• Title/Summary/Keyword: The law of diffusion

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A Study on the Improvement of Korean Logistics Policies (우리나라 물류비 절감을 위한 물류정책의 효율성 제고방안에 관한 연구)

  • Park, Kwang-So;Yu, Kwang-Hyun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.45
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    • pp.139-163
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    • 2010
  • Companies make a great effort for saving costs because a rise in logistics costs weaken trade companies competitive position in the international market. Therefore it is important for companies and government to enhance logistics competitive. This article focus on the logistics laws and policies to improvement companies competitiveness and save logistics costs. It has researched from the point of view rather government basis than company basis. Korean Logistics policies have some fundamental problems that the law and policies are spreaded to several administrations such as, Ministry of Knowledge Economy, Ministry of Land, Transport and Maritime Affairs etc. We propose the solutions as follows; First of all, we review the laws and policies on logistics and point out the problems. Second, setting up the principle of Korean Logistics Policies according to the changes in international logistics paradigm and circumstances. Third, adjustment of systems and tasks of administrations related to logistics. Fourth, innovation plan for logistics policies. The plan can carry out two ways demonstration business and diffusion business in order.

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Can herbal extracts be used as skin penetrating agent

  • Chung, Leung Ping;Xin, Zhao;Tak, Law Wai;David, Lau Tai Wai
    • Advances in Traditional Medicine
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    • v.7 no.3
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    • pp.211-216
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    • 2007
  • Swollen and painful extremities have been treated with herbal baths in attempts to alleviate the symptoms. A popular herbal bath used in China, contains a component called 'bone-penetrating herb' which is believed to facilitate the penetration of herbal substances across the skin to the swollen site, so swollen site, so that pain and swelling will be improved. A search from the Chinese pharmacopedia revealed that 22 different herbs have been traditionally used as 'bone-penetrating herb'. Five of these herbs were available in market and were chosen for experimental studies. Standard diffusion experiments were done to identify the most effective herb among the five, in the penetration facilitation. Glechoma longituba at a concentration of 20% was found to give the best results in the facilitation of Bromophenol blue diffusion across artificial and biological membranes. When compared with one commonly used diffusion facilitator, viz. azone, azone was found to be more effective than glechoma longituba. The encouraging observations support future studies on the basic science behind the use of herbal components as topical agents to treat pain and swelling.

An Empirical Study on the User's Acceptance and Resistance in Adoption Stage of the uTradeHub (uTradeHub 수용단계별 사용자 저항 및 수용에 관한 연구)

  • Kim, Jung Sok;Song, Chae Hun;Song, Sun Yok
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.57
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    • pp.243-282
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    • 2013
  • This study aims to develop the research model about the factors that have impact on uTradeHub users' acceptance and resistance to innovation. The followings show the research hypotheses and the results of test. i) The result of H1 empirical analysis confirmed that relative advantage and task adaptedness of e-Trade have more impact on acceptance of innovation than on resistance to it. And also perceived risk and complicity of e-Trade have more impact on resistance of innovation than on acceptance to it. ii) The result of H2 analysis confirmed that the characteristics of foreign trading companies (support by CEO and IT infra maturity) has more impact on acceptance of innovation than on resistance to it. iii) The result of H3 analysis confirmed that characteristics of uTradeHub user' resistance has more impact on resistance of innovation than on acceptance to it. And also, it was confirmed that acceptance of innovation has more impact on the diffusion of e-Trade than resistance to innovation. iv) The result of H4 analysis confirmed that the difference of the degree and factors that has impact on the user's resistance and acceptance by adoption stage of e-Trade. This study has significance in that it arranges the concept and stages of e-Trade systematically and, unlike other studies, it goes beyond the acceptance and diffusion of e-Trade to the inclusion of resistance together in the model.

