• 한국응용과학기술학회지
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• 제31권3호
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• pp.453-465
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• 2014

본 논문에서는 바이오매스로부터 급속열분해를 통해 난방용, 발전용 및 수송용 연료로 사용하기 위해 바이오오일을 생산하는 기술개발 현황을 나타내었다. 바이오매스를 작은 규모의 액체연료로 전환하기 위해 가장 효율적인 방법 중 하나는 급속열분해이다. 급속열분해를 통한 바이오오일은 $450^{\circ}C{\sim}600^{\circ}C$ 온도에서 바이오매스가 신속히 열분해 되어 증기 급냉를 위해 외부 산소가 없는 조건에서 생산된다. 이 바이오오일은 최초 건조 바이오매스 기준 최대 75 무게%까지 생산할 수 있지만, 일반적으로 60-75 무게% 수준이 적합하다. 본 연구에서는 바이오매스의 원료특성, 바이오오일 생산원리, 바이오오일의 특성 및 활용분야에 대한 최근의 개발현황을 살펴보았다.

• 한국추진공학회지
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• 제18권5호
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• pp.79-86
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• 2014

터보펌프 실매질 시험설비는 액체산소와 케로신을 토대로 터보펌프 조립체의 성능을 검증하는 시험설비이다. 이 시험설비 중에서 가장 핵심적인 부분은 터보펌프의 구동력을 생성시키는 고온공기 생성시스템이다. 고압공기와 에탄올을 사용하는 알코올버너에 의해 시험시설에서 요구되는 유량과 온도가 생성된다. 본 연구에서는 국내기술로 제작한 알코올버너의 개발시험을 수행하였으며, 터보펌프 실매질 시험설비 구축에 앞서 버너의 제작기술과 운용경험을 확보할 수 있었다. 75톤급 터보펌프 실매질 시험에서는 이 알코올버너가 2기 동시 운용되어 터빈이 요구하는 구동력을 충족시킬 것으로 보인다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권6호
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• pp.80-90
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• 2014

The laboratory and field studies were conducted to identify an optimal injection concentration of nanoscale zero-valent iron particles (NZVI) and to evaluate the applicability of NZVI-based reactive zone technology to the site contaminated with trichloroethylene (TCE) DNAPL (Dense Non-Aqueous Phase Liquid). The laboratory test found an optimal injection concentration of NZVI of 5 g/L that could remove more than 95% of 0.15 mM TCE within 20 days. Eleven test wells were installed at the aquifer that was mainly composed of alluvial and weathered soils at a strong oxic condition with dissolved oxygen concentration of 3.50 mg/L and oxidation-reduction potential of 301 mV. NZVI of total 30 kg were successfully injected using a centrifugal pump. After 60 days from the NZVI injection, 86.2% of the TCE initially present in the groundwater was removed and the mass of TCE removed was 405 g. Nonchlorinated products such as ethane and ethene were detected in the groundwater samples. Based on the increased chloride ion concentration at the site, the mass of TCE removed was estimated to be 1.52 kg. This implied the presence of DNAPL TCE which contributed to a higher estimate of TCE removal than that based on the TCE concentration change.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.110-110
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• 2019

Beet (Beta vulgaris) is a crop similar to sugar beet, chard and leaf beets, and its origin is the Mediterranean coast of southern Europe and Central Asia. Among the components contained in beet, betalain, the main component of the root, has been reported to prevent lipid peroxidation induced by active oxygen and free radicals due to its high radical scavenging ability. Among these, the betalain, betanin (Betanidin 5-O-${\beta}$-glucoside) contains both phenolic and cyclic amine groups, all of which are highly electron-donating and act as antioxidants and has tyrosinase inhibitory activity. Betanin accounts for about 75-95% of the total pigment found in the beet. EM stands for effective microorganisms and is a collection of beneficial microorganisms. EM includes yeast, lactic acid bacteria, mycelia, photosynthetic bacteria, actinomycetes, etc. Human patch test according to CTFA guidelines was observed to be a safe source of no stimulation when 5% (v/v) of the EM fermentation liquid was applied to the human body. In addition, beneficial microorganisms are synergistic in the process of co-existence and cultivation and it has the effect of increasing antioxidant capacity and inhibiting corruption. This study confirms the difference in tyrosinase inhibitory activity and betanin content of beetroot extracts and EM fermented beetroot extracts. Hence, these results confirm that EM fermented beetroot extracts are highly beneficial for the human body.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.81-81
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• 2019

Ginseng seeds are one of short-lived seeds species which loose their viability easily in the condition of conventional storage. Cryopreservation using liquid nitrogen (LN) has been recommended as a alternative storage for this kind of germplasm short lived or dessiccation-sensitive. This study was performed to find out whether cryopreservation could affect physiological change such as enzyme activity induced by reactive oxygen species. In this work, the redox ratio of ascorbate and glutathione were examined onto ginseng seedlings before and after LN storage of seeds for 1 day using spectrophotometer method. Reduced ascorbate (ASA) was increased while oxidized ascorbate (DHA) was decreased slightly for both after 1d-LN storage. And for glutathione also, reduced form (GSH) was increased while oxidized form (GSSG) was decreased slightly for both after 1d-LN storage. Consequently total phenol compound and ion leakage after LN storage showed no significant differences. Additionally root growth from the seeds after LN storage was not affected by ultra low temperature. From the above results, we may suggest that cryopreservation could be recommended for storage tool of ginseng seeds even with low viability also and expected to make slower seed aging process during preservation period through further study.

