• Title/Summary/Keyword: effective diffusion

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Studies on the Adsorbents for Cigarette Filter I. Effect of Pore Voume Distribution and Specific Area of Adsorbents on the Removal Efficiency of Smoke Components by Triple Filter (담배필터용 흡착제에 관한 연구 제1보. 흡착제의 종류와 동공특성이 담배연기성분 제거능에 미치는 영향)

  • 박태무;이영택;김성한;오영일
    • Journal of the Korean Society of Tobacco Science
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    • v.10 no.1
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    • pp.75-82
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    • 1988
  • Cigarettes were made using a triple filter with several porous materials in its cavity. The removal effect of the adsorbents on carbon monoxide and hydrogen cyanide in cigarette smoke was investigated with the variation of their surface area and pore volume distributions. Several attempts were made to activated coconut shell based char under the fixed steam purging rate. 1. The specific surface area increased in number of micropore. It was found for transitional pore to have a little effect on the total surface area. 2. A Small amount of the particulate matter adsorbed on the adsorbents with transitional pores, Zeolite showed a little effect on the carbon monoxide adsorption though its small pore volume, but there was no significant difference in the adsorption capacity zeolite and the others. 3. In the adsorption for hydrogen cyanide as a vapor phase in cigarette smoke, the adsorption effect of the adsorbents increased remarkably with increasing their surface area and number of micropore. It was considered that the adsorbents with small pore volume like molecular seive 4A, in which the capillary diffusion of adsorbates could not be able, would not be effective for the adsorption of hydrogen cyanide.

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The Effect of Enhancers on the Penetration of Clenbuterol through Hairless Mouse Skin (클렌부테롤의 피부투과에 미치는 경피흡수촉진제의 영향)

  • Choi, Han-Gon;Rhee, Jong-Dal;Yu, Bong-Kyu;Yong, Chul-Soon
    • Journal of Pharmaceutical Investigation
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    • v.33 no.1
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    • pp.29-36
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    • 2003
  • Clenbuterol, a selective ${\beta}_2-adrenergic$ receptor stimulant, has been introduced as a potent bronchodilator for patients with bronchial asthma, chronic obstructive bronchial disease, chronic bronchitis and pulmonary emphysema. The percutaneous permeation of clenbuterol was investigated in hairless mouse skin after application of 50/50 buffer(pH 10)/propylene glycol solvent mixture. The enhancing effects of various penetration enhancers such as terpenes, non-ionic surfactants, pyrrolidones, fatty acids and some other enhancers on the permeation of clenbuterol were evaluated using Franz diffusion cell. Among terpenes studied, 1,8-cineole was the most effective enhancer, which increased the permeability of clenbuterol approximately 39.33-fold compared with the control without penetration enhancer, followed by menthone with enhancement ratio of 23.57. Nonionic surfactants did not have significant enhancing effects. N-Lauryl-2-pyrrolidone increased the permeability of clenbuterol approximately 4.51-fold compared with the control. Lauric acid increased the permeability of clenbuterol approximately 35.57-fold with decreasing the lag time from 2.64 to 0.52 hr. Oleic acid, linoleic acid, linolenic acid and capric acid showed enhancement ratio of 22.62, 19.60, 17.45 and 16.51, respectively. $Labrafil^{\circledR}$ enhanced the permeability of clenbuterol 9.24-fold compared with that without enhancer.

Basic Concepts of Western Medicine Toxicology and $LD_{50}$ in Herbal Drugs (서양의학 독성학의 기본적 개념 및 한약의 $LD_{50}$)

  • Park Yeon-Chul;Lee Sun-Dong;Park Kyoung-Sik
    • Journal of Society of Preventive Korean Medicine
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    • v.3 no.2
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    • pp.91-100
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    • 1999
  • Today, toxicology is used for many purpose, in many fields. Classification of special toxic effect is related next 4 important principles. 1. The chemical substance must move to target organ or tissue that can induce Biological effect. For this movement, we have to understand the physical-chemical characteristic of substance, and the rout of absorption, metabolism, diffusion and excretion of toxic substance. 2. Every biological effect that induced by chemical substance is not harmful. For example, some specific chemical substance is not harmful in liver enzyme system. 3. The strength of biological effect induced by chemical substance is deep related with dose. Nearly all substance is not effective below the specific dose, and it may toxic to death over the specific dose. It is the 'Dose - response relationship' But carcinogen may toxic whether it is law dose or not. 4. The information that was obtained by experimental animal test, could have to adapt in human biology. Because biological effect of chemical substance could be different in every biological species. In past, drugs was obtained by animal or plants. But in the future, it could be obtained by biochemistry, and genome project. Therefore, in Oriental medicine, research and approach is needed at this time, and have to develop new method of experience in toxic method.

