• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.463-468
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• 2017

Waxy rice starch purified from Hwaseonchal white rice was modified by octenyl succinic anhydride (OSA) for use as an emulsifier. OSA-modified starches (1, 2, and 3% OSA, pH 8.5, 6 h) were investigated to understand their physicochemical and pasting properties, and emulsion stability. The degree of substitution (DS) of 1, 2, and 3% OSA starches was 0.0062, 0.0182, and 0.0214, respectively. FT-IR spectroscopy showed that OSA starches showed weak peaks at 1724 and $1572cm^{-1}$ and the peak at $3300cm^{-1}$ was reduced by an increase in the DS. Native and OSA starches showed A type crystallinity and a similar granular size. The OSA starch increased the peak viscosity, but decreased the onset and peak temperatures, and enthalpy with an increase in OSA concentration. The creaming index of emulsion of OSA starches decreased with an increase OSA concentration. It was suggested that the emulsion stabilizing capacity of OSA waxy rice starches increased with an increase in the OSA concentrations.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.27-36
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• 2015

The improved analytical method with gas chromatography (GC) and GC-mass spectrometry was established to identify and quantify disaccharides and trisacchrides in honey. In this method, the analysis of trimethylsilyl (TMS), TMS-oxime and TMS-methoxime sugars takes into account the determination of a single peak of complete separation on the chromatogram. The number of possible peaks for the qualitative and quantitative determination of TMS, TMS-oxime, and TMS-methoxime sugars was 17, 22, and 25, respectively. This new analytical method allowed for the determination of diand trisaccharides in honey by TMS-oxime and TMS-methoxime derivatives. This study suggested that the improved method is more suitable and precise than the other analytical methods for the simultaneous determination of sugars in honey.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.600-607
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• 2007

In this study, attempts were made to develop a method for controlling the volatile sulfur compounds in garlic. Crude alliinase extracted from fresh garlic was applied to garlic pulp blanched far 5 min at $100^{\circ}C$, and the changes in the thiosulfinates and volatile compounds of the blanched garlic pulp reacted with the enzyme were investigated. Eight kinds of thiosulfinates from garlic were separated by HPLC, and identified by LC/MS/MS. When the alliinase was added to the blanched garlic pulp at 100, 200, 300, or 400 units, and reacted for 15 min, respectively, thiosulfinates were generated in the amounts of 37, 68, 77, and 80% of the fresh garlic content (control). Under the same conditions, we analyzed the volatile compounds, where 28 peaks were identified by GC/MSD. Of the 28 peaks, 23 were volatile sulfur compounds. The results of the analysis showed that all the volatile compounds were generated at amounts of 25, 36, 66, and 76% of the content of the control, respectively. These results indicate that the sulfur compound content of garlic can be regulated, depending upon the reaction conditions of allinase.

• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.117-127
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• 2008

The characteristics of phosphate adsorption-desorption on kaolinite was studied by batch adsorption experiments and detailed adsorbed state of phosphate on kaolinite surface was investigated using ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) spectroscopy. The phosphorous contents were measured using UV-VIS-IR spectrophotometer with 820 nm wavelength. The adsorbed P was generally increased with increasing pH value in the range of pH 4 to pH 9, however it is not distinct. Moreover the adsorbed P was significantly changed with different initial phosphate concentration. The adsorption isotherms were well fitted with the Langmuir equation, Temkin equation, and Freundlich equation in descending order. The maximum Langmuir adsorption capacity of kaolinite KGa-2 is 232.5 ($204.1{\sim}256.5$) mg/kg and has very higher value than that of kaolinite KGa-1b. Most of adsorbed phosphate on kaolinite were not easily desorbed to aqueous solution, but might fixed on kaolinite surface. However it needs further research about the exact desorption experiment. It was impossible to recognize phosphorous adsorption bands on kaolinite in ATR-FTIR spectrum from kaolinite bands themselves, because the absorption peaks of phosphorous have very similar positions with those of kaolinite, and the intensities of the former were very weak in comparison with those of the latter.

• Journal of the Korean Electrochemical Society
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• v.12 no.3
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• pp.276-281
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• 2009

Electrochemical behaviors of $U^{3+}$ and $Gd^{3+}$ were investigated in LiCl-KCl eutectic molten salt by using various electrochemical techniques. The electrodeposition and dissolution currents for uranium show the maximum at -1.51V and -1.35V, respectively while, for gadolinium,at -2.15V and -1.9V, respectively. In case of LiCl-KCl molten salt containing both of $U^{3+}$ and $Gd^{3+}$, the peak potential of electrodeposition of gadolinium shifts to more positive potential than in the solution without $U^{3+}$. The potentials in chronopotentiometric data suddenly dropped to negative value as soon as the reduction currents were applied and became constant at the potential around which the $U^{3+}$ and $Gd^{3+}$ are electrodeposited. The results of normal pulse voltammetry (NPV) and square wave voltammetry show that those methods can be used to qualitatively analyze the elements in the melts. Especially, the differentiation of NPV result was found to be useful for the separation of the peaks of which potentials are close each other.

