• Title/Summary/Keyword: pressure capsule

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Synthesis of $TiB_{2}/Cu$ FGM by SHS process (SHS법에 의한 $TiB_{2}/Cu$계 경사기능재료의 제조)

  • 박현철;연석주
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.5 no.4
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    • pp.386-393
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    • 1995
  • A Abstract Producing process of FGM by SHS process has been investigated and $TiB_2$/Cu based FGM was fabricated by the process. When raw material powders were stacked on, Cu substrate, composition profile can be graded. This stacked body was compressed and vacuum­s sealed into the capsule for the synthesis. This sample was ignited and compressed under high h hydro - pressure. By the observation of the crystal phases and microstructures of produced $TiB_2$/Cu FGM samples, the compositional gradient was able to be identified.

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PREDICTION OF THE AERODYNAMIC CHARACTERISTICS OF AN ORBITAL BLOCK OF A LAUNCH VEHICLE IN THE RAREFIED FLOW REGIME USING DSMC APPROACH (DSMC 해석기법을 이용한 희박유동 환경에서의 발사체 Orbital Block 공력특성 예측)

  • Kim, Young-Hoon;Ok, Ho-Nan;Choi, Young-In;Kim, In-Sun
    • 한국전산유체공학회:학술대회논문집
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    • 2007.04a
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    • pp.79-82
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    • 2007
  • The aerodynamic coefficients of Apollo capsule are calculated using a DSMC solver, SMILE, and the results agree very well with the data predicted by NASA. The aerodynamic characteristics of an orbital block which operates at high altitudes in the free molecule regime are also predicted. For the nominal flow conditions, the predicted aerodynamic force is very small since the dynamic pressure is extremely low. And the additional aerodynamic coefficients for the analysis of the attitude control are presented as the angle of attack and the side slip angle vary from $+45^{\circ}\;to\;-45^{\circ}$ of the nominal angle.

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Microencapsulation of Anchovy Oil by Sodium Alginate (알긴산소다를 이용한 멸치어유의 미세캡슐화)

  • 임상빈;좌미경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.4
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    • pp.890-894
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    • 1999
  • Microencapsulation of anchovy oil as a core material in sodium alginate as a wall material was inves tigated. Microencapsulation was accomplished by injecting an oil/water emulsion, consisting of a mixture of liquefied sodium alginate and emulsifier, under high pressure through an orifice submerged in a calcium lactate solution. Microcapsules suspended in a dispersion fluid were observed under a fluorescence mi croscope to verify the presence of the capsules and to note coalescence or degradation of the capsules. Optimum conditions for microencapsulation of anchovy oil were obtained when 1.0% aqueous solution of sodium alginate contained 3% of a 1:1 ratio of ESPR 25(polyglycerine+polylinoleate) and TW 20(sorbitan laurate+ethylene oxide) as an emulsifier in terms of capsule size and size distribution, and emulsion stability. The airless sprayer produced microcapsules with a diameter between 15.9 and 73.9 m with different concentration of a wall material. The optimum mixing ratio of wall material to core material was 90:10(wt/wt). 0.2% calcium lactate was appropriate as a dispersion fluid.

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Physio-biochemical changes correlated with cadmium adaptation and detoxification mechanism in klebsiella aerogenes (Klebsiella aerogenes의 카드뮴 적응 및 해독기작에 관련된 생리생화학적인 변화)

  • 이기성;송인극;박영식;윤성녀;최영길
    • Korean Journal of Microbiology
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    • v.28 no.3
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    • pp.249-257
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    • 1990
  • In the course of operating the accommodative and detoxifying mechanism against cadmium, its physio-biochemical changes were observed in Klebsiella aerogenes ATCC 10031. Changes of enzyme activity concerned phosphate metabolism, changes of phospholipid composition and in view of energy metabolism the changes of the nucleotide pool were examined. Activities of both alkaline and acid phosphatase were derepressed 4-10 folds under cadmium added cultures. Moreover, production of phospholipid such as lysophosphatidyl choline (LPC), phosphatidyl serine (PS) and phosphatidyl ethanolamone (PE) was increased and uridylate nucleotide pool was increased under Cd-surplus culture. These results i.e. overproduction of phosphatase catalyzing phosphate residue, increase of the production of PE and PS which have a close affinity with cadmium, and indrease of uridylate nucleotide pool used as a carrier of polysaccharide synthesis like bacterial capsule exhibited cellular responses for active defence against Cd-pressure. It was postulated that these phenomena should play another assistant roles in Cd-detoxifing mechanism.

