• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.5-14
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• 2017

This study was conducted to investigate the effects of nutrient solution strength on growth and nutrient element concentrations in leaf lettuce (Lactuca sativa L. cv. 'Dduksum') by hydroponic culture under fluorescent lamp and LED. Leaf lettuce were grown in closed hydroponic cultivation systems supplied with 1/2, 1 and 2 strength of nutrient solution recommended by horticultural experiment station in Japan. The growth of 'Dduksum' was highest in the 2 strength of standard nutrient solution. The amount of nutrient element in the recycled nutrient solution was higher at 2, 1 and 1/2 strength of nutrient solution. The concentration of NO₃-N, Ca²⁺, Mg²⁺ in the recycled nutrient solutions increased in 1 and 2 strength of nutrient solution but that of NH₄-N decreased gradually in 1/2 and 1 strength of nutrient solution. The concentration of K, Ca, Mg in leaf lettuce was maintained in the normal range, whereas the concentration of phosphorous was 1.3 to 1.6%, which was higher than proper range. As the concentration of NH₄-N decreases gradually in all the treatments, it is necessary to raise the rate of NH₄-N or add it.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.139-151
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• 2017

This study was conducted to confirm the rumen fermentation characteristics of large-scale CoenzymeQ10(CoQ10) producing bacteria R. spharoides in rumen. We conducted in vitro continuous culture test to investigate the characteristics of rumen fermentation with 5% R. spharoides as a direct fed microorganism. A rumen microbial fermentation characteristic has stability at after 12 days for 15 day of experimental period. pH value, NH₃-N, microbial protein synthesis, ADF digestibility and NDF digestibility were not shown significantly differences between control and treatment. However, UDP was significantly higher in treatment than control (p<0.05). CoQ10 concentration was 336.0mg/l with 5% R. spharoides. On the other hands, CoQ10 was not detected without R. spharoides. Our study was shown that R. spharoides can produce CoQ10 in rumen environment without harmful effects on rumen fermentation parameter. CoQ10 in rumen may transfer into cow milk through cow metabolism. This strategy might be helpful for producing functional dairy cow milk.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.5-13
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• 2019

The first commercial planting of sweet cherry in Korea is thought to be done in early 1920s. The planting area of sweet cherry in Korea is about 500 ha in 2017. Although sweet cherry is considered a minor fruit in Korea, it is one of premium fruits in market and popular among children and women, especially among pregnant women. The import of sweet cherry fruits has increased dramatically in recent years. Seedlings of Prunus lannesiana or clones of 'Colt' (P. avium × P. pseudocerasus) were usually used as sweet cherry rootstocks in Korea. During recent decades new dwarfing rootstocks for cherry such as 'Gisela' series were developed in Germany. Among them, several 'Gisela' series have been mainly used in international nurseries. In this study, we investigated optimum rooting condition of a dwarfing rootstock 'Gisela 5' in summer season cuttings. Among eight soil conditions tested, saprolite + commercial nursery soil (1:1) and saprolite + vermiculite (1:1) showed higher rooting percentage than others, showing 93.6% and 88.9%, respectively. More than 95% of 'Gisela 5' rootstocks produce roots when it was treated with IBA for several seconds just before cuttings, irrespective of concentrations (500 to 2000 mg·L^-1).

• Journal of Korean Society of Disaster and Security
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• v.16 no.3
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• pp.1-15
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• 2023

This study focuses on modeling the impact of ammonia leakage from the storage tank in a combined cycle power plant's flue gas denitrification facility. It employs accident impact assessments and diffusion models to determine the optimal scenarios for ammonia storage tank leakage accidents. The study considers the operating conditions of variables as standard conditions for predicting the extent of damage. The Taean combined cycle power plant is chosen as the target area, taking into account seasonal factors such as temperature, humidity, wind speed, atmospheric stability, and wind direction. By utilizing a Gaussian diffusion model, the concentration of ammonia gas at various locations is estimated to assess the potential extent of external damage resulting from a leak. The study reveals that in conditions of high temperature and stable atmosphere within the specified range, lower wind speeds contribute to increased damage to the human body due to ammonia diffusion.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.57-57
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• 2020

