This study was conducted in Cheonan of central region in South Korea to evaluate the forage characteristics of early-maturing Italian ryegrass (IRG) within September, 2021 to June, 2023. The three different varieties of Italian ryegrass were prepared in this study 'Kogreen', 'Kospeed' and 'Kowinearly'. The results of heading date in this study, 'Kogreen' was the earliest in among cultivars and recorded 24th of April, whereas 'Kowinearly' was recorded the latest. In case of plant length parameter, 'Kowinearly' was the highest, in addition lodge tolerance score 'Kowinearly' also superior in whole cultivars. The dry matter yield of 'Kowinearly' was recorded significantly the highest (11,027 kg/ha), in contrast 'Kospeed' was recorded significantly the lowest (8,455 kg/ha). As a result of ADF and NDF content 'Kospeed' was recorded excellent value as compared the other two cultivars. The CP content of this study was excellent in the order of 'Kospeed' > 'Kowinearly' > 'Kogreen'. In case of the monosaccharides content 'Kogreen' had relatively higher glucose and fructose content than other four cultivars, therefore the 'Kogreen' has advantage for preparing high quality of silage. In conclusion, among the three different early varieties of Italian ryegrass, 'Kowinearly' was the superior in forage productivity, 'Kospeed' was the highest in feed value and 'Kospeed' had the highest in glucose and fructose content.

In this study, we performed thermal safety design of the electric module of a heat-loaded equipment with consideration of its heat dissipation performance. Initially, we calculated the heat dissipation of natural convection to choose a cooling method. Based on this, we found that some modules required forced convection and selected an air-cooling method with an outdoor temperature of 43 degrees Celsius, which is the maximum temperature in Korea. Prior to module production, we performed thermal analysis of each module and proceeded with a design to increase the thermal conductivity of the module as a primary step, and subsequently proceeded with Heat Sink design to maximize the heat dissipation performance. After considering various constraints according to the system requirements and designing the cooling path, we experimentally and analytically secured thermal safety at the operating temperature of the equipment.

흰점박이꽃무지[Protaetia brevitarsis seulensis (Kolbe)]의 적정 사육 밀도를 구명하기 위해 상대적으로 발육기간이 긴 3령 유충을 대상으로 밀도 실험을 수행하였다. 3령 유충기부터 번데기까지의 발육기간과 3령 유충부터 성충까지의 발육기간은 모두 30마리 밀도에서 가장 짧았다. 하지만, 번데기에서 성충까지 걸리는 시간은 유의미한 차이가 없었다. 성충의 외형적 특성도 밀도 간 통계적으로 유의미한 차이가 나타났는데, 그중 20마리 밀도 조건에서 사육된 성충은 무게와 체장, 체폭이 가장 우량하였다. 암수의 외형적 특성 차이는 주로 20마리 조건에서 유의미하게 나타났다. 암컷은 밀도 조건에 영향을 받지 않았지만, 수컷의 경우는 모든 외형적 특성에서 밀도에 영향을 받는 것으로 분석되었으며, 특히 20마리 조건은 다른 조건보다 성충의 크기가 큰 것을 확인하였다. 결론적으로, 흰점박이꽃무지의 3령 유충은 3L 사육상자에 30마리 밀도 조건으로 사육하는 것이 효율적이며, 이를 통해 3령에서 성충까지의 발육기간을 단축할 수 있고, 사료 비용도 절감할 수 있다.

