Search Results (92)

Background/Objectives: Military Service Members (SMs) require optimal nutrition to support health, readiness, and job performance. However, they often fall short of meeting nutrition guidelines. This study aimed to determine the impact and feasibility of implementing the U.S. Marine Corps (USMC) “Fueled to Fight^®” (F2F) nutrition program in non-appropriated fund (NAF) food venues. Objectives included evaluating changes in Military Nutrition Environment Assessment Tool (mNEAT) scores, feasibility of implementing and maintaining F2F strategies, and influence on customer purchasing patterns. Methods: Researchers conducted a pre-post interventional study from January to December 2024 at three NAF food venues across two USMC bases. F2F strategies, including identifying items using a stoplight color coding system (Green = healthy, Yellow = less healthy, Red = least healthy), menu revisions, food placement, promotion, and marketing, were implemented. Data included mNEAT assessments, sales reports, and stakeholder focus groups. Generalized Estimating Equations models were used to analyze sales data. Results: mNEAT scores increased across all venues post-intervention. Availability and sales of Green items increased, while sales of Red items decreased in some venues. Profit increased at all three food venues. Focus groups revealed feasibility and provided insights for future interventions. Conclusions: F2F interventions in NAF food venues are feasible and can positively impact the food environment and customer purchasing patterns without negatively affecting profit. This study highlights the importance of integrating nutrition programs into all military food venues, not just government-funded dining facilities, to support the nutritional fitness and readiness of SMs. Full article

This study evaluates the risk assessment and hazard identification of hydrothermal liquefaction (HTL)-derived bio-oil from the MARINES project, which converts military organic waste into fuel. The high oxygen content (35–50 wt%), acidic pH (2–4), and viscosity (10–1000 cP) of bio-oils pose unique challenges, including oxidative polymerization, corrosion, and micro-explosions during combustion. Key hazards include storage instability, particulate emissions (20–30% higher than diesel), and aquatic toxicity (LC50 < 10 mg/L for phenolics). Mitigation strategies such as inert gas blanketing, preheating, and spill containment are proposed. While offering renewable fuel potential, HTL bio-oil demands rigorous safety protocols for military/industrial deployment, warranting further experimental validation. Full article

Nowadays, many various types of drive and transmission mechanisms characterized by various parameters and characteristics for different types of vehicles have been designed, developed and optimized with regard to the featured applications. Our research is focused on the creation of a complex simulation model of the drive and transmission mechanism of the vehicle Iveco LMV 4 × 4 M65. The correctness of the simulation model was verified using an analytical approach. The created numerical simulation model will serve as a basis for the further optimization of dynamic, operational and economical parameters of the vehicle. As the modification or replacement of the particular components of the drive and transmission mechanism is very complicated regarding the vehicles used in military operations, our research is focused on the enhancement of the control processes. More specifically, the main goal of the presented research activities is the modification of the gearshift logic and the adjustment of the gearshift map in order to improve the dynamic properties of the vehicle and, at the same time, reduce the fuel consumption. In spite of its complexity, the proposed simulation model can serve as a basis for the optimization of not only the gearshift control under specific input or output quantities and operational or environmental conditions but also for the simulation of the system behavior with modified or replaced components of the drive and transmission mechanism of this type of truck vehicle. Full article

Unmanned aerial vehicles (UAVs) are becoming a major part of the civil and military aviation industries. They meet user needs for effective supply transportation and the real-time acquisition of accurate information during air operations. Recently, concerns about greenhouse gas (GHG) emissions have increased due to the use and depletion of fossil fuels, shifting attention toward the broader use of electric propulsion as a green technology in different sectors, including transportation. The long-term objective of this work is to build a prototype of a hybrid electric propulsion system (HEPS) dedicated to a multi-rotor unmanned aerial vehicle with a MTOW of 25 kg and an onboard electric voltage of 44.4 V. The main components and operating principles of the HEPS were defined. The main HEPS digital twin block modules and their operations were described. Using the developed digital twin structure and operational model, simulations were carried out. Based on the results, it can be demonstrated that the use of hybrid electric propulsion allows for a significant increase in the flight time of a multi-rotor UAV. The developed DT can be used as a tool for optimizing the operation of the HEPS prototype and for redefining mathematical models of individual components. Full article

