• 한국재료학회지
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• 제21권2호
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• pp.106-110
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• 2011

A high thermal conductive AlN composite coating is attractive in thermal management applications. In this study, AlN-YAG composite coatings were manufactured by atmospheric plasma spraying from two different powders: spray-dried and plasma-treated. The mixture of both AlN and YAG was first mechanically alloyed and then spray-dried to obtain an agglomerated powder. The spray-dried powder was primarily spherical in shape and composed of an agglomerate of primary particles. The decomposition of AlN was pronounced at elevated temperatures due to the porous nature of the spray-dried powder, and was completely eliminated in nitrogen environment. A highly spherical, dense AlN-YAG composite powder was synthesized by plasma alloying and spheroidization (PAS) in an inert gas environment. The AlN-YAG coatings consisted of irregular-shaped, crystalline AlN particles embedded in amorphous YAG phase, indicating solid deposition of AlN and liquid deposition of YAG. The PAS-processed powder produced a lower-porosity and higher-hardness AlN-YAG coating due to a greater degree of melting in the plasma jet, compared to that of the spray-dried powder. The amorphization of the YAG matrix was evidence of melting degree of feedstock powder in flight because a fully molten YAG droplet formed an amorphous phase during splat quenching.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.395.3-396
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• 2002

A simple, rapid and reliable high performance liquid chromatography (HPLC) method has been developed for the measurement of lansoprazole in human plasma, and the application of pharmacokinetic study has been evaluated. Omeprazole was used as an internal standard. After adding methyl tert-butyl ether, samples were stored at －7$0^{\circ}C$. The extracts were easily obtained only with pouring the organic phase. The mobile phase was prepared using acetonitrile and water at the volume ratio of 38:62. (omitted)

• Journal of Pharmaceutical Investigation
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• 제14권4호
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• pp.161-169
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• 1984

The tests of dissolution and bioavailability of six formulas of lorazepam tablet under various binders were performed. Lorazepam can be seperated in pharmaceutical preparation and biological plasma by high performance liquid chromatograph. Dissolution process of lorazepam tablet was largely influenced by binder and the dissolution rate was increased by sodium starch glycolate and microcrystalline cellulose, the slower dissolution rate in starch. Bioavailability of lorazepam tablet got relationship with dissolution rate, because tablets containing sodium starch glycolate and microcrystalline cellulose as binder maintained higher plasma level than other binders.

• Bulletin of the Korean Chemical Society
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• 제18권11호
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• pp.1172-1175
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• 1997

Calcium isotopic ratios are precisely measured by removing isobaric interferences originated from water in the plasma. Liquid Ar cryogenic trap combined with membrane desolvator could eliminate backgrounds at m/z 42 and 44. Slow drift of ICP-MS is corrected by the frequent running of the standards. It is found necessary to separate Ca from the sample matrix using Ca oxalate precipitation technique. Currently, the RSD is 0.5-1.0% for 2 minutes of measurement but is expected to be improved if the measurement time is increased. The technique was applied to 42Ca enriched baby fecal samples and successfully determined 42Ca/44Ca ratio changes.

• 대한수의학회지
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• 제28권2호
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• pp.321-325
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• 1988

This experiment was carried out to determine the progesterone concentration of bovine plasma by liquid phase double antibody enzyme immunoassay. The optimum conditions of assay-system, double (first and second) antibody and carrier (normal rabbit serum) were investigated. The optimum dilution rate of first antibody, second antibody and normal rabbit serum was $10{\times}10^3$ to $15{\times}10^3$, 20 and $1{\times}10^3$ times, respectively.

• 분석과학
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• 제22권6호
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• pp.514-518
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• 2009

코엔자임 큐텐은 비타민과 유사한 물질로 체내 중 미토콘드리아에 주로 분포 되어 있으며 항산화 작용을 나타낸다고 알려져 있다. 본 연구는 27-44세의 건강한 성인 남 녀 24명을 대상으로 하였고 혈장내 코엔자임 큐텐의 농도를 정량 평가하기 위하여 UV 검출기가 장착된 고성능액체 크로마토그라피를 사용 하였다. 혈장 내 코엔자임 큐텐을 분리하기 위해서 메탄올로 지방단백질을 제거하였고 노말헥산을 이용하여 액체-액체 추출법으로 코엔자임 큐텐을 용해 시켰다. 그 후 원심분리를 실시하여 노말헥산과 제단백된 물질을 층분리 시키고 상층액을 다른 유리 시험관에 옮겨 담았다. 옮겨진 노말헥산 층은 질소 가스를 이용하여 증발 농축을 시켰으며 남은 잔사에 순수한 에탄올로 재용해 시켜 검사 장비 내로 주입 하였다. 이 때 사용된 컬럼은 C18 역상 컬럼이었고 275 nm의 파장이 이용되었으며 메탄올과 에탄올을 85:15로 섞은 이동상을 1.7 mL/min의 유속으로 흘렸다. 본 검사 방법의 정량한계(limit of quantitation : LOQ, N/S=10)는 0.02 mg/L로 평가 되었고 0.1-2.0 mg/L의 농도 범위에서 검량선을 작성 하였다. 대상군 24명의 혈장 중 코엔자임 큐텐의 농도는 0.41-0.98 mg/L의 범위에서 분포 하고 있었으며 평균 농도는 $0.62{\pm}0.13mg/L$ 였다. 본 연구의 결과 본 검사 방법은 특수성을 가지고 있었으며 혈장 내 $CoQ_{10}$을 분석하는데 충분한 정량한계를 가지고 있었기에 임상에 적용이 가능하고 연구 기관에서 사용하기에 적합하다고 사료 된다.

