Military Technical College

A thiol-decorated MOF demonstrated excellent water stability and selectivity toward heavy metal uptake.

In the competitive shoe manufacturing industry, efficient production scheduling often struggles to balance minimizing makespan (MS) and reducing the number of cells, leading to increased complexity. This study introduces a biobjective optimization model to minimize the MS and the number of cells in a cellular manufacturing (CM) system. The model includes three phases: (1) a capacity phase calculates the required number of cells to meet the production demand within a suitable production rate; (2) a scheduling phase calculates the start and finish times for each product within a machine; (3) an optimization phase uses genetic algorithm (GA) for generating a set of optimal solutions considering the workforce distribution and product sequencing. The performance of the developed model was evaluated using a case study discussed in the literature to demonstrate its capabilities and highlight its superiority over similar models. These results showed a significant reduction of 0.4% in MS while maintaining the same number of cells compared to other models. A sensitivity analysis is conducted by varying the crossover and mutation probabilities. The findings indicate that the model achieves the most stable and consistent performance for paired crossover–mutation settings with crossover probabilities between 70% and 90% (corresponding to mutation probabilities between 30% and 10%), resulting in the lowest average MS and the most balanced cell utilization. The capabilities of the developed model provide production managers with reliable insights for identifying the production requirements of the shoe manufacturing company. The algorithm was also benchmarked on 12 published instances using 30 independent runs per instance to assess solution quality and stability.

The coverage area problem in Directional Sensor Networks (DSNs) presents several research challenges, including optimizing the number of active directional antennas and minimizing overlapping sensing area among them. In this manipulation, the problem of target detection and the overlapped coverage area where the target is located are solved by constructing a mathematical model with two different algorithms to precisely determine the location of a target detected with four directional antennas located in specific places on the ground with defined coordinates. The two models depend on the intensity of the power received by each antenna and accordingly a beam is constructed towards the target from each antenna with a known, calculated angle. Using these four beams, the area of the polygon in the first algorithm formed by the intersection parts between the coverage belt (the 4 beams) of the four directional antennas is calculated. And, an approximate confidence circle formed by the intersections of four virtual lines from the four antennas is calculated in the second algorithm where the target is located. A solved example is executed and examined to validate the model with two algorithms. Also, a C++ simulation is used to test the efficiency of the algorithms.

Re-entry vehicles (RVs) experience highly nonlinear and coupled dynamics during atmospheric flight, which complicates trajectory prediction and impact accuracy. This paper investigates the effect of terminal-phase control on re-entry vehicle performance through a comparative analysis of two cases: with and without terminal guidance and control. A high fidelity, six-degree-of-freedom simulation model is developed, incorporating realistic aerodynamic coefficients, atmospheric conditions, and actuator dynamics. For the controlled case, a terminal guidance law is applied to minimize position error and achieve a precise impact point. Simulation results show that the implementation of terminal phase control reduces the landing error radius from approximately 1.6 km to less than 30 m, achieving an improvement of over $98 \%$ in impact accuracy. Moreover, the landing footprint is reduced by about $60 \%$, with negligible effects on aerodynamic and structural loads. These results quantitatively confirm the effectiveness of terminal-phase control in improving both trajectory precision and stability. The study provides valuable insights for re-entry mission designers, demonstrating that terminal-phase control significantly enhances mission accuracy and reliability, particularly for precision landing and strike applications. Index Terms-Re-entry vehicles (RVs), Navigation Guidance and Control (GNC) and Circular Error Probable (CEP).

This study investigates sustainable rigid pavements using slag-based cement concrete enhanced with supplementary materials. Industrial slag, an eco-friendly and cost-effective by-product, partially replaced cement to improve strength, durability, and environmental performance. Thirteen concrete mixes were designed with varying slag contents (400–500 kg/m³) and fly ash replacement ratios (0–30%), along with nanomaterials (3% nano-silica, 10% silica fume, 3% metakaolin) and high-range water-reducing admixtures. Polypropylene fibers (1% by volume) were added to enhance crack resistance. Mechanical properties, including compressive, tensile, and flexural strengths, and durability indicators were evaluated. Results showed slag-based mixes outperformed conventional concrete, with nanomaterials and pozzolanic additives refining the microstructure, reducing porosity, and increasing flexural capacity.Rigid pavement slabs were tested under repeated impact loading using different reinforcement schemes. Slabs reinforced with Gavazzi glass fiber meshes, alone or combined with steel reinforcement, exhibited significantly higher impact resistance. The number of blows to first cracking increased from 2 in control slabs to 8 in reinforced ones, with minimal crack displacement (0.21 mm), and failure occurred after up to 70 blows, demonstrating high energy absorption. Numerical simulations using ABAQUS closely replicated experimental crack propagation, failure modes, and displacement, validating the model.Overall, integrating slag-based concrete with advanced nanomaterials and fiber reinforcement produces durable, high-performance, and sustainable pavements. Future work should explore long-term performance under varying service conditions.

This paper studies cognitive radio (CR) for aeronautical air-ground communications of the underlay mode, where secondary users (SUs) share spectrum with primary users (PUs) while controlling interference. Recognizing the rapid channel variations inherent to aircraft mobility, the analysis models outdated channel state information (CSI) and adopts Nakagami-m fading to capture line-of-sight and scattering effects typical of aeronautical links. The work formulates SU operation subject to simultaneous constraints on peak interference at the PU and reliability at the SU receiver, and derives closed-form expressions for the SU outage probability. The impact of CSI and fading severity on performance is characterized analytically and corroborated by Monte Carlo simulations, showing close agreement between theory and experiment. The results provide tractable performance benchmarks and design guidance for interference-aware SU power control in rapidly time-varying aeronautical environments, and clarify the conditions under which coexistence between primary and secondary systems remains feasible without compromising PU protection.

This paper presents the design and validation of a GUI thermal tool intended for the preliminary thermal analysis of CubeSats with both single and multi-node methodology approaches to enable fast assessment of the spacecraft thermal response due to numerous orbital scenarios. The main objective is to save both time for building a thermal model and the high cost of using a thermal analysis software license, which includes orbital parameter propagation, such as THERMAL DESKTOP. The results are verified using COMSOL Multiphysics and Thermal Desktop simulations and validated with experimental measurements from the Turk-Sat 3U Nanosatellite to confirm the tool's accuracy and reliability. Usage of this tool gives quick predictions for the CubeSats' temperature field with a deviation percentage of 1.03% in the hot case and 11% in the cold case relative to TURK-SAT 3U Nanosatellite measurements.

A lot of interest has been focused on carbon allotropes, especially graphene and reduced graphene oxide. This is due to their outstanding electrical and mechanical properties, which enable their use in many electronic applications. In this work, graphene and reduced graphene oxide (RGO) samples were prepared by different techniques. Graphene was prepared by a physical sputtering method, whereas RGO was prepared by the improved Hummer’s chemical method followed by chemical reduction. The prepared samples were characterized using Raman, X-ray diffraction, and energy-dispersive X-ray spectroscopy techniques. The graphene and RGO samples were qualified and compared to similar published works. A comparable quality factor value as high as 0.63 was obtained for the graphene compared to 0.09 for the RGO. The electrical conductivity of both graphene and RGO samples was also calculated from the I–V curves. A relatively high electrical conductivity of 153 S/cm was obtained for the graphene sample compared to 1.3 × 10–4 S/cm for the RGO sample. Graphene thin film shows higher electric conductivity relative to RGO thin film, which is in agreement with the proposed quality factor results.