The solid-fuel scramjet has become a potential power device for hypersonic missiles in the future and has important military application prospects due to its advantages in gas flow regulation, flame stability, and blended combustion efficiency. This paper summarizes the research progress of three types of solid-fuel scramjet, including a large number of landmark numerical and experimental results. At the same time, the research progress of supersonic steady combustion and combustion enhancement technology, thermal protection technology, and the improvement of solid-fuel and combustion performance are reviewed. On this basis, the key technologies of the solid solid-fueled scramjet are summarized, and several internal scientific problems are summarized, such as the combustion organization strategy of the wide velocity domain solid rocket scramjet, efficient combustion chamber loading and thermal bulking technology, combustion instability, etc. Finally, some suggestions for the future development of the solid-fuel scramjet are put forward. Full article

Solar-powered unmanned aerial vehicles are fixed-wing aircraft designed to operate solely on solar power. Their defining feature is an advanced power system that uses solar cells to absorb sunlight during the day and convert it into electrical energy. Excess energy generated during flight can be stored in batteries, ensuring uninterrupted operation day and night. By harnessing the power of the sun, these aircraft offer key benefits such as extended flight endurance, reduced dependence on fossil fuels, and cost efficiency improvements. As a result, they have attracted considerable attention in a variety of military and civil applications, including surveillance, environmental monitoring, agriculture, communications, weather monitoring, and fire detection. This review presents selected aspects of the development and use of solar-powered aircraft. First, the general classification of unmanned aerial vehicles is presented. Then, the design process of solar-powered unmanned aerial vehicles is discussed, including issues such as the structure and materials used in solar-powered aircraft, the integration of solar cells into the wings, the selection of appropriate battery technologies, and the optimization of energy management to ensure their efficient and reliable operation. General information on the above areas is supplemented by the presentation of results discussed in the selected literature sources. Finally, the practical applications of solar-powered aircraft are discussed, with examples including surveillance, environmental monitoring, agriculture, and wildfire detection. The work is summarized via a discussion of the future research directions for the development of solar-powered aircraft. The review is intended to motivate further work focusing on the widespread use of clean, efficient, and environmentally friendly unmanned aerial vehicles for various applications. Full article

This paper presents the research and numerical modeling of heat flow through a textile heat sink (THS). The aim of this research is to create a numerical model of a THS that not only simulates the thermal behavior of knitted fabrics, which are used to construct a THS, but also serves as a predictive tool for the heat flow coming from different devices, thus increasing thermal management safety. By integrating modeling tools with textile engineering, this study contributes valuable insights to the development of effective passive cooling solutions for textronics applications, e.g., in thermal management in the military or air space sectors. THS is a support tool for multilayer insulation (MLI) blankets in space satellites, used to maintain the insulation performance of MLI to retain the extremely low temperature of satellite sensors or fuel tanks. The textile radiator made of spacer knitted 3D fabric consists of monofilament yarns covered with aluminum. THS samples were made on the HD 6/20-65 EL machine of Karl Mayer, with the calibration number E12. Numerical modeling was performed using ANSYS software. The numerical simulations of the temperature gradient presented the heat flow for source temperatures of 50 °C and 70 °C for different values of air velocity. Full article

Although truck platooning enhances transportation efficiency, reduces fuel consumption, and lowers freight transport costs, it can also create limited overtaking opportunities, potentially leading to risky overtaking maneuvers. The present study examines the impact of platooned heavy military vehicles on the quantification of Passing Sight Distance (PSD). Two distinct cases are examined: single and platooned military vehicles passing, the latter formed by five trucks. The authors, by realistically modeling the passing task, examined the interaction between vehicle dynamic parameters and roadway grade utilizing an existing vehicle dynamics model. The analysis of various speed values revealed significant PSD variations depending on the examined impeding (overtaken) vehicle’s platooning configuration and utilized grade. The present assessment accurately quantifies the grade impact on the required PSDs for such special vehicle arrangements and can be applied to any vehicle platooning configuration. Moreover, a preliminary tool is introduced to assist road designers in accurately assessing the impact of roadway grade on the passing process. This tool, when combined with a more in-depth analysis of additional factors, can help justify the need for an extra lane in road sections where platooning regularly occurs. Full article

