• Title/Summary/Keyword: Diffusion Term

Search Result 379, Processing Time 0.024 seconds

Durability Properties of High Volume Blast Furnace Slag Concrete for Application in Nuclear Power Plants (고로슬래그 다량치환 콘크리트의 원전 콘크리트 적용을 위한 내구성능 평가)

  • Seo, Eun-A;Lee, Jang-Hwa;Lee, Ho-Jea;Kim, Do-Gyeum
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.5 no.1
    • /
    • pp.45-52
    • /
    • 2017
  • This study evaluated the durability of nuclear power plant concrete. The main parameters were the water-to-binder ratio and admixture type. The results revealed that high-volume ground granulated blast-furnace slag(GGBS) concrete had lower initial strength, while the strength reached higher after 28 days. On the other hand, the initial strength of fly ash blended concrete was high, but the long-term strength of the robbery was low. The measured durability of GGBS blended concrete was found to be better than that of the existing concrete mix for use in the construction of nuclear power plants. Especially, the GGBS blended concrete was more durable than the fly ash blended concrete in terms of chloride attack, carbonation resistivity and freezing-thawing durability in low compressive strength. The effects of concrete compressive strength according to gamma rays were minor.

A Study on the Transfer of Amino Acids across the Human Placenta at Term of Pregnancy (임신말 태반을 통한 아미노산 이동에 관한 연구)

  • Ahn, Hong-Seok
    • Journal of Nutrition and Health
    • /
    • v.18 no.3
    • /
    • pp.209-216
    • /
    • 1985
  • The plasma levels of 23 free amino acids in both the umbilical circulation (umbilical vein and artery) and the maternal circulation (antecubital vein, uterine vein and iliac artery ) of 34 pregnant women were measured at delivery by the cesarean section. Each amino acid with the exception of glutamate was found to be in higher concentration in the fetal blood and the cord plasma characterized by hyperaminoacidemia with a marked increase of the lysine and ornithine levels. The linear relationships found between the amino acids concentrations of iliac artery and those of umbilical vein suggest three transport groups across the placental membrane One group consists of neutral amino acids whose slopes are equal to one and the other two groups are characterized by their slopes higher and lower than unity respectivly. This division into three groups is tentatively explained by the result of a dynamic equilibrium between active transport towards the fetus and diffusion back towards the maternal circulation.

  • PDF

Analysis of User Tendency between Subscriber and Non-subscriber to Bundling Service of LTE (LTE서비스의 결합상품 여부에 따른 사용자 특성분석)

  • Kim, KeunHyung;Son, Younghwan;Oh, SungRyoel
    • The Journal of the Korea Contents Association
    • /
    • v.14 no.5
    • /
    • pp.356-363
    • /
    • 2014
  • With Sales of bundling service in telecommunications service are on the increase due to continuous technology progress and the raised demand into convergence and integration service. In this paper, we analyzed the tendencies differences between subscriber and non-subscriber of the bundling service in telecommunications service to establish marketing strategies of the bundling service. we derived the subjective norm and personal innovation as tendency variables of users in using LTE(Long Term Evolution) services, which are based on bundling sales motivation theory, theory of reasoned action, and diffusion of innovation theory. The tendency variables were compared between subscriber and non-subscriber of the bundling service through statistical T-test in empirical study. As a result, we discovered that there are differences in both subjective norm and personal innovation between subscriber and non-subscriber of the bundling service. We also discovered that the subjective norm and the personal innovation of subscriber are stronger than non-subscriber. At last, we derived two implications to increase the sales of the bundling services. First, the bundling service should designed more innovative. Second, it would be effective to apply buzz marketing strategies based on the surrounding people.

HISTOPATHOLOGY AND PERCUTANEOUS ABSORPTION OF TOPICAL FORMULATION CONTAINING NEW CAPSAICIN ANALOG.

