This study was carried out to get information on the concentration and species of airborne fungi in wood ear mushroom (Auricularia heimuer) cultivation houses. Air samplings were conducted at three wood ear mushroom farms located in Iksan and Wando in 2022. Two out of the three cultivation houses exceeded the Ministry of Environment’s recommended indoor air quality standards for fungi concentration in multi-use facilities. A total of 12 genera and 15 species of airborne fungi were isolated and identified. There were species belonging to 6 genera at the genus level. Overall, the genus Cladosporium accounted for the majority with three species. Among the identified species, there were fungi that affect the human body, such as Aspergillus niger, Lichtheimia ramose, and Rhizomucor pusillus, as well as Alternaria alternata, Cladosporium ramotenellum, Cladosporium subuliforme, and Curvularia lunata, which cause diseases in plants. Penicillium brevicompactum was detected as a fungus affecting mushroom cultivation. This study is the first report in Korea on airborne fungi in wood ear cultivation houses and provides useful information for environmental hygiene management of cultivation houses.

본 연구는 정서가 어떻게 표상되고 그 구조가 어떠한지 파악하기 위한 목적으로 진행되었다. 이에 정서 영상에서 유발된 정서에 대해 웨어러블 기구 기반 EEG 반응이 어떻게 분류되고 표상되는지 알아보고자 하였다. 이를 위해 참가자간 분류분석으로 참가자들 간의 정서 반응의 일관성을 확인하였다. 또한 분류분석의 결과로 도출된 정서 영상 별 정확 및 오분류를 오차행렬을 통해 기술하였다. 다음으로, 핵심정서 모델을 기반으로 EEG 데이터에 다차원척도 법을 적용하여 정서가 정서가와 각성가 두 가지 차원에서 어떻게 표상되는지 확인하였다. 마지막으로, 표상 유사성 분석을 통해 행동 데이터, 생리 측정 데이터, EEG 데이터 중 정서 차원을 가장 잘 설명하는 데이터가 무엇인지 확인하였다. 참가자간 분류분석 결과, 정서유형이 유의미하게 분류되었고 이는 EEG 데이터에 정서에 따라 참가자들 간 공유되는 패턴이 있음을 시사한다. 다차원척도법 결과, 정서 자극에 따른 EEG 데이터가 각성가 차원에서 표상이 잘 이루어졌다. 표상 유사성 분석 결과, 정서가 차원은 행동 데이터가, 각성가 차원은 EEG 데이터와 생리 측정 데이 터가 잘 설명하였다. 본 연구는 웨어러블 기구를 통해 측정된 영상 자극에 따른 EEG 데이터를 사용해 기존의 정서 이론과 부합하는 결과를 얻은 것에 의의가 있다.

Recently, high-rise residential buildings in Korea have adopted slender shear walls with irregular section shapes, such as T-shape, H-shape, and C-shape. In the seismic design of the slender shear walls, the transverse reinforcement for lateral confinement should be provided in the boundary elements to increase deformation capacity and subsequent ductility. However, in practice, the irregularity of the shear walls is not adequately considered, and the lateral confinement region is calculated for the rectangular wall segments. This study investigated the proper design method for lateral confinement regions using finite element analysis. The lateral confinement region was considered in analysis for two cases: 1) as a typical rectangular wall segment and 2) as an irregular wall. When the irregularity of the walls was considered, the compression zone depth was increased because the vertical reinforcement in the flange was addressed. The effect of lateral confinement design methods on the structural performance of the walls was directly compared under various design parameters, including the length of the flange, concrete compressive strength, vertical rebar layout, axial load ratio, and loading direction. According to the results of the parametric analysis, the peak strength and deformation capacity could be significantly increased when the lateral confinement region was calculated based on irregularly shaped walls, regardless of the design parameters. In addition, the effective compression zone was located within the lateral confinement region. Thus, it is recommended that the lateral confinement region of T-shaped walls is calculated by addressing the irregularity of the walls.

