• Title/Summary/Keyword: Expansion Method

Search Result 3,557, Processing Time 0.03 seconds

Isolation of Schwann Cell and Separation of Schwann Cell-Neuron Network from Mouse Embryo (마우스 배아에서 슈반세포-뉴런 네트워크의 분리와 슈반세포의 분리)

  • Kweon, Tae-Dong;Sa, Young-Hee;Hong, Seong-Karp
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2013.10a
    • /
    • pp.943-945
    • /
    • 2013
  • The study of Schwann cell myelination has been facilitated by the availability to isolate and establish pure population of primary Schwann cells. Dorsal root ganglia (DRG) of mouse embryo as source of Schwann cells were used in this study. This method includes three steps: first step of dissociation of the embryonic DRG, second step of expansion of Schwann cell precursors, followed by mechanical separation of the Schwann cell-neuronal network from the underlying fibroblasts, and third step of purification of Schwann cells from the associated neurons and subsequent expansion of the purified Schwann cells. We made a highly purified population of Schwann cells and Schwann cell-neuron networks in a short period using this procedure.

  • PDF

The International Development Strategy of Les Enphants Roots in China Market

  • Huang, Shu-Tzu;Cho, Hsin-Ying;Hsu, Yin-Chieh
    • International Journal of Costume and Fashion
    • /
    • v.14 no.1
    • /
    • pp.75-93
    • /
    • 2014
  • Facing a mature domestic market and the challenges of the global consumer market, retailers in Taiwan are in pursuit of international development strategies for increasing its market opportunities as one of its key growth strategies. In the global market, the Chinese market becomes Taiwan retailers' main international development milestone due to its similarity of language, culture and historical background with China. Therefore, this research uses case study method based on Eclectic paradigm (Dunning 1981) to explore the various advantages of a Taiwanese children's clothing retailer Les Enphants, which include ownership advantage, internalization advantage, and location advantage. These advantages in turn demonstrate rationales behind Les Enphants' internationalization necessity (Why to Go), selecting China as an expansion target (Where to Go), and management and operation strategies implemented in China (How to Go). Our study highlights a successful entry and expansion model of the Taiwanese children clothing retailer, and may have solid contribution to the practical application of internationalization strategy theory.

Study on the Expansion Technique of Compressor Characteristic Map to Sub-Idle range (저속영역으로의 압축기 특성맵 확장기법 연구)

  • Jun, Yong-Min;Lim, Byung-Jun;Rhee, Dong-Ho;Choi, Jong-Su
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2010.11a
    • /
    • pp.694-699
    • /
    • 2010
  • Reliable starting capability of a gas turbine engine calls the engine industry's attention recently. So far the gas turbine engine performance researches have focused on the range between idle to Max rpm, but recent attention on the starting has brought interests in the range of "Sub-dile". As component characteristic maps are essential for the starting research, various kinds of studies have been doing and proposing ways to expand the existing maps toward sub-idle range. In this paper, previous studies were discussed and a new method suggested and validated.

  • PDF

Movement and evolution of macromolecules in a grooved micro-channel

  • Zhou, L.W.;Liu, M.B.;Chang, J.Z.
    • Interaction and multiscale mechanics
    • /
    • v.6 no.2
    • /
    • pp.157-172
    • /
    • 2013
  • This paper presented an investigation of macromolecular suspension in a grooved channel by using the dissipative particle dynamics (DPD) with finitely extensible non-linear elastic (FENE) bead spring chains model. Before studying the movement and evolution of macromolecules, the DPD method was first validated by modeling the simple fluid flow in the grooved channel. For both simple fluid flow and macromolecular suspension, the flow fields were analyzed in detail. It is found that the structure of the grooved channel with sudden contraction and expansion strongly affects the velocity distribution. As the width of the channel reduces, the horizontal velocity increases simultaneously. Vortices can also be found at the top and bottom corners behind the contraction section. For macromolecular suspension, the macromolecular chains influence velocity and density distribution rather than the temperature and pressure. Macromolecules tend to drag simple fluid particles, reducing the velocity with density and velocity fluctuations. Particle trajectories and evolution of macromolecular conformation were investigated. The structure of the grooved channel with sudden contraction and expansion significantly influence the evolution of macromolecular conformation, while macromolecules display adaptivity to adjust their own conformation and angle to suit the structure so as to pass the channel smoothly.

