• Title, Summary, Keyword: Mass fraction profile

Search Result 29, Processing Time 0.041 seconds

Velocity and Temperature Profiles of Steam-Air Mixture on the Film Condensation (막응축 열전달에서 공기-수증기 혼합기체의 속도 및 온도분포)

  • 강희찬;김무환
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.18 no.10
    • /
    • pp.2675-2685
    • /
    • 1994
  • A study has been conducted to provide the experimental information for the velocity and temperature profiles of steam-air mixutre and to investigate their roles on the film condensation with wavy interface. Saturated gas mixture of steam-air was made to flow through the nearly horizontal$(4.1^{\circ})$ square duct of 0.1m width and 1.56m length at atmospheric pressure, and was condensated on the bottom cold plate. The air mass fraction in the gas mixture was changed from zero(W =0, pure steam) to one(W =1, pure air), and the bulk velocity was varied from 2 to 4 m/s. Water film was injected concurrently to investigate the effect of wavy interface on the condensation. The velocity and temperature profiles were measured by LDA system and thermocouples along the three parameters ; air mass fraction, mixture velocity and film flow rate. The profiles moved toward the interface with increasing steam mass fraction, mixture velocity and film flow rate. The Prandtl and Schmidt numbers were near one in the present experimental range, however there was no complete similarity between the velocity and temperature profiles of gas mixture. And the heat transfer characteristics and interfacial structure were coupled with each other.

The Prediction of Void Fraction in the Subcooled Boiling Region (서브쿨드 비등 영역에서의 기포계수 계산에 관한 연구)

  • Goon Cherl Park
    • Nuclear Engineering and Technology
    • /
    • v.16 no.4
    • /
    • pp.195-201
    • /
    • 1984
  • A state-of-the-art mechanistic model has been developed to accurately predict the void fraction in the subcooled boiling region having axial nonuniform heat flux. In this study, the void-dependent drift-flux parameters of the Lahey/Ohkawa model were introduced and the mass flux-dependent condensation coefficient were determined by fitting with the experimental data. This model was tested against several experimental data sets to verify its accuracy. Finally the comparison between the predicted void fraction profiles with this model and the profile-fit model for the hot assembly of Kori-Unit 1, Cycle 1 has been performed. It is conclusive that the results show the good agreement between the measured and predicted void fractions, and the profile-fit model has been found to underestimate the void fraction in the subcooled boiling region.

  • PDF

Modeling the tidal connection between in and around galaxy clusters

  • Song, Hyun-Mi;Lee, Joung-Hun
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.36 no.2
    • /
    • pp.53.1-53.1
    • /
    • 2011
  • We analyze the halo and galaxy catalogs from the Millennium simulations at redshifts z=0, 0.5, 1 to determine the alignment profiles of cluster galaxies in terms of the matter density correlation coefficient and discuss a cosmological implication our result has for breaking parameter degeneracies. For each selected cluster, we measure the alignment between the major axes of the pseudo inertia tensors from all satellites within cluster's virial radius and from only those satellites within some smaller radius. Then we average the measured values over the similar-mass sample to determine the cluster galaxy alignment profile as a function of top-hat scale difference at each redshift. It is shown that the alignment profile of cluster galaxies is well approximated by a power-law of the nonlinear density correlation coefficient that is independent of the power spectrum normalization and bias factor. The alignment profile of cluster galaxies is found to have higher amplitude and lower power-law index when averaged over the larger-mass sample and to have rather weak redshift-dependence. This result is consistent with the picture that the satellite galaxies retain the memory of the external tidal fields right after merging and infalling into the clusters but they gradually lose the initial alignment tendency as the cluster's relaxation proceeds. Demonstrating that the nonlinear density correlation coefficient varies sensitively with the density parameter and neutrino mass fraction, we discuss a potential power of the cluster galaxy alignment profile as an independent probe of cosmology.