• 한국분무공학회지
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• 제24권1호
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• pp.35-42
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• 2019

Syngas is widely produced by incomplete combustion of coal, water vapor, and air (oxygen) in a high-temperature/high-pressure gasifier through a coal-gasification process for power generation. In this study, a simulation syngas which was mainly composed of $H_2$, CO, $CO_2$, and $N_2$ was fueled with diesel. A modified single cylinder compression ignition (CI) engine is equipped with intake port syngas supply system and mechanical diesel direct injection system for dual fuel combustion. Combustion and emission characteristics of the engine were investigated by applying various syngas composition ratios and compression ratios. Diesel fuel injection timing was optimized to increase indicated thermal efficiency (ITE) at the engine speed 1,800 rpm and part load net indicated mean effective pressure ($IMEP_{net}$) 2 to 5 bar. ITE of the engine increased with the $H_2$ concentration, compression ratio and engine load. With 45% of $H_2$ concentration, compression ratio 17.1 and $IMEP_{net}$ 5 bar, ITE of 41.5% was achieved, which is equivalent to that of only diesel fuel operation.

• The Plant Pathology Journal
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• 제35권3호
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• pp.208-218
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• 2019

Here, we reported a novel secreted protein elicitor PeBL2 from Brevibacillus laterosporus A60, which can induce hypersensitive response in tobacco (Nicotiana benthamiana). The ion-exchange chromatography, high-performance liquid chromatography (HPLC) and mass spectrometry were performed for identification of protein elicitor. The 471 bp PeBL2 gene produces a 17.22 kDa protein with 156 amino acids containing an 84-residue signal peptide. Consistent with endogenous protein, the recombinant protein expressed in Escherichia coli induced the typical hypersensitive response (HR) and necrosis in tobacco leaves. Additionally, PeBL2 also triggered early defensive response of generation of reactive oxygen species ($H_2O_2$ and $O_2{^-}$) and systemic resistance against of B. cinerea. Our findings shed new light on a novel strategy for biocontrol using B. laterosporus A60.

• Journal of Ceramic Processing Research
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• 제20권2호
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• pp.158-163
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• 2019

Er3+/Yb3+-codoped NaLa(MoO4)2 colloidal nanocrystals were synthesized by pulsed laser ablations in de-ionized water and sodium dodecyl sulfate (NaC12H25SO4, SDS) aqueous solution for up-conversion (UC) luminescence bio-labeling applications. The influences of the SDS molecules on the crystallinities, crystal morphologies, crystallite sizes, and UC luminescence properties of the prepared Er3+/Yb3+-codoped NaLa(MoO4)2 colloidal nanocrystals were investigated in detail. Under a 980-nm excitation, the Er3+/Yb3+-codoped nanocolloidal NaLa(MoO4)2 suspension exhibited a weak red emission near 670 nm and strong green UC emissions at 530 and 550 nm, corresponding to the intra 4f transitions of Er3+ (4F9/2, 2H11/2, 4S3/2) → Er3+ (4I15/2). When the SDS solution was used, a smaller average crystallite size, narrower size distribution, and enhanced UC luminescence were observed. These characteristics were attributed to the amphoteric SDS molecules attached to the positively charged Er3+/Yb3+-codoped NaLa(MoO4)2 colloidal nanocrystals, effectively occupying the oxygen defect on their surfaces. The Er3+/Yb3+-codoped nanocrystalline NaLa(MoO4)2 suspension prepared in the SDS solution exhibited a remarkably strong green emission visible to the naked eyes.

• 한국추진공학회지
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• 제25권3호
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• pp.89-100
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• 2021

본 논문에서는 메탄엔진 연소시험을 위한 연소시험설비 구축과 예비 시험들을 다루었다. 먼저 액체산소/기체메탄을 추진제로 사용하는 1 kN급 연소기 연소시험설비를 설계 및 구축하였다. 연소시험 전 각 추진제 라인의 수류시험 및 토치 점화기/애프터버너의 점화시험을 통해 연소시험설비의 추진제 공급 안정성, 제어 및 계측시스템 작동, 성공적인 점화를 검증하였다. 마지막으로 예비 연소시험을 수행하여 연소기 시제품의 연소 효율, 열유속, 연소 안정성을 측정하였다. 구축된 연소시험설비는 메탄엔진 연소기 기초연구 및 개발에 유용하게 활용될 예정이다.

• The Plant Pathology Journal
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• 제38권3호
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• pp.182-193
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• 2022

Turfgrass, the most widely grown ornamental crop, is severely affected by fungal pathogens including Sclerotinia homoeocarpa, Rhizoctonia solani, and Magnaporthe poae. At present, turfgrass fungal disease management predominantly relies on synthetic fungicide treatments. However, the extensive application of fungicides to the soil increases residual detection frequency, raising concerns for the environment and human health. The bacterial volatile compound, 2,3-butanediol (BDO), was found to induce plant resistance. In this study, we evaluated the disease control efficacy of a combination of stereoisomers of 2,3-BDO and commercial fungicides against turfgrass fungal diseases in both growth room and fields. In the growth room experiment, the combination of 0.9% 2R,3R-BDO (levo) soluble liquid (SL) formulation and 9% 2R,3S-BDO (meso) SL with half concentration of fungicides significantly increased the disease control efficacy against dollar spot and summer patch disease when compared to the half concentration of fungicide alone. In field experiments, the disease control efficiency of levo 0.9% and meso 9% SL, in combination with a fungicide, was confirmed against dollar spot and large patch disease. Additionally, the induction of defense-related genes involved in the salicylic acid and jasmonic acid/ethylene signaling pathways and reactive oxygen species detoxification-related genes under Clarireedia sp. infection was confirmed with levo 0.9% and meso 9% SL treatment in creeping bentgrass. Our findings suggest that 2,3-BDO isomer formulations can be combined with chemical fungicides as a new integrated tool to control Clarireedia sp. infection in turfgrass, thereby reducing the use of chemical fungicides.