• 제목/요약/키워드: 물질전달모델

검색결과 212건 처리시간 0.026초

Therapeutic efficacy of the photoactivated sickle cells as novel drug delivery vehicle (약물전달 시스템 개발을 위한 여기된 광감응제의 응용)

  • Choe, Se-woon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 한국정보통신학회 2015년도 추계학술대회
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    • pp.958-960
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    • 2015
  • Sickle cells possess a unique combination of traits that may enable their use as models for novel synthetic tumor targeting controlled release drug carriers with the ability to treat disseminated tumors in advanced metastatic disease. In this study, we assess the ability of light-activated release sickle cells to enhance tumor delivery of the fluorescent dye calcein by delayed photolysis controlled release compared to free systemic administration of calcein. Sickle cells from mouse models of the disease were shown to preferentially accumulate in tumors compared to adjacent tissue, in 4T1 tumors in mice on a time scale about 12 hours. Sickle cells photosensitized with protoporphyrin IX achieved delayed release of 50% of contents 8-16 hours after photoactivation, which was deemed useful for in vivo delivery of cargo to tumors given the tumor accumulation time of the sickle cells. Sickle cells may be useful as a model for new synthetic drug carrier particles with delayed photolysis controlled release properties.

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Modeling and Simulation of Heat Transfer inside the Packaging Box for Vaccine Shipping (백신 수송용 포장재 내부에서 열 전달의 모델링 및 시뮬레이션)

  • Duong, Dao Van;Choi, Ho-Suk;Lee, Sung-Chan;Bae, Yoon-Sung
    • Korean Chemical Engineering Research
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    • 제46권3호
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    • pp.604-609
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    • 2008
  • This study is about the modeling and simulation of heat transfer in the box for packaging and shipping of vaccines. Comparison of the simulation results with experimental data revealed that a one-dimensional model (a spherical model of using a radius equivalent to the rectangular geometry of box) showed good agreement with experimental data during cooling process but did not successfully simulate heating process. It is considered that a rigorous boundary condition is not properly applied for outer surface of the box. However, we could successfully develop a basic algorithm for simulating heat transfer through multi-slabs combined with different materials including phase change material.

Analysis of Potential on Measurement of SO2 and NO2 using Radiative Transfer Model and Hyperspectral Sensor (복사전달모델과 초분광센서를 이용한 아황산가스와 이산화질소의 농도 측정 가능성 분석)

  • Shin, Jung-il;Kim, Ik-Jae;Choi, Min-Jae;Lim, Seong-Ha
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제19권6호
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    • pp.658-663
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    • 2018
  • Current measuring methods for air quality are based on ground measurement networks and satellite data. New methods of collecting evidence with advanced sensors are needed because current methods have limitations in collecting evidence for the illegal emission of air pollutants at narrow areas or specific sites. This study analyzed the possibility of using an ultraviolet hyperspectral sensor to measure the concentration of nitrogen dioxide and sulfur dioxide. Two types of spectra were used: simulated spectra for gases with various concentrations using a radiative transfer model and observed spectra for each gas for a concentration. To understand the possibility of using a hyperspectral sensor, the differences between the simulated spectra and the observed spectra were analyzed, and the variation of simulated spectra were then analyzed according to the concentration. The results showed good agreement between observed spectra and simulated spectra. In addition, the absorption depth at specific wavelengths in the simulated spectra had a very strong correlation with the gas concentration. The gas concentration could be estimated using the hyperspectral sensor. In the future, validation would be needed to estimate the gas concentration through observations of various concentrations of gases using a hyperspectral sensor.

Research on the Correlation of the Surface Tension and Sensory Quality of Bitter Substances (쓴 맛 물질의 표면 장력과 쓴 맛의 상관 관계)

  • Kim, Jeong-Mee;Pfeilsticker, Konrad
    • Korean Journal of Food Science and Technology
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    • 제27권5호
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    • pp.646-651
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    • 1995
  • The correlation between the bitter taste and the surface tension was found for bitter tasting, aqueous solutions. By the Szyszkowski's equation, the surface tension (STR) and taste curves (JND) were derived more clearly using the Techplot program. The specific capillary activity (log b values) for bitter tasting solutions are negatively correlated to the recognition threshold. It was shown that a more bitter substances has greater capillary activity. The correlation between the recognition threshold $(log\;C_{1})$ and the substance specific constant (a and b values) of sensory (JND) and surface tension values indicates good agreement. This means that the model of surface area adsorption in the solution/air system can apply also for the sensory model microvillus membrane in the mouth.

