• 한국산학기술학회논문지
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• 제20권12호
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• pp.555-562
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• 2019

본 연구의 목적은 다양한 항균활성을 지닌 천연물 유래 물질 신남알데히드를 이용한 안정한 자가미세유화 약물전달시스템을 개발하는 것이다. 이러한 목표를 달성하기 위하여 신남알데히드의 주 분해산물인 신남산과 신남알데히드의 동시 정량법을 확립하였으며, 설정된 분석법을 이용한 용해도 시험으로 신남알데히드에 대한 용해도 개선효과가 우수한 계면활성제를 선별하였다. 계면활성제로 Cremophor EL, 공계면활성제로 Transcutol P를 이용한 신남알데히드의 pseudo-ternary phase diagram을 작성하여 에멀전의 입자크기를 최소화시킬 수 있는 조성비로 신남알데히드 : Cremophor EL : Trasncutol P = 10 : 70 : 20%(v/v/v)인 SMEDDS 조성물을 제조한 후 안정성 시험을 통해 신남알데히드의 함량변화 및 에멀전의 입자크기 변화에 대해 확인하였다. 본 연구를 통해 제조된 신남알데히드의 자가유화 나노에멀전은 신남산의 생성량이 적고 신남알데히드의 함량 저하 속도가 느려 안정성이 우수하였으며, 안정성 기간 중에 최초의 입자크기를 잘 유지하는 특성이 확인되었다. 따라서 이 조성물은 신남알데히드를 위한 의약품 제형으로의 활용 가능성이 높을 것으로 사료된다.

• 한국응용과학기술학회지
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• 제33권1호
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• pp.155-167
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• 2016

Surface-active substances in defatted rapeseed cake were obtained using a supercritical fluid extraction method. Then, it was purified by removing sinapine in the extract through a series of steps using a mixed solvent: diethyl ether and ethyl acetate (1:1, v/v). Emulsifying properties of purified surface-active substances were investigated, including fat globule size, zeta potentials and creaming stability and its antioxidant activity in emulsion systems were also studied by peroxide value and $^1H$-NMR spectrum. It was found that fat globules in emulsions with purified surface-active substances were much smaller than ones with the unpurified. In addition, as pH of the emulsion lowered and with increasing NaCl concentration in the emulsion, they were observed to increase, which led to worse creaming stability. These properties were reflected in changes of zeta potentials of emulsions. The oxidative stability was better in emulsions with purified surface-active substances than ones with Tween 20 or commercial lecithin, possibly resulted from the existence of sinapic acid in the extract. It was concluded that purified surface-active substances from defatted rapeseed cake could be simultaneously used as emulsifier and antioxidant agent in emulsion system.

• Journal of Pharmaceutical Investigation
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• 제34권4호
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• pp.299-303
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• 2004

Prescription filling in powder form is performed in community pharmacy practice to adjust dose for children and patients who cannot swallow whole tablet. However, there are few reports regarding the stability of the active ingredient and possible microbial growth after the medication is dispensed to powder form. This study examined the stability of atenolol, an antihypertensive agent, and microbial growth in the unit dose pouches dispensed at twenty-one community pharmacies located in Taegu area. Randomly chosen first unit dose pouch contained 77.4% of the prescribed dose of the drug and there were only four community pharmacies that dispensed the drug within 10% deviation from the dose prescribed by physician. Surprisingly, there were three community pharmacies that dispensed the drug with greater than 40% deviation, which may pose a major concern regarding the efficacy and safety of the drug prescribed for the treatment of hypertension. Atenolol content during a month did not indicate significant change, showing 5.4%, 4.3%, and 3.3% of decrease in 50%, 80%, and 90% relative humidity conditions, respectively. Microbiological examination during a month showed less than 0.5 microorganism in high power field (hpf) in all the relative humidity conditions tested. Based on this study, pharmacy practice in community pharmacy needs to be rigorously regulated to ensure that the dose of the prescribed drug is properly incorporated into the unit dose pouch dispensed as powder form.

• 한국통신학회논문지
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• 제32권8B호
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• pp.502-508
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• 2007

본 논문은 네트워크 기반(L2, MAC ADDRESS)과 어플리케이션 기반(L7, ID/PASSWORD)의 이중 인증 시스템을 구현을 통하여 허용되지 않은 자원과 사용자의 네트워크 접속을 차단할 수 있는 방안을 제시하였다. 인증 게이트웨이 시스템은 중앙 관리 서버로부터 보안/인증 정책을 물려받아 모든 패킷을 허가/차단/제어한다. 사용자의 컴퓨터에 에이전트 없이 모든 클라이언트의 자원(H/W, S/W)을 수집하며 OS 패치 여부 및 바이러스 감염 여부 등을 체크하여 안정적인 네트워크를 운영하고, 침해 사고가 발생한 때에도 신속히 대응 할 수 있는 방안을 제시하였다. 또한 유무선 네트워크의 경우, IEEE802.1x 인증을 요구하는 시스코 NAC에 비해 구축이 용이하고, 비용 절감을 실현할 수 있는 방안을 제시하였다.

