The consumption of enoki mushrooms has been associated with cases of listeriosis produced by Listeria monocytogenes, highlighting the significance of sanitizing food-contact surface, such as the velcro used in welding processing of enoki mushrooms, to ensure microbial safety. We investigated the inhibitory activity of nine chemical disinfectants at regular concentrations against L. monocytogenes isolated from a mushroom farm environment. The bacterial suspension was prepared in phosphate buffered saline and mushroom extract broth and inoculated onto the velcro surface. After inoculation, most disinfectants reduced the initial 8 log CFU/coupon concentration by less than 2 log CFU/coupon during a 5-min treatment. Slightly acidic hypochlorous water showed a reduction of approximately 4 log CFU/coupon when tested for more than 30 min at the maximum allowable concentration of 200 mg/L. Sodium hypochlorite solution showed a reduction of approximately 5 log CFU/coupon when used at 100 mg/L for 60 min. Peracetic acid, at the maximum allowable concentration of 300 mg/L, showed the most effective reduction of 5 log CFU/coupon or more when the surface was treated with 37.5 mg/L for 30 min. These results indicate that peracetic acid can be used as the disinfectant strategy to control cross-contamination of L. monocytogenes on the velcro surface of plastic wrappers used in the welding processing of enoki mushrooms.

코로나 이후 시기가 도래하며 세계 각국은 빠른 경제 회복을 목표로 다양한 노력을 강구하고 있다. 이러한 측면에서 고성장기업에 관한 관심 역시 지속해서 높아지고 있는데, 지금까지 이루어진 다양한 고성장기업의 연구를 통해 국가 경제발전이나 고용 창출에 있어 고성장기업의 높은 기여도가 입증되었기 때문이다. 이처럼 기존 고성장기업 관련 연구의 경우 국가 경제 차원, 특히 고용 창출에 있어서 고성장기업의 역할을 강조하고 있다. 하지만, 혁신 관점에서 고성장기업의 역할을 언급하고 있는 연구는 많지 않다. 이에 본 연구에서는 기업 재무 데이터와 과학기술정책연구원의 2021년 한국기업혁신조사(KIS)(서비스업 분야)를 병합한 통합데이터를 구축하고 서비스업 고성장기업의 혁신 활동과 혁신성과에 대해 분석해보았다. 방법론 측면에서는 고성장기업이 갖는 특성으로 인해 발생할 수 있는 선택편의 문제를 해결 하기 위해 성향점수매칭방법론을 활용하였다. 분석 결과를 살펴보면 서비스업 고성장기업은 일반기업 대비 더 다양한 혁신 활동을 통해 더 많은 혁신성과물을 창출하고 있는 것으로 나 타났다. 특히, 상품혁신이나 비즈니스 혁신성과물 창출에 있어서 고성장기업이 긍정적인 역 할을 한다는 것은 기존 경제·사회적 관점에서 강조되어오던 고성장기업의 중요성을 혁신성 장 관점으로 확대하여 해석할 수 있는 결과이다. 다만, 연구·개발 유형이나 협력 R&D에서는 일반기업과 차별점을 찾을 수 없었는데, 이는 협력 연구·개발 강화를 통해 고성장기업이 보 유한 혁신역량이 일반기업자들에게 파급될 필요가 있음을 보여주는 결과이다. 이상의 분석 결과를 바탕으로 본 연구에서는 국가 혁신역량 강화를 위한 고성장기업 육성과 모니터링의 필요성, 고성장기업의 협력 활동 유인 통한 혁신의 파급효과 확대 등의 시사점을 제시하고자 한다.

In this study, the abnormal noise phenomenon generated intermittently in the shock absorber of the combat armored vehicle was approached from the side of the squeak joint to solve the phenomenon. In order to identify the cause of the noise, the factors causing friction in the shock absorber were checked from the viewpoint of problem product analysis, process, and design. As an improvement plan, by improving the non-lubricated section in the nitrogen chamber, the operating noise was reduced to a level lower than that of a general automobile engine along with the elimination of noise. Considering that this is a combat vehicle, it is judged that it has been improved so as not to affect the survivability and health of the crew during equipment operation. Through the improvement of this study, it is expected to prevent power loss and improve the emotional quality of our soldier.

Despite the presence of the p-Channel MOSFET inrush current limiter circuit within the power supply unit of military radar, The internal MOSFET and DC-DC Converter has been damaged due to the high inrush current. In this paper, the cause of the high inrush current was identified by analyzing the p-Channel MOSFET inrush current limiter circuit. Based on the analysis, the high inrush current was reduced by about 60% by adjusting the time constant of the source-to-gate elements compared to before improvement.

This study explores strategies to address the variability of heat energy using renewable energy and heat grids to achieve carbon neutrality. Renewable energy source introduce fluctuations that can impact the stability of power systems, while heat grids provide a systematic infrastructure for efficient supply of heat energy and power generation. Jeju Island is chosen as a case study, focusing on balance control based on groundwater-based geothermal energy to optimize the distribution of heat energy. The results demonstrate that the 3rd control method is the most effective in maintaining the target temperature in greenhouses, and specific temperature settings and objectives are proposed for each control method based on crop requirements. These research findings contribute to achieving carbon neutrality and reducing power consumption.

In this paper, the EMP-related standards and test methods used by the civilian and military have been introduced. The incoming EMP signal for seven military RF antennas which are the first to face EMP threats among military weapon systems have been also measured and analyzed. Overall, as the applied signal strength increased, the strength of the EMP signal entering in the antenna also showed an upward trend. The highest level of entering was observed at the peak value of the applied EMP signal, 50 kV/m. And at the peak value, all antennas received threatening signals. In particular, antennas in low frequency bands such as AM and FM were getting high voltage signals as high as thousands of volts. This means that the weapon systems linked to the antennas could suffer severe damage. Therefore, based on this paper, systematic research for EMP threat should be conducted to identify EMP vulnerabilities of major weapons systems and to devise practical protective measures.

The demand for LNG Carrier and LNG fuel ships are increasing due to global carbon neutrality declaration and ship emissions regulation of IMO, domestic shipyards pay technology fees(about 5~10% of ship price per vessel) to GTT company in France for making LNG cargo hold. Localization of LNG cargo hold is needed to reduce technology fees and engage technological competitiveness, it is important to secure the critical technology like automation process development of insulation system process. Especially, the automation rate of membrane-type insulation system is very low due to interference caused by corrugation and difficulty in securing optimal variable welding condition. In this study, to solve this problem, automatic welding is performed using developed automatic welding equipment on STS304L steel which is used in flat and corner area of membrane-type LNG cargo hold's lap joint. After welding, Cross-sectional observations and Tensile strength tests were conducted to evaluate reliability of equipment and welding condition. As a result of the test, it was confirmed that the strength of the welded zone exceeded that of base material, and secured the optimal welding condition to apply automatic welding.