A total of 51 vegetables and fruits, commonly consumed agriculture products in Korea, were analyzed for their α-carotene, β- carotene, and β-cryptoxanthin contents as provitamin A. The beta-carotene content (μg/100 g) was high in a few green leaf vegetables such as coriander (5,924.07), gegeol radish leaf (5.855.72), and curried mallow (5,138.01), while α-carotene and β-cryptoxanthin contents were not detected. The β-carotene in 8 kinds of 20 general vegetables was detected in the range of 214.06~1,437.67 μg/100 g, while α-carotene was detected at 460.17 μg/100 g in only old pumpkin. The β-cryptoxanthin was detected in the range of 106.55~315.49 μg/100 g in Japanese elm, watermelon, white cucumber, and lettuce. However, carotenoids were not detected in 10 kinds of agricultural products including oriental melon, potato, etc. In fruits, the beta-carotene contents ranged from 165.72~3,997.39 μg/100 g, showing maximum value in apple mango and minimum value in persimmon. The β-cryptoxanthin was detected at 232.22 μg/100 g in only passion fruit, while the α-carotene was detected at 77.25 μg/100 g in only darae. Thus, based on the analyzed results of carotenoids of agriculture products consumed or cultivated in Korea, and it was found that green leaf vegetables comprise high beta-carotene overall.

해수 속의 용존 유기·무기물과 플랑크톤 등의 상호 작용은 해수의 색과 광학적 특성을 결정한다. 동중국해에 위치한 이어도 해양과학기지(I-ORS) 주변의 해역은 서쪽으로 양자강 저염수, 남쪽으로 대마 난류에 영향을 받아 한반도 주변의 해수 순환과 광특성 변동 연구에 적합하다. 본 연구에서는 MODIS/Aqua로 관측한 위성 원격 반사도와 NOMAD 실측 원격 반사도를 이용하여 2016년 1월부터 2020년 12월까지 I-ORS 주변의 해수의 원격반사도를 스펙트 럼 특성에 따라 23가지의 유형으로 분류하였으며, 이어도 해양 과학기지 주변 해역(d ≤ 10 km)의 위성 일치점 자료 59,532개를 이용하여 연구 해역 수형의 계절 변동 특성을 제시하였다. 각 관측 지점에서의 원격 반사도 스펙트럼은 분 광 각도법을 이용하여 기준 스펙트럼과의 유사도를 비교함으로써 가장 근접한 기준 수형으로 분류 하였으며 분광 유사 도가 10o 이내일 때만 유의미하다고 판단하였다. 연구 기간내 I-ORS 주변 해역에서는 상대적으로 맑은 해역에서 잘 나 타나는 수형이 50% 이상으로 가장 빈번하게 관측되었다. 계절별 수형의 도수분포에서 여름과 겨울의 분포 양상이 다르 게 나타났고, 특히 여름에는 맑은 해수에서 주로 나타나는 7 이하의 수형이 주로 출현한 반면에 겨울에는 전체 4% 미 만으로 존재하였다. I-ORS 주변을 비롯한 동중국해의 수형의 공간 분포 특성을 고려할 때 I-ORS는 해수 수형의 전이 대에 위치한 것으로 판단된다. 본 연구는 한반도 연안에서의 수형 변동을 분석함으로써 해수의 광학 특성 이해을 이해 하고 인공위성 해색 변수의 정확도 향상을 위한 토대 마련에 기여할 것으로 기대된다.

A strain of Alexandrium species was established by isolating cells from Jangmok Bay, Korea. Its morphology and molecular phylogeny based on LSU rRNA gene sequences were examined. In addition, growth responses of this Alexandrium species to changes in temperature, salinity, and nutrient concentrations were investigated. This Alexandrium species from Jangmok Bay had a ventral pore on the 1′, which was morphologically consistent with previously described Alexandrium tamarense and A. catenella. Phylogenetic analyses revealed that this isolate was assigned to A. pacificum (Group IV) within A. tamarense species complex. In growth experiments, relatively high growth rates and cell densities of A. pacificum (Group IV) were observed at 15°C and 20°C. This species also grew under a wide range of salinity. This indicates that this Korean isolate of A. pacificum (Group IV) is a stenothermic and euryhaline species. In growth responses to changes in nutrient levels, enhanced growth rates and cell densities of A. pacificum (Group IV) were observed with additions of nitrate and phosphate. In particular, rapid uptakes of phosphate by A. pacificum (Group IV) were observed in experimental treatments, indicating that the increase in phosphate concentration could stimulate the growth of A. pacificum (Group IV).

