• The Journal of Korean Physical Therapy
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• 제13권3호
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• pp.719-726
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• 2001

Transdermal drug delivery offers various advantages over conventional drug delivery systems, such as avoidance gastrointestinal degradation and hepatic first-pass effect. encourages patient compliance. and possible sustained release of drugs. However, transdermal transport of drugs is low permeability of the stratum corneum, the superficial layer of the skin. Many physicochemical and biological factors influencing transdermal transport is described together with the corresponding experimental and clinical results. Phonophoresis is medical treatment with drugs introduced into the skin by ultrasound energy. Enhanced drug penetration is through to result from the biophysical alterations of skin structure by ultrasound waves. The frequency used for phonophoresis is usually from 20 kHz to 15MHz. Phonophoresis can be categorized in to three ranges: low-frequency range(below 1 MHz). therapeutic frequency range(1 to 3MHz), and high-frequency range(above 3 MHz). The depth of penetration of ultrasound into skin is inversely proportional to the frequency. Cavitation may cause mechanical stress. temperature elevation, or enhanced chemical reactivity causing drug transport. One theory is that ultrasound affects the permeation of the stratum corneum lipid structure as the limiting step in permeating through the skin. The range of indications for phonophoresis is wide. Aspecific classification of the range of indications is obtained by classification of pathological conditions. The continuous research is needed for many interesting issucs of phonophoretic transdermal delivory in new future.

• 한국해안해양공학회지
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• 제5권2호
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• pp.143-150
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• 1993

이중 주파수(Dual Frequency)를 사용한 Prototype형 천해 지층 탐사기를 사용하여 얻은 탐사 기록지가 제시되었다. 이중 주파수로는 3.5/100KHz 혹은 15/100KHz를 이용해서 고주파수에 의한 고해상도(High Resolution)을 얻고 동시에 저주파수(3.5~15KHz)에 의한 심층 투과력을 높이는데 본 연구의 목적이 있다. 특히 탐지하는 목표물이 Fresnel 반경에 비해서 매우 작을 때는 쌍곡선형 회절무늬(Hyperbolic Diffraction)가 나타나기 때문에 쉽게 목표물을 찾을 수 있다. 감쇠상수가 큰 모래층은 작은 감쇠상수를 갖고 있는 점토보다 지진파의 투과력을 약하게 만든다. 이와같이 이중 주파수의 동시 운용은 해저 지질. 모래와 점토(Silt/Clay) 분포 오니토 및 해양고고학 유물 탐사에 크게 활용할 수 있다.

• Archives of Pharmacal Research
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• 제29권10호
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• pp.928-933
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• 2006

Percutaneous delivery of NSAIDs has advantages of avoiding hepatic first pass effect and delivering the drug for extended period of time at a sustained, concentrated level at the inflammation site that mainly acts at the joint and the related regions. To develop the new topical formulations of pranoprofen that have suitable bioadhesion, the gel was formulated using hydroxypropyl methylcellulose (HPMC) and poloxamer 407. The effects of temperature on drug release was performed at $32^{\circ}C$, $37^{\circ}C$ and $42^{\circ}C$ according to drug concentration of 0.04%, 0.08%, 0.12%, 0.16%, and 0.2% (w/w) using synthetic cellulose membrane at $37{\pm}0.5^{\circ}C$. The increase of temperature showed the increased drug release. The activation energy (Ea), which were calculated from the slope of lop P versus 1000/T plots was 11.22 kcal/ mol for 0.04%, 10.79 kcal/mol for 0.08%, 10.41 kcal/mol for 0.12% and 8.88 kcal/mol for 0.16% loading dose from the pranoprofen gel. To increase the drug permeation, some kinds of penetration enhancers such as the ethylene glycols, the propylene glycols, the glycerides, the non-ionic surfactants and the fatty acids were incorporated in the gel formulation. Among the various enhancers used, propylene glycol mono laurate showed the highest enhancing effects with the enhancement factor of 2.74. The results of this study suggest that development of topical gel formulation of pranoprofen containing an enhancer is feasible.

