This paper proposes the armored combat bulldozer, essential for amphibious tasks, requires water ingress prevention and submersion capabilities, typically addressed by a centrifugal pump. This study aims to boost the bulldozer's drainage pump efficiency by replacing the traditional aluminum 3-blade impeller with one made of ASA material using 3D printing. Analysis via ANSYS Fluent revealed that the 5-blade impeller increased discharge volume by 19.31% and efficiency by 6.07%, while the 6-blade variant saw a 27.07% increase in discharge volume and 8.81% efficiency improvement. Further scrutiny with ANSYS Static Structure ensured the new impellers' structural integrity and robustness under extreme conditions. This research confirms the potential of 3D printing in enhancing military equipment, demonstrating significant improvements in pump performance and opening paths for advanced manufacturing techniques to meet the demanding needs of combat vehicles.

High-Manganese (Mn) austenitic steel, with over 24 wt% Mn content, offers outstanding mechanical properties in cryogenic settings, making it a potential replacement for existing cryogenic materials. This high manganese steel exhibits high strength, ductility, and wear resistance, making it promising for applications like LNG tanks, flanges, and valves. To operate in cryogenic environments, hot forging and heat treatment processes are vital, especially in flange production. The cooling rate during high-temperature cooling after hot forging plays a critical role in influencing the microstructure and mechanical properties of high manganese steel. The rate at which cooling occurs during this process influences the size of the grains and the distribution of manganese and consequently has an impact on mechanical properties. This study assessed the microstructure and mechanical properties based on different cooling rates during the hot forging of High-Mn steel flanges. Comparing air and water cooling after hot forging, followed by heat treatment, revealed notable differences in grain size. These differences directly impacted mechanical properties such as tensile strength, hardness, and Charpy impact property. Understanding these effects is crucial for optimizing the performance and reliability of High-Mn steel in cryogenic applications.

이 글은 대만 중멍훙 감독의 영화에서 나타나는 가족 간의 갈등과 갈등의 해소, 그리고 이러한 것을 형상화한 영화적 장치에 대하여 주목하고 있다. 첫째, 이들 영화 에서는 죽음과 이혼 등 가족 구성원과의 이별이 나타나며, 이러한 구성원의 상실은 불안과 상처의 원인으로 작용한다. 그리고 이러한 갈등과 상처는 가족의 의미를 알 아가는 과정이며, 가족의 정신적 성장을 다루고 있다고 할 수 있다. 둘째, 영화에서 인물들이 겪는 심리적 불안은 그들의 내면과 정신적인 분열로 확장되어 나타난다. 그리고 이러한 인물의 내적 불안은 빛의 명암과 색채로 운용된다. 내면의 감정은 주 로 푸른색과 노란색의 원색적인 색채, 햇빛의 명암이 사용되고 있다. 빛과 색채가 만 들어내는 영상미는 중멍훙 영화의 특징이자 다른 감독들과 구분되는 지점이라고 할 수 있다.

ZnO/Cu/ZnO (ZCZ) thin films were deposited at room temperature on a glass substrate using direct current (DC) and radio frequency (RF, 13.56 MHz) magnetron sputtering and then the effect of post-deposition electron irradiation on the structural, optical, electrical and transparent heater properties of the films were considered. ZCZ films that were electron beam irradiated at 500 eV showed an increase in the grain sizes of their ZnO(102) and (201) planes to 15.17 nm and 11.51 nm, respectively, from grain sizes of 13.50 nm and 10.60 nm observed in the as deposited films. In addition, the film’s optical and electrical properties also depended on the electron irradiation energies. The highest opto-electrical performance was observed in films electron irradiated at 500 eV. In a heat radiation test, when a bias voltage of 18 V was applied to the film that had been electron irradiated at 500 eV, its steady state temperature was about 90.5 °C. In a repetition test, it reached the steady state temperature within 60 s at all bias voltages.

Transparent conductive tungsten (W) doped indium oxide (In2O3; IWO) films were deposited at different substrate bias voltage (-Vb) conditions at room temperature on glass substrates by radio frequency (RF) magnetron sputtering and the influence of the substrate bias voltage on the optical and electrical properties was investigated. As the substrate bias voltage increased to -350 Vb, the IWO films showed a lower resistivity of 2.06 × 10-4 Ωcm. The lowest resistivity observed for the film deposited at -350 Vb could be attributed to its higher mobility, of 31.8 cm2/Vs compared with that (6.2 cm2/Vs) of the films deposited without a substrate bias voltage (0 Vb). The highest visible transmittance of 84.1 % was also observed for the films deposited at the -350 Vb condition. The X-ray diffraction observation indicated the IWO films deposited without substrate bias voltage were amorphous phase without any diffraction peaks, while the films deposited with bias voltage were polycrystalline with a low In2O3 (222) diffraction peak and relatively high intensity (431) and (046) diffraction peaks. From the observed visible transmittance and electrical properties, it is concluded that the opto-electrical performance of the polycrystalline IWO film deposited by RF magnetron sputtering can be enhanced with effective substrate bias voltage conditions.

