• 한국산업보건학회지
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• 제20권2호
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• pp.88-93
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• 2010

To confirm and quantify asbestos fibers released from the asbestos-cement slate roofs due to weathering, three houses, selected based on the year of built - 60's, 70, and 80's, were investigated. All of them were located in the downtown of Seoul. Rain or snow-melt water was collected from the roof in a 3.5 liter plastic bottle. A known amount of collected water was filtered on the 37 mm membrane filter, ashed in a muffle furnace, and subsequently treated with HCl to remove organic material. The treated remaining was refiltered on a 25mm membrane filter for PLM and PCM analyses. The NIOSH 7400 method was utilized for PCM counting. In addition, SEM/EDX was used to confirm the asbestos types. The results of this study showed that chrysotile fibers were confirmed by PLM in all samples analyzed. A significant amount of asbestos fibers were found in the water samples. The ranges of asbestos fibers counted from the samples collected in the 60's, 70's, and 80's were; 10,406.3~55,575.6 f/L, 5,218.8~38,126.2 f/L, and 2,906.3~7,798.6 f/L, respectively. As anticipated, concentrations of asbestos fibers increased with time of installment of the roofing material. We conclude that weathering can be a significant factor on the release of asbestos fibers from the asbestos cement products. Since asbestos fibers released into environment can be a source of significant health hazard, countermeasures, such as replacement, removal, and encapsulation of weathered asbestos slate, should be initiated immediately.

• 폴리머
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• 제26권3호
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• pp.400-409
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• 2002

기능성 오일 (citronella oil)을 함유하는 폴리우레탄 마이크로 캡슐을 계면중합을 이용하여 tolulene 2,4-diisocyanate (TDI)와 ethylene glycol (EG)로부터 제조하였으며 제조된 마이크로캡슐을 적외선분광분석, 자외선분광분석, 입도분석기, 열중량측정기, 주사전자현미경을 이용하여 분석하였다. 마이크로캡슐의 제조시 이용된 분산제의 농도 및 교반속도와 같은 변수가 제조된 마이크로캡슐의 입자크기 및 분포에 미치는 영향을 조사하였다. 또한, 적외선분광분석을 통해 citronella 오일이 성공적으로 캡슐화되었음을 알 수 있었고 열중량측정으로 마이크로캡슐은 약 $220^{\circ}C$ 정도까지 안정함을 알 수 있었다. 마이크로캡슐을 메탄올 용매에 넣어 캡슐 속의 citronella 오일의 방출거동을 자외선분광분석을 통해 조사하였다. Citronella 오일의 방출양은 캡슐 제조 시 적용된 교반속도 및 분산제의 농도를 증가시킴에 따라 증가하였다. Citronella 오일을 함유하는 마이크로캡슐은 우수한 방충효과를 나타내었다.

• 약학회지
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• 제55권2호
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• pp.131-137
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• 2011

The dissolution test method and an analytical procedure by HPLC were developed and validated for dobesilate calcium tablets and acepifylline tablets. These drugs were not yet characterized by the dissolution specifications in Korean Pharmaceutical Codex. So, with each reference and test drugs, we did the preliminary and standard experiments based on the Korean Pharmacopeia Guideline of dissolution testing for solid oral dosage forms. The dissolution test for dobesilate calcium tablets was carried out under sink conditions as following: dissolution medium water, paddle rotation speed 50 rpm and vessel volume 900 ml. More than 90% of its label amount was released within 30 min in this method. Also the dissolution test for acepifylline tablets was carried out under sink conditions as follows: dissolution medium water, paddle rotation speed 100 rpm and vessel volume 900 ml. More than 90% of its label amount was released within 45 min in this method. The dissolution samples were analyzed with a precise and accurate HPLC method. The developed dissolution test showed specificity, linearity, precision and accuracy within the acceptable range. The dissolution testing method described above was adequate for the purpose and may be proposed as a pharmacopeial standard to assess the performance of dobesilate calcium tablets and acepifylline tablets.