• Computers and Concrete
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• 제19권2호
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• pp.171-177
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• 2017

Water pressure test operation is used before the grouting to determine the rate of penetrability, the necessity and estimations related to grouting, by the penetration of water into the borehole. One of the parameters which have the highest effect is pressure of water penetration since the application of excessive pressure causes the hydraulic fracture to occur in the rock mass, and on the other hand, it must not be so small that prevents from seeing mechanical weaknesses and the rate of permeability. Mathematical modeling is used for the first time in this study to determine the optimum pressure. Thus, the joints that exist in the rock mass are simulated using cylindrical shell model. The joint surroundings are also modeled through Pasternak environment. To obtain equations governing the joints and the surroundings, energy method is used accompanied by Hamilton principle and an analytical solution method is used to obtain the maximum pressure. In order to validate the modeling, the pressure values obtained by the model were used in the sites of Seymareh and Aghbolagh dams and the relative error rates were measured considering the differences between calculated and actual pressures. Modeling in the sections of Seymareh dam showed 4.75, 3.93, 4.8 percent error rates and in the sections of Aghbolagh dam it rendered the values of 22.43, 5.22, 2.6 percent. The results indicate that this modeling can be used to estimate the amount of pressure for hydraulic fracture in water pressure test, to predict it and to prevent it.

• 대한치과교정학회지
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• 제43권1호
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• pp.29-34
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• 2013

Objective: To examine the prophylactic potential of 3 orthodontic bonding adhesives: Fuji Ortho SC, Illuminate, and Resilience. Methods: Thirty-six Wistar Wag rats were randomly divided into 4 groups consisting of 9 rats each. One of the groups received no treatment and was used as a control. In the other groups, individual bands coated with one of the 3 adhesives were cemented to the lower incisors. Enamel samples were obtained after 6 and 12 weeks and analyzed using scanning electron microscopy in combination with energy dispersive spectrometry. Results: Six weeks after band cementation, no fluoride was found in the enamel of the lower incisors. After 12 weeks, there was no fluoride in the enamel of teeth coated with the Resilience composite. However, in the case of the Illuminate composite and the resin-modified glass ionomer Fuji Ortho SC cement, the depth of fluoride penetration reached $2{\mu}m$ and $4.8-5.7{\mu}m$, respectively. Conclusions: Fluoride ions from orthodontic adhesives can be incorporated into the surface layer of the enamel. Orthodontists may apply orthodontic adhesives, such as the Fuji Ortho SC, to reduce the occurrence of caries during orthodontic treatment with fixed appliances.

• 설비공학논문집
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• 제27권8호
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• pp.409-417
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• 2015

A simplified rotary heat-exchanger model was developed with an assumption of a linear temperature distribution along the flow direction. Based on the model, the exact fluid solution and solid temperature variations were obtained and verified from a comparison with previous numerical studies. The heat transfer in the rotary heat exchanger was investigated using the theoretical solutions. The heat exchanger's effectiveness was shown to be saturated, with a rotational-speed increase that is higher than a critical value that is solely dependent on the thermal capacity of the solid matrix but independent of the fluid flow rate; the saturated value of the effectiveness was determined only by the NTU of the heat exchanger. Where the thermal diffusivity of the solid matrix is so slight that the thermal penetration depth becomes smaller than the matrix thickness, the effective thermal capacity of the solid matrix decreased according to the penetration depth.

