• Journal of the Korean Wood Science and Technology
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• 제12권4호
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• pp.12-18
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• 1984

열판온도(熱板溫度)가 내화약제(耐火藥劑)로 처리(處理)된 합판(處理)의 재건조(再乾燥) 후(後) 곡강도(曲强度)에 미티는 영향(影響)을 조사(調査)하기 위해 두께 3.5mm 메란티합판(合板)을 황산(黃酸)암모늄, 제1(第一)인산암모늄, 제2인산(第二燐酸)암모늄 그리고 혼합약제(混合藥劑)인 붕사(硼砂) 붕산(硼酸) 및 미나리스 등(等) 5종(種)의 내화제(耐火劑)의 20% 수용액(水溶液)에 9시간(時間)동안 침지처리(浸漬處理)한 다음, 각각(各各) 열판온도(熱板溫度) $90^{\circ}C$, $120^{\circ}C$ 및 $150^{\circ}C$를 적용(適用)한 단계별(段階別) 건조방식(乾燥方式)으로 건조(乾燥)하여 곡강도시험(曲强度試驗)을 행(行)하였다. 비례한계(比例限界)에서의 응력(應力), 탄성계수(彈性係數), 파괴계수(破壞係數) 및 비례한계(比例限界)까지의 단위체적당(單位體積當) 일 등(等)을 조사(調査)한 바, 수분처리대조구(水分處理對照區)의 경우, 열판온도(熱板溫度) $120^{\circ}C$까지 유지(維持)되던 강도(强度)가 $150^{\circ}C$에 이르러서는 현저한 감소경향(減少傾向)을 나타내었으나, 내화약제처리합판(耐火藥劑處理合板)은 $150^{\circ}C$까지 열판온도(熱板溫度)가 상승(上昇)함에도 불구(不拘), 강도(强度)가 유지(維持)되었으며 일부 약제처리(藥劑處理)의 경우엔 오히려 증가(增加)하는 양상(樣相)도 보여주었다. 건조속도(乾燥速度)와 강도유지(强度維持)의 측면(側面)을 고려할 때, 바람직한 열판건조온도(熱板乾燥溫度)는 $150^{\circ}C$ 였으며 내화약제중(耐火藥劑中) 보강효과(補强效果)가 가장 좋은 약제(藥劑)는 붕사(硼砂) 붕산(硼酸)이었다.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.438-442
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• 2006

The formation of astaxanthin by Xanthophyllomyces dendrorhous mutant JH1 depends on the culture conditions. Therefore, the effects of inoculation rate (1-5%, v/v) and medium compositions (various carbon and nitrogen sources) on cell growth and astaxanthin formation in X. dendrorhous mutant JH1 were investigated. Inoculation at 3% (v/v) was optimal for cell growth and astaxanthin formation. The most effective carbon source for cell growth and astaxanthin formation was glucose, and the best nitrogen source was yeast extract. The 3% (w/v) glucose and 0.2% (w/v) yeast extract showed the best effect on cell growth and astaxanthin formation, compared with others tested. The 3% glucose, 0.2% yeast extract, $0.15%\;KH_{2}PO_{4}$, $0.05%\;MgSO_4$, $0.01%\;MnSO_4$, and $0.01%\;CaCl_2$ were selected for cell growth and astaxanthin formation. Under the conditions selected, the maximum concentrations of cell and astaxanthin obtained after 168 h of cultivation were 5.43 g/l and 28.20 mg/l, respectively.

• 환경영향평가
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• 제7권2호
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• pp.5-14
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• 1998

This study was performed to estimate interrelation between characteristics of sediment and nutrient releare from sediment in Dae-cheong lake. For the investigations, sediments were sampled in June and October 1997 at fish farms, embayment, and the main stream of Dae-cheong lake. Items for investigation are as follows; water content, weight loss on ignition(IG), porosity of sediment, Total Kjeldahl Nitrogen(TKN), content of element(H, N, C), nutrient release rate. Water content and porosity were measured to conjecture the physical trait and grain size. And weight loss on ignition was measured to determine the contents of organic substance. For the determination of nutrient release rate, $PO_4-P$ and $NH_4-N$ concentration of interstitial water and overlying water were measured. Release rate of nutrients which has direct influenced upon the water quality were 0.05-8.63mg-$P/m^2{\cdot}day$ and 4.99-36.56mg-$N/m^2{\cdot}day$. And it was found that release rate was measured higher in the 1st sampling than in the 2nd sampling. And for determination of the humus level of sediment, carbon and nitrogen content were measured by using elemental analyzer. Generally, C/N ratio is used to determine humus level of lake sediment. As a result of elemental analysis, C/N ratio was determined in the range of 7.64~11.55, so humus level of Dae-cheong lake sediment was estimated from mesohumic state to oligohumic state.

