Airpower plays a key role in neutralizing military threats and securing victory in wars. This study analyzes newly introduced fighter forces by considering factors like performance, power index, operational environment, airbase capacity, survivability, and sustainment capability to devise an optimal deployment strategy that enhances operational efficiency and effectiveness. Using optimization methods like mixed integer programming (MIP), the study incorporates constraints such as survivability and mission criticality. The focus is on major Air Force operations, including air interdiction, defensive counter-air, close air support, and maritime operations. Experimental results show the proposed model outperforms current deployment plans in both wartime and peacetime in terms of operations and sustainment.

The feeder pipes of the primary cooling system in a pressurized heavy water reactor (PHWR) are composed of carbon steel SA 106 GR.B. On the surface of this structural material, corrosion oxide layers including radionuclides are formed due to the presence of active species from water decomposition products caused by radiation, as well as the high temperature and high-pressure environment. These oxide layers decrease the heat transfer efficiency of the primary cooling system and pose a risk of radiation exposure to workers and the environment during maintenance and decommissioning, making effective decontamination essential. In this study, we simulated the formation of the corrosion oxide layer on the surface of carbon steel SA 106 GR.B, characterized the formed corrosion oxide layer, and investigated the dissolution characteristics of the corrosion oxide layer using oxalic acid (OA), a commercial chemical decontamination agent. The corrosion oxide layer formed has a thickness of approximately 4 μm and consists of hematite ( Fe2O3) and magnetite ( Fe3O4). The carbon steel coupons with formed oxide layers were dissolved in 10 mM and 20 mM OA solutions, resulting in iron ion concentrations of 220 ppm and 276 ppm in the OA respectively. In 10 mM and 20 mM OA, the corrosion depths of the coupons were 8.93 μm and 10.22 μm, with corrosion rates of 0.39 mg/cm2·h and 0.45 mg/cm2·h, respectively. Thus, this demonstrates that higher OA concentrations lead to increased dissolution and corrosion of steel.

A substantial quantity of discarded tires has inflicted harm on the environment. Microwave pyrolysis of discarded tires emerges as an efficient and environmentally friendly method for their recycling. This research innovatively utilizes the characteristics of microwave rapid and selective heating to pyrolyze waste tires into porous graphene under the catalysis of KOH etching. Moreover, this study comprehensively investigates the dielectric characteristics and heating behavior of waste tires and different proportions of waste tire–KOH mixtures. It validates the preparation of graphene through KOH-catalyzed microwave pyrolysis of waste tires, tracking morphological and structural changes under varying temperature conditions. The results indicate that optimal dielectric performance of the material is achieved at an apparent density of 0.68 g/cm3 at room temperature. As the temperature increases, the dielectric constant gradually rises, particularly reaching a notable increase around 700 °C, and then stabilizes around 750 °C. Additionally, the study investigates the penetration depth and reflection loss of mixtures with different proportions, revealing the waste tire–KOH mass ratio of 1:2 demonstrates favorable dielectric properties. This research highlights the impressive microwave responsiveness of the waste tire–KOH mixture, Upon the addition of KOH, the mixed material exhibits an augmented dielectric constant and relative dielectric constant, supporting the viability of KOH-catalyzed microwave pyrolysis for producing porous graphene from waste tires. This method is expected to provide a new method for the valuable reuse of waste tires and a technology for large-scale, efficient and environmentally friendly production of graphene.

Carbon quantum dots (CQDs) are novel nanocarbon materials and widely used nanoparticles. They have gradually gained popularity in various fields due to their abundance, inexpensive cost, small size, ease of engineering, and distinct properties. To determine the antibacterial activity of metal-doped CQDs (metal-CQDs) containing Fe, Zn, Mn, Ni, and Co, we chose Staphylococcus aureus as a representative Gram-positive strain and Escherichia coli as a representative Gram-negative bacterial strain. Paper disc diffusion tests were conducted for the qualitative results, and a cell growth curve was drawn for quantitative results. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and IC50 were measured from cell growth curves. As a result, all of the metal-CQDs showed toxicity against both Gram-positive and Gram-negative bacteria. Furthermore, Gram-negative bacteria was vulnerable to metal-CQDs than Gram-positive bacteria. The toxicity differed concerning the type of metal-CQDs; Mn-CQDs exhibited the highest efficacy. Hence, this study suggested that CQDs can be used as new nanoparticles for antibiotics.