• 한국건축시공학회지
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• 제12권1호
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• pp.22-30
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• 2012

Four types of foaming agents, including Alcohol Ethoxy Sulfate (AES), Alpha Olefin Sulfonate (AOS), Vegetable Soap (VS), and Fe-Protein (FP), are widely used in the construction field. These have different surface tensions and viscosities in water of the same concentration, affecting the flow speed of liquid, size and distribution of foam, and foam stability. However, there is a lack of data regarding the properties of foam concrete using various foam agents. The purpose of this study is to investigate influence of foaming agents on the properties of foamed concretes with various densities. We find that the foaming agent type has little effect on the density, compressive strength, and thermal conductivity of foam concrete, but considerably affects the unit weight of foam, flow and flexural strength of foamed concrete. While almost all properties of foam concrete are affected by density in fresh or hardened state, the potential energy changed by slurry density and the viscosity of foam are dominant factors in the flowability of foam slurry.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권3호
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• pp.315-320
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• 1994

General anesthesia is necessary to operation in dept. of oral and maxillofacial surgery. Halothane is one of the most commonly used anesthetic agent for general anesthesia because of its property of nonexplosive, inexpensive, strong activeness and chemical stability. Halothane is fluorinated hydrocarbone anesthetic agent and structurally similiar to chloroform. On the contrary halothane has been reported to result in severe hepaitc necrosis in a small number of individuals. Although the mechanism of halothane induced toxic hapatitis is unclear, it appears to be closely related to reducting metabolite, reactant intermediate product, immune reaction, hypersensitivity and so on. This is a case report of 27 years old male patient occured halothane induced hepatitis following after operation of mandible fracture.

• Advances in robotics research
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• 제2권2호
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• pp.161-182
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• 2018

This paper proposes a novel receding horizon control (RHC) algorithm for formation control of a swarm of unmanned surface vehicles (USVs) using particle swarm optimization (PSO). The proposed control algorithm provides the coordinated path tracking of multi-agent USVs while preventing collisions and considering external disturbances such as ocean currents. A three degrees-of-freedom kinematic model of the USV is used for the RHC with guaranteed stability and convergence by incorporating a sequential Monte Carlo (SMC)-based particle initialization. An ocean current model-based estimator is designed to compensate for the effect of ocean currents on the USVs. This method is compared with the PSO-based RHC algorithms to demonstrate the performance of the formation control and the collision avoidance in the presence of ocean currents through numerical simulations.

• 펄프종이기술
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• 제46권4호
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• pp.54-61
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• 2014

Effects of artificial thermal aging on color variations of various commercial papers (fine paper, coated paper, newsprint and filter paper) were investigated. With thermal aging at $105^{\circ}C$, most of papers showed a special trend in $a^*-b^*$ plane: the $a^*$ (red-green) values of the samples were initially reduced (heading to - $a^*$ side) and after a turning point they increased to +$a^*$ side while the $b^*$(blue-yellow) values were kept increased to +$b^*$ side (yellowing of paper). Different papers had different turning points for $a^*$ value. The filter paper consisted of a pure chemical pulp and the copy paper with OBA (optical brightening agent) showed the latest turing points. In addition, the papers without OBA showed less reduction in brightness compared with that with OBA, suggesting that OBA could adversely influence the brightness stability during thermal aging.

• 동력기계공학회지
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• 제8권3호
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• pp.36-43
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• 2004

The effect of bath composition, plating condition and plating rate on the magnetic property of electroless Co-Cu-P deposits were investigated. With increasing $CuCl_2$ concentration in the bath, plating rate increased, while the Br value of deposit decreased sharply. Deposited surface were inferiority by the increase pH above 10.5, bath temperature higher than $80^{\circ}C$. Plating reaction had been ceased by the increase of pH above 11, bath temperature higher than $90^{\circ}C$ and under $40^{\circ}C$. The Br value of deposit was uniform with various concentration of complexing agent(sodium citrate) in the bath. The Br value of deposit was almost equal to that found by the addition of stabilizer (thiourea) and accelerator(NaF). The Br value of deposit was uniform in plating time(20min) and heat treatment temperature(below $200^{\circ}C$), and were confirmed to have adequate bath stability for practical use.

• 생명과학회지
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• 제14권3호
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• pp.509-513
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• 2004

혈전 관련 질환 예방 및 혈류개선 기능성 식품의 개발을 목표로, 식용 및 약용 산채류 55종의 메탄을 추출물을 조제한 후 트롬빈 저해활성을 검색하였다. 그 결과, 대조군으로 사용된 아스피린보다 우수한 항혈전 활성을 나타내는 붉나무, 사삼, 우산나물, 쥐다래, 참나물, 할미밀망, 큰까치수영, 첫버들 추출물 등 8종을 선별하였으며, aPTT, 혈전 용해활성, 열 안정성, 기타 소화효소 저해활성 등을 평가하며 참나물, 큰까치수영 및 갯버들 추출물을 최종 선별하였다. 참나물의 경우 열안정성이 낮은 반면 소화효소 비저해로 인해 그 이용성이 높으며, 큰 까치수영 및 갯버들의 경우 부분적인 소화효소 저해능이 있으나 우수한 항혈전활성 및 열 안정성을 나타내어 다양한 식품소재로 개발이 가능함을 확인하였다.