This study examines the correlation between livestock odor civil petitions and the establishment of malodor control areas in Jeju Special Self-Governing Province, focusing on swine farms where numerous civil petitions regarding malodors have been received. After the designation of the malodor control areas, high odor concentrations occurred in Aewoleup and Jocheon-eup, and the odor concentration decreased in other areas. The number of civil petitions shows a consistent annual trend, with increased petitions from March, peaking during summer (July and August), and decreasing from September into winter. In Jeju-si, there were many civil petitions in Hallim-eup and Aewol-eup where there were many malodor control areas. However, in Seogwipo-si, there were also many civil petitions in Pyoseonmyeon, where there is no malodor control area. Additionally, we compared the average multiple of compound malodors and the rate of exceeding the maximum allowable emission level for compound malodors with the number of livestock malodor civil petitions to assess the actual state of malodors. The results reveal a stronger correlation between the number of civil petitions and the rate of exceeding the compound malodors allowable emission level than the average multiple for compound malodors. These findings provide valuable insights into addressing livestock odor concerns and enhancing malodor control measures in Jeju Island.

Damage to gas and fire protection piping systems can lead to secondary disasters after an earthquake, so their seismic design is crucial. Accordingly, various types of seismic restraint installations are being devised, and a new suspended piping trapeze restraint installation has also recently been developed in Korea. In this study, a cyclic loading test was performed on the developed trapeze support system, and its performance was evaluated according to ASHRAE 171, the standard for seismic and wind restraint design established by the American Society of Refrigeration and Air Conditioning Engineers (ASHRAE). The three support system specimens did not break or fracture, causing only insignificant deformations until the end of the experiment. Based on the experimentally rated strength and displacement performance, this trapeze support system is expected to control the seismic movement of piping during an earthquake.

This study proposed a seismic reinforcement of RC columns with non-seismic details, a fiber reinforcement method of aramid sheets and MLCP (high elasticity aromatic polyester fiber material) with different characteristics, and 4 full-size column specimens and conducted experiments. The results show that a non-seismic specimen (RC-Orig) rapidly lost its load-bearing capacity after reaching the maximum load, and shear failure occurred. The RC column reinforced with three types of aramid did not show an apparent increase in strength compared to the unreinforced specimen but showed a ductile behavior supporting the load while receiving a lateral displacement at least 1.57 to 1.95 times higher than the unreinforced specimen. The fracture mode of the specimen, according to the application of lateral load, also changed from shear to ductile fracture through aramid-based reinforcement. In addition, when examining the energy dissipation ability of the reinforced specimens, a ductile behavior dissipating seismic energy performed 4 times greater and more stably than the existing specimens.

Since the increased focus on the essential role of recovering cognitive function after stroke, cognitive rehabilitation of stroke survivors has been important. This study aimed to provide basic data on the successful cognitive rehabilitation of stroke survivors through an literature review of virtual reality cognitive rehabilitation. Methods: The literature review method of Whittemore and Knaf was used. Data was searched on papers published before April 2023, and RISS, NDSL, and KISS were used for the search. Four studies were selected for analysis. Results: The cognitive function of the experimental group applied with the virtual reality cognitive rehabilitation was significantly improved. In the three studies, cognitive function was significantly improved compared to the control group. Conclusion: Findings from the review suggest the necessity of a virtual reality cognitive rehabilitation for older stroke survivors to verify its effectiveness.

Purpose: As the coronavirus disease 2019 (COVID-19) emerged as a global crisis in 2020, nursing students experienced an abrupt transition from offline to online classes. An in-depth understanding of the online learning experiences of nursing students can be used to reorganize nursing education during the pandemic. Therefore, this study explored the online learning experiences of nursing students during the COVID-19 pandemic. Methods: A descriptive qualitative design was employed. This study used purposive sampling to recruit 20 nursing students from a nursing college. Data were collected between November 2021 and March 2022 using semi-structured focus groups or one-to-one in-depth interviews. The collected data were analyzed using inductive content analysis. Results: Five main categories emerged from the analysis: (a) ambivalence toward rapidly changing learning methods, (b) becoming familiar with online learning, (c) facing the limitations of online learning environment, (d) discovering the charm of online learning, and (e) making suggestions for future online learning. Conclusion: Nursing students experienced disappointments and concerns about online learning classes in rapidly changing situations but also experienced an efficient aspect. Psychological support and the latest information should be provided to nursing students who may experience psychological distress during this pandemic. Additionally, learning strategies and methods should be reorganized to reflect the characteristics of nursing courses and the preferences of nursing students.