The economical manufacturing of high-quality graphene has been a significant challenge in its large-scale application. Previously, we used molten Sn and Cu as the heat-transfer agent to produce multilayer graphene on the surface of gas bubbles in a bubble column. However, element Sn and Cu have poor catalytic activity toward methane pyrolysis. To further improve the yield of graphene, we have added active Ni into Sn to construct a Sn–Ni alloy in this work. The results show that Sn–Ni alloy is much more active for methane pyrolysis, and thus more graphene is obtained. However, the graphene product is more defective and thicker because of the faster growth rate. By using 300 ml molten Sn–Ni alloy (70 mm height) and 500 sccm source gas ( CH4:Ar = 1:9), this approach produces graphene with a rate of 0.61 g/hr and a conversion rate of methane to carbon of 37.9% at 1250 ℃ and ambient pressure. The resulting graphene has an average atom layer number of 22, a crumpled structure and good electrical conductivity.

For metal-free carbocatalysts, heteroatom doping and hierarchically porous structure are the significant factors to improve their catalytic performances. Herein, N-, P-co-doped hierarchically porous carbon fiber (NPC–2–800) was prepared by pyrolyzing bamboo pulp in combination with ( NH4)2HPO4 and activator K2CO3. It was found that ( NH4)2HPO4 not only provides N and P atoms, but also significantly affect the morphology and pore structure of the porous carbon. An appropriate dosage of ( NH4)2HPO4 facilitates the formation of hierarchically porous carbon fiber in NPC-2–800. Whereas, the carbon fragments with only micropores were obtained in absence of ( NH4)2HPO4. The hierarchical porosity and the co-doping of N and P atoms in the NPC-2–800 contribute to its outstanding catalytic performances in the 4-Nitrophenol (4-NP) reduction assisted by NaBH4. The NPC-2–800 exhibits an attractive turnover frequency (TOF) value of 4.29 × 10– 4 mmol mg− 1 min− 1, a low activation energy (Ea) of 24.76 kJ/mol, and an acceptable recyclability for 7 cycles without obvious decrease in activity. Kinetics analyses suggest that the 4-NP reduction proceeds through the Langmuir–Hinshelwood model. In addition, the NPC-2–800 can also efficiently catalyze the 2-NP and 3-NP reduction. Moreover, in the real water body, the NPC-2–800 also showed superior catalytic activity to catalyze 4-NP reduction. This study provides an efficient catalyst for pollutant conversion and elimination as well as guidelines for designing versatile carbon-based catalysts.

This study delves into the potential application of whisker carbon nanotube (w-CNT) in terms of electrical heating performance, with a particular emphasis on its significance in high-efficiency electrothermal conversion applications. Meanwhile, a comparative study was conducted on traditional carbon nanotubes (T1 and T3) with different aspect ratios. A uniform and dense carbon nanotube paper (BP) was prepared using a vacuum filtration method, including single-layer (T1, T3 and w-CNT BP), double-layer gradient composite (T1/T3-g, w-CNT/T3-g), and mixed composite (T1/T3-m and w-CNT/T3-m). The thickness of each type of BP is approximately 100 μm. The results demonstrated that electrical conductivity and electrical heating performance of single-layer BPs follow the order of T1 > T3 > w-CNT. While, mixed composite BPs are superior to double-layer gradient composite BPs in electrical conductivity and thermal performance. Notably, w-CNT/T3-m BP exhibits excellent electrothermal performance. Under an applied voltage of 5 V, the surface temperature of w-CNT/T3-m BP reaches 190 ℃. When the voltage is increased to 6 V, the surface temperature rises by 150℃ within 10 s, reaching a steady-state temperature of 318 ℃. This excellent electrothermal performance can be attributed to the introduction of w-CNT, which has a perfect and defect free structure according to Raman analysis. In-depth analysis using X-ray diffraction (XRD) indicated a more complete and higher degree of crystallinity in the w-CNT structure. In summary, this study not only provides experimental and theoretical basis for the application of high-performance electrothermal materials based on carbon nanotubes, but also foreshadows their broad application prospects in the field of macroscopic materials.

