designed in accordance with the pre-1970s building codes to represent BC connections requiring strengthening. The second specimen was strengthened with eight 8 mm steel bars embedded within the concrete core in the joint area and epoxied to maintain the bond between the concrete and the steel bars. The strengthened specimen had superior performance compared to that of the control specimen in terms of joint shear stress, normalised principal tensile stress demand and stiffness degradation. The results show that shear stress of the joint was enhanced by about 8% whereas the enhancement in the principal tensile stress demand was 24% compared to that of the control specimen. The results showed that the proposed technique is capable in upgrading the seismic performance of seismically deficient RC BC connections.

Biological aerated filters (BAFs) are an emerging wastewater treatment technology designed for a wide range of municipal and industrial applications. This review paper presents and discusses of the influence C/N ratio, nitrification and denitrification principle, effect of pH, DO and alkalinity on the nitrification and denitrification systems, organic and hydraulic loading of BAF reactor, etc. Results from upflow and downflow biofilter pilot at different condition, with nitrification and denitrification are reviewed. Under the optimal conditions, significant amount of COD, ammonia-nitrogen and total nitrogen were removed. Removal rates based on reactor volume for different carbon-aceous COD and ammonia loading rate are reported. The BAF system for the nitrification and denitrification processes for carbon and nitrogen removal from the wastewater need to be evaluated and applied properly to protect of our environment and resources.

Recent technological advancements in wireless communications are fundamentally changing the manner by which devices communicates with one another. Modern wireless devices build networks on their own and aid each other in passing information to any device in the network. The aim of this research is to design and develop a robust routing protocol using network coding technique for Vehicular ad hoc networks (VANET). The purpose of the protocol is to disseminate vehicular traffic to the vehicles approaching the problem area, rather than those leaving the problem area. The designed protocol during the research will be more robust, reliable, and efficient with topology change. In this research, network coding and geographical routing models will be used to develop network coding based VANET routing protocol for alerting vehicles approaching the accident area and emergency message dissemination. The network coding model assumed will serve to increase throughput, in this sense reducing packet loss which will provide a robust broadcast routing protocol.

This paper investigates the development of swelling with time for a highly plastic and potentially expansive clay from Sudan. Soil samples were prepared in the laboratory at different moisture content values. The prepared samples were placed in the oedometer ring at three density levels and then placed in an oedometer cell which allows one dimensional swelling. Swelling was observed at different time intervals to 48 hours. The data was analyzed to determine the development of swelling with time. The data analysis clearly demonstrated three stages of swelling, initial, preliminary and secondary for all tested samples except the quasi-saturated ones. The swell percent and primary swelling were very sensitive to the initial moisture content and dry density of the tested samples. Most of the swelling took place during the first 24 hours for all the tested specimens. The hyperbolic model was assessed for prediction of the percent swell. The 12 hours data was found to be very successful in predicting the percentage swell.

Prestress losses in precast concrete beams include the short-term effects of elastic shortening and the long-term effects of concrete shrinkage, concrete creep and steel relaxation. Temperature effects are, however, excluded. The aim of this research was to monitor the behaviour of a prestressed precast concrete bridge beam, focussing on temperature effects and destressing. Successful monitoring assists in comparing the real performance of a structure to the expected design performance, and in managing the durability of the monitored structure. The effect of temperature variation on strains in prestressed beams was investigated by instrumenting a precast beam. Temperature and strains were monitored from the day of casting up to and including the cutting of the pretensioning strands. Daily temperature variations causing vertical non-linear temperature profiles resulted in internal strains of up to 28 % of the strains caused by destressing. It was therefore concluded that thermal effects before destressing resulting from elevated curing temperatures and daily temperature changes should be considered in the calculation of prestress losses. The monitoring techniques used were successful in determining the stresses and strains within the beam, which can be used to compare real prestress losses with the losses assumed in design.

Metalworking fluids, the class of lubricants most susceptible to microbial attack, metalworking fluid must also be safe for human use and exposure, The failure of the fluid to perform any of its functions has the potential to result in operational problems, process shutdowns, decreased tool life, and product-quality issues, all of which will result in increased costs. Perhaps one of the most common and controllable complications is microbial degradation specially standing from the fact that metalworking fluids contain the nutrients that can permit unchecked microbial growth. In this work we prepared Antimicrobial metal working fluid additive which fulfills the criteria of successful local production in Egypt, as the commercial availability of starting components, effectiveness of the prepared additive, easiness of addition and homogenization with other MWF additives, good environmental profile and biodegradability. The effectiveness of the prepared additive was evaluated by standard method ASTM E645-97 test. It was revealed that; the formic acid which condensate with the polyethylene glycol 400 and ethylene glycol had excellent antibacterial action, it could also greatly reduce growth of bacteria.

This study investigates the self-curing concrete using baby polymer diapers as substitute method of curing process in order to improve mechanical and physical properties of concrete. Three different proportion of baby polymer diapers which are 1%, 3% and 5% were mix with concrete. Slump, compressive strength and drying shrinkage test were performed in order to study the workability, strength and durability of the concrete. All concrete were tested for 1, 3, 7, 14, and 28 days for drying shrinkage test. Meanwhile, all concrete were test at 3, 7 and 28 days for compressive strength test. Compressive strength of concrete containing 5% baby polymer diapers show the highest strength at 28 days compared to others percentage. Thus, it indicates that application of baby polymer diaper as self-cure agent can improve the concrete performances.

