• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.87-91
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• 2002

Lab scale batch and column tests were performed to investigate the treatability of petroleum contaminated soil using the in-situ soil flushing method. The pyrex column (4.5$\times$25 cm) was used to investigate optimal washing agent, surfactant concentration, mixing ratio, and inlet velocity. The miked surfactant of $POE_{14}$ and SDS were determined as ideal systems for the batch tests. From the results of preliminary tests, mixed surfactant was found to be more harmful for microorganisms. So $POE_{5}$ and $POE_{14}$ were chosen as the surfactant system for the batch study. The washing efficiency for the diesel contaminated soil was increased until 1 %, and decreased after l %. When applied as selected mixed surfactant, the ideal mixed ratio was recognized as 1:1. Therefore we selected miked surfactant $POE_{5}$ and $POE_{14}$, surfactant concentration 1%, and mixed ratio 1:1 for the remediation of diesel contaminated soil. In column tests, the total removal efficiency was improved as the flux of washing agent was increased. At the same pore volume, small flux showed better removal efficiency.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.18 no.1
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• pp.42-63
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• 1992

In order to investigate the effect of nonionic surfactants on the antimicrobial activity of preservatives in the presence and absence of p.0.E(20) Sorbitan fatty acid ester commonly used in cosmetics and pharmaceutical systems, these experiments were carried out by determining Minimum Inhibitory Concentration(MIC) values and MIC values of adaptation against test organisms. And also the inactivation of the preservative against each microorganism in formula added with various concentrations of P.0.E(20) Sorbitan monostearate were measured by use of a preservative death time curve The results obtained were as fort low : 1) Nonionic surfactant inactivated Methylparaben to varying extents, but not Imidazolidinyl urea. 2) A combined preservative system was inactivated to a little extent (range of 0.16-0.20% Conc.), no adaptation was observed for the 5. aureus ATCC 6538. Imidazolidinyl urea complex combined with Methylparaben had a broad antibacterial spectrum against the Gram(.) and the Gram(-) bacteria It was found that preservatives had a synergistic effect by use of mixed form of preservatives, 3) In formula preserved with 0.2% Methylparaben containing 0.5, 1.0 and 2.0% P.0.E(20) Sorbitan monostearate, E. coli ATCC 10s36 and P. aeruginosa NCTC 10490 died quickly within in 2hr 4) However, from Fig.5, S. aereus ATCC 6538 died more slowly within increasing surfactant concentration and the D-values(Decimal reduction time) were 5.2, 8 and 14 hr. for samples containing 0.5, 1 0 and 2.0% P 0. E(20) Sorbitan monostearate, respectively. 5) In the case of Methylparaben, no adaptation for the E. coli ATCC 10536 6) All of the nonionic surfactant, p.0. E(20) Sorbitan fatty acid ester used in the experiments decreased the effectiveness of Methylparaben, but not of Imidazolidinyl urea.

• The Korean Journal of Soil Zoology
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• v.4 no.2
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• pp.81-85
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• 1999

Efficiencies of hand sorting, vermifuge application and combined methods of them for sampling earthworms in the field were compared. 1) hand sorting : sampling unit of soil (50 cm${\times}$50 cm${\times}$30 cm, width${\times}$length${\times}$depth) was dug out and earthworms were sorted by hands. 2) Vermifuge application : Solution of mustard, pepper or formalin was treated onto the soil surface of smpling unit (50 cm${\times}$50 cm, width${\times}$length). 3) Combined method : In a sampling unit of soil (50 cm${\times}$50 cm${\times}$30 cm, width${\times}$length), hand sorting was carried out into the depth of 10 cm or 15 cm and then vermifuge was treated. Earthworms were collected more in numbers by hand sorting than vermifuge application although it was much more time-consuming and labor intensive. Efficiency of mustard to extract earthworms was as same as formalin but much better than that of pepper. Combined method of hand sorting with mustard treatment was more efficient than vermifuge applications and other combined methods. And it could collect earthworms as many as hand sorting, but was much less time-consuming and labor-intensive than hand sorting. Thus combined method of hand sorting (to the depth of 15 cm) with mustard treatment could be recommended for the sampling of earthworms in the field.