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Effect of Al Addition on the Reaction Behavior of Pure Cobalt with Molten Zinc (용융 아연과 WC-Co 코팅층 내 코발트의 반응거동에 미치는 아연욕 중의 Al 첨가 영향)

  • Seong, Byeong-Geun;Kim, Kyoo-Young;Kwon, Sung-Hee;Lee, Kee-Ahn
    • Journal of the Korean institute of surface engineering
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    • v.40 no.1
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    • pp.23-31
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    • 2007
  • The objective of this study is to investigate the effect of Al addition on the reaction behavior of cobalt with molten zinc. Pure cobalt specimen was immersion tested in the three kinds of molten zinc (pure, 0.12%Al added and 0.24%Al added) baths at $460^{\circ}C,\;490^{\circ}C\;and\;520^{\circ}C$. For the understanding of degradation processes, specimens were analyzed with scanning electron microscope (SEM) and energy dispersive spectrum (EDS), and electrochemical stripping method. When 0.12% and 0.24% Al was added in molten zinc baths, three intermetallic compounds layers of ${\gamma},\;{\gamma}_1,\;and\;{\gamma}_2$ were formed on the Co matrix and ${\beta}_1$ layer was not formed between the Co matrix and the ${\gamma}$ layer. Particles of CoAl intermetallic compound were formed at the interface between the ${\gamma}_2$ layer and zinc melt and they did not adhere to the Co-Zn intermetallic layer. Weight loss of the Co specimen increased as Al content in the molten zinc increased and the relationship of weight loss vs. immersion time followed parabolic rate law. Rate controlling process for the reaction rate of Co with Al added molten zinc was analyzed as the diffusion process of Al atom through a boundary layer between the ${\gamma}_2$ layer and the Al added zinc melt.

The Drying Characteristics of Apples at Various Drying Conditions (사과의 건조조건(乾燥條件)에 따른 건조특성(乾燥特性))

  • Jung, Shin-Kyo;Choi, Yong-Hee;Shon, Tae-Hwa;Choi, Jong-Uck
    • Korean Journal of Food Science and Technology
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    • v.18 no.1
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    • pp.61-65
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    • 1986
  • This study was performed to examine the drying characteristics of apples at various drying conditions. Air velocity has no effect on the drying rate except the constant rate period. In this experiment the diffusion coefficients of moisture in the apple tissue were in the range of $1.1470-2.2148{\times}10cm^2/sec$. As a result of balance of heat and mass transfer during the falling rate period. an empirical equation based on Fick's law was obtained as follows; $log{\Delta}t\;=\;log\;t_o\;-\;D{\frac{{\pi}^2{\theta}}{4d.}}$ This equation can be used to calculate the temperature of apples during the falling rate period, provided the diffusion coefficients of apple are known. The experimental values of the internal moisture distribution during apple dehydration were nearly in accord with the theoretical values.

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Analytical Modelling for Recarbonation Process of Concrete Repaired with Patching Repair Material (단면복구재로 보수된 콘크리트의 재탄산화 과정에 대한 분석적 모델링)

  • Do, Jeong-Yun;Kim, Doo-Kie;Song, Hun;Jo, Young-Kug
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.2
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    • pp.89-96
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    • 2010
  • This study presented the analytical evaluation model effective in the concrete structure repaired with a patching material. The model considered the effect of the repair material on carbon dioxide penetration into the repaired concrete as evaluating the remaining service life of the CO2-deteriorated concrete structure after repair. The diffusion profiles of carbon dioxide as well as the carbonated concrete were effectively able to be modelled with analytical method based on Fick's 1st diffusion law. The evaluation of the model equation showed the good result and rational process quantitatively and numerically to evaluate the remaining service life of the repaired concrete structure after repair.

Modeling and Analysis for the Growth/Dissolution of Oxygen Precipitation in CZ-grown Silicon (CZ 방법에 의해 성장된 실리콘에서 산소 석출물의 성장/감소에 관한 모델 및 해석)

  • 고봉균;곽계달
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.10
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    • pp.29-38
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    • 1998
  • In this paper, we have induced a model for the growth and dissolution of oxygen precipitates which is generated during arbitrary thermal treatments or VLSI processes in CZ-grown silicon. Based on diffusion-limited growth law and detailed balance equilibrium theory, growth and dissolution rates are induced and inserted into a set of chemical rate equations and a Fokker-Planck equation. Then this is solved by numerical analysis. And because phenomenon at the silicon surface must be considered differently in various annealing conditions, in particular in $O_2$ ambient we have considered the growth model of SiO$_2$ at the surface of silicon wafer and the enhancement of oxygen solubility. By this method, oxygen depth profile and density distribution of oxygen precipitates are calculated more accurately than the other simulation results.