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Effects of Joint Mobilization Techniques on the Joint Receptors (관절 가동운동(mobilization)이 관절 감수기(joint receptors)에 미치는 영향)

  • Kim, Suhn-Yeop
    • Physical Therapy Korea
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    • v.3 no.2
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    • pp.95-105
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    • 1996
  • Type I, II, III are regarded as "true" joint receptors, type IV is considered a class of pain receptor. Type I, II and III mechanoreceptors, via static and dynamic input, signal joint position, intraarticular pressure changes, and the direction, amplitude, and velocity of joint movements. Type I mechanoreceptor subserve both static and dynamic physiologic functions. Type I are found primarily in the stratum fibrosum of the joint capsule and ligaments. Type I receptors have a low threshold for activation and are allow to adapt to changes altering their firing frequency. Type II receptors have a low threshold for activation. These dynamic receptors respond to joint movement. Type II receptors are thus termed rapidly adapting. Type II joint receptors are located at the junction of the synovial membrane and fibrosum of the joint capsule and intraarticular and extraarticular fat pads. Type III receptors have been found in collateral ligaments of the joints of the extremities. Morphologically similar to Golgi tendon organ. These dynamic receptors have a high threshold to stimulation and are slowly adating. Type IV receptors possess free nerve ending that have been found in joint capsule and fat pads. They are not normally active, but respond to extreme mechanical deformation of the joint as well as to direct chemical or mechanical irritation. Small amplitude oscillatory and distraction movements(joint mobilization) techniques are used to stimulate the mechanoreceptors that may inhibit the transmission of nociceptors stimuli at the spinal cord or brain stem levels.

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Effects of Joint Mobilization Techniques on the Joint Receptors (관절 가동운동이 관절 감수기에 미치는 영향)

  • Kim, Suhn-Yeop
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.2 no.1
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    • pp.9-19
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    • 1996
  • Type I, II, III are regarded as "true" joint receptors, type IV is considered a class of pain receptor. Type I, II and III mechanoreceptors, via static and dynamic input, signal joint position, intraarticular pressure changes, and the direction, amplitude, and velocity of joint movements. Type I mechanoreceptor subserve both static and dynamic physiologic functions. Type I are found primarily in the stratum fibrosum of the joint capsule and ligaments. Type I receptors have a low threshold for activation and are allow to adapt to changes altering their firing frequency. Type II receptors have a low threshold for activation. These dynamic receptors respond to joint movement. Type II receptors are thus termed rapidly adapting. Type II joint receptors are located at the junction of the synovial membrane and fibrosum of the joint capsule and intraarticular and extraarticular fat pads. Type III receptors have been found in collateral ligaments of the joints of the extremities. Morphologically similar to Golgi tendon organ. These dynamic receptors have a high threshold to stimulation and are slowly adating. Type IV receptors possess free nerve ending that have been found in joint capsule and fat pads. They are not normally active, but respond to extreme mechanical deformation of the joint as well as to direct chemical or mechanical irritation. Small amplitude oscillatory and distraction movements(joint mobilization) techniques are used to stimulate the mechanoreceptors that may inhibit the transmission of nociceptors stimuli at the spinal cord or brain stem levels.

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Effect of Neutron Energy Spectra on the Formation of the Displacement Cascade in ${\alpha}-Iron$

  • Kwon Junhyun;Seo Chul Gyo;Kwon Sang Chul;Hong Jun-Hwa
    • Nuclear Engineering and Technology
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    • v.35 no.5
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    • pp.497-505
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    • 2003
  • This paper describes a computational approach to the quantification of primary damage under irradiation and demonstrates the effect of neutron energy spectra on the formation of the displacement cascade. The development of displacement cascades in ${\alpha}-Iron$ has been simulated using the MOLDY code - a molecular dynamics code for simulating radiation damage. The primary knock-on atom energy, key input to the MOLDY code, was determined from the SPECTER code calculation on two neutron spectra. The two neutron spectra include; (i) neutron spectrum in the instrumented irradiation capsule of the high-flux advanced neutron application reactor (HANARO), and (ii) neutron spectrum at the inner surface of the reactor pressure vessel steel for the Younggwang nuclear power plant No.5 (YG 5). Minor differences in the normalized neutron spectra between the two spectra produce similar values of PKA energy, which are 4.7 keV for HANARO and 5.3 keV for YG 5. This similarity implies that primary damage to the components of the commercial nuclear reactors should be well simulated by irradiation in the HANARO. Moreover, the application of the MD calculations corroborates this statement by comparing cascades simulation results.