• Korean Journal of Materials Research
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• v.5 no.4
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• pp.426-432
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• 1995

윤활제인 zinc stearate의 첨가량 (0~4wt%)을 변화시켜 U$O_{2}$분말의 겉보기밀도, 성형시의 분말입자간 마찰과 입자/다이벽 마찰간의 상관관계를 조사하였다. 소량의 윤활제 첨가시에는 U$O_{2}$분말입자간 박막의 윤활제 도포층이 형성되어 겉보기밀도가 증가한 반면 다량의 윤활제를 첨가한 경우에는 U$O_{2}$ 분말입자에 두꺼운 윤활제 도포층이 형성되고 미혼합된 윤활제가 존재하여 겉보기밀도는 감소하는 경향을 보였다. 윤활제를 첨가혼합한 상태에서 다이벽 윤활도포 유무에 따라 구한 U$O_{2}$ 성형체의 성형압력/성형밀도 자료로부터 분말입자간 마찰, 입자/다이벽 마찰 그리고 성형시 lubrication/inhibition등의 상대적 중요성을 조사하였다. 입자/다이벽 마찰에 의한 압력손실은 입자간 마찰에 의한 압력손실보다 크게 나타났다. 입자/다이벽 마찰에 의한 압력손실은 다이벽 윤활제 도포에 의해 최소화될 수 있지만 상대적으로 바람직하지 않은 성형시의 inhibition이 야기되는 것으로 나타났다.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.67-72
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• 2006

Several propellants were investigated experimentally for ignition characteristics in subatmospheric pressure. The threshold ignition pressure was 4 psia for HTPB/AP composite propellant. The partial replacement of AP in HTPB/AP propellant by $5{\sim}l5%$ of HMX, HNIW showed that the improvements in ignition delay was over 50% and the threshold pressure was below 0.4 psia. This appears to be due to the characteristics of HMX and HNIW exothermic dissociated at the temperature(${\sim}220^{\circ}C$) love. than that of AP. The ignition substance $B/KNO_3$ was coated thinly on the propellant surface for better ignition performance. As a result, ignition delay time of 15% was improved. NC is applied to $B/KNO_3$ ignition substance as a secondary binder and $NC-B/KNO_3$ suspension solution is coated to the propellant surface.

• Korean Journal of Clinical Pharmacy
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• v.13 no.2
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• pp.91-96
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• 2003

Paclitaxel과 cephalosporines(제 1세대인 ceftezole sodium과 cephradine, 제2세대인 cefamandole sodium과 cefmetazole sodium, 제3세대인 cefoperazone sodium과 cefotaxime sodium 그러고 제4세대인 cefepime hydrochloride)을 $5\%$포도당주사액 그리고 $0.9\%$ 염화나트륨주사액과 함께 Y-Site 장치를 써서 환자에게 주입할 때 paclitaxel의 안정성에 관하여 연구하였다. Paclitaxel 0.3 mg/ml 및 1.2 mg/ml과 cephalosporines 20 mg/m을 각각 1 : 1로 혼합한 후 0, 1, 2, 4, 12시간 시점에서 paclitaxel의 농도를 HPLC로 분석하였다. 방해물질에 의한 분석오차를 줄이기 위해 분석법을 여러 상태에서 확인하였으며, 각 농도에서 3차례씩 실험하였고 각 샘플은 2차례 반복하여 HPLC로 분석하였다. 분석전에 각 시료의 투명도, 색의 변화, 침전상태 및 pH를 검사하였다. Paclitaxel 0.3 mg/ml 및 1.2 mg/ml와 cephalosporines 20 mg/ml를 각각 혼합하였을 때 12시간 동안 안정하였으며, 주사액의 혼탁이나 색의 변화 및 침전은 나타나지 않았으며 pH도 변하지 않았다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.347-347
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• 1994