• 원예과학기술지
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• 제29권3호
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• pp.187-194
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• 2011

광강도와 배양액 농도에 따른 칼랑코에(Kalanchoe blossfeldiana 'Marlene')의 생육단계별 양수분 흡수율과 작물생육을 조사하였다. 광강도는 일적산 광합성유효광양자속(PPF)이 6.5, 10.3, $18.2mol{\cdot}m^{-2}{\cdot}d^{-1}$의 3수준으로, 배양액의 농도는 유묘기 EC 0.5, 1.0, 1.5, $2.0dS{\cdot}m^{-1}$의 4수준, 단일처리 후 EC 1.0, 1.5, 2.0, $3.0dS{\cdot}m^{-1}$의 4수준으로 처리하였다. 유묘기 초장은 저광 조건에서 가장 길었고, 엽면적과 건물중은 PPF $10.3mol{\cdot}m^{-2}{\cdot}d^{-1}$에서 가장 높았다. 유묘기 모든 광조건에서 EC $1.5dS{\cdot}m^{-1}$일 경우에 최대 건물중과 엽면적이 나타났다. 단일처리기 초장 역시 저광 조건에서 길었고, 엽면적, 건물 중, 분지수는 광강도가 증가함에 따라 현저하게 증가하였다. 모든 광조건에서 엽면적, 건물중, 분지수는 배양액농도가 EC 1.0-$2.0dS{\cdot}m^{-1}$까지 증가하다가 EC $3.0dS{\cdot}m^{-1}$에서 현저히 감소하였고, EC $2.0dS{\cdot}m^{-1}$에서 가장 높았다. 생육이 양호하였던 EC 처리구(유묘기 EC $1.5dS{\cdot}m^{-1}$, 단일처리기 EC $2.0dS{\cdot}m^{-1}$)의 $NO_3$-N, $H_2PO_4{^-}$, $K^+$, $Ca^{2+}$, $Mg^{2+}$ 이온간의 상호간 비율을 분석한 결과 육묘단계에서는 광강도에 따라 큰 차이가 없었지만, 단일처리기에서는 큰 차이가 확인되었다. 따라서 작물의 최적의 생장을 위해 유묘기에는 광도 별 EC 조절로 충분하지만, 단일처리기에는 광강도에 따른 배양액 조성과 EC조절이 필요하다.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.583-591
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• 2002

Biodegradation of fat, oil, and grease (FOGs) plays an Important role in wastewater management and water pollution control. However, many industrial food-processing and food restaurants generate FOG-containing waste waters for which there Is no acceptable technology for their pretreatment. To solve these problems, this study evaluated the feasibility of effective FOG-degrading microorganisms on the biodegradation of olive oil and FOG-containing wastewater. Twenty-two strains capable of degrading FOGs were isolated from five FOG-contaminated sites for the evaluation of their FOG degradation capabilities. Among twenty-two strains tested, the lipase-producing Pseudomonas sp. strain D2D3 was selected for actual FOG wastewater treatment. Its biodegradability was performed at 3$0^{\circ}C$ and pH 8. The extent of FOG removal efficiency was varied for each FOG tested, being the highest for olive oil and animal fat (94.5% and 94.4%), and the lowest for safflower oil (62%). The addition of organic nitrogen sources such as yeast extract, soytone, and peptone enhanced the removal efficiency of FOGs, but the addition of the inorganic nitrogen nutrients such as $NH_4$Cl and $(NH_4)_2SO_4$ did not increase. The $KH_2PO_4$ sources in 0.25% to 0.5% concentrations showed more than 90% degradability. As a result, the main pathway for the oxidation of fatty acids results in the removal of two carbon atoms as acetyl-CoA with each reaction sequence: $\beta$-oxidation. Its lipase activity showed 38.5 U/g DCW using the optimal media after 9 h. Real wastewater and FOGs were used for determining the removal efficiency by using Pseudomonas sp. strain D2D3 bioadditive. The degradation by Pseudomonas sp. strain D2D3 was 41% higher than that of the naturally occurring bacteria. This result indicated that the use of isolated Pseudomonas sp. strain D2D3 in a bioaugmentating grease trap or other processes might possibly be sufficient to acclimate biological processes for degrading FOGs.

