• Korean Journal of Metals and Materials
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• v.50 no.2
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• pp.116-121
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• 2012

Equilibria between Mn-Si melts and $MnO-SiO_2$ slags were studied at 1673 K and 1773 K in MnO crucibles to accurately determine the thermodynamic property of the Mn-Si melts. The Unified Interaction Parameter Formalism (UIPF) was used to describe the thermodynamic property of the Mn-Si liquid. Using the UIPF, the experimental results obtained in the present study were thermodynamically analyzed to determine the activity coefficient of Si at infinite dilution and the 1st- and 2nd-order self-interaction parameters of Si in the Mn-Si melts.

• Journal of Life Science
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• v.16 no.5
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• pp.794-798
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• 2006

A tomato (Lycopersicon esculentum cv. Naomi F1) juice was separated into ascorbate and phenolic portions using a Sep-pak $C_{18}$ cartridge, and its each portion was tested for inhibition of N-nitrosodimethylamine (NDMA) formation. Ascorbate and phenolic portions of tomato juice inhibited NDMA formation by $81.37{\pm}0.25%$ and $72.03{\pm}0.25%$, respectively. The phenolic portion was further fractionated by prep-HPLC and inhibitory effects of NDMA formation by 4 fractions $(1{\sim}4)$ from tomato juice was tested under the different pH conditions (pH 1.2 and 4.2). Fraction 2 inhibited NDMA formation by $50.10{\pm}0.46%$ (pH 1.2) and $64.30{\pm}0.20%$ (pH 4.2), respectively. Fraction 2 was further separated into 4 subfractions $(2a{\sim}2d)$. Subfraction 2b especially inhibited NDMA formation by $70.62{\pm}0.45%$ (pH 1.2) and $75.30{\pm}0.45%$ (pH 4.2). This subfraction was confirmed o-coumaric acid through the analysis of GC-Mass spectrum, $^1H-NMR$ and $^{13}C-NMR$.

• Journal of Oral Medicine and Pain
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• v.25 no.1
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• pp.117-128
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• 2000

The present study explored the influence of temporomandibular disorders(TMD) with anterior open bite on swallowing. Fifteen subjects with anterior open bite(group A), 9 subjects with anterior open bite and TMD(group B), and 24 subjects without malocclusion or TMD symptoms (group C) were included. BioPAK system(Bioresearch Inc., Milwaukee, WI, USA) was used to record the muscle activities of anterior temporal, masseter, sternocleidomastoid(SCM) and anterior digastric muscles during maximum clenching and swallowing. Positional change of the mandible during swallowing was also recorded using the same system. The obtained results were as follows: 1. Group A, B, and C did not show significant differences each other in the muscle activity of resting position in most of head and neck muscles. 2. Group B showed significantly lower muscle activity in maximum clenching than group C in anterior temporal(p<0.01), masseter(p<0.05), SCM(p<0.05) and digastric muscles(p<0.05). 3. Group A showed significantly lower muscle activity during swallowing than group C in anterior temporal and masseter muscles(p<0.01). Group B showed significantly lower muscle activity during swallowing than group C in anterior temporal(p<0.01), masseter(p<0.01), and SCM muscles(p<0.05). 4. Group A and B showed increased positional change of the mandible during swallowing measured from vertical, anteroposterior and lateral aspects, and prolonged swallowing(p<0.05). 5. After given instructions for normal swallowing pattern, group A and B showed increased muscle activity during swallowing in anterior temporal, masseter and SCM muscles(p<0.01). Positional change of the mandible and time elapsed for swallowing also decreased after the instruction(p<0.01). 6. Occlusal splint did not change the muscle activity during swallowing. However, vertical change(p<0.01) and swallowing time(p<0.05) were decreased with splint.