본 연구는 국내 자생 방향성 식물의 자원발굴과 증식, DB 구축을 위하여 수행되었다. 배초향은 꿀풀과에 속하는 다년생 식물로 대표적인 한국의 방향식물이다. 한의학에서는 배초향의 지상부를 곽향이라 하여 음식으로 인한 체증, 오한, 복통 등을 치료하는 한약재로 사용되며 그 밖의 관상용, 밀원용, 식품용, 향신료 등 다양한 산업제품의 원료로 사용되고 있다. 배초향의 유전형질 특성 및 정유성분 조사를 위하여 국립농업유전자원센터로부터 배초향 종자(30자원)를 분양받아 발아시킨 후 시험연구포장에 증식하였다. 증식된 배초향을 대상으로 개화기, 식물 및 꽃의 색, 잎의 모양 등 개체별 형질특성을 조사하였으며 일정시기에 일시 수확하여 정유추출 후 GC/MS 분석을 통하여 정유의 화학성분을 분석하였다. 배초향의 개화시기는 6월 10일 경~7월 29일 경이었고 초장은 약 80cm~186cm이었다. 잎의 모양은 30자원 중 광난형 12자원, 피침형 10자원, 난형 8자원의 분포였고 식물체의 색은 green과 red-purple 계열이 각각 22자원과 8자원이었다. 배초향 꽃의 색깔은 RHS Colour chart 참조하여 149P 10P 8/4, 129B 10P 7/8, 37V 2.5RP 4/12의 색으로 분류하여 조사하였다. 129B 10P 7/8에 해당하는 자원이 18자원으로 가장 많은 분포를 차지하였다. 배초향의 정유성분 분석 결과, 정유수율은 0.11%~0.44%이었고 정유성분은 estragole, methyl eugenol, menthone 등이었다. 배초향의 주성분으로 알려진 estragole은 30자원 중 13자원의 주요정유성분인 것으로 나타났다.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.590-595
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• 2023

Novel aromatic imine derivatives with yellow were designed and synthesized for their potential application in color filters for image sensors. The synthesized compounds possessed chemical structures using aromatic imine groups. This innovative material was evaluated thoroughly, considering its optical and thermal properties under conditions similar to commercial device manufacturing processes. Following a rigorous performance evaluation, it was found that (E)-3-methyl-4-((3-methyl-5-oxo-1-phenyl-1H-pyrazol-4(5H)-ylidene)methyl)-1-phenyl-1H-pyrazol-5(4H)-one, abbreviated as MOPMPO, exhibited an impressive solubility of 0.5 wt% in propylene glycol monomethyl ether acetate, predominantly utilized as the solvent in the industry. Furthermore, MOPMPO showed exceptional performance as a color filter material for image sensors, having a high decomposition temperature of 290 ℃. These data unequivocally establish MOPMPO as a viable yellow dye additive for coloring materials in image sensor applications.

• Journal of Life Science
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• v.33 no.12
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• pp.987-994
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• 2023

This study examined the associations between the genotypes of the galactose mutarotase (GALM) gene and carcass traits in the Hanwoo population of Jeju Island, South Korea. The GALM genotypes were determined by the 14-bp (5'-GGTCTAATGACCAG-3') insertion/deletion (InDel) polymorphisms of the 3'-untranslated region (UTR). All three genotypes (LL, LS, and SS) were found in the Hanwoo steer population. The association analysis showed significant associations between genotypes and several carcass traits, including traits related to intramuscular fat content, such as meat quality, marbling score, and backfat thickness (p<0.05). Animals harboring the SS genotype showed not only higher levels of intramuscular fat content but also lower levels of backfat thickness than animals harboring the LL and LS genotypes. On the other hand, no significant associations were found between the GALM genotypes and carcass weight, eye muscle area, meat color, or fat color (p>0.05). Deleting the 14-bp segment in the 3'-UTR resulted in the modification of the secondary structure of RNA and appeared to affect gene expression by interfering with the binding ability of GALM mRNA with RNA-binding proteins and microRNAs. These results suggest that the 14-bp InDel polymorphism in the 3'-UTR region of the GALM gene affects cattle growth traits and carcass quality through galactose metabolism-mediated fat accumulation in muscle and backfat tissues.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.5
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• pp.375-387
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• 2023