• Journal of Periodontal and Implant Science
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• 제31권3호
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• pp.555-564
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• 2001

The purpose of this study is to evaluate the bioresorbability of Calcium Polyphosphate added with $Na_2O$ and chitosan. Though calcium phosphate ceramics meet some of the needs for bone replacement, they have some limitation of unresorbability and fibrous encapsulation without direct bone apposition during bone remodelling. To solve these problem, we developed a new ceramic, calcium polyphosphate(CPP), and report the biologic response to CPP in extraction sites of beagle dog. Porous CPP granules were prepared by condensation of anhydrous $Ca(H_2PO_4)_2$ to form non-crystalline $Ca(PO_3)_2$. CPP granules added with $Na_2O$ and chitosan were implanted in extraction sockets and histologic observation were performed at 12 weeks later. Histologic observation at 12 weeks revealed that CPP matrix were mingled with and directly apposed to new bone without any intervention of fibrous connective tissue. CPP granules added with chitosan were well adatped without any adverse tissue reaction and resorbed slowly and spontaneously. CPP granules added with $Na_2O$ and chitosan show multinucleated giant cells and osteoblast-like cells around grafted material and newly formed bone. This result revealed that CPP, regardless of its additive component, had a high affinity for bone and had been resorbed slowly. From this results, it was suggested that CPP is promising ceramic as a bone substitute and addition of $Na_2O$ and chitosan help biodegradation. In further study , it will be determined which concentration of $Na_2O$ help biodegradation and the other additive components increase the degradation rate.

• Journal of Plant Biotechnology
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• 제31권1호
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• pp.89-94
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• 2004

본 실험은 기내 배양된 홍경천으로부터 캘러스를 유도하고 가장 잘 자라는 생장조건을 찾기 위해 수행되었다. 실험 결과를 종합해 보면 캘러스의 증식을 위한 배양조건은 최적배지를 조사한 결과,2B$_{5}$배지에서 생장율이 가장 좋았으며, 탄소원으로는 sucrose를 3%로 첨가했을 때 생장율이 가장 높았다. 질소원으로써는 49.6mM KNO$_3$와 2.0mM (NH$_4$)$_2$SO$_4$를 첨가했을 때 생장율이 가장 좋았으며, 인산의 농도는 2.16mM에서 높은 생장율을 보였다. 암배양과 광배양을 비교했을 때 암배양의 경우가 생장율이 높았으며,pH6에서 세포의 생장율이 가장 좋은 조건임을 확인되었다. 기내에서 배양된 캘러스와 자연산 뿌리는 TLC로 분석하여 salidroside를 확인하였으며, HPLC로 salidroside를 정량한 결과, 자연상태 홍경천의 뿌리는 건중량 당 0.17%으로 나타났으며 5% sucrose처리구에서 0.41%의 생산성을 보여, 자연산 홍경천의 뿌리에 비하여 캘러스에서 salidroside의 함량이 높은 것으로 나타났다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.185-185
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• 1994

관상동맥은 전기적으로 자극하여도 활동전위가 쉽게 유발되지 않는 조직인데, 이는 세포내의 $Ca^{2+}$에 의해서 활성화되는 $K^{+}$통로때문이라고 여겨지고 있다. 저자들은 단일 이온통로 수준에서 이러한 관상동맥 $K^{+}$ 통로의 성질을 조사하고, 아울러 $K^{+}$ 통로 개방제를 포함한 몇가지 약물이 $K^{+}$ 통로에 미치는 영향을 알아보고자 본 연구를 수행하였다. 막소포는 돼지의 심장에서 관상동맥을 분리하여 균질화 및 원심분리하여 준비하였으며, sucrose 20/30%에 있는 층을 취하여 분주한 후 -7$0^{\circ}C$로 보관하여 사용하였다. 평지방막은 1-palmitoyl, 2-oleoyl-phosphatidyl ethanolamine과 1-palmitoyl, 2-oleoyl phosphatidylcholine (4:1)을 n-decane에 녹인지방액(25mg/m1)을 200 $\mu\textrm{m}$의 구멍에 칠하여 만들었다. 단일 $K^{+}$ 통로는 막소포 (1-5$\mu\textrm{g}$/ml)를 평지방막의한쪽에 추가하고 자석으로 저어 융합이 되도록 하였으며, 통로의 활성은 막의 양쪽에 150 mM KCI, 10 mM HEPES-KOH, 0.5 mM EGTA, 0.6 mM $CaCl_2$ (pH 7.2)로 된용액이 존재하는 상태에서 막전압을 다르게 하며 기록하였다. 단일 이온 통로 전류는 amplifier를 통하여 VCR tape에 녹화하여 후에 분석에 이용하였으며, 동시에 종이기록지에 기록하였다. 단일이온통로 활성의 분석은 pClamp (Ver5.5)를 이용하여 수행하였다. 관상동맥에서 가장 흔히 기록되는 이온통로는 막전압과 $Ca^{2+}$의 농도에 의하여 변하는 $K^{+}$ 통로이었는데 pCa 4.0과 -10 mV에서 초기 활성도(Po)는 0.1에서 0.8까지 다양하였다. 전류와 전압과의 관계는 -60 - +60mV의 전압범위에서 직선형이었다.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.183-196
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• 1998