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Migration of Low Molecular Weight Substances from Expanded Polystyrene Cup to Aqueous Food Simulant (발포 폴리스티렌 용기로부터 증류수로의 저분자물질 이행)

  • 이동선;송봉수;최진옥;박우포
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.6
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    • pp.1056-1062
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    • 2004
  • Migration of low molecular weight components from expanded polystyrene (ESP) to distilled water was measured at different temperature conditions. Overall migration and specific monomer migration were measured. Diffusion model based on Fick's law was used to determine the apparent diffusion coefficients at various experimental conditions. The overall and specific migration levels were estimated to give some practical implications for regulatory guideline development and safe package design. Diffusion coefficients for overall migration in KMnO$_4$ oxidizable extractives and specific migration of styrene monomer from ESP at 6$0^{\circ}C$ were 0.030 and 6.8${\times}$10$^{-5}$ $\textrm{mm}^2$/h, respectively. Their temperature dependence could be explained by Arrhenius equation with respective activation energies of 80.5 and 98.6 kJ/㏖. Experimental conditions ensuring desired migration level were suggested for reliable examination of migration from the packaging material. Some explanatory estimations of migrations were given for some typical conditions of potential usages.

Evaluation of Service Life in RC Column under Chloride Attack through Field Investigation: Deterministic and Probabilistic Approaches (염해 실태조사를 통한 철근 콘크리트 교각의 내구수명 평가 - 결정론적 및 확률론적 해석방법)

  • Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.5
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    • pp.67-74
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    • 2015
  • RC (Reinforced Concrete) structures are considered as cost-benefit and durable however performances of structural safety and durability are degraded due to steel corrosion. Service life in RC structure is differently evaluated due to different local environmental conditions even if it is exposed to the same chloride attack. In the paper, 25 concrete cores from field investigation are obtained from 4 RC columns with duration of 3.5~4.5 years exposed to sea water. Through total chloride content measurement, surface chloride contents and apparent diffusion coefficients are evaluated. Service life of the target structure is estimated through deterministic method based on Fick's $2^{nd}$ Law and probabilistic method based on durability failure probability, respectively. Probability method is evaluated to be more conservative and relatively decreased service life is evaluated in tidal zone and splash zone over 40.0 m. Chloride penetration behavior with coring location from sea level and the present limitations of durability design method are investigated in the paper.

The Moisture Absorption Properties of Liquid Type Epoxy Molding Compound for Chip Scale Package According to the Change of Fillers (충전재 변화에 따른 Chip Scale Package(CSP)용 액상 에폭시 수지 성형물 (Epoxy Molding Compound)의 흡습특성)

  • Kim, Whan-Gun
    • Journal of the Korean Chemical Society
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    • v.54 no.5
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    • pp.594-602
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    • 2010
  • Since the requirement of the high density integration and thin package technique of semiconductor have been increasing, the main package type of semiconductor will be a chip scale package (CSP). The changes of diffusion coefficient and moisture content ratio of epoxy resin systems according to the change of liquid type epoxy resin and fillers for CSP applications were investigated. The epoxy resins used in this study are RE-304S, RE310S, and HP-4032D, and Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The micro-sized and nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these epoxy molding compound (EMC) according to the change of filler size. The temperature of glass transition (Tg) of these EMC was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these EMC according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these EMC were calculated in terms of modified Crank equation based on Ficks' law. An increase of diffusion coefficient and maximum moisture absorption ratio with Tg in these systems without filler can be observed, which are attributed to the increase of free volume with Tg. In the EMC with filler, the changes of Tg and maximum moisture absorption ratio with the filler content can be hardly observed, however, the diffusion coefficients of these systems with filler content show the outstanding changes according to the filler size. The diffusion via free volume is dominant in the EMC with micro-sized filler; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the EMC with nano-sized filler.