  • PDF

Simultaneous Determination of Biliary Free and Phospholipid Fatty Acids Using Gas Chromatography-Mass Spectrometry (GC-MS를 이용한 담즙내 유리 지방산 및 인지질 지방산들의 동시 분석)

  • Yang, Yoon Jung;Lee, Seon Hwa;Chung, Bong Chul
    • Analytical Science and Technology
    • /
    • v.13 no.5
    • /
    • pp.592-600
    • /
    • 2000
  • The concentration of free fatty acids and fatty acid composition as well as cholesterol supersaturation in bile may be an important factor in the gallstone formation. Therefore, we simultaneously determinded 23 fatty acids in bile by selected ion monitoring (SIM) method of gas chromatography-mass spectrometry (GC-MS). Biliary fatty acids were extracted by aminopropyl column and the extracts with (phospholipid fraction) or without (free fatty acid fraction) alkaline hydrolysis of phospholipid were derivatized with MSTFA/TMCS (N-methyl-N-trimethylsilyl-trifluoroacetamide/trimethylsilylchloride) mixture in order to be detected on the GC-MS. The recovery range of this method was 61.1-99.0% and the RSD value of within-a-day and day-to-day test were 3.1-25.6% and 3.8-27.0%, respectively. Using this method, biliary profile was investigated in the bile of normal controls and patients with gallstones. The amounts and their distribution of free and phospholipid fatty acids showed different pattern between normal subjects and patients.

  • PDF

Classification of Individual Ambient Particles by CCSEM (CCSEM을 이용한 대기 중 개별분진의 분류에 관한 연구)

  • 장여진;김동술
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.13 no.5
    • /
    • pp.345-353
    • /
    • 1997
  • The purpose of the study was to stastically classify individual PM-10 measured by SEM/EDX (scanning electron microscopy/energy dispersive x-ray analyzer). The SEM/EDX provided various physical parameters like optical diameter, as well as major 18 chemical information (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb) for a particle-by-particle basis. The total of 1,419 particles were analyzed for the study. Thus density and mass of each particle can be estimated based on its chemical composition. Further the study developed 4 semisource profiles including highway, oil boiler, incinerator, and soil emissions, where each sample was collected near the source in the ambient air The profiles developed were consisted of mass fractions and their uncertainties based on a particle class concept. To obtain mass fraction of each particle class, an agglomerative hierarchical cluster analysis was initially applied to create particle classes for each sample. Then uncertainties were calculated for each class based on the jacknife method. The 1,258 particles out of 1,419 (88.7%) were assorted in newly generated particle classes. The study provides opportunities to identify particle's source quantitatively and to develope various receptor models.

  • PDF

Individual Particle Analysis for Developing a Source Profile of Yellow Sands (황사의 오염원분류포 개발을 위한 개별입자분석)

  • 강승우;김동술
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.16 no.6
    • /
    • pp.565-572
    • /
    • 2000
  • To quantitatively estimate mass contribution of long-range transported yellow sand, their sources should be separated independently from various local soil sources having similar elemental compositions. While it is difficult to estimate total mass loadings of pure yellow sand by traditional bulk analysis, it can be clearly solved by an particle-by-particle analysis. To perform this study, two yellow sand samples and three local soil samples were collected by a mini-volume sampler. These samples were three analyzed using a scanning electron microscope(SEM) equipped with an energy dispersive x-ray analyser (EDX) was used to obtain basic chemical information of individual yellow san particles. A total of 19 elements in a single particle were measured to develop a source profile with newly created homogeneous particle classes (HPCs) as chemical variables. The present study showed that the yellow sand samples as well as three local soil samples were characterized with reasonably well created HPCs. Finally the mass fraction of each HPC in each sample was calculated and then compared each other.

  • PDF

A Study on the Source Profile Development for Diesel and Gasoline-Powered Vehicles (디젤 및 가솔린자동차 배출원의 구성물질 성분비 개발에 관한 연구)

  • Kang, Byung-Wook;Cho, Min-Shik;Lee, Seung-Bok;Bae, Gwi-Nam;Lim, Cheol-Soo;Na, Kwang-Sam;Lee, Hak-Sung
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.26 no.3
    • /
    • pp.318-329
    • /
    • 2010
  • The purpose of this study was to develop the $PM_{2.5}$ source profiles for diesel and gasoline-powered vehicles, which contained mass abundances in terms of mass fraction of $PM_{2.5}$ of chemical species. Seven diesel-powered vehicles and nine gasoline-powered vehicles were sampled from a chassis dynamometer exhaust dilution system. The species measured were water-soluble ions, elements, elemental carbon (EC), and organic carbon (OC). From this study, the large abundances of EC (54.5%), OC (26.0%), ${SO_4}^{2-}$ (1.5%), ${NO_3}^-$ (0.8%), and S (0.6%) were observed from the diesel-powered vehicle exhaust showing that carbons were dominant species. The gasoline-powered vehicle exhaust emitted large abundances of OC (38.3%), EC (4.2%), ${SO_4}^{2-}$ (3.6%), ${NH_4}^+$ (3.5%), and ${NO_3}^-$ (3.0%). The abundances of ${SO_4}^{2-}$, ${NH_4}^+$, and ${NO_3}^-$ from gasoline vehicle were greater than those of diesel vehicle. The emissions of P, S, Ca, Fe, and Zn among trace elements for the gasoline vehicle were greater than 1% of the $PM_{2.5}$ mass unlike those for the diesel vehicle. Particularly, the fraction of Zn was five times higher from the gasoline vehicle than that from the diesel vehicle. The source profiles developed in this work were intensively examined by applying chemical mass balance model.