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An Efficient Update of Estimation Model Using Delayed Update in Sensor Networks (센서 네트워크에서의 지연 갱신을 이용한 효율적인 예측 모델의 갱신)

  • Noh, Hyun-ho;Kim, Hongyeon;Min, Jun-Ki
    • Proceedings of the Korea Information Processing Society Conference
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    • 한국정보처리학회 2011년도 추계학술발표대회
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    • pp.1243-1247
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    • 2011
  • 센서 네트워크는 많은 수의 센서들로 구성되며 물질세계와 상호작용하여 실시간 감시를 할 수 있는 큰 규모의 네트워크이다. 현실 세계의 물리적 변화를 지속적으로 감시하기 위하여 센서 네트워크에 속해 있는 각 센서들은 주기적으로 측정값을 읽어서 기지국(base station)에 전달하는 기능을 수행한다. 이러한 경우, 각 센서들의 지속적인 통신에 따른 에너지 낭비가 발생하여 센서 네트워크 전체의 수명을 단축시키게 된다. 따라서 데이터 모니터링에 있어서 예측을 통한 근사 데이터 수집을 통해 센서 네트워크의 수명을 연장하고자 하는 연구들이 진행되고 있다. 그러나 현재의 예측을 통한 근사 데이터 수집은 측정값의 변화가 클수록 예측 모델의 갱신이 잦다. 따라서 본 논문에서는 지연 갱신을 이용한 효율적인 예측 모델 갱신 기법을 제안한다. 제안된 기법에서는 예측이 실패하였을 경우 즉시 예측 모델을 갱신하는 대신 문제가 되는 구간의 측정값들을 지연, 근사화하여 전송함으로써 예측 모델의 잦은 갱신을 방지할 수 있다.

3X3 봉다발에서의 국소 열전달에 관한 실험적 연구

  • 정장환;정문기;유성연
    • Proceedings of the Korean Nuclear Society Conference
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    • 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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    • pp.356-361
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    • 1996
  • 물질전달과 열전달의 유사성을 이용하는 나프탈렌 승화법을 핵연료집합체 모델에 적용하여 봉다발에서의 국소 열전달 계수의 분포를 측정하였다. 실험 모델은 가압경수형 원자로에서 나타나는 부수로 즉, 벽면 부수로와 모서리 부수로 및 내부 부수로로 구성되는 3$\times$3 봉다발이다. 봉다발에서의 국소 열전달 계수 값은 부수로의 형상과 인접한 봉 및 벽면의 영향이 크게 작용하는 것으로 측정되었다. 내부 부수로에 둘러져 있는 봉에서의 국소 열전달계수값은 봉과 봉 사이에서는 부수로 중심 방향보다 낮았고, 평균열전달계수는 Dittus-Boelter의 상관식보다 약간 낮은 값을 보였다. 벽면 부수로에 인접한 봉에서의 열전달계수는 벽면의 영향으로 내부 부수로에 있는 봉보다 상대적으로 낮았으며, 모서리 부수로의 봉에서는 벽면의 영향이 증대되어 더욱 낮게 나타났다.

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Modeling the effect of mass transfer on the kinetics of fructo-oligosaccharide production by immobilized cells (고정화 세포에 의한 Fructo-oligosaccharides 생산 반응메카니즘에서 물질전달 영향에 대한 수학적 모델)

  • 윤종원;전영중이민규송승구
    • KSBB Journal
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    • 제8권3호
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    • pp.266-271
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    • 1993
  • The effective diffusion coefficients of glucose, sucrose and fructo-oligosaccharides in Ca-alginate gel beads at high concentration of sucrose solutions were investigated at $50^{\circ}C$. A mathematical model for the kinetics of fructo-oligosaccharide production using immobilized cells was proposed and compared with experimental results varying the bead size, the substrate concentration and the bead ratio. Very low values of diffusion coefficients ranging $1.2-7.6\times10^{-7}\textrm{cm}^2$/sec were obtained, and the predicted results were in good agreement with experimental ones in all cases tested.

