• 한국기계가공학회지
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• 제11권4호
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• pp.131-137
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• 2012

This article is about using the fuel mixed with 10% and 20% bio-ethanol to gasoline for the engine as a way to reduce carbon emission before commercializing future automobiles like fuel cell cars. The fuel mixed with 10% and 20% bio-ethanol showed output equivalent to that of the previous gasoline fuel. CO and $CO_2$ emission was somewhat reduced, but the difference was not significant. And the consumption of the fuel increased slightly. However, bio-ethanol is produced from bio mass growing with the absorption of carbon dioxide, so the total amount of carbon dioxide did not increase according to the result. In NOx, as the use of ethanol increases, the effect of reduction gets greater, and the emission of oxygen showed almost no change compared with gasoline.

• Journal of Applied Biological Chemistry
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• 제59권1호
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• pp.5-7
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• 2016

딱지꽃(Potentilla chinensis)은 약초식물의 하나로 항염, 지혈, 해독 그리고 해열 등의 효과가 알려져 있다. 특히 딱지꽃의 뿌리는 약제로써 중요한 가치를 지니고 있다. 그러나 기존에 딱지꽃의 줄기나 잎에 대한 유효성분에 대한 연구가 시도된 반면 딱지꽃의 뿌리의 주요성분을 분석한 사례가 없었다. 따라서 본 연구는 딱지꽃의 뿌리를 다양한 용매별로 추출하고 주요한 물질을 분리정제 하였다. 분리 정제된 물질을 NMR과 mass 분석을 통하여 물질을 동정하였고 그 결과 주요성분이 화합물 (1)임을 확인하였다. 또한, 동정된 물질의 산업적 응용을 위해 딱지꽃 뿌리에서 용매별로 화합물 (1) 추출양을 정량하였다.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.273-278
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• 2002

Two-step fed-batch fermentations were carried out to overproduce Bacillus licheniformis maltogenic amylase (BLMA) in recombinant Escherichia coli. The first step was to increase the cell mass by controlling the feeding of a glucose solution, while the second step was designed to improve the amylase expression efficiency by supplementing organic nitrogen sources. The linear gradient feeding method was successfully adopted to maintain the glucose concentration below 0.2 g/l during the fed-batch mode, as effectively minimizing acetic acid formation. When the dissolved oxygen (DO) level became limiting, an accumulation of acetic acid and drastic decrease in specific BLMA productivity were observed. Glucose and organic nitrogen sources consisting of yeast extract and casein hydrolysate were simultaneously supplied in the pH-stat mode to further increase the specific BLMA expression efficiency. An organic nitrogen source consisting of 200 g/1 yeast extract and 100 g/1 casein hydrolysate was found to be the best among the various combinations tested. The feeding of an organic nitrogen source in the second-step fed-batch period was highly beneficial in enhancing the BLMA production. The optimized two-step fed-batch culture resulted in 78 g/l maximum dry cell mass and 443 U/ml maximum BLMA activity, corresponding to 1.5-fold increase in the dry cell mass and 3.7-fold enhancement in BLMA production, compared with the simple fed-batch fermentation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.275-275
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• 2013

Formation and characterization of self-assembled monolayers (SAMs) on various surfaces are the essential basis for many other applications, including molecular switches, biosensors, microfluidics, and fundamental studies in surfaces and interfaces. To improve the performance at these applications, it is a key to control the quantity of each molecule in various mixed SAMs on the surface. In this study, using mixed SAM of carbamate-based hydroquinone (HQ)-PhBr and11-mercaptoundecanol, the quantitative mass spectrometric method of mixed SAM was developed based on comparison study with XPS and FT-IR methods. In addition, our method was applied to another mixed SAM of biotinylated PEG alkane thiol and 11-mercaptoundecanol for verification purpose. Time-of-flight secondary mass spectrometry (ToF-SIMS) analysis was performed to identify and quantify each molecule of mixed SAM along with principal component analysis (PCA). Since there is no matrix effect in the X-ray photoelectron spectroscopy (XPS) and Fourier transform-infrared (FT-IR) techniques, we compared ToF-SIMS results with XPS and FT-IR results. Because PCA results from ToF-SIMS analysis are well matched with XPS and FT-IR results from both mixed SAMs, we are expecting that our method will be useful to identify and quantify each molecule in various mixed SAMs.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.192-199
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• 2021

