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Until now many regions around the world are still uncovered by cellular terrestrial mobile system services due to the lack of economic feasibility as well as the difficulty of introducing such services. Conversely, a large geographic region can be covered by using only a single satellite, so it is worthwhile to extend the actual terrestrial services using satellite system. The new hybrid integrated “terrestrial-satellite” cellular system, known under the name of Non-Terrestrial Networks (NTN), will see the light with the support of future 6G technology. It is expected that 6G cellular mobile system will play the role of integrating terrestrial, aerial, maritime, and space communications into a universal network that could support a massive number of terminals with ultra-low latency. For the realization of the NTN system, new technologies should be introduced at the level of terrestrial cellular network, arial network, and satellite network. One of these promising technologies is represented by an efficient multiplexing technique known under the name of non-orthogonal multiple access (NOMA). With this technique, multiple users can be served on a single time-frequency resource block by using the concepts of superposition coding at the transmitter and successive interference cancellation (SIC) at the receiver. Moreover, NOMA has an achievable performance gain in terms of spectral efficiency over the traditional orthogonal multiple access (OMA) technique. Evaluation of a NOMA-based NTN system supported by 6G technologies in terms of system parameters and channel capacity represent the main objective of this paper.

The culture of active transportation (walking or cycling) in the Kingdom of Saudi Arabia (KSA) is less prevalent than in other societies. This study aims to understand the perceptions of people in the KSA about the role of cultural dimensions on active transportation. The study was conducted in Jeddah, prominent urban city in Saudi Arabia. The city suffers from rapid growth in vehicle users compared to active transportation. An online survey was employed with around 800 individuals participating from King Abdulaziz University. The results were analysed based on participants’ sex. Few participants reported walking as the mode of transportation from home to work/school and no participants reported using a bicycle as daily commute. Females identify societal tradition and norms as the main factors that impede their engagement in active transportation. Males, who were embarrassed to walk/cycle, defined clothing and social status as the main barriers. Most males and females identify climate (high temperature throughout the year) as one of the main obstacles to walk/bike. Significant social, environmental, and infrastructural predictors of participants’ modal choice were the distance from home to school/workplace, age, social values, family size, citizenship, and road safety.

The world witnessed significant economic growth due to the rapid recovery of businesses and industries in the post-epidemic era. Nonetheless, the problems of the emission of harmful gases, with all its attendant dangers, have recently attracted considerable attention. Using effective methods to accurately monitor these harmful gases is the first thing to be done for solving these problems. Within this work, by means of the first-principles density functional theory, a B3O3 monolayer (B3O3ML) gas sensor was introduced in order to monitor the harmful gas acetone (ACT). The negative adsorption energies of the complex of ACT/B3O3ML demonstrated that adsorption of the ACT molecules over the B3O3ML was favorable in terms of energy and the process of adsorption was exothermic. After the adsorption of ACT on the surface of the B3O3ML, there were noticeable changes in the electronic properties of ACT and in the density of sates. The recovery time of the B3O3ML for the detection of the ACT molecule was estimated to be 2.07 × 10−5 s, suggesting the rapid regeneration of the sensor at room temperature. Hence, the B3O3ML is a promising candidate for detecting the ACT molecule and will inspire experimentalists to design an efficient gas sensor.

This study presents a comprehensive analysis of the transmission dynamics of monkeypox, considering contaminated surfaces using a deterministic mathematical model. The study begins by calculating the basic reproduction number and the stability properties of equilibrium states, specifically focusing on the disease-free equilibrium and the endemic equilibrium. Our analytical investigation reveals the occurrence of a forward bifurcation when the basic reproduction number equals unity, indicating a critical threshold for disease spread. The non-existence of backward bifurcation indicates that the basic reproduction number is the single endemic indicator in our model. To further understand the dynamics and control strategies, sensitivity analysis is conducted to identify influential parameters. Based on these findings, the model is reconstructed as an optimal control problem, allowing for the formulation of effective control strategies. Numerical simulations are then performed to assess the impact of these control measures on the spread of monkeypox. The study contributes to the field by providing insights into the optimal control and stability analysis of monkeypox transmission dynamics. The results emphasize the significance of contaminated surfaces in disease transmission and highlight the importance of implementing targeted control measures to contain and prevent outbreaks. The findings of this research can aid in the development of evidence-based strategies for mitigating the impact of monkeypox and other similar infectious diseases.