Anthropogenic disturbances on freshwater ecosystem are known to degrade biodiversity, especially on fish assemblage. In this study, we have conducted fish surveys to identify impact of a bridge construction on fish assemblages. A total of eight study sites were surveyed in the Danjang and the Dong Stream in southern part of South Korea from June to November in 2021. The fish samplings were carried out five times, using cast-nets (10×10 mm mesh size), scoop-nets (4×4 mm, 5×5 mm mesh size), set-nets (10×10 mm mesh size), and fish traps (3×3 mm mesh size), along with the Stream/River Ecosystem Survey and Health Assessment by the Ministry of Environment of Korea and basic water quality measurement. Also, we applied the species diversity index and length-weight relationship regressions on certain species to identify interspecific growth rate differences in accordance with study sites. As a result, a total of 782 individuals, 23 species and 10 families were collected. The dominant species was Zacco Koreanus and relative abundance was 50.89%. When applying the length-weight relationship regressions on certain species, the ‘b’ value for Z. Koreanus was lower at the downstream points than at the upstream points of the construction site. In addition, when comparing to the results of the past survey, relative density of demersal fish at the upstream and downstream points decreased from 26% to 1.4%, and from 18% to 6.3%, respectively. In conclusion, it is considered that bridge construction negatively affects the habitat of fishes, especially on demersal fishes. Therefore, appropriate conservation efforts such as installation of silt protector and sand sedimentation pond are needed to alleviate the disturbance in habitat such as occurrence of turbidity and destruction of micro-habitats.

Coffee is the most popular beverage in the world and various pollutants, including volatile organic compounds (VOCs), are emitted from the coffee manufacturing workplace (roasting process). In this study, we analyzed the characteristics of VOCs emissions from roasted Arabica coffee bean powder using a VOCs emission chamber with a PTR-ToF-MS. The emission test was maintained under constant temperature (20 ± 2oC) and humidity (50 ± 5%) conditions. As a result of the emission test, most of the target compounds had a high concentration in the initial period, and decreased emissions as time lapsed. Acetaldehyde showed the highest concentration and was initially 78 ppm during the test period. Acetaldehyde was followed by propionic acid at 61 ppm, propanal at 51 ppm, and isobutanal at 50 ppm. As a result of comparing the occupational exposure limits (OELs) of individual VOC emitted during the coffee roasting process, the OELs of four substances, including acetaldehyde, propionic acid, acetic acid, and pyridine were identified. Of all four substances, only pyridine exceeded the OELs, and the other compounds had levels of 10% to 30% of the OELs.

The purpose of this study is to evaluate seismic performances of a modular house system developed by a simple 4-clip fastening method and double metal assembly made of lightweight metals. In order to evaluate structural and non-structural seismic performances of the system. Shaking table test was carried out with full-scale modular units, and a nonlinear pushover analysis was performed to obtain suitable seismic responses for story drifts, displacements, force resistances and dynamic properties of the system. Through 3D analysis and shaking table test, the current method of lightweight modular metal unit assembly and systems with seismic performance of a 4-clip fastening type modular house were demonstrated safe and effective to seismic design.

In this paper, the instability of the domed spatial truss structure using wood and the characteristics of the buckling critical load were studied. Hexagonal space truss was adopted as the model to be analyzed, and two boundary conditions were considered. In the first case, the deformation of the inclined member is only considered, and in the second case, the deformation of the horizontal member is also considered. The materials of the model adopted in this paper are steel and timbers, and the considered timbers are spruce, pine, and larch. Here, the inelastic properties of the material are not considered. The instability of the target structure was observed through non-linear incremental analysis, and the buckling critical load was calculated through the singularities and eigenvalues of the tangential stiffness matrix at each incremental step. From the analysis results, in the example of the boundary condition considering only the inclined member, the critical buckling load was lower when using timber than when using steel, and the critical buckling load was determined according to the modulus of elasticity of timber. In the case of boundary conditions considering the effect of the horizontal member, using a mixture of steel and timber case had a lower buckling critical load than the steel case. But, the result showed that it was more effective in structural stability than only timber was used.

큰앵초의 특성조사는 소백산(연화봉), 주흘산(주봉), 덕유산(삿갓봉), 가야산(두리봉), 지리산(노고단) 등 5개 지역을 대상으로 2018년 4월부터 2020년 11월까지 실시하였다. 큰앵초의 높이는 23.1∼31.3㎝이고, 평균 26.8㎝이며, 잎의 수는 2.9∼4.7개이고, 평균 3.8개이다. 엽신의 길이는 6.2∼7.6㎝이고, 평균 7.1㎝이며, 엽신의 너비는 7.8∼9.3㎝이고, 평균 8.7㎝이며, 엽병의 길이는 10.9∼16.5㎝이고, 평균 13.5㎝이다. 잎의 길이와 폭의 비율은 0.79∼0.82로 광타원형이다. 엽연의 형태는 결각이 둔하고 불규칙적인 것과 예리하고 깊으며 규칙적인 것으로 나타났다. 뿌리의 길이는 5.9∼10.9㎝이고 평균 7.2㎝이며, 뿌리 수는 27.6∼48.2개이고, 평균 37.7개이다. 개화기는 5월말∼6월 초이며, 꽃의 수는 5.4∼10.1개이고, 평균 7.2개이다. 화관너비는 21.7∼26.2㎜이고, 평균 23.4㎜이다. 열매의 길이는 1.3㎜∼2㎜이고, 평균 1.8㎜이며, 종자의 수는 10개∼18.2개이고, 평균 14.2개이다. 조사지의 상층우점종은 신갈나무이고, 중층은 당단풍나무, 노린재나무, 함박꽃나무 등이며, 하층은 철쭉, 진달래, 미역줄나무, 국수나무 등으로 나타났고, 종다양도는 0.7534∼0.9950으로 나타났다. 조사지의 토양 pH는 4.1∼4.6이고 염기포화도는 3.18%∼9.09%로 나타났다. EC는 0.18∼0.7dSm-1으로 나타났고, NaCl은 0.003∼0.006%로 나타났다.