Mo-ODS alloys have excellent mechanical properties, including an improved recrystallization temperature, greater strength due to dispersed oxides, and the ability to suppress grain growth at high temperatures. In ODS alloys, the dispersed Y2O3 and added Ti form Y-Ti-O complex oxides, producing finer particles than those in the initial Y2O3. The complex oxides increase high-temperature stability and improve the mechanical properties of the alloy. In particular, the use of TiH2 powder, which is more brittle than conventional Ti, can enable the distribution of finer oxides than is possible with conventional Ti powder during milling. Moreover, dehydrogenation leads to a more refined powder size in the reduction process. This study investigated the refinement of Yi2Ti2O7 in a nano Mo-ODS alloy using TiH2. The alloy compositions were determined to be Mo-0.5Ti-0.5Yi2O3 and Mo-1.0Ti-0.5Yi2Oi2. The nano Mo-ODS alloys were fabricated using Ti and TiH2 to explore the effects of adding different forms of Ti. The sintered specimens were analyzed through X-ray diffraction for phase analysis, and the microstructure of the alloys was analyzed using scanning electron microscopy and transmission electron microscopy. Vickers hardness tests were conducted to determine the effect of the form of Ti added on the mechanical properties, and it was found that using TiHi2 effectively improved the mechanical properties.

안전은 해군과 같은 위험성이 높은 환경에서 활동하는 조직에게 필수적이다. 효과적인 안전관리는 지속적인 개선과 보완을 통 해 유지되어야 하며, PDCA cycle을 활용하는 것이 일반적이다. 하지만 해군에서는 안전 규정 강화와 교육 확대에도 불구하고 안전사고가 지속적으로 발생하고 있다. 이는 안전사고 분석 및 분류 시스템 개선의 필요성을 보여준다. 본 연구에서는 해군 안전사고 분류체계를 분 석하고 문제점을 파악하여 효과적인 분류체계를 구축하는데 중점을 두었다. 이를 통해 안전사고 결과를 데이터화하고, 사고의 근본 원인 을 파악하며, 중장기적인 안전관리 정책 수립에 기여할 수 있도록 12자리의 해군 안전사고 분류 코드를 제안하였다.

본 연구는 유통 주류의 당류 함량 및 저칼로리 감미료 의 사용 실태를 조사하고자 탁주 10건, 약주 6건, 청주 5 건, 맥주 5건, 과실주 12건, 소주 5건, 일반증류주 5건, 리 큐르 9건, 기타주류 15건을 수거하여 총 72건을 검사하였 다. 당류와 알룰로스는 HPLC-RI로 분석하였고 감미료 5 종은 HPLC-UV와 LC-MSMS를 이용하였다. 전체 주류의 당류 평균함량은 4.13±5.16 g/100 g 이었으며, 유형별로는 발효주(탁주, 약주, 청주, 맥주, 과실주) 0.00-8.92 g/100 g, 증류주(소주, 일반증류주, 리큐르) 0.00-30.55 g/100 g, 기타 주류는 0.14-17.02 g/100 g의 분포를 보였다. 당류의 함량이 가장 높은 유형은 리큐르로 평균 검출 농도가 100 g 당 12.41±9.66 g였다. 저칼로리 감미료의 함량은 아세설팜칼륨 28.6-121.5 mg/kg, 사카린나트륨 42.3 mg/kg, 아스파탐 34.1- 141.5 mg/kg, 수크랄로스 23.3-88.1 mg/kg로 나타났으며 사이 클라메이트와 알룰로스는 모든 주류에서 검출되지 않았다. 72건의 주류 중 24건에서 감미료가 검출되었으며, 검출된 감미료 사용량은 모두 식품첨가물 기준 이내였다.

Molten salt reactors represent a promising advancement in nuclear technology due to their potential for enhanced safety, higher efficiency, and reduced nuclear waste. However, the development of structural materials that can survive under severe corrosion environments is crucial. In the present work, pure Ni was deposited on the surface of 316H stainless steel using a directed energy deposition (DED) process. This study aimed to fabricate pure Ni alloy layers on an STS316H alloy substrate. It was observed that low laser power during the deposition of pure Ni on the STS316H substrate could induce stacking defects such as surface irregularities and internal voids, which were confirmed through photographic and SEM analyses. Additionally, the diffusion of Fe and Cr elements from the STS316H substrate into the Ni layers was observed to decrease with increasing Ni deposition height. Analysis of the composition of Cr and Fe components within the Ni deposition structures allows for the prediction of properties such as the corrosion resistance of Ni.

