• 한국세라믹학회지
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• 제44권9호
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• pp.471-476
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• 2007

The hydration mechanism of the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system in the presence of alkali sulfates has been investigated. The early hydration rate of $3CaO{\cdot}Al_2O_3$ was accelerated by the addition of $Na_2SO_4$ and $K_2SO_4$. This is closely related to the formation of syngenite $(CaSO_4{\cdot}K_2SO_4{\cdot}H_2O)$, and the U-phase added $K_2SO_4$ and $Na_SO_4$ in the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system, respectively. The formation of the rigid syngenite and U-phase structure led to rapid setting and decreases the sulfate content in the liquid phase of the hydrating cement to the extent that it cannot adequately retard the hydration of $3CaO{\cdot}Al_2O_3$. In case of the alkali sulfate not added to the $3CaO{\cdot}Al_2O_3-CaSO_4{\cdot}2H_2O$ system, the ettringite was transformed to monosulfoaluminate immediately after the consumption of gypsum. However, when the alkali sulfates were added to this system, the ettringite did not transform to monosulfoaluminate immediately even though the gypsum was completely consumed. There was a stagnation period to transform to the monosufoaluminate after the consumption of gypsum because the syngenite and U-phase remained as the sulfate source.

• 한국식생활문화학회지
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• 제38권6호
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• pp.434-441
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• 2023

This study investigated quality characteristics and antioxidant activity of beetroots after blanching. Beetroots were blanched in distilled water, 2% NaCl water, and 2% citric acid water at 100℃ for 3 minutes (the blanched group). The moisture content was highest in the control (CON) at 91.30% (p<0.05), and cooking loss was lowest in the water-blanched beetroot (BW) at 5.39% (p<0.01). Chromaticity decreased after blanching compared to CON (p<0.001). Total polyphenol contents (TPC) and total flavonoid contents (TFC) decreased after blanching, and as a result of comparing the True retention (TR) of the blanching treatment group, BW had the highest with TPC TR 91.22% and TFC TR 70.51%. DPPH and ABTS+radical scavenging activities were highest in the CON, and in the blanching group BW was highest scavenging activity. The total number of microorganisms in the CON group was 2.97 log CFU/g, whereas no microorganisms were detected in the blanched groups. Therefore, this study, blanching in water without additives is the most appropriate method for preserving physiologically active substances and nutrients in beetroots and inhibiting microbial growth.

• 센서학회지
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• 제4권4호
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• pp.1-9
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• 1995

반지름이 1.25 cm인 구형 BGO 섬광 검출기의 감마선 검출 특성을 결정하기 위하여 감마선 에너지 deposition 스펙트럼을 Monte Calro법으로 계산하였다. 이때 계산에 이용된 감마선 에너지 deposition 스펙트럼 계산 code는 personal computer 에서 사용할 수 있도록 qbasic을 이용하여 작성하였다. 또한 직접 제작된 구형 BGO 섬광 검출기를 이용하여 방사성 선원 $^{22}Na$, $^{137}Cs$ 및 $^{207}Bi$ 의 감마선 에너지 스펙트럼도 측정하였다. 이 측정 감마선 에너지 스펙트럼의 광전 peak을 Gauss함수로 fitting하여, 광전 peak의 표준편차를 구하고, 이를 Nardi의 경험식을 이용하여 $X^{2}$ fitting하므로서 2000 keV이하의 감마선 에너지에서 구형 BGO 섬광 검출기의 분해능에 대한 에너지 의존성도 조사하였다. 이를 이용하여 에너지 deposition 계산 스펙트럼을 펼치므로서 $^{22}Na$ 및 $^{137}Cs$의 측정 에너지 스펙트럼과 비교하였다. 또한 감마선 에너지 deposition 스펙트럼 계산 code를 이용하여 반지름이 1.25 cm인 구형 BGO 검출기에 대한 절대효율과 고유 peak 효율도 계산하였다.

• 대한화학회지
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• 제30권5호
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• pp.433-440
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• 1986

反陽性子性 溶媒인 dimethylsulfoxide中에서 p-nitrobenzeneazoresororcinol<4n-BAR>에 대하여 직류 폴라로그래피적 거동을 조사하였다. 0.05M $NaClO_4$의 DMSO溶媒中에서 4n-BAR은 1電子 2段階의 還元過程을 거쳐 hydrazo기를 포함하는 化合物로 還元된다. 還元反應의 中間 生成物은 比較的 反陽性子性 溶媒 속에서 安定하였다. 各 段階의 還元電流는 擴散支配的이었으며 一部 反應電流도 包含되었다. 酸을 添加함에 따라서 2個의 還元波가 하나로 合致되며 [acid]/[reductant]의 몰 (M)비가 M = 2인 條件에서 加電位(-E)에 대해 $log(i_d-i)(Mi_d/2-i)/i$/의 可逆性은 1電子 2段階 還元反應이고 非可逆的이었다.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.509-514
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• 2004

Six new serovarieties of B. thuringiensis carrying specific H-antigen have minor differences in biochemical characteristics and morphological characteristics of crystals, which are commonly resistant against four antibiotics. The B. thuringiensis serovar. coreanensis is nontoxic to silkworm larvae, but it is moderately toxic against the Culex pipiens larvae. The B. thuringiensis serovar. konkukian and leesis are nontoxic against mosquitos larvae, but are toxic against silkworm larvae. The B. thuringiensis serovar. seoulensis, sooncheon, and yosoo are highly toxic to B. mori larvae and moderately toxic to C. pipiens larvae. The six serovarieties harbor different plasmid DNA patterns. A 102-kDa protein is a major crystal protein in the four serovarieties and a 86-kDa protein is in one serovariety.

