• Title/Summary/Keyword: Process of formation

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Studies on the Formation and Stability of Colloids (II) : pH and Temperature Effects on the Secondary Micelle Formation of Sodium Deoxycholate

  • Park, Joon-Woo;Chung, He-Sson
    • Bulletin of the Korean Chemical Society
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    • v.8 no.2
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    • pp.118-122
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    • 1987
  • The micelle formation of NaDC was studied by fluorometric and viscometric measurements. The thermodynamic parameters of the primary and secondary micellization of the bile salt were evaluated. The primary micelle formation was appeared to be an entropy driven process due to hydrophobic effect, while the major driving force for secondary micelle formation of the bile salt is the large negative enthalpy. The secondary micelle provides less hydrophobic environment to pyrene than the primary micelle does. The cooperative aggregation of primary micelles via hvdrogen bond formation was proposed for the secondary micelle formation.

A Study on the Burr Formation of Miniature Drilling process (미소 드릴링시의 Burr 형성에 관한 연구)

  • 박동삼
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.04a
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    • pp.6-11
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    • 1997
  • In most machining operations, undesirable burr are formed on the edge of the workpiece adjacent to the machined surface. Such burrs are often the cause of various problems during automatic maching process. Therefore, it is very important to know characteristics of burr formation in maching process. This paper describes characteristic of exit burrs generated during miniature drilling process. In particular, the effect of spindle speed, feedrate and drill diameter on burr formaton is investigated. The result showed that exit burr height increased significantly with increasing feedrate.

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NUMERICAL SIMULATIONS OF GALAXY FORMATION

  • Peiran, Sebastien
    • Publications of The Korean Astronomical Society
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    • v.25 no.3
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    • pp.71-76
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    • 2010
  • The current status of numerical simulations of galaxy formation is reviewed. After a description of the main numerical simulation techniques, I will present several applications in order to illustrate how numerical simulations have improved our understanding of the galaxy formation process.

Use of the Thermodynamic Solution Properties of Xenon in n-Alkanes for the Examination of Models for the Cavity Formation Process

  • Park, Jung-Hag;Brady, James E.;Carr, Peter W.
    • Bulletin of the Korean Chemical Society
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    • v.10 no.3
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    • pp.309-314
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    • 1989
  • The interaction energies of Xenon in n-alkanes were estimated by using three models for the cavity formation process, Hildebrand's regular solution theory, Pierotti's scaled particle theory and Sinanoglu-Reiss-Moura-Ramos' solvophobic theory in an attempt to examine the validity of three models. It appears that Pierotti's implementation of scaled particle theory yields a reasonable estimate of cavity formation energy over a considerable range in solvent size provided that the solute is spherical enough as are the inert gases.

Prediction of Chip Formation Mechanism Using Acoustic Emission (음향방출을 이용한 칩 발생 기구의 예측)

  • 맹민재
    • Journal of the Korean Society of Safety
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    • v.16 no.2
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    • pp.22-26
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    • 2001
  • The machining process on be considered as a planned interaction of the workpiece, the tool and the machine tool. In an unmanned situation, the results of this interaction are to be continuously monitored so that any changes in the machining environment on be sensed to corrective actions. In order to design the process monitoring system for unmanned manufacturing, the identification of chip formation is proposed. The system proposes the method of using acoustic emission(AE) signal analysis to identify the chip formation during cutting.

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MOLECULAR OUTFLOWS AND THE FORMATION PROCESS OF VERY LOW-MASS OBJECTS

  • PHAN-BAO, NGOC;DANG-DUC, CUONG;LEE, CHIN-FEI;HO, PAUL T.P.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.83-86
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    • 2015
  • We present observational results characterizing molecular outflows from very low-mass objects in ${\rho}$ Ophiuchi and Taurus. Our results provide us with important implications that clarify the formation process of very low-mass objects.

A Study on the Creating and Prosperity Process of the Siheyuan in China (중국 사합원의 생성과 발전과정에 관한 연구)

  • Choi, Jang-Soon
    • Journal of the Korean Institute of Rural Architecture
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    • v.7 no.1
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    • pp.112-120
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    • 2005
  • The object of this study is one of the traditional houses about Siheyuan(courtyard house) which is one of the most remarkable types of dwelling in China. The purpose of this paper is to examine and analyse the formation process of the Siheyuan. Its organizational formation process are based on historical and natural-geographical background. With the passage of time this house developed into one of the Chinese house style. The technique of Siheyuan's spatial composition goes so far back in the New Stone Age. The relics of this are the colony layout, the system of four sides, the layout type of a palace, the picture of lacquered ware, the picture of brick, the earthenware of house type, the painting of cave, the paintings of painters and others.

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Formation Process & Background Factor of a Sphere of the Traditional Clan Villages in Andong Area of the Yi-Dynasty (전통주거지 조영에서 나타난 안동지방 동족반촌마을권의 형성과정 과 배경요인)

  • 이학동;최종현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.19 no.4
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    • pp.58-79
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    • 1992
  • This is a study of Sadaebu(previllaged class in a Yi-Dynasty士 大夫) clan villages in the Andong Area with emphasis on Formantion Process of development. The purposes and the contents of this study are as following : 1. To review the process and the background fo growth of Myung-Mun-Se-Ga(名文大家:the traditional famed & mighty clans) in Yi-Dynasty, in cases of Andong(安東) province. 2. To analyze about formation process of a sphere of their homogeneous clan villages, and to understand the factors affecting their sphere. 3. To identity the background factor of formation of their sphere of traditional clan villages in Andong province.

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Solid-State $^1H$ and $^{29}Si$ NMR Studies of Silicate and Borosilicate Gel to Glass Conversion

  • 양경화;우애자
    • Bulletin of the Korean Chemical Society
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    • v.17 no.8
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    • pp.696-699
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    • 1996
  • Silicate and borosilicate gels were prepared by the sol-gel process and thermally treated in the 150-850 ℃ temperature range. Solid-state 1H MAS and 29Si CP/MAS NMR spectroscopy were used to investigate the effects of heat treatments on the silicate gel to glass conversion process. The 1H NMR isotropic chemical shifts and the relative intensities of hydrogen bonded and isolated silanol groups have been used to access the information concerning the dehydration process on the silicate gel surface. The 29Si NMR isotropic chemical shifts affected by the local silicon environment have been used to determine the degree of crosslinking, i.e. the number of siloxane bonds. These NMR results suggest that the silicate gel to glass conversion process is occurred by two stages which are dependent on the temperature; (1) the formation of particles up to 450 ℃ and (2) the formation of large particles by aggregation of each separated single particle above 450 ℃. In addition, the effects of B atom on the formation of borosiloxane bonds in borosilicates have been discussed.

Dynamic Simulation of Retention and Formation Processes of a Pilot Paper Machine

  • Cho, Byoung-Uk;Garnier, Gil;Perrier, Michel
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.1 s.119
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    • pp.8-15
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    • 2007
  • In an effort to develop control strategies for the wet-end of paper machines, dynamic models for retention and formation processes have been developed. The retention process, including headbox total and filler consistencies, white water total and filler consistencies, the basis weight and the ash content of paper, can be modeled from first-principles (mass balances). To include the effect of wet-end chemistry variables, first-pass retention was included as a parameter dependent on operating conditions. In addition, dynamics of formation was simulated by developing an empirical model of formation and coupling with the dynamic models for the retention process. A series of experiments were performed using a pilot paper machine. The experimental results and the model predictions showed relatively good agreement.