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The study on the effect of the solar radiation on thermal comfort and ventilation performance in room space (태양일사가 실내공간의 열적 쾌적성과 환기성능에 미치는 영향에 관한 연구)

  • Yeon, Seong Hyeon;Lee, Hyo Joon;Rhee, Gwang Hoon
    • Journal of the Korean Society of Visualization
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    • v.14 no.1
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    • pp.19-26
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    • 2016
  • Modern people spend much time at indoor space. So, People want to make better indoor air condition. But the facade of building is made of glass to be seen urbanely, the effect of solar radiation makes indoor environment worse. This study designs an open space affected by solar radiation with 4-way cassette air-conditioner. Using numerical simulation, this paper investigates thermal comfort and ventilation performance with discharge angles $30^{\circ}$ and $45^{\circ}$. To study thermal comfort, this paper studies distribution of velocity, temperature and effective draft temperature. Also, this paper introduces concept of air age to study ventilation performance. The flow influenced by solar radiation determines thermal comfort and ventilation performance in room space. This study shows that discharge angle of 45 degree has better thermal comfort and ventilation performance than that of 30 degree.

Study on the aquifer utilization for a ground water heat pump system (지하수 히트펌프 시스템의 대수층 활용 사레 연구)

  • Shim, Byoung-Ohan;Lee, Chul-Woo
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.32-35
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    • 2006
  • The validation of a groundwater source heat pump system installation site is estimated by bydrogeothermic model ing. The hydraulic characteristics of the aquifer system is evaluated from pumping and recovery tests. In addition, the temperature distribution by the pumping and the injection of groundwater, and water level fluctuations are simulated by numerical modeling. The total cooling and heating load for the building is designed as 120RT(refrigeration ton) and the ground water source heat pump system covers 50RT as a subsidiary system The scenario of heat pump operation is organized as pumping and inject ion of groundwater that is performed for 8 hours per day in cooling mode for 90 days during the summer season The heat transfer by the injected warm water is limited near the inject ion wells in the simulated temperature distribution. The reason is that the given operation time is too short to expect broad thermal diffusion in large volume of the aquifer in the simulation time The simulated groundwater level and temperature distribution can be used as important data to develope an energy effective pumping and injection well system. Also it will be very useful to evaluate the hydraulic capacity of a target groundwater reservoir.

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Remedial treatment of decayed wood using borate rod (붕산염 막대를 이용한 부후재의 구제처리)

  • Kim, Gyu-Hyeok;Kim, Jae-Jin;Kim, Hyoung-Jun
    • Journal of Conservation Science
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    • v.8 no.1 s.11
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    • pp.23-27
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    • 1999
  • This study was conducted to investigated the feasibility of using a fused borate rod for the remedial treatment, using pine specimens decayed by Tyromyces palustris and Gloeophyllum trabeum. The borate rod appears to be a useful remedial product for eliminating as well as preventing decay. However, the easiness of retention gradient of boron according to the distance from a rod treatment site, is required for more effective treatment. The effect of the extension of diffusion period and rod size on retention gradient of boron should be fully investigated for successful remedial treatments using borate rod.

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Antifungal Synergy of Theaflavin and Epicatechin Combinations Against Candida albicans

  • Betts, Jonathan W.;Wareham, David W.;Haswell, Stephen J.;Kelly, Stephen M.
    • Journal of Microbiology and Biotechnology
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    • v.23 no.9
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    • pp.1322-1326
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    • 2013
  • New antifungal agents are required to compensate for the increase in resistance to standard antifungal agents of Candida albicans, which is an important opportunistic fungal pathogen that causes minor infections in many individuals but very serious infections in those who are immune-compromised. In this study, combinations of theaflavin and epicatechin are investigated as potential antifungal agents and also to establish whether antifungal synergy exists between these two readily accessible and cost-effective polyphenols isolated from black and green tea. The results of disc diffusion assays showed stronger antibacterial activity of theaflavin:epicatechin combinations against C. albicans NCTC 3255 and NCTC 3179, than that of theaflavin alone. Minimum inhibitory concentrations (MICs) of 1,024 ${\mu}g/ml$ with theaflavin and 128-256 ${\mu}g/ml$ with theaflavin:epicatechin combinations were found. The fractional inhibitory concentration indexes were calculated, and the synergy between theaflavin and epicatechin against both isolates of C. albicans was confirmed. Theaflavin:epicatechin combinations show real potential for future use as a treatment for infections caused by C. albicans.