피부를 대상으로 한 살균을 목적으로 하는 외용소독제 의 경우 식품 취급자에 오염된 미생물의 사멸 또는 제거 를 목적으로 활용될 수 있으며, 최근 개인위생에 대한 관 심 증가에 따라 제품 소비 증가와 제품 다양화가 두드러 지게 나타나고 있다. 살균 효능은 소독제의 핵심 품질 평 가 요소로서 수행 절차 및 조건에 따라 상이한 결과가 나 타날 수 있기 때문에 시험법의 효율성과 정확성을 높이기 위한 연구가 필요하다. 이에 본 총설논문에서는 주요 제 형별(겔형, 액제형, 와이프형) 시험법 개발 현황을 파악하 고 시험법별 특장점 분석 결과와 최근 관련 연구를 통하 여 제시된 시사점을 기반으로 향후 효능 평가 체계의 발 전 방향을 제시하고자 하였다. 인체 대상 시험법의 경우 시험 유형에 따라 소독제를 시험 대상 피부 표면에 처리 하는 조건이 다양화되어 있어 시험법 간 동등성에 대한 평가를 통해 소독제 제품의 성분이나 특성에 따라 최적의 시험 유형을 파악하고 그에 대응되는 적절한 평가 체계 및 관련 규제의 표준화의 필요성을 시사하였다. 특히 와 이프형 소독제의 경우 처리 방식이 미생물 제거 및 살균 에 직접적으로 영향을 미침에도 불구하고 피부에 노출하 는 손 대상 처리를 위한 사용 패턴의 표준화 사례가 부족 하였다. 한편 [전처리 - 소독제 노출 - 미생물 회수] 등 각 시험 절차별로 결과에 영향을 미치는 주요 결정 요인을 발굴하는 연구의 지속 수행을 통해 기존 시험법을 개선하고 신규 시험법을 개발하고자 하는 노력이 요구된다. 최 근 활발하게 개발되고 있는 ex vivo 시험법은 인체 시험 의 제한적인 연구 재현성과 같은 한계를 극복하면서도 인 간 피부 환경을 구현하기 위한 기술의 적용을 통해 연구 결과의 신뢰도를 확보할 수 있을 것으로 판단된다. 한편 손 피부를 대상으로 한 균총 연구 등 소독제 처리 전후 미생물의 특성과 분포 분석 관련 연구가 최근 다수 보고 되고 있어 이를 활용한 미생물 군집 단위의 소독제 효능 평가 시험법의 확립이 기대된다. 본 연구를 통해 제시된 소독제 효능 시험법의 현황 기반 발전 전략은 보다 효과 적인 개인위생 관리 확립을 통해 손을 통해 교차 오염되 는 미생물에 의한 감염성 질병 발생을 최소화하여 공중보 건 및 식품 안전성 향상에 기여할 수 있다.

In this paper, durability verification of forged wheels for automobiles were performed using the finite element method for bending fatigue analysis and impact analysis. In addition, the durability analysis environment of forged wheels was implemented. By analyzing the stress distribution on the surface of the forged wheel, the area with a high possibility of breakage was identified and improved. The durability analysis of the initial model forged wheel was performed by bending fatigue analysis and impact analysis, The stress distribution of the forged wheel surface was analyzed through the analysis results of the initial model. and the spokes, flanges, hubs, and rear parts are less likely to be damaged were cut to reduce the weight by about 10%, and the reliability of the improved model was confirmed.

Although monitoring of radon has been extensively implemented throughout South Korea, the risk assessment has been mainly limited to indoor environments such as schools, workplaces, and multi-use facilities, and evaluations have normally been performed separately. In this study, the differences in radon exposure according to two groups (< 1 and 1-6 years old) were evaluated considering various indoor and outdoor environments, timeactivity patterns, variations in radon concentrations, and dwelling type (single detached and apartment house) using Monte-Carlo simulation. The distribution and representative values of radon concentration by micro-environments were confirmed through the Anders-Darling test, and a uniform distribution was applied in case of uncertainty. The effective dose ranged from 1.81 ± 1.19 to 2.81 ± 3.02mSv/y. Comparing the levels recommended by EPA, WHO, and ICRP with the value of the 95th percentile of this study, it was found that the results for those dwelling in detached houses exceeded recommended levels. Infants that spend a lot of time in homes with relatively high levels of concentration of radon are assessed to be somewhat more vulnerable to radon exposure.

본 실험은 붕어(Crucian carp, Carassius carassius)(무게 39.7±3.1 g, 전장 14.8±0.5 cm)의 수인 성 니켈 0, 10, 20, 40, 80 및 160 mg Ni2+/l 농도로 96시간 급성 노출을 실시하였다. 수인성 니 켈에 노출된 붕어의 반수치사농도(LC50)는 117.69 mg Ni2+/l으로 나타났다. 혈액학적 성상에서 RBC count는 수인성 니켈 96시간 급성 노출 중 48시간에서 유의적으로 증가한 반면, 96시간에 서 유의적 감소가 나타났다. MCV와 MCH는 96시간에서 80 mg Ni2+/l 농도에서 유의적으로 증 가했다. Calcium, magnesium, glucose, cholesterol, total protein, AST, ALT 및 ALP 와 같은 혈장 성분은 수인성 니켈 노출에 의해 유의적 변화가 나타났다. 이 연구의 결과는 수인성 니켈 노출 에 따른 붕어의 생존율, 혈액학적 성상 및 혈장 성분의 변화를 확인하고 이는 수인성 니켈의 독성에 의한 것으로 판단했다.

In this work, the ablation behavior of monolith ZrB2-30 vol%SiC (Z30S) composites were studied under various oxy-acetylene flame angles. Typical oxidized microstructures (SiO2/SiC-depleted/ZrB2-SiC) were observed when the flame to Z30S was arranged vertically. However, formation of the outmost glassy SiO2 layer was hindered when the Z30S was tilted. The SiC-depleted region was fully exposed to air with reduced thickness when highly tilted. Traces of the ablated and island type SiO2 were observed at intermediate flame angles, which clearly verified the effect of flame angle on the ablation of the SiO2 layer. Furthermore, the observed maximum surface temperature of the Z30S gradually increased up to 2,200 °C proving that surface amorphous silica was continuously removed while monoclinic ZrO2 phase began to be exposed. A proposed ablation mechanism with respect to flame angles is discussed. This observation is expected to contribute to the design of complex-shaped UHTC applications for hypersonic vehicles and re-entry projectiles.