Study on Properties of Epoxy Resin Compositions Containing Novolac Derivatives (바이페닐 유도체를 도입한 에폭시 수지 조성물의 특성에 관한 연구)

  • Choi, Su Jung;Kim, Young Chul
    • Journal of Adhesion and Interface
    • /
    • v.12 no.4
    • /
    • pp.138-143
    • /
    • 2011
  • Recently epoxy resin compositions having backbone of novolac derivatives with biphenylene compounds have been used as materials of eco-freindly EMC (Epoxy Molding Compound), because the cured epoxy resin compositions show the self-extinguishing without flame retardant additives. In this study, epoxy resin compositions were prepared and cured using novolac derivateves with biphenylene. Their propeties - structures of phenol derivatives and reactivity, thermal expansion, modulus, and thermal degradation - were obtained by DSC, DMA, TMA, TGA method. When both epoxy resin and hardenr had the biphenyl novolac structure, epoxy resin compositions showed low thermal expansion, good mechanical property, and combustion retardation.

Successful treatment of growing skeletal class II children with Twin-Block appliance. (트윈블록을 이용한 성장기 II급 아동의 성공적인 하악골 성장 치료)

  • Kim, Seong Sik;Kim, Sung Hun;Kim, Yongil;Park, Soobyung;Son, Woosung
    • The Journal of the Korean dental association
    • /
    • v.56 no.2
    • /
    • pp.103-112
    • /
    • 2018
  • The treatment of skeletal Class II growing patient is to move the mandible into the Class I molar positon via facilitating mandibular growth. The functional appliances are to be designed to exert three major functions such as palatal expansion, forward growth of mandible and increase of the posterior vertical dimension. One of the devices that can achieve both the palatal expansion and the eruption of the mandibular molar is the Twin-Block introduced by Clark in 1982. In this part, we present the treatment method with Twin-Block functional appliance for the correction of skeletal Class II growing patient.

  • PDF

A Basic Study on Autogenous Shrinkage and physical property of the Ultra-High-Strength Concrete (초고강도 콘크리트의 자기수축 및 물리적 특성에 관한 기초적 연구)

  • Park, Hyun;Yoon, Ki-Hyun;Cho, Seung-Ho;Kim, Kwang-Ki;Kim, Woo-Jae;Jung, Sang-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2009.05b
    • /
    • pp.57-60
    • /
    • 2009
  • In ultra-high-strength concrete, autogenous shrinkage is larger than dry shrinkage due to the consume of a large amount of cement and cementitous material, and this is a factor deteriorating the quality of structures. Thus, we need a new technology for minimizing the shrinkage strain for ultra-high-strength concrete. So, this paper have prepared super-high-strength concrete with specified mixing design strength of over 150MPa and have evaluated a method of reducing autogenous shrinkage by utilizing expander and shrinkage-reducing agent. According to the results of this study, with regard to the change in length by autogenous shrinkage, an expansion effect was observed until the age of seven days. The expansion effect was higher when the contents of the expander material were higher. In addition, ultra-high-strength concrete showed a shrinkage rate that slowed down with time, and the effect of the addition of expander material on compressive strength was insignificant. That is shown that required more database to be accumulated through experimental research for the shrinkage strain of members.