• Journal of Pharmaceutical Investigation
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• 제24권3호spc1호
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• pp.1-9
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• 1994

In order to assay the human plasma concentration of nifedipine in patients with bronchopulmonary dysplasia (BPD) and pulmonary hypertension, a modified high performance liquid chromatography (HPLC) method was applied. The retention times for nifedipine and an internal standard (11-ketoprogesterone) were $10.5\;{\pm}\;0.41$ and $13.1\;{\pm}\;0.63$ min, respectively. Absolute recovery from the plasma was $102.9\;{\pm}\;7.07%$. Reproducibility was excellent and variability between the runs was small. There was a negligible degradation during the assay procedure. The calibration curve shows a good linearity in the range of the desired plasma concentrations of nifedipine. A stability test of nifedipine in the human plasma shows 8 and 13% degradation during the storage of 5 and 9 months, respectively. There were no interferences on the HPLC assay with any possible medications for the BPD. The method has been used to monitor the drug concentrations in a patient. The concentration-time curve of a patient after a single oral dose of 0.3 mg/kg shows a double-peak phenomenon that was quite different from the previous report, suggesting non-bolus administration. However the hemodynamic responses were corresponding to the plasma concentration levels of nifedipine.

• 한국환경과학회지
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• 제27권8호
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• pp.621-629
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• 2018

Many chemically active species such as ${\cdot}H$, ${\cdot}OH$, $O_3$, $H_2O_2$, hydrated $e^-$, as well as ultraviolet rays, are produced by Dielectric Barrier Discharge (DBD) plasma in water and are widely use to remove non-biodegradable materials and deactivate microorganisms. As the plasma gas containing chemically active species that is generated from the plasma reaction has a short lifetime and low solubility in water, increasing the dissolution rate of this gas is an important challenge. To this end, the plasma gas and water within reactor were mixed using the air-automizing nozzle, and then, water-gas mixture was injected into water. The dissolving effect of plasma gas was indirectly confirmed by measuring the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the formation of OH radical) solution. The plasma system consisted of an oxygen generator, a high-voltage power supply, a plasma generator and a liquid-gas mixing reactor. Experiments were conducted to examine the effects of location of air-automizing nozzle, flow rate of plasma gas, water circulation rate, and high-voltage on RNO degradation. The experimental results showed that the RNO removal efficiency of the air-automizing nozzle is 29.8% higher than the conventional diffuser. The nozzle position from water surface was not considered to be a major factor in the design and operation of the plasma reactor. The plasma gas flow rate and water circulation rate with the highest RNO removal rate were 3.5 L/min and 1.5 L/min, respectively. The ratio of the plasma gas flow rate to the water circulation rate for obtaining an RNO removal rate of over 95% was 1.67 ~ 4.00.

• 한국결정성장학회지
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• 제7권2호
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• pp.235-243
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• 1997

$YBa_2Cu_3O_x$ 고온 초전도체 상을 MgO 단결정위에 증착시키기 위하여 액상의 에어로 졸 입자를 저온 플라즈마의 화학증기 증착로안에 유입하였다. 플라즈마의 분포를 조절하기 위한 반응로의 설계에 따라 초전도체상의 미세구조가 변화하는 양상을 관찰하였으며, 이때 증착 기판 위에서 관찰되는 입자들의 생성원인에 대하여 고찰하였다. 입자생성의 주된 원인으로는 불안정한 플라즈마의 분포와 출발원료의 낮은 기화속도에 기인하는 것으로 나타났다. 또한 증착속도는 출발원료가 기화되는 곳으로부터 멀어질수록 급격히 감소하는 것으로 밝혀졌다.

• 한국가스학회지
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• 제18권1호
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• pp.1-7
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• 2014

본 연구에서는 LPG자동차용 LPG 액상분사 인젝터의 분사구 앞에 장착할 수 있는 플라즈마 개질기의 개발을 진행하였다. 이 개질기는 플라즈마 방전이 발생하는 영역에 공기와 LPG 연료를 분사시켜 고분자 탄소연료를 열해리시키고 추가로 수소를 발생시키기 위한 목적으로 개발되었다. 인젝터와 플라즈마 발생부와의 거리와 기하학적인 방전길을 최적화하여 개질 반응이 일어나는 인젝터 개질기를 완성하였으며, 개질 결과 공급 전력 70~100W 일 때 HC은 전체 개질가스의 약 0.7% 이며, 수소는 1.2~1.5% 발생하였다.