Hydrodynamic noise is induced by hydrodynamic phenomena, such as pressure fluctuations, shear layers, and eddy currents, which have a significant impact on ship performance, pumping equipment efficiency, detection accuracy, and the living environment of marine organisms. Specifically, hydrodynamic noise increases fluid resistance around the hull, reduces speed and fuel efficiency, and affects the stealthiness of military vessels; whereas, in pumping equipment, noise generation is usually accompanied by energy loss and mechanical vibration, resulting in reduced efficiency and accelerated wear and tear of the equipment. Traditional physical experiments, theoretical modeling, and numerical simulation methods occupy a key position in hydrodynamic noise research, but each have their own limitations: physical experiments are limited by experimental conditions, which make it difficult to comprehensively reproduce the characteristics of the complex flow field; theoretical modeling appears to be simplified and idealized to cope with the multiscale noise mechanism; and numerical simulation methods, although accurate, are deficient in the sense that they are computationally expensive and difficult to adapt to complex boundary conditions. In recent years, intelligent algorithms represented by data-driven algorithms and heuristic algorithms have gradually emerged, showing great potential for development in hydrodynamic noise optimization applications. To this end, this paper systematically reviews progress in the application of intelligent algorithms in hydrodynamic noise research, focusing on their advantages in the optimal design of noise sources, noise prediction, and control strategy optimization. Meanwhile, this paper analyzes the problems of data scarcity, computational efficiency, and model interpretability faced in the current research, and looks forward to the possible improvements brought by hybrid methods, including physical information neural networks, in future research directions. It is hoped that this review can provide useful references for theoretical research and practical engineering applications involving hydrodynamic noise, and point the way toward further exploration in related fields. Full article

The field of indoor localization is fast developing and has important ramifications for a number of areas, such as smart infrastructure development, healthcare settings, industrial automation, and military operations. Advances in a range of technologies, each suited to certain use cases and objectives, have been fueled by the capacity to precisely locate objects or people inside places. Prominent indoor localization technologies like Bluetooth, Wi-Fi, ultra-wideband (UWB), ZigBee, and RFID-based systems are examined in this review, along with hybrid solutions that combine several technologies to get around their individual drawbacks and enhance system performance. The field still faces several obstacles in spite of these developments. Widespread acceptance is hampered by persistent problems such as signal interference, high energy consumption, and restricted scalability. The deployment of these systems is further complicated by elements like cost-effectiveness, privacy issues, and compatibility in a variety of situations. This study also examines potential avenues for future research to improve the precision, dependability, and versatility of indoor localization technology in order to overcome these obstacles. Designing systems with increased resilience to environmental changes, utilizing edge computing for real-time processing, and integrating artificial intelligence for predictive modeling are all promising areas of emphasis. This study attempts to help academics and practitioners navigate the changing terrain of indoor localization by offering a comprehensive picture of the field’s present status and future directions. Full article

Helium, as a by-product of the natural gas industry, will be impacted by the decline in consumption of fossil fuels as the world moves towards net-zero carbon emissions. In September 2022, all assets relating to the US government’s previous helium industry were sold. In the US, helium is now only available from private suppliers. In June 2022, Russia banned the export of helium to “unfriendly” countries, highlighting the geopolitical issues surrounding the industry. In the past, helium was popularized, and the industry was supported by its military applications (filling dirigible aircraft, welding fighter jets and purging rocket engines). It also plays an important role in supporting present-day technologies (e.g., MRI machines and spectroscopy) and will also be important for a high-tech future (e.g., in quantum computing, fusion power, and space exploration). Shortages of helium will inevitably cause skyrocketing prices and consequently lead to significant challenges for research and development (as has happened in the past) and technological progress, as well as a slowdown in world economic growth and prosperity. Anticipated declines in natural gas production, associated with moves towards net-zero carbon emissions targets, make helium less accessible. While this is problematic for industry in the short term, it perhaps preserves some low entropy helium within the ground, making it more accessible to future generations. Given anticipated limitations to the future supply of helium, technological developments are currently focused on a few areas: the replacement of helium by other gases in industrial applications, changing technological approaches to not require helium, and reducing the cost of obtaining helium from the atmosphere. This paper explores the past, present and future of helium, focusing on the sustainability of the helium industry. Full article