효소억제제와 투과촉진제를 첨가하지 않은 경우 비강, 직장 및 질점막을 통한 YAGH니 투과정도를 검토한 결과 donor측 잔존률이 경시적으로 급격히 감소하여 24시간후각각 7.04, 4.21 및 51.34％ 잔존하였다. 또한 receptor측으로의 투과량는 비강점막의 경우 8시간대에 3.9%의 투과율을 기점으로 다시 분해되었으며 직장 점막에서는 최대 0.72% 로 거의 검출되지 않았다. 질점막의 경우에는 24시간대에 1.8％의 투과에 머물렀다. 한편 혼합효소억제제로 TM가 EDTA를 양측 셀에 첨가한 조건에서는 첨가되지 않은 경우와 비교하여 donor측에서의 YAGFM이 서서히 감소됨과 동시에 receptor cell로의 투과량이 다소증대되었다. 더욱 양측 셀에 혼합효소억제제를 넣고 donor cell에 투과촉진제를 첨가한 경우 점막투과성을 현저히 증대시켰으며 LPC를 사용한 경우 효소억제제만을 사용한 경우와 비교하여 비강에서 3.6배, 직장에서 3.2배 및 4.1배 투과 flux를 증가시켰다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.47-53
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• 2006

The oxidizer-rich preburner is applied to the high efficiency closed cycle rocket propulsion system. This system is generally operated on oxidizer-fuel mixture ratio over than 50. The spray quality and mixing performance are very important for safe combustion of this preburner. This paper presents basic concept and spray characteristic of the preburner injector.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.409-418
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• 1989

The oxidative stability of the ramyon prepared with ricebran oil fortified with ${\alpha}-tocopherol$, BHA, TBHQ, and ascorbyl palmitate+citric acid or blended with palm oil was studied to assess the suitability of the oil as the frying oil. The antioxidants were added to a ricebran oil at 0.02% level, respectively, while blended oils were prepared by adding a palm oil to the ricebran oil at ratios of 3:7, 5:5, and 7:3. Ramyon samples were prepared by frying steamed noodel with the oils. They were stored in dark at $35.0{\pm}0^{\circ}C$. for 90 days. Peroxide, acid, iodine values, dielectric constant, and fatty acid composition of the oils extracted from the samples were determined regularly. The oxidative stability of the extracted oils and storage stability of the samples were estimated from the results of the determinations. ${\alpha}-tocopherol$ did not exert any appreciable antioxidant effect on the extracted oil while BHA demonstrated some effect. Ascorbyl palmitate with citric acid and especially TBHQ exerted a considerable effect. The storage stability of the samples fried with the oil fortified with TBHQ was as good as that of the samples prepared with the palm oil. The stability of the samples improved as the palm oil content In the frying oil increased. The stability of the samples fried with the blended oil containing 70f) palm oil was comparable to that of the samples prepared with the pure palm oil

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.234-238
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• 2007

Highly conducting Polypyrroles soluble in organic solvents were synthesized using functional doping agents, such as mixed dopants [sodium di(2-ethylhexyl)sulfosuccinate (DEHSNa) Naphthalenesulfonic acid (NSA), DEHSNa Toluenesulfonic acid (TSA), DEHSNa Dodecylbenzensulfonic acid (DBSA)] and mixed oxidants [$(NH_4)_2S_2O_8{\cdot}FeCl_3$, $(NH_4)_2S_2O_8{\cdot}Fe_2(SO_4)_3$]. Ppy-DEHS powder using an oxidant, such as $(NH_4)_2S_2O_8$ (10 wt%/vol.) showed higher solubility than the mixed dopant (DEHSNa NSA, 3 wt%/vol.) and mixed oxidant [$(NH_4)_2S_2O_8{\cdot}Fe_2(SO_4)_3$, 4 wt%/vol.] in DMF solvent. But Ppy-DEHS free standing film using a mixed dopant, such as DEHSNa NSA (16 S/cm) and a mixed oxidant, such as $(NH_4)_2S_2O_8{\cdot}Fe_2(SO_4)_3$ (13 S/cm) cast from DMF solvent showed higher electrical conductivity than $(NH_4)_2S_2O_8$ (2 S/cm). For the Ppy-DEHS films using various condition cast from DMF solvent, three dimensional various range hopping model (3D VRH ; $\{{\sigma}_{dc}(T)={\sigma}_oexp[-(T_o/T)^{1/4}]\}$) provided fit to the results of temperature dependence of electrical conductivity measurement.