• 한국식품영양과학회지
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• 제27권1호
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• pp.75-79
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• 1998

The effects of filling amount and temperature of orage juices on the release of tin from can were investigated according to storage period and temperature. For the experiment, the orange juice in can with the full weight of 200g were filled respectively with 170g, 180g, 190g, respectively, changing filling temperature to 8$0^{\circ}C$, 88$^{\circ}C$, 93$^{\circ}C$. In the case of 170g orange juice content all samples with the filling temperature at 8$0^{\circ}C$, 88$^{\circ}C$, 93$^{\circ}C$ and the storage temperature at 4$^{\circ}C$, 26$^{\circ}C$, 4$0^{\circ}C$ surpassed 150ppm(the permitted limit of tin) of released tin content after 30 days in ascending order. In the case of 180g orange juice content, all samples except the one with the filling temperature at 93$^{\circ}C$ and storage temperature at 4$^{\circ}C$, which took 90 days to surpass the limit, surpassed 150ppm of released tin content after 30days. In the case of 190g orange juice content, the samples with the filling temperature of 88$^{\circ}C$ and 93$^{\circ}C$ and with the storage temperature at 4$0^{\circ}C$ took 60 days to reached to the limit, while the samples with the storage temperature at 4$^{\circ}C$ and 26$^{\circ}C$ contained within the 150ppm limit for 240 days. The vacuum of can increased as the filling temperature was increased, and the sample with higher filling amount and temperature at the lower storage temperature decreased the release of tin.

• 수산해양교육연구
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• 제27권4호
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• pp.981-989
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• 2015

This study aims to investigate how ovulation induction of sevenband grouper, Epinephelus septemfasciatus varies when treated with different hormonal substances such as ovaprim, pimozide, LHRHa, and HCG. As for LHRHa, we injected it in different concentrations: $50{\mu}g/kg$, $100{\mu}g/kg$, $150{\mu}g/kg$, and $200{\mu}g/kg$. All hormonal substances including LHRHa were injected into back muscles. As a result, ovulation occurred in all sample groups. The sample group injected with HCG released the largest amount of eggs, and the dimeter of eggs and oil globules were also significantly bigger than those of others. Fertilization rate, embryonic survival rate, and hatching rate were the highest in a LHRHa ($100{\mu}g/kg$) +pimozide ($1,000{\mu}g/kg$) group and buoyant rate in a LHRHa group. Ovulation rate was 100% when LHRHa was injected in different concentrations. The largest amount of eggs was released in $200{\mu}g/kg$. The diameter of eggs and oil globules were the biggest in $200{\mu}g/kg$ and the smallest in $50{\mu}g/kg$. Fertilization rate showed no significant difference through all different levels of concentration: 94.6-95.3%. Buoyant rate was the highest in $100{\mu}g/kg$ and embryonic survival rate and hatching rate in $150{\mu}g/kg$. Based on these experimental results, we concluded that LHRHa in $100{\mu}g/kg$ is the most efficient for the ovulation induction of sevenband grouper.

• 농업과학연구
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• 제46권1호
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• pp.33-44
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• 2019

This study was conducted to examine the components of phytoncide from a pine forest in the southern temperate zone. Recent studies have found that a large amount of phytoncide is released not only from cypress trees but also from pine trees. Because the amount released is the highest during summer, we selected a warm climate region in the southern temperate zone and measured the concentration in the month of August. To capture the phytoncide from the forest atmosphere, we used the adsorption tube method with a mini pump and successfully gathered 9 L of forest air at a flow rate of 150 mL/min. We performed duplicate sampling from two different tubes installed at the same location and derived the mean value. A gas chromatography/mass spectrometer detector with thermal desorption spectroscopy was utilized to perform quantitative and qualitative analyses of the captured material. The results showed that the average phytoncide particle of the pine forest in the southern temperate zone contained a number of components as follows in descending order: ${\alpha}$-Pinene (39%, $0.28ng/m^3$), followed by ${\beta}$-Pinene (16%, $0.11ng/m^3$), D-Limonene (8%, $0.06ng/m^3$), camphor (6%, $0.04ng/m^3$), camphene (6%, $0.04ng/m^3$), and p-Cymene (5%, $0.04ng/m^3$). There were also 13 additional phytoncide components in trace amounts. The results of this study are expected to provide a useful dataset for building a "Healing-forest".

• 공업화학
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• 제22권3호
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• pp.336-339
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• 2011

해조류는 잠재력이 있는 풍부한 발효기질이다. 해조류의 효소가수분해를 상업용 셀룰라아제 및 비스코자임과 함께 알칼리 과산화수소 전처리에 의해서 검토하였다. 본 연구에서 사용된 해조류는 구멍갈파래이며, 전처리 평가는 효소가수분해 후 얻어진 글루코오스의 수율로 나타내었다. 알칼리 과산화수소는 과산화수소 1 wt%에 수산화나트륨을 1~1.75 wt% 범위로 혼합하였다. $60^{\circ}C$에서 3 h 동안 전처리한 결과 5 wt% 과산화수소를 사용했을 때에 가장 높은 글루코오스 전환율을 보였다. 알칼리 과산화수소로 전처리한 후 필요한 효소의 양은 전처리하지 않은 구멍갈파래에 비하여 상당히 절감되었으며, 아울러 효소 가수분해동안 얻어진 글루코오스의 양은 증가되었다.