In this study, ester co-solvents and fluoroethylene carbonate (FEC) were used as low-temperature electrolyte additives to improve the formation of the solid electrolyte interface (SEI) on graphite anodes in lithium-ion batteries (LIBs). Four ester co-solvents, namely methyl acetate (MA), ethyl acetate, methyl propionate, and ethyl propionate, were mixed with 1.0 M LiPF6 ethylene carbonate:diethyl carbonate:dimethyl carbonate (1:1:1 by vol%) as the base electrolyte (BE). Different concentrations were used to compare the electrochemical performance of the LiCoO2/ graphite full cells. Among various ester co-solvents, the cell employing BE mixed with 30 vol% MA (BE/MA30) achieved the highest discharge capacity at − 20 °C. In contrast, mixing esters with low-molecular-weight degraded the cell performance owing to the unstable SEI formation on the graphite anodes. Therefore, FEC was added to BE/MA30 (BE/MA30-FEC5) to form a stable SEI layer on the graphite anode surface. The LiCoO2/ graphite cell using BE/MA30-FEC5 exhibited an excellent capacity of 127.3 mAh g− 1 at − 20 °C with a capacity retention of 80.6% after 100 cycles owing to the synergistic effect of MA and formation of a stable and uniform inorganic SEI layer by FEC decomposition reaction. The low-temperature electrolyte designed in this study may provide new guidelines for resolving low-temperature issues related to LIBs, graphite anodes, and SEI layers.

With the development of photocatalytic hydrogen production technology, the effective transport of photogenerated carrier electrons is still one of the main factors affecting the performance of photocatalytic hydrogen evolution. In this work, graphdiyne was prepared by ball milling method. The CoMo-MOF with polyhedral structure was introduced into graphdiyne to construct S-scheme heterojunction to promote the efficient transfer of photogenerated carriers and enhanced hydrogen evolution activity. Graphdiyne is a new carbon material with adjustable band gap, which is synthesized from the hybrid of sp and sp2, and has excellent electrical conductivity. CoMo-MOF is a polyhedral structure that can provide more active sites and promote photocatalytic hydrogen evolution. The weak point of poor conductivity in CoMo-MOF has been successfully improved by combining CoMo-MOF with graphdiyne, and the migration rate of photogenerated carriers has been accelerated. The hydrogen evolution property of graphdiyne/CoMo-MOF is 300 μmol, which is 19.61 times that of graphdiyne and 9.03 times that of CoMo-MOF. Therefore, the construction of S-scheme heterojunction provides a transport channel for electron transfer and improves the efficiency of photogenerated carrier separation. This work provides a new train of thought of design to introduce MOFs materials into carbon materials for photocatalytic hydrogen evolution.

Various transition metal oxides are deposited on the surface of materials such as stainless steel, which is used in the coolant systems of nuclear power plants. The task of removing harmful radionuclides can be solved through the dissolution reaction of the deposited corrosion oxide layer. In this study, for the first time, the reaction thermodynamics of the hydrazine-based reductive metal ion decontamination (HyBRID) reaction developed by the Korea Atomic Energy Research Institute were studied considering the formation of a strong ion − ligand chemical bond complex between Cu ions and hydrazine. When considering complex formation, we found that it had a significant impact on the thermodynamic decontamination reactions of magnetite, nickel ferrite, and chromite. The reactions were proven to be much more thermodynamically favorable than the reaction energies reported thus far, which did not consider complex formation. We demonstrated that not only the thermodynamic energy but also the structures of the HyBRID reaction products can be significantly changed, depending on complex formation considerations.