• Analytical Science and Technology
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• v.16 no.2
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• pp.125-133
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• 2003

In order to determine the contents of trans-resveratrol in red wine, which was mainly consumed in Korea, both LC/MS-ESI and LC/MS-APCI methods were used after solid-phase (Sep-Pak $C_{18}$-cartridges) extraction. The contents of trans-resveratrol obtained by LC/MS-ESI were detected in the range of $0.06-4.31{\mu}g/mL$. The recoveries were ranged from 88.4 to 97.9%. The values of relative standard deviation were ranged from 0.6 to 4.6% and the detection limit was $0.001{\mu}g/mL$. The contents of trans-resveratrol obtained by LC/MS-APCI were detected in the range of $0.09-4.02{\mu}g/mL$ and the detection limit was $0.005{\mu}g/mL$.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.1
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• pp.49-59
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• 1997

This study was performed to analyze the purity of technical grade ${\alpha}$-naphthylamine, to establish optimal analytical condition of ${\alpha}$-naphthylamine in urine and to determine the urine sample of workers exposed to ${\alpha}$-naphthylamine. The purity of technical grade ${\alpha}$-naphthylamine were $96.5{\pm}2.38%$, $94.1{\pm}0.97%$, $97.0{\pm}0.02%$ by gas chromatography-mass selective detector. To analyze ${\alpha}$-naphthylamine in urine, high performance liquid chromatography-electrochemical detector and gas chromatography-electron capture detector operating conditions have been optimized by preliminary expriment. In high performance liquid chromatography-electrochemical detector, the mobile phase was consisted of acetonitrile(35%) and water(65%), and the flow rate was maintained at 1.0ml per minute. Optimal detective condition was 9.0V(10nA/V) of electrochemical detector. The recovery of sep-pak treatment method was highly estimated as pretreatment of ${\alpha}$-naphthylamine in urine. The free amine was isolated by gas chromatography-electron capture detector after basic hydrosis, sep-pak treatment, toluene elution and HFBA(heptafluoro-butyric anhydride) derivatization of urine. The recovery of ${\alpha}$-naphthylamine in urine was $98.73{\pm}3.29%$ by gas chromatography-electron capture detector. The sensitivity was more higher than that of high performance liquid chromatography-electrochemical detector. Urinary ${\alpha}$-naphthylamine was detected in only one worker among nine workers. The level of ${\alpha}$-naphthylamine in urine was 6.42 ng/ml.

• Journal of Sericultural and Entomological Science
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• v.41 no.2
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• pp.102-107
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• 1999

To analysis a promoter strength of Atographa californica nucler polyhedrosis virus (AcNPV) IE1 gene, an immediate viral gene, ${\beta}$-glactosidase gene as a reporter gene was introduced under the control of the IE1 promoter. The restriction fragment containing IE1 promoter and ${\beta}$-galctosidase gene from pAcIE1-gal were inserter into pBacPAK9 to yield transfer vector pAcNPV-IE1-gal. The pAcNPV-IE1-gal was cotransfected with AcNPV genomic DNA BacPAK6 into Sf9 cells to produce recombinant baculovirus AcNPV-IE1-gal. In addition, recombinant bacvulovirus AcNPV-gal, which express ${\beta}$-galac-tosidase under the control of the polyhedrin promoter, was constrer, was constructed to compared with AcNPV-IE1-gal. The recombinant viruses were respectively infected into Sf9 cells and characterized by the virus titer and expression of ${\beta}$-galactoxidase in Sf9 cells. The promoter strength of IE1 and polyhedrin promoters was determined by the amount of ${\beta}$-galactosidase secreted into medium by viral infection. The titer of AcNPV-IE1-Gal determined by plaque assays in Sf9 cells was similar to that of AcNPV-gal. However, expression level of ${\beta}$-galactosidase by AcNPV-IE1-gal was significantly lower than that by AcNPV-gal. In conclusion, promoter strength of IE1 was approximately 25-fold lower than that of polyhedrin.