This study investigated the changes in fruit quality characteristics and how they correlated with the storage conditions and storage period. The firmness of peaches stored in cold storage decreased rapidly after 14 days (13.0 N), but the firmness of peaches stored in CA storage remained high for 28 days (20.9 N). The titratable acidity of peaches stored in cold storage decreased rapidly from 0.23 to 0.26% after 21 days, but there was no change until 7 days for peaches stored in CA storage, and then it decreased to 0.23% after 28 days. The soluble solid content increased significantly as the storage period elapsed under cold storage, but there was no notable difference for CA storage. After 28 days of storage, the weight loss rate of peaches stored in CA storage(8%) was lower than peaches stored in cold storage( 23%). The was significant background color for peaches stored in cold storage after 7 days, and changed to a completely different color after 28 days of storage. As for the correlation between the quality characteristics of peach fruits stored at low temperatures, weight loss rate, sunny side ΔE value, background color lightness, background color redness, and ΔE value showed high correlations, and CA storage showed high correlations with weight loss rate and coloration. In conclusion, according to our study results, 'Kunika' peaches can be stored for 14 days in low-temperature storage and up to 28 days in CA storage, and it is thought that the weight loss rate, firmness, and coloration during storage can be used as factors for quality prediction.

To predict the quality of Fuji apples, this study investigated the characteristics and correlations of their fruit quality according to storage method and storage period. Fuji apples were stored in cold storage at 0oC for 250 days with no treatment, with 1-MCP treatment, and under controlled atmosphere (CA) storage. According to the storage method, the weight loss was the lowest in the CA-treated group (3.43%) until 250 days, and the change in fruit firmness was the least in the 1-MCP group. The titratable acidity remained above 0.2% for 1-MCP and CA storage until 250 days and decreased to 0.1% for cold storage. The principal component analysis showed a difference in quality between the 1-MCP group, CA group, and cold storage group after 200 days of storage. Six types of volatile components were commonly detected in all storage methods, while three types of independent components with a low threshold were detected in 1-MCP. Weight loss, titrable acidity, and firmness were highly correlated with physicochemical quality, and CA storage was judged to be a long-term storage technology that satisfies consumers’ tastes by maintaining excellent flavor and quality.

The experimental fish transplanted from China in 2015 was used after seedling production and cultivated. Breeding management for experiment was carried out from October 2020 to February 2021. Also, it succeeded in inducing artificial maturation three to four months earlier than wild broodstock and secured good quality fertilized eggs. The average size of fertilized eggs was 1.22 mm, at 20℃ Blastodisc (15 minutes post-fertilization), 2 cell (50 minutes), 4 cell (1 hours), 8 cell (2 hours), 16 cell (2 hours and 30 minutes), 32 cell (2 hours and 50 minutes), morula (3 hours), blastula (8 hours), gastrula (15 hours), skull formation (20 hours), organ formation (30 hours) and hatching yolk larvae stage (35 hours). The total length of the just hatched larvae were 2.50 ± 2 mm, and then gain growth of 42.5 mm by 60 days, reaching 45 ± 5 mm.

본 연구는 다양한 결실기로 육성한 산초나무 5개의 신품종(한초 915호, 한초 930호, 한초 10호, 한초 1020호, 한초 1030호)에 대해 잎과 가시의 형태적 특성을 조사하여 비교하였다. 조사는 질적 특성과 양적 특성으로 구분하여 실시하였으며, 양적 특성은 일원배치 분산분석(One-Way ANOVA)과 Scheffe의 다중검증(Scheffe's multiple range test)으로 품종 간 차이를 확인하였다. 또한 요인분석을 이용하여 조사한 특성의 기여도를 확인하였다. 그 결과 잎 길이에서는 유의한 차이를 확인하지 못했으나, 정소엽의 거치 수, 소엽의 수, 가시의 크기에서 품종 간 유의한 차이가 있었으며, 요인분석도 유사한 결과를 확인 하였다. 또한 비가중평균결합(Unweighted pair-group method using arithmetic averages) 군집분석을 수지도(dendrogram)로 확인한 결과, 한초 1020호와 1030호가 근접하고, 한초 915호와 930호가 근접하였으나 개화기와 결실기에서 뚜렷한 차이로 품종이 구분되는 것을 확인할 수 있었다.