Alpine glaciers harbor a large quantity of bio-labile dissolved organic matter (DOM), which plays a pivotal role in global carbon cycling as glacial-fed streams are headwaters of numerous large rivers. To understand the complexity, origin, and fate of DOM in glaciers and downstream-linked streams and lakes, we elucidated the molecular composition of DOM in two different Tibetan Plateau glaciers, eight glacial-fed streams and five lakes, using an ultrahigh-resolution 15 Tesla Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The compositional changes of the DOM samples revealed that glacier DOM mostly exhibited sulfur-containing organic compounds (CHOS species). We also found that aliphatic formulae contributed more than 50% of the total abundance of assigned molecules in glacier samples, and those compounds were significantly related to CHOS species. The CHO proportions of glacial-fed streams and lakes samples increased with increasing distance from glacial terminals. The relative contribution of terrestrial-derived organics (i.e., lignins and tannins) declined while microbial-originated organics (aliphatics) increased with increasing elevation. This suggested the gradual input of allochthonous materials from non-glacial environment and the degradation of microbe-derived compounds along lower elevations. Alpine glaciers are retreating as a result of climate change and they nourished numerous streams, rivers, and downstream-linked lakes. Therefore, the interpretations of the detailed molecular changes in glacier ice, glacial-fed streams, and alpine lakes on the Tibetan Plateau could provide broad insights for understanding the biogeochemical cycling of glacial DOM and assessing how the nature of DOM impacts fluvial ecosystems.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.44-44
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• 2019

This study aimed to develop a suitable method for inducing the proliferation of prothallus and producing sporophytes of rock polypody (Polypodium vulgare L.). The prothalli used in all experiments were obtained from spore germination and sub-cultured for 8-week intervals. The most appropriate media for prothallus propagation were investigated by culturing 300 mg of prothallus in MS ($1/4{\times}$, $1/2{\times}$, $1{\times}$, and $2{\times}$ strength) medium and in Knop medium for 8 weeks. Cultures were maintained at a temperature of $25{\pm}1^{\circ}C$, light intensity of $30{\pm}1.0{\mu}mol-m-2{\cdot}s-1$, and a photoperiod of 16/8 h (light/dark). Fresh weight of prothalli was 4.8 g on $1{\times}$ MS, 4.5 g on $1/2{\times}$ MS and 4.3 g on 1/4 MS medium. To select a suitable soil combination for sporophyte formation, 1.0 g of prothallus was ground with distilled water, spread in five combinations onto different soil substrates (decomposed granite, horticultural substrates, peat moss, and perlite), and then cultivated for 13 weeks. The sporophyte cultures were maintained at a temperature of $25{\pm}1^{\circ}C$, light intensity of $43{\pm}2.0{\mu}mol-m-2{\cdot}s-1$, humidity of $84{\pm}1.4%$, and a photoperiod of 16/8 h (light/dark). The results showed that a mixture containing a 2:1 (v:v) ratio of horticultural substrate and perlite, increased sporophyte formation to 462.5 sporophytes per pot (7.5 cm2). The other soil substrates produced from 314.5 to 405.3 sporophytes per pot. Therefore, our results will provide conditions suitable for mass production of Polypodium vulgare L.

• Journal of Applied Biological Chemistry
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• 제50권3호
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• pp.164-169
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• 2007

Three coniferous essential oils were extracted from Abies koreana, Cryptomeria japonica, and Torreya nucifera by hydrodistillation. The chemical composition of each oil was analyzed by GCMS, and their antimicrobial activities were tested against two bacteria and one yeast strains. Fortyseven compounds were identified from A. koreana oil, 39 from C. japonica, and 59 from T. nucifera. Main components of the essential oils were limonene (23.5%), bornyl acetate (17.9%), ${\alpha}-pinene$ (11.1%), and camphene (10.2%) in A. koreana, kaurene (26.3%), ${\gamma}-eudesmol$ (19.0%), elemol (6.9%), and sabinene (5.1%) in C. japonica, limonene (13.5%), ${\delta}-cadinene$ (10.5%), ${\alpha}-bisabolol$ (10.2%), and ${\alpha}-copaene$ (7.7%) in T. nucifera. Among the three coniferous trees tested, the essential oils of A. koreana exhibited higher and broader antimicrobial activity against the tested organisms than those of C. japonica and T. nucifera.

• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1341-1352
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• 2001

Vacuum freeze drying process by which frozen water in a drying material is removed sublimation under vacuum condition, is now applied to various industrial field such as the manufacturing and packaging of pharmaceuticals in pharmaceutical industry, the drying of bio- products in bio-technology industry, the treatment of various quality food stuff in food technology, and so on. The Knowledge about the heat and mass transfer characteristics related with the vacuum freeze drying process is crucial to improve the efficiency of the process as well as the quality of dried products. In spite of increasing needs for understanding of the process, the research efforts in this fields are still insufficient. In this paper, a numerical code that can predict primary drying in a vial is developed based on the finite volume method with a moving grid system. The calculation program can handle the axis- symmetric and multi-dimensional characteristics of heat and mass transfer of the vial freeze drying process. To demonstrated the usefulness of the present analysis, a practical freeze drying of skim Milk solution in a vial is simulated and various calculation results are presented.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2001년도 The 8th International Symposium
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• pp.85-86
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• 2001

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2001년도 추계정기 학술발표회 초록집
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• pp.23-23
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• 2001