  • Kim, Chong-Hyuk;Lee, Beom-Jin;Cha, Bong-Jin;Kim, Soon-Hoe;Kim, Won-Bae
    • Proceedings of the Korean Society of Applied Pharmacology
    • /
    • 1997.04a
    • /
    • pp.115-115
    • /
    • 1997
  • A new capsaicin analog modified with 4-hydroxyl and alkyl chain of capsaicin was a very potent antiinflammatory analgesic drug and may be clinically useful for those who have rheumatoid arthritis, diabetic neuropathy and cancer. The purpose of this study was to investigate histopathology after short and long term application of poloxamer-based gels, and percutaneous absorption of various topical formulations. Poloxamer-based gel was prepared by cold method using poloxamer 407. The poloxamer gels was applied to dorsal sites of hairless mouse skin during one week or one month for the evaluation of skin irritation. The applied site was then sectioned for histopathologic examination. The topical formulations were also prepared using CMC, HPMC, MC, carbopol and glycerylmono stearate. Skin variation of poloxamer gels was studied using excised hairless mouse, rat, hamster and human penis skin. Franz-type diffusion cells were used far skin penetration of drug against receptor phase filled with about 10$m\ell$ of 0.9% saline solution kept at 32$^{\circ}C$. The concentration of drug was determined by the reverse phased C18, Symmetry HPLC with fluorometeric detector. No skin erythema was observed after dorsal application of poloxamer-based gels for one week or one month. No histopathologic changes was also examined, suggesting no skin toxicity of poloxamer-based gels. The order of flux rate was HPMC > MC ( CMC > poloxamer >> glycerylmono stearate ( carbopol. There was a skin variation of poloxamer gels. The flux rate of poloxamer gels was highest in case of hairless mouse followed by rat, human and hamster skin. The Partial support-Ministry of Science and Engineering (HAN project).

  • PDF

An Analytical Model for Predicting Heat Transport due to a Point Source in Coastal Water under a Spring-Neap Modulation of Tidal Currents (조류의 대.소조 변동이 존재하는 연안역에서의 점열원에 의한 열오염의 이동 예측을 위한 해석해 모형)

  • 이호진;김종학
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.16 no.2
    • /
    • pp.92-102
    • /
    • 2004
  • In this paper, an analytical solution of calculating the excess temperature field due to a point heat source is presented in the presence of spring-neap modulation of convective alongshore flow. The basic form of the solution is identical to that given by Jung et al. (2003) but the convective term in the exponential kernel function is extended and a spring-neap variation in the horizontal eddy diffusivity is newly introduced. A set of calculations have been performed to examine the sensitivity of the heat build-up to the change in current fields and turbulent dispersion. Results indicate that the excess temperature field is confined within the tidal excursion distance, while the excess temperature field beyond the distance is mainly controlled by the horizontal diffusion. The heat build-up within the distance is considerably affected by the spring-neap variation in the horizontal eddy diffusivity; the relatively high excess temperature more than 1$^{\circ}C$ is extended further when the eddy diffusivity has spring-neap modulation.

Developing the Role Model of the Local Cultural Industries Agency for Promoting the Innovative Milieu in the Regional Cultural Industries (지방문화산업지원센터의 산${\cdot}$학 협력 기반 혁신환경 조성사업 모델 개발 연구)

  • Yim, Hak-Soon
    • Cartoon and Animation Studies
    • /
    • s.9
    • /
    • pp.59-79
    • /
    • 2005
  • The paper concerns the role model of the local cultural industry agencies, which were established by the local government for the purpose of fostering the regional cultural industries. In this article, the term of the innovative milieu refers to the interaction and network system for the creation, diffusion and application of knowledge. In doing so, the case on the Gyeonggi Digital Content Agency(GDCA), which has managed the Digital Animation Academy and the cultural heritage based digital content development project will be examined in terms of the network between academic and industry. As a result of the case study, it is not certain that the activities and policy programs of the GDCA has affected the improvement of the knowledge and network environment in the field of cultural content industries. This demonstrates industries rather than the innovation system as a whole. In this respect, the paper develops the Cultural Content R & D Network Model for the improvement of the creative partnership among universities, companies and public sector organizations. In addition, the paper suggests that the Digital Animation Academy should be managed in terms of the improvement of the innovative environment of the regional cultural content cluster.

  • PDF

Sustained Release of Water-Soluble Blue Dextran from PLGA Nanoparticles (PLGA 나노파티클로부터 수용성 블루 덱스트란의 서방성 방출)

  • Ryu, Sang-Hwa;Hwang, Sung-Joo;Park, Jeong-Sook
    • Journal of Pharmaceutical Investigation
    • /
    • v.36 no.2
    • /
    • pp.109-114
    • /
    • 2006
  • Biodegradable poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were developed for sustained delivery of water-soluble macromolecules. PLGA nanoparticles were fabricated by spontaneous emulsification solvent diffusion method generating negatively charged particles and heterogeneous size distribution. As a model drug, blue dextran was encapsulated in PLGA nanoparticles. In addition, nanoparticles were also prepared with varying ratio of poloxamer 188 (P188) and poloxamer 407 (P407), and coating with poly(vinyl alcohol) (PVA). Then, the particle size, zeta potential and encapsulation efficiency of nanoparticles containing blue dextran were studied. In vitro release of blue dextran from nanoparticles was also investigated. The surface and morphology of nanoparticles were characterized by scanning electron microscopy (SEM). In case of nanoparticles prepared with PLGA, P407, and different organic solvents, particle size was in the range of $230{\sim}320\;nm$ and zeta potentials of nanoparticles were negative. The SEM images showed that ethyl acetate is suitable for the formulation of PLGA nanoparticles with good appearance. Moreover, ethyl acetate showed higher encapsulation efficiency than other solvents. The addition of P188 to formulation did not affect the particle size of PLGA nanoparticles but altered the release patterns of blue dextran from nanoparticles. However, PVA, as a coating material, altered the particle size with increasing the PVA concentration. The nanoparticles were physically stable in the change of particle size during long-term storage. From the results, the PLGA nanoparticles prepared with various contents of poloxamers and PVA, could modulate the particles size of nanoparticles, in vitro release pattern, and encapsulation of water-soluble macromolecules.