A Comprehensive Identification of Synaptic Vesicle Proteins in Rat Brains by cRPLC/MS-MS and 2DE/MALDI-TOF-MS

  • Lee, Won-Kyu;Kim, Hye-Jung;Min, Hye-Ki;Kang, Un-Beom;Lee, Cheol-Ju;Lee, Sang-Won;Kim, Ick-Young;Lee, Seung-Taek;Kwon, Oh-Seung;Yu, Yeon-Gyu
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.9
    • /
    • pp.1499-1509
    • /
    • 2007
  • Proteomic analyses of synaptic vesicle fraction from rat brain have been performed for the better understanding of vesicle regulation and signal transmission. Two different approaches were applied to identify proteins in synaptic vesicle fraction. First, the isolated synaptic vesicle proteins were treated with trypsin, and the resulting peptides were analyzed using a high-pressure capillary reversed phase liquid chromatography/tandem mass spectrometry (cRPLC/MS/MS). Alternatively, proteins were separated by two-dimensional gel electrophoresis (2DE) and identified by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF/MS). Total 18 and 52 proteins were identified from cRPLC/MS-MS and 2DE-MALDI-TOF-MS analysis, respectively. Among them only 2 proteins were identified by both methods. Of the proteins identified, 70% were soluble proteins and 30% were membrane proteins. They were categorized by their functions in vesicle trafficking and biogenesis, energy metabolism, signal transduction, transport and unknown functions. Among them, 27 proteins were not previously reported as synaptic proteins. The cellular functions of unknown proteins were estimated from the analysis of domain structure, expression profile and predicted interaction partners.

Metabolism of Triprolidine in Rat (흰쥐에서의 트리프로리딘의 대사)

  • Jung, Byung-Hwa;Eom, Khee-Dong;Yoo, Young-Soo;Chung, Bong-Chul;Park, Jong-Sei
    • YAKHAK HOEJI
    • /
    • v.36 no.1
    • /
    • pp.26-36
    • /
    • 1992
  • The metabolic profile of triprolidine, 2-[1-(4-methylphenyl)-3-(1-pyrrolidinyl-1-propenyl)] pyridine, was determined in rat urine and bile. The free fractions of urinary and biliary extracts were obtained without hydrolysis, and the conjugated fractions of extracts were obtained with enzyme hydrolysis using ${\beta}-glucuronidase$ from Escherichia coli. The mixture of N-methyl-N-trimethylsilyltrifluoroacetamide/trimethylsilyl chloride (100 : 1, v/v) was used to derivatize the extracts and then analyzed by gas chromatography/mass spectrometry. Hydroxymethyltriprolidine, hydroxytriprolidine, triprolidine carboxylic acid, dihydroxytriprolidine 1, dihydroxytriprolidine 2, oxotriprolidine carboxylic acid and unchanged triprolidine were detected in rat urine and bile, which were obtained after oral treatment with triprolidine hydrochloride. The maximum urinary excretion rate of triprolidine and hydroxymethyltriprolidine which were extracted from free fraction was at 1 to 2 hours after drug administration. Hydroxymethyltriprolidine was detected in conjugated fraction, and the maximum urinary excretion rate of that metabolite was at 2 to 3 hours in rat. In rat bile analysis, triprolidine was detected only in free fraction and its biliary excretion rate showed the maximum within 30 minutes after drug administration and decreased continuously thereafter. The excretion percentage of triprolidine and hydroxymethyltriprolidine to the initial dose of the parent drug in bile and urine of rats were all low.

  • PDF