This paper focuses on the impact of mosquito biting bias on the success of malaria intervention strategies. The initial model is developed considering the existence of symptomatic and asymptomatic humans, as well as vector bias. The model is then analyzed to demonstrate how the malaria-endemic equilibrium always exists and is globally asymptotically stable if the basic reproduction number is larger than one. On the other hand, malaria will always go extinct in the population if the basic reproduction number is less than one. For intervention analysis, the model is extended by considering mosquito repellent and hospitalization as control strategies. The control reproduction number is shown analytically. Using the Pontryagin maximum principle, we characterize our optimal control problem. Several scenarios are conducted to observe the dynamics of control variables under different circumstances. We found that the intervention of mosquito repellent and hospitalization together is the most cost-effective strategy to reduce the spread of malaria. Furthermore, we have shown that the more biased the vector attracted to infected individuals, the higher the cost needed to implement the control strategy.

يهدف البحث إلى بيان العلاقة بين تبني معيار (IFRS13) والهشاشة المالية ضمن القطاع المصرفي العراقي، وشملت عينة البحث التقارير المالية لبعض المصارف المدرجة في سوق العراق للأوراق المالية وعددها (14) مصرفاً وللفترة من (2016) لغاية (2021) لتكون عدد المشاهدات (84) مشاهدة، وقد اعتمد الباحثان في قياس القيمة العادلة معيار(IFRS13) على مقياسين هما الأهمية النسبية للقيمة العادلة لصافي الدخل، والأهمية النسبية للقيمة العادلة للدخل الشامل، أما الهشاشة المالية فتم قياسها بمؤشر(Z-Score)، وتوصل البحث إلى أن هناك علاقة إيجابية ذات دلالة إحصائية بين تبني القيمة العادلة معيار(IFRS13) والهشاشة المالية.

DFT calculations on sensor-drug interactions are necessary for understanding binding mechanisms, predicting sensor performance, evaluating stability and reactivity, and rational design of sensor materials. We scrutinized the adsorption of amphetamine (AFE) on the pure magnesium oxide nano-cage (MgONC) by applying density functional theory. All geometries and single point energy computations were optimized at M06–2X/6–311 G (d, p). Furthermore, we performed an analysis of the natural bond orbital (NBO) and evaluated the values of partial natural charges. Additionally, we investigated donor-acceptor (D-A) interactions and examined the Wiberg bond index (WBI) in greater depth. The MgONC was capable of adsorbing AFE with greater strength with the energy of adsorption (Eads) of −48.19 kcal/mol (for stable configurations). Moreover, the NBO method demonstrated more effective D-A interactions between AFE and the MgONC. Based on the computations, for the most stable configuration, there was a substantial alteration in the HOMO-LUMO gap of the MgONC following the drug adsorption, thus increasing the electrical conductance (EC) of the MgONC. The sensing mechanism is related to the gap difference, which depends on the change in the EC. We adopted the conventional transition state theory for the prediction of recovery time. The computations indicated that the MgONC+ AFE configuration had a short recovery time for the desorption of AFE. Finally, based on our findings, we could conclude that the MgONC is an appropriate choice for the improvement of effective AFE sensors. DFT study of drug sensors will focus on enhancing sensitivity, selectivity, and stability while exploring novel materials and optimizing performance through theoretical simulations and analysis.

The human body is a remarkably aggressive medium and applied materials must be extremely resistant to corrosion and destruction, so copper, which is a biological material and is widely used in medicine, is being considered. Copper corrosion may be associated with inflammation in body because it releases ions that are toxic to humans. In aggressive solutions, biomolecules called amino acids act as corrosion inhibitors. In the present research, the purpose is to study the inhibitory action of l-alanine (L-Ala) and l-Leucine (L-Leu) amino acids on the corrosion of Cu. By density functional theory (DFT), inhibition behavior of l-Ala-and l-Leu-and their conformers against Cu corrosion have been investigated. According to values of back-donation of electrons (Eback-d), fraction of electron transferred (ΔN), electrophilicity (ω), electronegativity (χ), softness (σ), hardness (η), energy gap (Eg), ELUMO, and EHOMO computed reactivity factors between copper surface and inhibitors are studied. l-Leu's theoretical indicators confirm its tendency towards adsorption. l-Leu-activity against corrosion has been investigated and favorable results have been obtained.