An Empirical Study on e-Logistics of Port & Logistics industry (항만물류산업의 e-Logistics 실증연구)

  • 조소희;허윤수;남기찬
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.365-370
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    • 2004
  • At the present, e-commerce takes the place of existing transaction form in structure in the world trade by advancement of Information Technology and diffusion of Internet. There is no exceptions of this tendency even in industry of maritime and logistics. So, global shipping lines and logistics companies try to construct the e-Business network system for increasing their competitiveness in an are of cyber. However, in Korea, most of companies prefer "final handshake" as the traditional way of transaction to "e-commerce", because they bear a distrust in mind about the outflow of transaction information and security of settlement. So, number of companies using e-commerce is very small, and this situation causes the limited factor for activating the transaction structure of it. The rate of using e-commerce in logistics industry is lower than other industries, even more higher effectiveness is expected when they use it. Especially, it is very necessary not only e-commerce but also e-Logistics which can serve information of freight cost on cargo flow, operation cost and schedule, and tracing information of cargo. Increasing the necessity of e-Logistics, this study research the rate rf using e-Logistics focused on maritime and logistics companies, and analyze the transaction form among members of these industries for improving them. In detail, this paper examine the drivers for activating e-Logistics, and present the effective factors for a successful development of these industries.

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Effect of L-Menthol on the Percutaneous Absorption of Ketorolac Tromethamine Across Human Cadaver Skin (사람 카다베르 피부를 통한 케토롤락 트로메타민의 경피 흡수에 L-menthol이 미치는 영향)

  • Lee, Yong-Seok;Oh, Heung-Seol;Kim, Ha-Hyung;Lee, Kwang-Pyo
    • YAKHAK HOEJI
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    • v.44 no.6
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    • pp.595-600
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    • 2000
  • Transdermal delivery of ketorolac tromethamine, a potent non-narcotic analgesic, through human cadaver skin was investigated in vitro. A mixture of ethanol/water (40/60) containing 0, 1, 3, 5, and 8 (w/v)% L-menthol were used as a vehicle and penetration enhancer respectively. The permeation of ketorolac through human cadaver skin from saturated drug solution was evaluated at $37^{\circ}C$ with modified Franz diffusion cell. The in vitro skin flux and lag time were $1.23\;{\pm}\;0.11\;{\mu}g/cm^2{\cdot}hr$ and $5.56\;{\pm}\;0.34\;hr$, respectively. The cumulative amount of penetrated ketorolac containing L-menthol in ethanol/water (40/60) binary system was increased by the following order; 3%, 5%, 8%, 1%, 0%, and the lag time was decresed by the following order; 3%, 5%, 8%, 0%, 1%. The results suggested that a potential use of 3% L-methol is an effective penetration enhancer of ketorolac tromethamine through the human cadaver skin.

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Functional Nannomaterials Based on Nanoporous Template

  • Kim, Jin-Gon;Yang, Seung-Yun;Byeon, Jin-Seok;Jeon, Geum-Hye;Jo, A-Ra
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.7.1-7.1
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    • 2011
  • Nanoporous templates have been widely used for the development of new functional nanostructured materials suitable for electronics, optics, magnetism, and energy storage materials. We have prepared nanoporous templates by using thin films of mixtures of polystyrene-block-poly (methyl methacrylate) (PS-b-PMMA) and PMMA homopolymers. These templates have cylindrical nanoholes spanning the entire thickness of the film. Some applications of nanoporous templates are introduced: a) anti-reflective coating, b) the preparation of conducting polymer nanowires of poly (pyrrole), poly (3,4-ethylenedioxy-thiopene) onto a glass coated with indium-tin-oxide, and c) the separation membranes for biomaterials. We found that when the pore fraction of nanoholes in the film was ~0.68, almost zero reflectance at a specific wavelength, which can be changed with film thickness, was achieved at visible wavelengths Furthermore, ultra high density array of conducting nanowires was successfully prepared onto various substrates including flexible polymer. Due to highly alignment of polymer chain along the nanowire direction, the conductivity was much increased. Furthermore, these nanoporous films were found to be very effective for the separation of human Rhinovirus type 14 (HRV 14), major pathogen of a common cold in humans, from the buffer solution. We also found that when the pore size was effectively controlled down to 6 nm, a single file diffusion was observed.

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