The global transportation sector is transitioning towards renewable energy to combat climate change, with biodiesel playing a critical role. Significant research over the past decades has focused on enhancing biodiesel through novel feedstocks and production methods. The defense community, a major diesel consumer, is particularly interested in biodiesel to support national sustainability goals while also leveraging the benefits of the new technology, including the ability to produce biodiesel locally at the point of need. This paper sets out to review recent advances in biodiesel technology and aligning them with the needs of the defense communities. By doing so, this paper provides insight into the challenges, benefits, and technical feasibility for the two primary consumers of military diesel fuel—naval ships and ground vehicles. For naval applications, algae-based biodiesel shows promise due to its potential for local production near ports. Advances in genetic engineering and cultivation are crucial for increasing lipid content and reducing costs. Innovative methods such as microwave-assisted transesterification and artificial neural networks for optimization could further enhance economic viability. In military ground vehicles, locally produced biodiesel could sustain operations by minimizing supply chain dependencies. Efforts are ongoing to develop mobile production facilities and improve feedstock diversity and methanol-independent transesterification processes. Overall, advancements in biodiesel production from various feedstocks and innovative techniques are poised to significantly benefit the military sector, promoting sustainability and operational efficiency. Full article

The impact of the active hostilities associated with Russia’s large-scale armed invasion of the territory of Ukraine on soil degradation as a result of military actions has resulted in soil damage due to heavy military armored vehicles. Debris from destroyed military equipment, ammunition, and fuel remnants lead to multi-factor damage to the soil system, causing local and global pollution and losses of soil resources. In all the studied cases, mechanical, chemical, and physical soil degradation were observed. This was manifested in changes in granulometric fractions at explosion sites, burning areas, and locations with heavy-metal contamination. Equipment incineration has resulted in an increase in the sand fraction (2.0–0.05 mm) by 1.2–1.8 times and a decrease in the clay fraction (<0.002 mm) by 1.1–1.2 times. The soil contamination levels with regard to heavy metals significantly surpass health standards, with the highest pollution levels observed for Pb, Zn, and Cd. Across all affected areas, changes occurred in the microbiome structure (a 20.5-fold increase in the proportion of mycelial organisms), microbiological process activity was suppressed (a 1.2-fold decrease), microbial biomass (a 2.1-fold decrease) was reduced, and high soil toxicity (99.8%) was observed. Explosions and the pyrolysis of armored vehicles have a significant impact on soil mesobiota and plants. The results indicate the existence of complex interactions between various factors in the soil environment post-explosion, significantly affecting soil health. Full article

Unmanned aerial vehicles (UAVs) have become an integral part of modern life, serving both civilian and military applications across various sectors. However, existing power supply systems, such as batteries, often fail to provide stable, long-duration flights, limiting their applications. Previous studies have primarily focused on battery-based power, which offers limited flight endurance due to lower energy densities and higher system mass. Proton exchange membrane (PEM) fuel cells present a promising alternative, providing high power and efficiency without noise, vibrations, or greenhouse gas emissions. Due to hydrogen’s high specific energy, which is substantially higher than that of combustion engines and battery-based alternatives, UAV operational time can be significantly extended. This paper investigates the potential of PEM fuel cells as an alternative power source for electric propulsion in UAVs. This study introduces an adaptive, fully functioning PEM fuel cell model, developed using a reduced-order modeling approach and optimized for UAV applications. This research demonstrates that PEM fuel cells can effectively double the flight endurance of UAVs compared to traditional battery systems, achieving energy densities of around 1700 Wh/kg versus 150–250 Wh/kg for batteries. Despite a slight increase in system mass, fuel cells enable significantly longer UAV operations. The scope of this study encompasses the comparison of battery-based and fuel cell-based propulsion systems in terms of power, mass, and flight endurance. This paper identifies the limitations and optimal applications for fuel cells, providing strong evidence for their use in UAVs where extended flight time and efficiency are critical. Full article

Multi-rotor drones, a kind of unmanned equipment which is widely used in the military, commercial consumption and other fields, have been developed very rapidly in recent years. However, their short flight time has hindered the expansion of their application range. This can be addressed by utilizing hydrogen fuel cells, which exhibit high energy density, strong adaptability to ambient temperature, and no pollution emissions, as the power source. Accordingly, the application of hydrogen fuel cells as the power source in multi-rotor drones is a promising technology that has attracted significant research attention. This paper summarizes the development process of hydrogen fuel cell multi-rotor drones and analyzes the key obstacles that need to be addressed for the further development of hydrogen fuel cell multi-rotor drones, including structural light weight, hydrogen storage methods, energy management strategies, thermal management, etc. Additionally, prospects for the future development of hydrogen fuel cell multi-rotor drones are presented. Full article