모기류는 흡혈을 통해 원충, 바이러스, 사상충 등 다양한 병원체를 보유하며 말라리아, 일본뇌염, 웨스트나일열, 뎅기열 등을 사람에게 매 개하는 위해성이 있는 위생해충이다. 이번 연구에서는 해외유입 모기류 감시를 위해 경상남도 고성군에 스마트 고공포집기를 설치하여 2022년 부터 2023년까지 모기류들을 모니터링하였다. 조사기간 동안, 총 3속 5종 43개체가 채집되었으며, 이중 삼일열말라리아를 매개하는 벨렌얼룩날 개모기(Anopheles belenrae)를 경남 지역에서 처음으로 발생함을 확인하였다. 본 연구에서는 스마트 고공포집기를 통해 해외에서 유입가능한 모 기류에 대한 실시간 모니터링이 가능함을 확인하였다.

Airborne bacteria are an important environmental factor that affects the hygiene of mushroom cultivation houses, as they can act as contaminants or pathogens in mushroom cultivation. To determine the distribution of airborne bacteria in the air of wood ear mushroom cultivation houses, air sampling and temperature and humidity measurements were conducted at three wood ear mushroom farms located in Iksan and Wando in 2022. Sampled air was analyzed to measure bacterial concentration levels and identify bacterial species. There was no significant difference in temperature and humidity changes detected between the three mushroom growing houses. Additionally, the concentration of bacteria in the air did not exceed 800 CFU/m², which is the maximum amount of airborne bacteria allowed by the Ministry of Environment’s indoor air quality maintenance standards. Eleven species of bacteria belonging to 11 genera were isolated and identified from air samples. These include five species of Micrococcales, four species of Bacilli, one species of Actinomycetia, and one species of Mycobacteriales. Of the 11 species identified, five are known to affect human health. However, no mushroom pathogens or species causing food poisoning were found.

Buckwheat leaves have the best antioxidant properties, including flavonoids, rutin, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability compared to common buckwheat and tartary buckwheat. The total dietary fiber content of the powder extracted by mixing buckwheat leaves and sea tangle was 30.5%. To manufacture bread containing mixed buckwheat flour, 10, 20, and 30% buckwheat flour was mixed in to produce buckwheat bread. The bread’s characteristics underwent significant changes with varying levels of buckwheat flour. As the buckwheat content increased, the size of the bread decreased, but its hardness, gumminess, and chewiness tended to increase. The sensory characteristics of the bread were not improved due to the addition of gluten in the case of bread mixed with 20% buckwheat flour. When the buckwheat flour content was mixed at 20%, and the mixed extract of buckwheat leaves and sea tangle were added at 0.4% and 1.0%, there was no significant difference in the appearance of the buckwheat bread. Still, regarding sensory properties, the preference was higher in the sample with 1.0% added buckwheat flour.

The existing wire mesh clip forming process requires improvement as the production process is semi-automatic, which greatly threatens the safety of workers and exposes them to labor intensity and industrial accidents. In this research and development, we designed and developed an automated wire mesh automatic clip system by improving problems in the existing welded wire mesh production process. As a result, the production volume per hour was improved from 450 to 516, and the clip formation time was improved, shortening the production time to 42.5 seconds. Additionally, the defect rate was reduced from 7% to less than 3%.