• 한국인쇄학회지
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• 제13권2호
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• pp.47-53
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• 1995

Photosensitive resin of azide type is good for resolution and inner solvent, but it is really problem to development of practical use because fanctional groups of polymer has many hydrophilic radicals. By careful attention to this point, this study was investigated synthesis term, photo property and development property of composed photosensitive resin of azida type, it is to this effect. 1) H-NMR spectrum of compared DABCI showed amion redical by $\delta$6.0~6.1ppm to substitude for azide radical by amino radical by $\delta$8.9~9.45ppm, and FT-IR absorption spectra showed the absorption bends at 2100cm. 2)FT-IR absorption spectra of PHS1-DAB, PHS2-DAB, CMM-DAB and CHM-DAB showed azida radical pick to be lost at after irradiation by UV light. 3) According to exposuer change of PHS1-DAB, PHS2-DAB, CMM-DAB and CHM-DAB, absorption maximum value of UV spectrum change was 280nm. 4) to compared relative sensitivity of compared photosensitive resin, PHS2-DAB was the best and to compared insolubility rate of compared photosensitive resin, CMM-DAB was the lower. 5)Solubility if NaOH was the best by 1.0mol/$\ell$ and solubility of developing solution of ethanol to water was it in the ratio of 4 to 1.

• Korean Chemical Engineering Research
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• 제53권1호
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• pp.6-10
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• 2015

효소 전극 anode와 PEMFC용 전극 cathode를 이용하여 효소연료전지를 구동하였다. 효소 anode는 그래파이트 분말과 효소로서 글루코스 산화제, 전자매개체로서 페로센을 혼합해 압축해서 만들고 Nafion 이오노머로 코팅하였다. anode 제조조건을 변화시키며 OCV를 측정해 효소 anode 제조 최적조건을 찾았다. 효소 anode 압축 시 최적 압력은 9.0 MPa였다. 효소 anode에서 그래파이트가 60%일 때 최고의 OCV를 나타냈다. anode 기질 용액의 최적 글루코스 농도는 1.7 mol/l이었으며, anode의 효소 활성은 7일 동안 안정적으로 유지되었다.

• 대한한방내과학회지
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• 제39권5호
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• pp.863-869
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• 2018

Objectives: The purpose of this case study was to report the effectiveness of Korean medicine treatment on severe lumbar disc herniation patient diagnosed by magnetic resonance imaging (MRI). Methods: The patient was treated with complex Korean medicine treatment, including acupuncture, pharmacopuncture, acupotomy, and Chu-na treatment. The treatment effect was evaluated by a Numerical Rating Scale (NRS), and MRI. Results: After the treatment, the NRS score of pain intensity was reduced from severe to mild degree. The volume of extruded disc in MRI images was clearly reduced. Conclusion: Korean medicine treatment might be effective in patients with lumbar disc herniation.

• Korean Chemical Engineering Research
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• 제54권2호
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• pp.171-174
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• 2016

효소 전극 cathode와 PEMFC용 전극 anode를 이용하여 효소연료전지를 구동하였다. 효소 cathode는 그래파이트 분말과 효소로서 Laccase, 산화환원 매개체로서 ABTS를 혼합해 압축해서 만들고 Nafion 이오노머로 코팅하였다. cathode 제조조건을 변화시키며 OCV를 측정해 효소 cathode 제조 최적조건을 찾았다. 효소 cathode 압축 시 최적 압력은 4.0 bar 였다. 효소 cathode에서 그래파이트가 95%일 때 최고의 OCV를 나타냈다. cathode기질 용액의 최적 글루코스 농도는 0.4 mol/l이었다.

• 농촌계획
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• 제24권4호
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• pp.89-97
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• 2018

This is a comparative study on the policy of Korea and Japan for improving upland farming mechanization. Purpose of the study is to set a policy direction of improving efficiency of farm management by using agricultural machinery. Research topic is the agricultural mechanization policy at the national level. The research attempts to classify mechanization policies into framework plan, R&D, rent and lease program, upland farm promotion policies. Major features of the comparative analysis are followed. First, there is a similarity between policies of Korea and Japan in terms of the aim of framework plan and other policies settings. However, Japanese policies focus more on the joint management of farming than Korean policies. Japanese policies take an entire system covering from farm to market into account. Second, Japanese policies have much attention to the agricultural organizations such as corporate, cooperatives that are eligible for using agricultural machinery. This is different from Korean policy. Thus, upland farming mechanization policy needs to set priority, and to have systemic approach. Also, upland farming mechanization policy has to be facilitated in accordance with producer organizations and their marketing strategies.