• Journal of Dairy Science and Biotechnology
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• v.21 no.2
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• pp.114-119
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• 2003

Acidocin 4A produced by Lactobacillus acidophilus GP4A was purified to homogeneity by ammonium sulfate precipitation and sequential chromatographies containing Octyl sepharose CL-4B column, $C_{18}$ Sep-Pak Cartridge, $C_{18}$ RP HPLC and HPLC gel filtration. Tricine SDS-PACE resulted in a single band with estimated molecular mass of 4.1 kDa corresponding to the polypeptide weight marker. Electron microscopy of acidocin-treated indicator cells(L. delbrueckii subsp. lactis ATCC 4797) confirmed that acidocin 4A presented bacteriolytic effect, resulting in cell lysis. Curing trial using ethidium bromide (EtBr) was carried out to examine whether acidocin 4A determinant was encoded either by chromosome or on plasmid. The plasmid designated as pLA4A, being about 20 kb in size, was responsible for acidocin 4A production and immunity to host cells.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.4
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• pp.5-13
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• 2020

This study was conducted to evaluate effects of compressed expansion rice hull (CERH) as bulking agent on physicochemical properties of composting poultry manure (PM) and of its fertilization on lettuce and pak choi growth. Treatments were designed as follows; sawdust treatment (90% PM + 10% sawdust; SP), peatmoss treatment (90% PM + 10% peatmoss; PP), and CERH treatments [PCR1 (90% PM + 10% CERH 1.3 mm) and PCR2 (90% PM + 10% CERH 3.0 mm)]. Physicochemical properties such as temperature, water content, pH, and total carbon of composted poultry piles for 31 days were unaffected by various bulking agents. However, total nitrogen content in compost pile was higher in PP and PCR1 than that of SP or PCR2. After composting for 31 days, content ranges of N, P2O5, and K2O in the composting PM piles were 19.1~19.7%, 47.6~51.6%, 2.76~3.65%, and 2.53~2.90%, respectively. As compared to SP treatment, dry weight of lettuce treated with PP and PCR1 increased by more than 10%, but only in PP for pak choi. These results indicated that CERH 1.3 could be used as bulking agents for composting PM on behalf of peatmoss or sawdust.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.52.2-52.2
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• 2015

In astronomical observations, stable auto-guiding and accurate target centering capabilities are critical to increase observation efficiency and sensitivity. Recently, Center for the Exploration of the Origin of the Universe (CEOU) has developed SQUEAN (SED camera for QUasars in EArly uNiverse). SQUEAN is installed and had successful observations at the 82 inch Otto Struve Telescope of McDonald Observatory in 2015 February. We have upgraded the existing auto-guiding softwares to KAP82 (KHU Auto-guiding Package for the McDonald 82 inch Telescope). Keeping the original hardware systems and the software algorithms of CAP (CQUEAN Auto-guiding Package), KAP 82 is completely re-written in Visual C++. We developed several center finding algorithms, e.g., 2D-gaussian fitting and weighted mean methods. In this presentation, we compare the auto-guiding performances with these algorithms.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.81.2-81.2
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• 2015

FU Orionis 형 천체는 태양 질량의 2배 이하인 T Tauri 별 중에서도 급격한 밝기 변화를 보이는 별들로서, 광도 증가폭이 최대 5등급에 이르는 것으로 알려져 있다. 이러한 현상의 원인은 FU Orionis를 둘러싼 강착 원반에서 나타나는 불안정성에 의해, 원반 안쪽의 물질이 한꺼번에 중심별로 쏟아져 내리기 때문인 것으로 분석된다. V1057 Cyg는 FU Orionis 형 천체 중 하나로, 1969년에 급격한 밝기 변화를 일으키며, 기존의 16등급에서 변화 직후 9등급 후반에 이르는 광도 증가를 보였다. 우리는 V, R, I 필터 대역에서 관측을 수행하였으며, 본 발표에서는 2013 ~ 2014년에 걸쳐 소백산, 레몬산 천문대 및 경희천문대에서 관측한 결과를 보고한다.