  • PDF

Changes in Physical and Mechanical Properties of Freon-Adsorbed and Heat - Treated Leaf Tobacco (Freon Gas흡착 및 열처리에 의한 담배조직의 물리적, 역학적 특성변화연구)

  • Kim, Ki-Hwan;Yoo, Kwang-Kun;Joo, Young-Serg
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.6 no.1
    • /
    • pp.39-49
    • /
    • 1984
  • In the tobacco industry, it is important to study the change of mechanical property occurring the expansion process. The purpose of this study is to attain basic data for development of a tobacco expansion method. 1 . Freon gas was adsorbed to tobacco under various conditions of temperature, relative humidity and pressure, and then the amount of freon gas adsorbed was analyzed by GC. Freon adsorption rate of Burley 21 was more than that of By104 at the same condition and about 17 $\pm$ 1% moisture content produced better adsorption rate. 2. Freon adsorbed sample were heated to about $150^{circ}C\;to\;230^{\circ}C$ in a drying oven and recycle duct form about 2 to 30 seconds, and then the change of mechanical property were measured. Heated leaf was damaged when the tissue was pressed by the force of above $0.5x10^8dyn/cm^2$. The optimum condition of no damage of the sample was below the temperature of 15$0^{\circ}C$ and heating time of 10 seconds. It was more economically advantages to treated sample in a recycle duct than to be in a drying oven. By this process, the specific volume of the heated sample was increased from 80 to 110 percent in comparison to that of untreated sample.

  • PDF

Method for expanding tobacco leaves with steam at high temperature and velocity (고온 증기를 이용한 잎담배의 팽화연구)

  • 김병구;김기환;정한주;유광근;이태호
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.17 no.1
    • /
    • pp.68-78
    • /
    • 1995
  • A study of expanding tobacco includes the steps of adjusting the moisture content of cut tobacco, without the use of exogenous impregnants by contacting the filler with a high velocity gaseous medium at elevated temperature such that heat is rapidly and substantially uniformly transferred from the medium to the filler for a total contact time sufficient to expand the tobacco leaves. Study is disclosed for drying and expanding cut tobacco by introducing the tobacco into an elongated tubular shaped conduit through which steam high temperature 150-35$0^{\circ}C$ and high velocity above the 18m1sec, super steam is recycled. moisture content of shreded tobacco leaves, immediately before treatment within the range of from 10% to 24% and, most preferably, within the range of from 18% to 21%. Expanding rate showed 70% in NC -82(B.3) and 42% in Burley -21(B.1) which is produced in 1993 under this condition. When expanding tobacco expanded tobacco did not change significally, but they were decreased at 27$0^{\circ}C$ very largely. The curtailment of cost price and physical and chemical properties of various items were improved in cigarettes. Key words : Expanding tobacco, Super steam tobacco expansion, Fast drying tobacco, High temperature treat tobacco, Puffing tobacco.

  • PDF

Enhancement of Hydroformability Through the Reduction of the Local Strain Concentration (국부적 변형 집중 저감을 통한 액압 성형성 개선연구)

  • Shin, S.G.R.;Joo, B.D.;Moon, Y.H.
    • Transactions of Materials Processing
    • /
    • v.23 no.5
    • /
    • pp.317-322
    • /
    • 2014
  • Bursting during tube hydroforming is preceded by localized necking. The retardation of the initiation of necking is a means to enhance hydroformability. Since high strain gradients occur at the necking sites, a decrease in local strain gradients is an effective way to retard the initiation of necking. In the current study, the expansion at potential necking sites was intentionally restricted in order to reduce the strain gradient at potential necking sites. From the strain distribution obtained from FEM, it is possible to determine strain concentrated zones, which are the potential necking sites. Prior to the hydroforming of a trailing arm, an incompressible material(such as lead) is attached to the tube where the strain-concentrated zone would contact the die. Due to the incompressibility of lead, the tube expansion is locally restricted, and the resultant strain extends to adjacent regions of the tube during hydroforming. After the first stage of hydroforming, the lead is removed from the tube, and the hydroforming continues to the final targeted shape without any local restriction. This method was successfully used to fabricate a complex shaped automotive trailing arm that had previously failed during traditional hydroforming fabrication.