Classification of Tumor cells in Phase-contrast Microscopy Image using Fourier Descriptor (위상차 현미경 영상 내 푸리에 묘사자를 이용한 암세포 형태별 분류)

  • Kang, Mi-Sun;Lee, Jeong-Eom;Kim, Hye-Ryun;Kim, Myoung-Hee
    • Journal of Biomedical Engineering Research
    • /
    • v.33 no.4
    • /
    • pp.169-176
    • /
    • 2012
  • Tumor cell morphology is closely related to its migratory behaviors. An active tumor cell has a highly irregular shape, whereas a spherical cell is inactive. Thus, quantitative analysis of cell features is crucial to determine tumor malignancy or to test the efficacy of anticancer treatment. We use 3D time-lapse phase-contrast microscopy to analyze single cell morphology because it enables to observe long-term activity of living cells without photobleaching and phototoxicity, which is common in other fluorescence-labeled microscopy. Despite this advantage, there are image-level drawbacks to phase-contrast microscopy, such as local light effect and contrast interference ring. Therefore, we first corrected for non-uniform illumination artifacts and then we use intensity distribution information to detect cell boundary. In phase contrast microscopy image, cell is normally appeared as dark region surrounded by bright halo ring. Due to halo artifact is minimal around the cell body and has non-symmetric diffusion pattern, we calculate cross sectional plane which intersects center of each cell and orthogonal to first principal axis. Then, we extract dark cell region by analyzing intensity profile curve considering local bright peak as halo area. Finally, we calculated the Fourier descriptor that morphological characteristics of cell to classify tumor cells into active and inactive groups. We validated classification accuracy by comparing our findings with manually obtained results.

The Study on Strategy of Policy through Development of the e-learning Standardization Roadmap (이러닝 표준화 로드맵 개발을 통한 정책 추진 전략 연구)

  • Choi, Mi-Ae;Cho, Yong-Sang
    • The Journal of Korean Association of Computer Education
    • /
    • v.13 no.3
    • /
    • pp.77-90
    • /
    • 2010
  • e-learning standardization has already had a major impact on budget reduction goals through the application of national policy projects such as Cyber Home Learning System and Digital Textbook. It also corresponds with green paradigm, recently attracting more attention, by contributing to reduce carbon dioxide through preventing duplicate development. In the 21st century the concept of convergence and the role of e-learning standardization to unite education and technology have gained popularity on conversation topic agendas. This research is aimed at establishing strategic countermeasures for international standards and help plot the direction for future standardization policy through the development of a mid-to long term roadmap using delphi research targeted at e-learning standardization experts. In addition, it attempts to establish a broad base to improve standardization awareness and diffusion.

  • PDF

A Study on the Infrastructure of All-electric Houses in the Viewpoint of Hydrogen Economy (수소경제 관점의 전기에너지주택 보급기반 구축에 관한 연구)

  • Hwang, Sung-Wook;Lee, Hyeon-Ju;Kim, Kang-Sik;Nah, Hwan-Seon;Kim, Jung-Hoon
    • Journal of Hydrogen and New Energy
    • /
    • v.23 no.1
    • /
    • pp.100-109
    • /
    • 2012
  • In this paper, some ideas are proposed to establish the infrastructure of all-electric houses which are able to reduce primary energy consumption and $CO_2$ emission by adopting heat pump systems and induction heating cookers excluding the use of fossil fuel energy. This electrification concept is based on the consumption of only one type of energy which means electricity as secondary energy and the conventional fossil fuel energy is just consumed to generate electricity as primary energy. All-electric house is laid on the extension of the hydrogen economy in a long-term viewpoint so that the effectiveness of this new conceptual house is estimated analyzing the reduction of $CO_2$ emission. In this analysis, the balance of electricity supply and demand is considered including the construction of new power plants by renewable energy such as nuclear, IGCC and fuel cell because decarbonization is an essential element of hydrogen technology and economy and this action is accomplished in both supply and demand side of electricity. The results are able to contribute to develop various useful hydrogen policies and strategies and some detail researches are required previously to make the best application of this new conceptual house.