Effect of Pressurization and Cooling Rate on Dissolution of a Stationary Supercooled Aqueous Solution (정지상태 수용액에서 가압과 냉각속도가 과냉각해소에 미치는 영향)

  • Kim, Byung-Seon;Peck, Jong-Hyun;Hong, Hi-Ki;Kang, Chae-Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.12
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    • pp.850-856
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    • 2007
  • In a supercooled or capsule type ice storage system, aqueous solution (or water) may have trouble with non-uniform dissolution though the system contributes to the simplicity of system and ecological improvement. The non-uniform dissolution increases the instability of the system because it may cause an ice blockage in pipe or cooling part. In order to observe the supercooled state, a cooling experiment was performed with pressurization to an ethylene glycol(EG) 3 mass% solution in stationary state. Also, the effect of the pressurization from 101 to 505 kPa to the dissolution of supercooled aqueous solution was measured with the dissolution time of the supercooled aqueous solution at a fixed cooling rate of brine. At results, the dissolution of supercooled point decreased as the pressure of the aqueous solution in the vessel increased. Moreover, the dissolution point increased as the heat flux for cooling increased.

Preparation of Micro-/Macroporous Carbons and Their Gas Sorption Properties

  • Hwang, Yong-Kyung;Shin, Hye-Seon;Hong, Jin-Yeon;Huh, Seong
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.377-382
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    • 2014
  • Micro-/macroporous carbons (MMCs) were prepared using a hollow mesoporous silica capsule (HMSC) as a sacrificial hard template. The carbonization process after the infiltration of furfuryl alcohol into the template-free HMSC material afforded MMC materials in high yield. The hard template HMSC could be removed by HF etching without deteriorating the structure of MMC. The MMC materials were fully characterized by SEM, TEM, PXRD, XPS, and Raman spectroscopy. The replication processes were so successful that MMCs exhibited a hollow capsular structure with multimodal microporosity. Detailed textural properties of MMC materials were investigated by volumetric $N_2$ adsorption-desorption analysis at 77 K. To explore the gas sorption abilities of MMCs for other gases, $H_2$ and $CO_2$ sorption analyses were also performed at various temperatures. The multimodal MMC materials were found to be good sorbents for both $H_2$ and $CO_2$ at low pressure.

Preparation and Characterization of Solid Dispersions of Itraconazole by using Aerosol Solvent Extraction System for Improvement in Drug Solubility and Bioavailability

  • Lee, Si-Beum;Nam, Kyung-Wan;Kim, Min-Soo;Jun, Seoung-Wook;Park, Jeong-Sook;Woo, Jong-Soo;Hwang, Sung-Joo
    • Archives of Pharmacal Research
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    • v.28 no.7
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    • pp.866-874
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    • 2005
  • The objective of this study was to elucidate the feasibility to improve the solubility and bioavailability of poorly water-soluble itraconazole via solid dispersions by using supercritical fluid (SCF). Solid dispersions of itraconazole with hydrophilic polymer, HPMC 2910, were prepared by the aerosol solvent extraction system (ASES) under different process conditions of temperature/pressure. The particle size of solid dispersions ranged from 100 to 500 nm. The equilibrium solubility increased with decrease (15 to 10 MPa) in pressure and increase (40 to $60^{\circ}C$) in temperature. The solid dispersions prepared at $60^{\circ}C$/15 MPa showed a slight increase in equilibrium solubility (approximately 27-fold increase) when compared to pure itraconazole, while those prepared at $60^{\circ}C$/10MPa showed approximately 610-fold increase and no endothermic peaks corresponding to pure itraconazole were observed, indicating that itraconazole might be molecularly dispersed in HPMC 2910 in the amorphous form. The amorphous state of itraconazole was confirmed by DSC/XRD data. The pharmacokinetic parameters of the ASES-processed solid dispersions, such as $T_{max},\;C_{max},\;and\;AUC_{0-24h}$ were almost similar to $Sporanox_{\circledR}$ capsule which shows high bioavailability. Hence, it was concluded that the ASES process could be a promising technique to reduce particle size and/or prepare amorphous solid dispersion of drugs in order to improve the solubility and bioavailability of poorly water-soluble drugs.