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A Prediction of Pollutant Emission Rate using Numerical Analysis and CFD in Double-Layered Building Materials (수치해석 및 CFD를 이용한 소형챔버내 복합건축자재의 오염물질 방출량 예측)

  • Kim, Chang-Nam;Leigh, Seung-Bok;Kim, Tae-Yeon
    • Proceedings of the SAREK Conference
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.277-282
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    • 2006
  • In order to predict the indoor air pollutant, the VOCs emission rate is used through small chamber in the design process. However, the small chamber method has limitations as the convective mass transfer coefficient, the most important factor when predicting VOCs contamination of indoor air, is different between the small chamber result and the measured data in the actual building. Furthermore, the existing studies which analyzed mass transfer coefficient in the small chamber were directed on the small chambers developed at the time and FLEC(Field and Laboratory Emission Cell), thus, are different from the current small chamber which has been changed with improvements. The purpose of this study is to determine the emission rate of pollutant in double-layered building materials through the CFD(Computational of Fluid Dynamics) and Numerical analysis based on the mass transfer coefficient on singled-layered building material by using the current small chamber widely used in Korea. Futhermore, this study used the new convective mass transfer coefficient($h_m'$) which indicates the existing convective mass transfer coefficient($h_m$) including VOC partition coefficient(k). Also, formaldehyde was selected as target pollutant.

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Modeling of Drying Cylinders in Paper Plants (제지공장 가열 실린더의 모델링)

  • Gwak, Gi-Yeong;Yeo, Yeong-Gu;Kim, Yeong-Gon;Choe, Gyeong-Seok;Gang, Hong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 한국펄프종이공학회 2003년도 추계학술발표논문집
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    • pp.249-271
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    • 2003
  • The purpose of the present study is to identify the drying cylinder model in paper plants and to analyze characteristics of process responses for changes in input variables. The model developed in this work is based on actual plant operation data and the steam pressure applied to the cylinder behaves as one the main variables. It is found that heat transfer coefficients from the condensate to the canvas could be represented as empirical relations based on heat conductivities and operation date. The effectiveness of the cylinder model is demonstrated by the measured moisture contents and web temperature. Using transfer functions derived from the cylinder model stability of the drying process is analyzed.

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The Effect of Turbulence Promoters on the Mass Transfer in Ultrafiltration (한외여과에서의 물질전달에 대한 난류촉진물체의 영향)

  • Oh, Won-Suhk;Park, Ham-Yong;Lim, Gio-Bin;Kim, Woo-Sik
    • Membrane Journal
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    • 제4권4호
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    • pp.221-231
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    • 1994
  • The GR51PP(MWCO 50,000) and GR40PP(MWCO 100,000) membranes manufactured by DDS were used in ultrafiltration of dextran(Mw. : 500,000) solution in flat plate ultrafiltration cell filled with various types of turbulence promoters. The flux improvement by using turbulence promoter was higher in laminar flow region than in turbulent flow region. The maximum improvements of permeate flux were foud as 112% and 50% I laminar flow region and turbulent flow region, respectively. Also, the solute rejection of the ultrafiltration membrane was improved by turbulence promoters and its effect was significant in the high transmembrane pressure and laminar flow region. The smaller the spacer mesh size was used, the higher the flux improved, but the pressure drop in ultrafiltration cell also increased. In laminar flow region, pressure drop by the spacer was negligible, but in turbulent flow region it changed significantly depending upon the mesh size of the spacer and therefore, its mesh size must be baken into account in the design of the process. The predicted results of the modified mass transfer correlation had better agreement with experimental results than those of unmodified one, The modified mass transfer correlations for laminar and turbulent flow region are shown as follow. $N_{sh}=0.151(N_{Re})^{0.199}(N_{Sc})^{0.22}(N_{Scm})^{0.197}\;(625 $N_{sh}=0.0165(N_{Re})^{0.428}(N_{Sc})^{0.33}(N_{Scm})^{0.223}\;(5015

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