The subsea power cables are increasingly important for harvesting renewable energies as we develop offshore wind farms located at a long distance from shore. Particularly, the continuous flexural motion of inter-array dynamic power cable of floating offshore wind turbine causes tremendous fatigue damages on the cable. As the subsea power cable consists of the helical structures with various components unlike a mooring line and a steel pipe riser, the fatigue analysis of the cables should be performed using special procedures that consider stick/slip phenomenon. This phenomenon occurs between inner helically wound components when they are tensioned or compressed by environmental loads and the floater motions. In particular, Vortex-induced vibration (VIV) can be generated by currents and have significant impacts on the fatigue life of the cable. In this study, the procedure for VIV fatigue analysis of the dynamic power cable has been established. Additionally, the respective roles of programs employed and required inputs and outputs are explained in detail. Demonstrations of case studies are provided under severely sheared currents to investigate the influences on amplitude variations of dynamic power cables caused by the excitation of high mode numbers. Finally, sensitivity studies have been performed to compare dynamic cable design parameters, specifically, structural damping ratio, higher order harmonics, and lift coefficients tables. In the future, one of the fundamental assumptions to assess the VIV response will be examined in detail, namely a narrow-banded Gaussian process derived from the VIV amplitudes. Although this approach is consistent with current industry standards, the level of consistency and the potential errors between the Gaussian process and the fatigue damage generated from deterministic time-domain results are to be confirmed to verify VIV fatigue analysis procedure for slender marine structures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.5
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• pp.23-29
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• 2023

The goal of this study is to evaluate the bursting characteristics and fire resistance performance of mixed cement concrete containing fibers at very high temperatures. For this purpose, FA-based, Slag-based, and each mix according to the amount of fiber mixed were heated to room temperature, 150℃, 300℃, 600℃, and 900℃, and then the burst shape, compressive strength, and elastic modulus were measured and evaluated. As a result of the experiment, it was found that relatively more surface damage occurred in FA-based specimens when heated at ultra-high temperatures than in slag-based specimens, and there was a difference between the mix without fibers and the mix with fibers when heated at ultra-high temperatures, that is, at 900℃. In the mix without fibers, a decrease in strength of more than 5% occurred. In addition, the elastic modulus also showed the same phenomenon as the compressive strength, and in particular, the decrease in elastic modulus was found to be greater than the amount of decrease in compressive strength. Meanwhile, estimation equations for compressive strength and elastic modulus according to heating temperature were statistically proposed.

• Land and Housing Review
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• v.15 no.2
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• pp.125-137
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• 2024

A conventional Design for Safety (DfS), introduced to eliminate potential hazards in the design phase proactively, has encountered persistent challenges, such as perfunctory risk assessments and hazard identifications based on 2D drawings and inefficient workflow processes. This study proposes a BIM-based approach to Design for Safety (DfS) to address the limitations of conventional methods, aiming to enhance efficiency and achieve practical safety management benefits. The proposed workflow process for BIM-based DfS has been refined and validated for on-site applicability through various case studies, including risk assessments during the design phase and field applications for safety management activities during the construction phase. Specifically, the critical process of risk assessment within the DfS methodology has also been transitioned to a BIM-based approach. This BIM-based risk assessment process has been evaluated through case studies, encompassing safety reviews for structural design, construction equipment operation, and construction methodology with sequence in design projects. Additionally, the proposed BIM-based DfS has demonstrated exceptional on-site applicability and efficiency, as validated by the application of a BIM deliverable embedded in DfS information for CDE-based daily activity briefing, VR-based safety training, AR-based mitigation measures inspections, and other safety management activities in the construction phase.