• Preventive Nutrition and Food Science
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• 제15권2호
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• pp.120-129
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• 2010

To elucidate the composition of extractive nitrogenous components in the fresh Capsosiphons fulvescens cultured off the southern coast of Korea, and to determine the monthly variation of these nitrogenous components, extract samples collected monthly from December to March at Jangheung-gun, Jeonnam Province were analyzed for total nitrogen, free and combined amino acids, ATP and related compounds, betaines, trimethylamine oxide (TMAO) and trimethylamine (TMA). The content of extractive nitrogen was 1,090~1,233 mg/100 g on dry basis. The number of 21~25 ninhydrin-positive substances was detected in the analysis of free amino acids, and their total amount was 3,710~4,788 mg/100 g on dry basis. Among them, free proline, asparagine, glutamic acid, alanine, taurine and glutamine were found to be abundant. The combined amino acids amounted to 1,573~2,121 mg/100 g in total and the total amount of ATP and related compound was 33.8~84.0 mg/100 g ($1.06{\sim}2.46\;{\mu}mol/g$) on dry basis. Betaine, glycinebetaine, $\beta$-alaninebetaine, $\gamma$-butyrobetaine, homarine and trigonelline were detected in most of samples. Levels of free and combined amino acids, ATP and related compounds fluctuated from sample to sample, with their contents higher in December and January and lower in March.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.434-437
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• 2003

The fate and the behavior of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the environment are mainly controlled by their interactions with various components of soils and sediments. Due to their large surface area and abundance in many soils, smectites may greatly influence the fate and transport of the contaminants in the environment. In our experiment, PAH sorption by hexadecyltrimethylammonium (HDTMA)-modified smectite linearly increased in proportion to the amount of HDTMA added on the clay. However, trimethylammonium (TMA)-modified smectite did not show superiority in its sorption of PAH compared with the HDTMA-smectite or dodecyltrimethylammonium (DTMA)-smectite. Meanwhile, the smectites modified with the same cationic surfactants adsorbed Cd$^{2+}$ (heavy metal) significantly from water at low surfactant loading level, but the Cd$^{2+}$ adsorption linearly decreased as the loading of surfactant increased. The result shows that the sorption tendency of organoclays for organic or inorganic contaminants was significantly influenced by the amount and size of the surfactants added on the clay. It means that the stabilization and configuration of cationic surfactant formed on the clay interlayer according to the loading amount of each surfactant of different sizes may be an important factor in effectively sorbing environmental pollutants.nts.

• E2M - 전기 전자와 첨단 소재
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• 제9권4호
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• pp.404-409
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• 1996

The structural and electric properties of $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$(x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) have been investigated by using XRD(X-ray diffraction), TMA(thennomechanical analysis), NMR(nuclear magnetic resonance) analysis and four probe method. $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$ samples were prepared by conventional solid-state reaction method using $Y_{2}$O$_{3}$, BaCO$_{3}$, CuO and YbF$_{3}$ power. TMA and high temperature XRD results shows that orthorhombic to tetragonal phase transition occurs in the unfluorinated 1-2-3 sample while the phase change is not observed in the fluorinated 1-2-3 samples. Superconducting transition temperature(T$_{c}$) increases with increasing YbF$_{3}$ content ; T$_{c}$, of the sample reaching maximum of 102K for x=0.3, and then decreases with further increasing YbF$_{3}$ content. The structural analysis and T$_{c}$ results shows that the fluorine doping stabilize the orthorhombic phase, together with the increase in T$_{c}$.}$ c/.TEX> c/.

• 설비공학논문집
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• 제17권2호
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• pp.125-130
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• 2005

This study was peformed to investigate the phase change temperature, the supercooling, the maintenance time of liquid phase and the change rate of volume of TMA 30 $wt\% clathrate compound with additives. TMA 30 $wt\% clathrate compound with additive was cooled at heat source temperature of $-6^{circ}C$. The additives are ethylene glycol and chloroform. Their concentration are 0.1$wt\% respectively. The experimental results showed that the phase change temperature was not affected by additives and this was average $5.3^{circ}C$. Also the supercooling and the maintenance time of liquid phase were decreased by additives. Especially, the average value of supercooling showed by $8.8^{circ}C$ and the maintenance time of liquid phase was by 19 minutes in the case of chloroform 0.1$wt\%. Additionally, the average change rate of volume showed by $1.26{\~}1.31\%$ according to additives and the volume was decreased by the phase change from liquid to solid.

• Journal of Magnetics
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• 제4권1호
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• pp.26-32
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• 1999

The HDDR process can be used as an effective means of processing of the coercive Nd-Fe-B-type or the Sm2Fe17Nx materials. The HDDR (hydrogenation, disproportionation, desorption, recombination) processed materials are feartured with a very fine microstructure. The thermomagnetic characteristics of the Nd-Fe-B-type or the Sm2Fe17Nx materials with fine microstructure due to the HDDR process were investigated. It has been found that the fine-microstructured hard magnetic materials showed an unusual TMA (Thermomagnetic analysis) tracting featured with a low and constant magnetization at lower temperature range and a peak just below their Curie temperatures when a low external field is applied. This thermomagnetic characteristic was immediate particularly in the TMA with a low applied field. This thermomagnetic characteristic was interpreted in terms of the competition between two counteracting effects; the decrease in magnetication due to the thermal agitation at an elevated temperature and the increase in magnetization resulting from the rotation of magnetization of the fine grains comparable to a critical single domain size due to the decreased magnetocrystalline anisotropy at an elevated temperature.