• ETRI Journal
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• v.11 no.3
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• pp.3-10
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• 1989

변조도핑 AIGaAs/GaAs 이종구조의 양자우물에 감금된 이차원 전자가스층의 생성과 그 농도 및 이동도의 파악은 이 구조를 이용한 소자의 성능을 평가하기 위해 필수적이다. 그리고소자제작에 앞서 이차원 전자가스층 생성여부의 확인은 에피층 성장공정과 제작공정을 분리 검증하여 소자 제작후에 나타나는 문제점을 해결하기 위한 진단 단계를 줄일 수 있다. 본 논문에서는 이차원 전자가스층의 확인방법을 개발하기 위하여 변조도핑 이종구조의 PL을 측정하여 분석하고 지금까지 보고된 자료를 분석하여 새로운 피크에 대한 기구해석과 검증방법을 마련하였다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.71-74
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• 2002

다고리방향족 탄화수소를 페놀에 적응된 미생물을 이용하여 분해하고자 하였다. 분리된 Stenotrophomons maltophilia는 나프탈렌과 페난스렌을 탄소원 및 에너지원으로 이용하였으며 10mg/$\ell$의 나프탈렌과 0.9mg/$\ell$의 페난스렌이 완전히 분해되는데 지체기후 약 2일과 3일이 소요되었다. 나프탈렌, 페난스렌의 분해시 중간생성물로 chromatography 상에 새로운 피크들이 생성되었으며, 이러한 중간생성물을 파악하여 다고리 방향족 탄화수소의 분해경로를 모색하고자 하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.285-290
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• 2008

Pyrotechnic shock or pyroshock is characterized as a transient vibration phenomena which shows large acceleration and high frequency range up to 10kHz during the operation of separation devices where explosives are used. During the flight of a launch vehicle, pyro-shock is mainly generated at several events such as satellite separation, fairing separation and stage separation. In this paper, characteristics of pyroshock are introduced briefly, and PEEK washer shock absorber is applied for the reduction of pyroshock in the high frequency range. With some electronic devices, reduction characteristic of pyroshock using washer type shock absorber are studied. Random vibration tests are also performed for the verification of vibrational characteristics.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.508-513
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• 1997

Thermal characteristics and granular morphology on enzyme-resistant starches (RS) formed during heat-moisture treatment (HMT) and retrogradation were investigated in high amylose corn starches, Hylon V and Hylon VII. With each treatment, both starches showed a similar trend in the increase of RS, but RS yield of Hylon VII is higher than that of Hylon V. Specially, RS was increased remarkably by HMT. It was more than doubled from 11.4% to 26.6% for Hylon V and from 15.9% to 32.8% for Hylon VII. A small increase of RS resulted from retrogradation. HMT on starch increased gelatinization temperature, decreased enthalpy. Retrograded starch exhibited small three endothermic transitions at $94^{\circ}C$, $110^{\circ}C$ and $140^{\circ}C$ in differential scanning calorimetry (DSC) thermogram due to the remained ungelatinized starch granules, dissociation of amylose-lipid complex and melting of recrystallized amylose, respectively. Enzyme-resistant starches isolated from native and heat-moisture treated starches showed a broad endothermic transition at higher temperature than native starch, while retrograded starch exhibited a very sharp peak at ${\sim}150^{\circ}C$ due to the melting of amylose crystallites. Under microscopy, starch granules with HMT was not changed, but retrograded starches showed the aggregates of starch granules because amylose leached out during gelatinization. Iodine stained RS clearly showed the differences in enzyme hydrolysis on the native, heat-moisture treated and retrograded starches.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.121-128
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• 1998

In fields of operating or handling a hydrogen isotope facility, and of the technology for nuclear fusion source management, gas chromatography has been used as one of the practical techniques lot separation and enrichment of hydrogen isotopic gases including tritium. Chromatographic separation experiments of the hydrogen isotope mixture (hydrogen, deuterium and tritium) were carried out by use of a commercially available gas chromatograph. An aliquot of gas sample was injected by a specially designed vacuum sampler into the stream of inert carrier gas which went through the separation column under liquid nitrogen temperature. The complete separation of hydrogen isotopic molecules was observed with an alumina adsorbent partially deactivated by coating with 10% manganese chlorine. In addition, fairly good separation conditions were obtained without any appearance of nuclear spin isomers with shorter retention time, which would be available for the practical applications of the hydrogen isotope separation and enrichment.