Code-compliant seismic design should be essentially applied to realize the so-called emulative performance of precast concrete (PC) lateral force-resisting systems, and this study developed simple procedures to design precast industrial buildings with intermediate precast bearing wall systems considering both the effect of seismic and blast loads. Seismic design provisions specified in ACI 318 and ASCE 7 can be directly adopted, for which the so-called 1.5S y condition is addressed in PC wall-to-wall and wall-to-base connections. Various coupling options were considered and addressed in the seismic design of wall-to-wall connections for the longitudinal and transverse design directions to secure optimized performance and better economic feasibility. On the other hand, two possible methods were adopted in blast analysis: 1) Equivalent static analysis (ESA) based on the simplified graphic method and 2) Incremental dynamic time-history analysis (IDTHA). The ESA is physically austere to use in practice for a typical industrial PC-bearing wall system. Still, it showed an overestimating trend in terms of the lateral deformation. The coupling action between precast wall segments appears to be inevitably required due to substantially large blast loads compared to seismic loads with increasing blast risk levels. Even with the coupled-precast shear walls, the design outcome obtained from the ESA method might not be entirely satisfactory to the drift criteria presented by the ASCE Blast Design Manual. This drawback can be overcome by addressing the IDTHA method, where all the design criteria were fully satisfied with precast shear walls’ non-coupling and group-coupling strength, where each individual or grouped shear fence was designed to possess 1.5S y for the seismic design.

This study presents code-compliant seismic details by addressing dry mechanical splices for precast concrete (PC) beam-column connections in the ACI 318-19 code. To this end, critical observations of previous test results on precast beam-column connection specimens with the proposed seismic detail are briefly reported in this study, along with a typical reinforced concrete (RC) monolithic connection. On this basis, nonlinear dynamic models were developed to verify seismic responses of the PC emulative moment-resisting frame systems. As the current design code allows only the emulative design approach, this study aims at identifying the seismic performances of PC moment frame systems depending on their emulative levels, for which two extreme cases were intentionally chosen as the non-emulative (unbonded self-centering with marginal energy dissipation) and fully-emulative connection details. Their corresponding hysteresis models were set by using commercial finite element analysis software. According to the current seismic design provisions, a typical five-story building was designed as a target PC building. Subsequently, nonlinear dynamic time history analyses were performed with seven ground motions to investigate the impact of emulation level or hysteresis models (i.e., energy dissipation performance) on system responses between the emulative and non-emulative PC moment frames. The analytical results showed that both the base shear and story drift ratio were substantially reduced in the emulative system compared to that of the non-emulative one, and it indicates the importance of the code-compliant (i.e., emulative) connection details on the seismic performance of the precast building.

콘크리트 도로포장의 보강재로 사용된 철근은 염해나 중성화 등으로 인하여 지속적인 손상이 발생하고 있으며, 이에 따른 유지관리 비용의 증대가 사회적 관심으로 대두되고 있다. 이를 해결하기 위하여 건설분야에서는 철근보다 내부식성 및 내알칼리성이 뛰어난 유 리섬유강화폴리머(Glass Fiber Reinforced Polymer, GFRP)가 사용되고 있다. 하지만, 수분 및 염해 등의 환경에 대한 내구성 검증은 충분히 이루어지지 않고 있는 실정이다. 따라서, 이 연구에서는 국내외에서 생산하는 직경 22mm GFRP 보강근을 ASTM D570에 의 거하여 흡수율 품질기준을 평가하였다. 흡수율 실험결과, 국내에서 생산된 GFRP의 경우 가장 높은 0.15% 수준의 흡수율을 나타내었으며, 해외에서 생산된 GFRP의 경우 0.03% 이내 수준의 흡수율을 나타내었다. 이는 KCI-GFRP 101 : 2024 및 ASTM D7957에서 제시하고 있는 GFRP 보강근 흡수율 품 질기준은 0.25% 이하를 모두 만족하는 것으로 분석되었다. 철근대체제로써 활용을 위해서는 장기침지 및 특수한 환경 등에 대한 내구 특성에 대한 추가적인 실험적 검토가 필요할 것으로 판단된다.

This study improved the work efficiency by supplementing the shortcomings of the manual process by developing a double tube feeding device, and the following results were obtained by conducting the production capacity, production length, and defect rate tests. Developed a double tube production system to enable the simultaneous production of two tubes, increasing the production volume by about 1.5 times. The product length has been improved from semi-automatic to automated, and the production capacity has been improved from 16 to 25 pieces per hour (based on 15m). Developed a double-tube input straight line automatic adjustment feeder, which resulted in reducing the defect rate to less than 1%.