• 농약과학회지
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• 제2권3호
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• pp.36-44
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• 1998

각기 다른 종류의 입상담체(extruded pellets, sands, zeolites)를 이용하여 보조제의 종류와 조성을 달리하고 주성분을 피복 또는 흡착시켜 제제한 제제품과 조립흡착식으로 제조된 butachlor + chlometholefen(3.5 + 7.0%, 부로트 입제) 혼합입제의 부유성, 수중확산 또는 붕괴성, 수중용출도 및 생물효과를 비교하여 우수한 물성 및 효과를 갖는 용출제어형 입제 제조법을 개발하고자 하였다. 물성이 다른 원제를 이용하여 입제를 제조하기 위해서 여러 제조방식을 이용하는데 원제 2개 이상 혼합된 입제를 제조하기 위해서 고상인 원제와 증량제 및 보조제를 첨가시켜 조립한 뒤 여기에 액상 원제를 흡착시켜 제조한 입제는 우수한 부유성과 수중붕괴성, 안정된 수중용출도를 나타내었으며, 생물효과도 안정적으로 발휘시킬 수 있었다. 기립입자를 담체로 이용하여 피복 또는 흡착시킨 기립피복식 입제들은 부유성, 수중붕괴성 및 생물효과면에서 기존 입제와 대등하거나 우수하였지만 불안정한 수중용출 경향을 나타내었다. 그러나 모래피복형의 경우 기립피복식이나 지오라이트피복식과 달리 액상의 binder가 비교적 안정적으로 주성분들의 수중용출에 도움을 주었고 분상의 dispersing agent보다 액상이 부유성, 수중붕괴성 및 생물효과 면에서 기존과 비슷했거나 좋았던 결과로 볼 때 적절한 binder와 액상의 dispersing agent를 선택하여 제조한다면 기존 조립흡착식 입제와 대등하거나 우수한 물성 및 생물효과를 발현하는 입제를 개발할 수 있는 제조방식인 것으로 판단되었다.

• 한국토양비료학회지
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• 제45권4호
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• pp.551-554
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• 2012

The present laboratory investigation was conducted to assess the effect of heavy metals on carbon mineralization. Soil was treated with three concentrations (50, 100 and $150{\mu}mol\;g^{-1}$ soil) of two heavy metals (Cd and Zn) in a factorial combination of treatments replicated four times. Determination of carbon mineralization was carried out at 3, 7, 14, 21, 28, 42 and 56 days after metal treatments.. The amount of $CO_2$-C released from heavy metal treated soils was found to be decreased at an increasing rate during the first 28 days, followed by slow release as incubation progressed. The total amounts of $CO_2$-C released were 448, 382 and $348mg\;kg^{-1}$ soil respectively for soils treated with 50, 100 and $150{\mu}mol\;g^{-1}$ soil of Zn. The corresponding figures for Cd treated soils were 406, 354 and $282mg\;kg^{-1}$ soil implying that dose-dependent reduction in cumulative $CO_2$-C released from soils. The inhibition of carbon mineralization was found to be high in Cd treated soils than that of Zn treated. Therefore, tolerance and adaptation of the microbial community is likely to be related to the concentration and the type of metal. According to the results, carbon mineralization can be considered as possible indicator of soil pollution by means of heavy metals.

• 폴리머
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• 제25권6호
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• pp.893-901
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• 2001

조직공학적 신경재생 및 파킨슨씨병 등의 시경퇴행성 질환에서의 치료에 이용 목적으로 신경성장인자(nerve growth factor, NGF)를 생분해성 고분자 담체에 NGF를 서방화시키고자 PLA 담체에 함유시켜 유화동결건조법으로 제조하였다. 제조된 NGF의 방출량은 생체외 pH 7.4, 37$^{\circ}C$의 PBS 조건하에서 4주 동안 방출실험 하였으며, 함유된 NGF의 활성을 확인하기 위하여 PC-l2 세포에 직접 배양하여 확인하였다. 제조되어진 PLA 담체는 열린 셀 구조를 가졌으며, 초기 NGF의 함량이 많을수록 방출량도 증가를 보였으며, 제조과정에서의 NGF의 환성을 확인하기 위하여 PC-12 세포를 배양한 결과 신경돌기가 성장하였다. 본 연구는 생분해성 고분자 특정인 확산과 분해에 의해서 생물학적 활성물질인 NGF의 방출을 조절할 수 있으며, 조직공학적으로 서방화되어 3차원적인 신경재생을 가능케 할 것으로 기대된다.