The purpose of this study was to determine the effect of bleaching technique on the shear bond strength of esthetic restorative materials to bovine enamel. The bleaching agent was used 35% $H_2O_2$(Hi-Lite, Shofu, U.S.A.). Experimental groups were divided into two divisions as group A and B. Experimental A groups for the effect of number of bleaching were as follows ; Group Al : no bleaching Group A2 : bleaching 1 time ( for 5 minutes ) Group A3 : bleaching 3 times ( each for 5 minutes ) Group A4 : bleaching 6 times ( each for 5 minutes ) Group A5 : bleaching 9 times ( each for 5 minutes ) Experimental B groups for the effect of storage period in artificial saliva were as follows ; Group B1 : not stored in artificial saliva after bleaching Group B2 : stored in artificial saliva for 1 day after bleaching Group B3 : stored in artificial saliva for 1 week after bleaching Group B4 : stored in artificial saliva for 2 weeks after bleaching Group B5 : stored in artificial saliva for 4 weeks after bleaching Composite resin and glass ionomer cement were bonded to all specimens, and the shear bond strength between enamel and r~storative material were measured in Instron Universal Testing Machine(Instron, 4467, U.S.A,), Additionally, the bleached enamel specimens were examed after etching with 37.4% $H_3PO_4$ for 1 min under SEM(S-2300, Hitachi Co., Japan) to observe the effect of bleaching procedure on enamel surface morphology. The result were as follows ; 1. In SEM findings, bleached bovine enamel was found to be superficially rough. 2. In bleached bovine enamel, the effect of acid etching was reduced with the increase of number of bleaching. 3. The mean shear bond strength of composite resin and glass ionomer cement to bleached enamel surface tended to be lower than those to non-bleached enamel surface. 4. With the increase of number of bleaching, the shear bond strength of composite resin and glass ionomer cement to bleached enamel were progressively decreased. 5. Increasing the, storage period in artificial saliva after bleaching, the shear bond strength of composite resin and glass ionomer cement to bleached enamel were progressively increased. 6. The mean shear bond strength of glass ionomer cement to bleached bovine enamel tended to be clearly lower than that of composite resin.

• 한국재료학회지
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• 제22권9호
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• pp.482-488
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• 2012

To fabricate a precise micro metal mold, the electrochemical etching process has been researched. We investigated the electrochemical etching process numerically and experimentally to determine the etching tendency of the process, focusing on the current density, which is a major parameter of the process. The finite element method, a kind of numerical analysis, was used to determine the current density distribution on the workpiece. Stainless steel(SS304) substrate with various sized square and circular array patterns as an anode and copper(Cu) plate as a cathode were used for the electrochemical experiments. A mixture of $H_2SO_4$, $H_3PO_4$, and DIW was used as an electrolyte. In this paper, comparison of the results from the experiment and the numerical simulation is presented, including the current density distribution and line profile from the simulation, and the etching profile and surface morphology from the experiment. Etching profile and surface morphology were characterized using a 3D-profiler and FE-SEM measurement. From a comparison of the data, it was confirmed that the current density distribution and the line profile of the simulation were similar to the surface morphology and the etching profile of the experiment, respectively. The current density is more concentrated at the vertex of the square pattern and circumference of the circular pattern. And, the depth of the etched area is proportional to the current density.