This paper investigates the development of swelling with time for a highly plastic and potentially expansive clay from Sudan. Soil samples were prepared in the laboratory at different moisture content values. The prepared samples were placed in the oedometer ring at three density levels and then placed in an oedometer cell which allows one dimensional swelling. Swelling was observed at different time intervals to 48 hours. The data was analyzed to determine the development of swelling with time. The data analysis clearly demonstrated three stages of swelling, initial, preliminary and secondary for all tested samples except the quasi-saturated ones. The swell percent and primary swelling were very sensitive to the initial moisture content and dry density of the tested samples. Most of the swelling took place during the first 24 hours for all the tested specimens. The hyperbolic model was assessed for prediction of the percent swell. The 12 hours data was found to be very successful in predicting the percentage swell.

A digital SAR image from the Canadian satellite Radarsat covering the city of Riyadh, the capital of Saudi Arabia, was used to test the potential of spacebome SAR systems for mapping waste-disposal sites. A PCI software was used to perform the various image processing operations. The results show that high resolution SAR imagery from space platforms could be a viable tool for the inventory of waste-disposal sites. This is an important conclusion for a big city like Riyadh where disposed waste should be regularly monitored in order to compact its adverse effects on the environment. Keywords: Radarsat, Waste-disposal, Monitoring

A spaceborne synthetic aperture radar (SAR) image acquired by the Canadian Radarsat-1 system and covering the city of Riyadh was used to investigate the potential of satellite radars for population estimation. Eight districts with population known apriori were utilized for the purpose. A PCI version 10 software was used to delineate district boundaries and to measure their areas in kilometers. A mathematical relationship was then established between area of district in square kilometers and population in thousands using information from four of these districts. The derived equation was then used to compute the population of the remaining districts. Errors in estimated population figures were then computed and averaged. The results showed that high resolution SAR imagery acquired from spaceborne platforms could be used to derive information about population to an accuracy of ±17%. Although this figure is large compared with those obtained from aerial photography (±6% – ±10%), it still points to the fact that when it is impossible or uneconomical to use aerial photography, radar imagery provides rough information about population. This is a worthwhile conclusion in circumstances such as relief operations and studying effects of natural disasters where preliminary information is urgently needed for the sake of taking further remedial actions. Keywords: Population estimation, Radar backscatter, Photointerpretor

This paper describes formulations of plastic bonded explosives (PBXs) based on three highly brisant explosives, namely 1,3,5-trinitro-1,3,5-triazinane (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) and pentaerythritoltetranitrate (PETN) with polyurethane (PU) based on Glycidyl azide polymer (GAP) as an energetic binder in comparison with composition-B, which used in the fragmentation warheads. The sensitivity and performance properties of different types of PBXs were evaluated by experimental results of prepared selected PBX compositions. Casting technique was used to prepare the selected compositions containing 14% PU based on GAP. It has been observed that the brisance of the PBX based on HMX was higher than that of comp-B by 21.3 %, the detonation velocity showed a remarkable increase of the order of 8480 (m/s) while that of comp-B was 7638 (m/s). A controlled fragmentation warhead with an outer grooving warhead case of dimensions 100x35x4 mm was used and arena test was carried out to determine the lethal zone of the fragmentation warhead. The lethal zone obtained from arena test for PBX composition based on HMX named PBXHG4 was higher than that based on RDX or PETN, and than that of comp-B by 40%.

In the present investigation, we used two types of thermoset resins (epoxy resin and phenol formaldehyde resin) with carbon fiber (CF) to produce composite materials. CF/epoxy resin composite and CF/phenolformaldhyde resin composite were fabricated and compared between their mechanical properties as compression, tension and flexural. it was found that mechanical properties of CF/epoxy composite higher than mechanical properties of CF/phenolformaldhyde resin composite such as flexural strength of CF/epoxy resin composite increased by 30 % than flexural strength of CF/phenolformaldhyde resin composite, tensile strength of CF/epoxy resin composite increased by 11.4 % than flexural strength of CF/phenolformaldhyde resin and axial compression strength of CF/epoxy resin composite increased by 14.5 % than flexural strength of CF/phenolformaldhyde resin.

Egypt is ranked among the countries with the highest rates of road accidents. According to the American Chamber of Commerce more than 96% of Egypt's goods are transported by trucks and due to their large volume and excessive weight, the severity and number of truck accident fatalities are much higher than other vehicles in Egypt. The present study aims at identifying truck driver's behavior and its influence on crash involvement. Due to the shortage in recording accident data and the inaccurate road accident audit, data was collected from several governorates in Egypt through questionnaire. Questionnaire forms were filled out through personal interviews with truck drivers. The total number of respondents was 643. The final analysis was made on the 615 questionnaires with complete answers. The data was analyzed and logistic regression was applied to accident related data to examine the contributing factors affecting accident occurrence of truck drivers. Results showed that fatigue in terms of driving hours (continuous and total) and lack of sleep, drug use during driving, and driver obesity are the most influencing factors on the occurrence of truck accidents in Egypt. The findings of this research highlight the important role human factors have on the risk of crash involvement amongst Egypt's truck drivers and the need to improve their work conditions.

Deterioration of reinforcing concrete structures is a common problem among all the Mediterranean countries. To protect steel from corrosion, cobalt oxide with zinc oxide were successfully deposited on silica and alumina layer according to Core–shell theory. This theory based on depositing a surface layer of expensive efficient anticorrosive coating on a cheap extender expressing the bulk. The combination of both core and shell compounds led to the production of new coating with improved properties different from each of its individual components. These improved properties lead to change in the efficiency of protection properties of coating films containing these new coating. The objective of the present work is to prepare a new ecologically friendly natural and inorganic coating of Egyptian mix (kaolin and ceramic waste) and zinc phosphate as corrosion inhibitors based on the solid–solid interaction to protect steel from corrosion in buildings construction. The results revealed that these new coating gives the best results in protecting steel substrates from corrosion especial in aggressive environment.