With the emergence of the new energy field, the demand for high-performance lithium-ion batteries (LIBs) and green energy storage devices is growing with each passing day. Carbon nanotubes (CNTs) exhibit tremendous potential in application due to superior electrical and mechanical properties, and the excellent lithium insertion properties make it possible to be LIBs anode materials. Based on the lithium insertion mechanism of CNTs, this paper systematically and categorically reviewed the design strategies of CNTs-based composites as LIBs anode materials, and summarized in detail the enhancement effect of CNTs fillers on various anode materials. More importantly, the superiorities and limitations of various anode materials for LIBs were evaluated. Finally, the research direction and current challenges of the industrial application of CNTs in LIBs were prospected.

Colorectal cancer (CRC) poses a significant global public health challenge, accounting for 10% of newly diagnosed cancer cases and causing 9.4% of cancer-related deaths. Conventional treatment methods like surgery, chemotherapy, and radiation have shown limited success despite the increasing incidence of CRC. Thus, there is an urgent need for innovative therapeutic approaches. Researchers are continually working on developing novel technologies, notably focused on the creation of safe and effective cancer nanomedicines, in their continuous effort to advance cancer treatment. Nanoparticles exist at the nanoscale. Nanoparticles at the nanoscale have distinctive properties that leverage the metabolic disparities between cancerous and normal cells. This property allows them to selectively induce substantial cytotoxicity in cancer cells while minimizing damage to healthy tissue. Carbon nanomaterials (CNMs), including graphene oxide (GO), carbon nanotubes (CNTs), and nanodiamonds (NDs), have undergone extensive investigation due to their biocompatibility, surface-to-volume ratio, thermal conductivity, rigid structural properties, and ability for post-chemical modifications. Notably, GO has emerged as a promising two-dimensional (2D) material for cancer treatment. Several groundbreaking nanoparticle-based therapies, predominantly utilizing GO, are currently undergoing clinical trials, with some already gaining regulatory clearance.

This study investigates how adding cognitive stimulation to exercise impacts overall outcomes. Cognitive stimulation involves engaging mental processes like attention, memory, and problem-solving while being physically active. The intervention integrates activities that challenge mental functions into exercise routines. Existing research suggests that such interventions can improve various aspects of exercise performance, such as adherence, enjoyment, and perceived effort. Additionally, they may also lead to enhanced cognitive function and mental well-being, hinting at potential combined benefits of mental and physical activity. Understanding the effects of cognitive stimulation on exercise can help in developing more effective strategies for promoting both physical and cognitive health. In summary, physical exercise emerges as a powerful tool for enhancing cognitive stimulation and mental well-being. By making regular physical activity a habit, individuals can reap cognitive benefits alongside physical ones, underlining the importance of including exercise in daily routines for optimal cognitive function and overall health.

선박의 조종성능은 조선해양공학 분야에서 매우 중요한 유체역학적 성능 중 하나입니다. 본 연구에서는 저수심에서 운용되는 24m급 쌍동선을 대상으로 직진성능 분석에 대한 연구를 진행하였습니다. Skeg의 설치를 통해 조종성능을 개선할 수 있는지 여부를 확인 하기 위해, 전산유체역학(CFD) 수치해석 시뮬레이션을 활용하여 가상의 포획 모형테스트를 진행하였습니다. 시뮬레이션은 PMM(Planar Motion Mechanism) 조화 시험 중 Pure-sway 및 Pure-Sway motion, 2가지 시험을 진행하였으며, 선박의 선회성능은 직진성능 지수(C)의 경험식 을 통해 확인하였습니다, 결론적으로, Skeg가 없는 기존 선체는 직진성능이 상대적으로 저조하며, Skeg 1을 적용해도 부정적인 C 지수 값 을 보여 항로유지 능력이 개선되지 않았다. 하지만 Skeg 2, 3 또는 4를 적용하였을 때, 긍정적인 C 지수 값을 보여 항로유지 능력이 개선 되는 것을 보이며, 이는 Sway motion의 드리프트 경향에 비해 선체가 Yaw 또는 방향을 더 바꾸기 쉽다는 것을 나타낸다.