PURPOSES : A methodology for estimating micro-emission factors using vehicle trajectory data collected from navigation and DTG devices and basic emission factors for each vehicle type of the MOtor Vehicle Emission Simulator (MOVES) is presented. The methodology can calculate micro-emissions based on only the traffic volume and average speed for each vehicle type. METHODS : Cluster analysis was performed by accumulating the trajectories of individual vehicles on a specific road section into speed groups in which vehicles drove with the same range of average speed. Then, the micro-emission factors were estimated for each speed group. RESULTS : Using the vehicle trajectory data revealed that the emissions calculated from micro-emission factors estimated by the proposed methodology were similar to the sum of the emissions calculated from the vehicle trajectories for each vehicle. CONCLUSIONS : The micro-emission factor database for each road type and vehicle type proposed in this study should be useful for estimating vehicle emissions on the road. The proposed method can calculate emissions in the same way as the macroscopic analysis method, using the traffic volume, average speed, and link length.

PURPOSES : The purpose of this study was to reduce greenhouse gases and prevent potholes on roads by evaluating the performances of hot and warm mixed asphalt mixtures. METHODS : Quality tests were conducted using an appropriate aggregate ratio of the asphalt mixture. The tests for comparing the warm mixed asphalt mixture are the indirect tensile strength and toughness, Marshall stability and flow, tensile strength ratio, and dynamic immersion test. A performance evaluation was conducted using a mixture that satisfied the quality test results. A performance evaluation test was also conducted using the dynamic modulus and Hamburg wheel tracking test. To analyze the performance based on the amine content, the performance was compared with that of a hot mixed asphalt mixture. RESULTS : All tests for the mixture results satisfied the standard values. The optimal amine content was analyzed through the high and low frequencies of the dynamic modulus test results and stripping inflection point with the final rut depth of the Hamburg wheel tracking test. The dynamic modulus test results demonstrated better crack resistance and plastic deformation when a high amine content ratio was used. The Hamburg wheel-tracking test showed water resistance and plastic deformation resistance. The test results of the Hamburg wheel tracking indicated better deformation resistance and water resistance when a high amine content ratio was used. CONCLUSIONS : The plastic deformation and crack resistance increased with an increase in amine content. Analysis of the comprehensive test revealed that the optimal amine content was between that of additives B(50%) and C(65%). Tests with a granular amine content are planned to confirm the specific components. Also planned are a simplified viscoelastic continuum damage test and a semicircular bending test to evaluate the performance better.

Novel Ni- and Fe-based alloys are developed to impart improved mechanical properties and corrosion resistance. The designed alloys are manufactured as a powder and deposited on a steel substrate using a high-velocity oxygen-fuel process. The coating layer demonstrates good corrosion resistance, and the thus-formed passive film is beneficial because of the Cr contained in the alloy system. Furthermore, during low-temperature heat treatment, factors that deteriorate the properties and which may arise during high-temperature heat treatment, are avoided. For the heattreated coating layers, the hardness increases by up to 32% and the corrosion resistance improves. The influence of the heat treatment is investigated through various methods and is considered to enhance the mechanical properties and corrosion resistance of the coating layer.

Asthma is a chronic inflammatory disease characterized by recurring symptoms, airflow obstruction, and bronchial hyper-responsiveness. The onset of asthma for most patients begins early in life, and current asthma treatment with anti-inflammatory agents can have adverse effects, eventually leading to impaired quality of life. In the pathogenesis of asthma, macrophages and basophils play a vital role during progression. Macrophages not only induce inflammation by secreting inflammatory cytokines but also promote DNA damage and mucus production through nitric oxide (NO) production. Basophils enhance eosinophil recruitment and aggravate asthma through the FcεRIα receptor with high affinity for histamine and IgE. Therefore, in this study, we investigated whether the activation of macrophages and basophils is suppressed by the individual extracts of 28 natural products. RAW 264.7 cells (mouse macrophages) were treated with the natural products in LPS, and 4 natural product extracts resulted in decreased NO production. In β-hexosaminidase assay using RBL-2H3 cells (rat basophils), 19 natural product extracts decreased β-hexosaminidase production. In NO production and β-hexosaminidase assay using macrophages and basophils, 3 natural product extracts (Plantago asiatica, Centella asiatica, and Perilla frutescens var. japonica) significantly inhibited NO production and β-hexosaminidase release. Overall, we examined the inhibitory effects of 28 natural product extracts on macrophage and basophil activity, and the findings demonstrated the potential of natural product extracts for treating asthma and macrophage- and basophil-related diseases.