• KIEAE Journal
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• 제10권1호
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• pp.65-72
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• 2010

The use of natural light has the potential for improving both the energy efficiency and indoor environmental quality in buildings. A light-pipe system can introduce daylight to spaces that would otherwise not be able to benefit from the advantages of daylight penetration. For the light-pipe system to be widely used in Korea, it is important to quantify its daylighting performance with due consideration regarding the effects imposed by the local climate conditions. This paper presents the evaluation results of existing semi-empirical models to predict daylighting performance of a light-pipe system. The evaluation of the existing models was based on the monitoring data obtained from a underground parking lot in which the light-pipe system was installed. Comparisons were made between the predicted and the monitored data obtained from the study. The results indicated that semi-empirical models which was developed using the experimental data obtained under the Korean climatic conditions had a good prediction performance. We also quantified the effects caused by sky conditions, solar altitudes, room dimensions, and the aspect ratio of a light-pipe system on both the daylighting performance of the light-pipe system and the indoor illuminance distributions of the space using the semi-empirical model. Finally, this paper provides the design guideline of the light-pipe system for its application to an underground parking lot space.

• 한국진공학회지
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• 제9권3호
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• pp.285-289
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• 2000

축방향의 약한 자기장(약 1∼20 gauss)으로 자화된 inductively coupled plasm의 투과깊이와 전파 상수의 특성변화를 계산하였다. 자화 플라즈마에 있어서 전자밀도의 증가로 인한 플라즈마의 투과깊이 감소와, 그와 상반되는 충돌주파수 증가로 인한 투과깊이 증가를 고려하여, 보다 균일한 플라즈마 공정을 위한 기초 자료로서 중성 입자와 전자간의 충돌주파수, 전자밀도 및 자기장의 크기와 플라즈마 투과깊이 간의 상관관계를 확인하였다. 통상적인 저압 공정 플라즈마 조건하에서, 약 4.8 gauss의 자기장이 축방향으로 인가되는 경우 cyclotron 공명에 의해 투과깊이가 최소값을 가지는 것을 재확인하였으며, 그 이상의 자기장에서는 원형 편광파의 침투깊이를 비롯한 제반 특성의 급격한 변화를 볼 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2099-2105
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• 2017

In a power system that has a high wind penetration, the output power fluctuation of a large-scale wind turbine generator (WTG) caused by the varying wind speed increases the maximum frequency deviation, which is an important metric to assess the quality of electricity, because of the reduced system inertia. This paper proposes a stable power-smoothing scheme of a doubly-fed induction generator (DFIG) that can suppress the maximum frequency deviation, particularly for a power system with a high wind penetration. To do this, the proposed scheme employs an additional control loop relying on the system frequency deviation that operates in combination with the maximum power point tracking control loop. To improve the power-smoothing capability while guaranteeing the stable operation of a DFIG, the gain of the additional loop is modified with the rotor speed and frequency deviation. The gain is set to be high if the rotor speed and/or frequency deviation is large. The simulation results based on the IEEE 14-bus system demonstrate that the proposed scheme significantly lessens the output power fluctuation of a WTG under various scenarios by modifying the gain with the rotor speed and frequency deviation, and thereby it can regulate the frequency deviation within a narrow range.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.28-35
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• 2004

Driven pile has the excellent bearing characteristics and good economics, so it is known as the comparative piling method. To use the advantages of driven pile fully, it is necessary to perform the proper construction management. Engineers must drive pile to the proper bearing layer with proper blow energy and measure the blow count and penetration per certain depth to analyze the bearing capacity and driveability. In conventional method, these parameters have been measured manually so it was difficult to get good accuracy. After PIR-D(Pile Installation Recorder-Driven Pile) was attached to the driving equipment, the hammer efficiency, blow count and penetration in blow/10cm were measured automatically. In this paper, to givethe rational judgement criteria of bearing layer, driveability, blow/10cm according to pile depth during pile driving, the some relationship between the driving resistance and ground layer distribution was analyzed. The ground investigation during piles (PHC ${\Phi}450,\;{\Phi}400\;&\;Steel\;Pile\;{\Phi}609{\ast}16t$) installation in the marine clay layer in Incheon, the sandy soil layer in Yongin and the tuff layer in Pusan was done. And measuring hammer efficiency not doing recently, we could compare hammer efficiency(Eh) by PIR-D and energy transfer ratio(ETR) by Pile Dynamic Analyzer(PDA).