• 한국수산과학회지
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• 제8권4호
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• pp.208-212
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• 1975

The study was conducted to determine the optimum conditions for keeping quality of shucked sea mussel, Mytilus edulis, during marketing under commercial handling. As quality factors, water holding capacity, pH, VBN and TMA content were measured. Water holding capacity was obviously affected by salt content of the sea mussel meat. Water was released at the salinity above $2.8\%$ and absorbed below the value. In case of distilled water added instead salt solution, $23.3\%$ weight was gained. Absorbing or releasing water of sea mussel meat was also influenced by temperature showing either water gain or loss was greater at, $3^{\circ}C\;than\;25^{\circ}C$. Osmotic quilibrium by salt between meat and liquor was held within 4 hours. The pH value of fresh sea mussle marked 6.0 which is somewhat lower when compared with that of other shellfishes, and it gradually decreased to 5.0 during storage. VBN contents of fresh muscle and shell liquor were $2.1mg\%$ and $1mg\%$ respectively. The sour odour began to be detectable with $5.0mg\%$ of VBN content. TMA in the sea mussel was not detected.

• 한국식품영양과학회지
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• 제27권1호
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• pp.69-74
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• 1998

자숙가리비의 shelf-life를 연장하기 위하여 열처리하여 탈각한 가리비에 보존제를 첨가한 다음 $5^{\circ}C$에 저장하면서 여러 가지 화학적 및 미생물적 변화를 분석하였다. pH는 저장기간이 증가할수록 감소하였으며, 보존제 첨가군들은 저장 후반에 급격한 pH 감소를 억제하였다. 보존제 첨가는 저장 후분에 있어서 TMA, VBN, 및 TBA 생성을 억제하였으며, 전반적으로 숙성 초기에 있어서 미생물의 성자을 억제하였다. 보존제 첨가는 자숙가리비의 shelf-life를 약 3~7일 정도 연장하였다.

• 대한가정학회지
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• 제23권2호
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• pp.37-43
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• 1985

The effect of irradiation at dose of 3~10 kGy on the extension of the shelf-life of sliced dried squid and dried file and on its quality were investigated during nine months of storage at room temperature. The number of microorganisms, TBA value and TMA-N content were used as objective indices concerned to the sensory evaluation. In the number of initial microbial loading, total bacterial count of sliced dried squid and dried file fish were $2.7{\times}10^{8}\;and\;2.0{\times}10^{5}$, yeast and mold were $5.7{\times}10^{5}\;and\;6.2{\times}10^{5}$ and coliform group were $2.1{\times}10^{5}$ and above 10 per gram of the samples, respectively. The number of total bacteria was sterilized by 99% with irradiation of 3~10 kGy and irradiation of above 7 kGy was shown to be effective for the radurization of yeast, mold and coliform group. TBA value of irradiated groups were higher than storage time. The TMA-N content of nonirradiated group was markedly increased by microbial spoilage during storage, however above 8 kGy irradiated group were indicated about 10 mg% after nine months storage. In the sensory evaluation, the nonirradiated group was off favor after three months storage and was changed in color of dried fishes but 7~10 kGy irradiated group were maintained good qualit compared with those of fresh samples after nine months storage at room temperature.

• 한국수소및신에너지학회논문집
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• 제29권5호
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• pp.458-465
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• 2018

This study reports the fabrication of anion exchange membranes (AEMs) containing two kinds of functional groups: i) trimethylphosphite (TMP) and ii) trimethylamine (TMA). We carried out the synthesis of polymers to enhance thermal stability and ion conductivity. The alternative polymer was prepared using 2,2-bis(4-hydroxy-3-methylphenyl)propane and decafluorobiphenyl. The membrane was fabricated by solution casting method. The thermal stability of membranes was examined by TGA. The physiochemical properties of membranes were also investigated in terms of water uptake, swelling ratio, ion exchange capacity, and ion conductivity. The hydroxide ion conductivity of the membranes reached about 20.2 mS/cm for quaternary ammonium poly(arylene ether) (QA-PAE) containing TMA moiety and 5.1 mS/cm for quaternary phosphonium PAE (QP-PAE) containing TMP moiety at $90^{\circ}C$.

• 수산해양교육연구
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• 제27권4호
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• pp.973-980
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• 2015

This study was done to investigate the quality characteristics of salmon frame with citric acid pretreatment. Sliced salmon frame samples were cured in soy sauce, sugar, pepper, and sodium nitrate for 12 h and then dried at 3 h and then dried at $60^{\circ}C$ for 3 h. As the autoclaving at $130^{\circ}C$ for 15 min, the pH, moisture content, crude ash, crude fat, crude protein, acid value (AV), peroxide value (POV), volatile basic nitrogen (VBN), trimethylamine (TMA), total plate count and E. coli were measured at $4^{\circ}C$, $25^{\circ}C$ and $35^{\circ}C$ of storage days. The AV, POV, VBN, TMA and total plate count for all samples significantly increased as during storage days (p<0.05). All samples of storage, for autoclaving on salmon frame, there were no growth on E.coli. In the making of autoclaving on salmon frame, technologies for more safety from microbial growth should accompany pretreatment with citric acid.