• Title/Summary/Keyword: Mass size distribution

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Secondary Ion Man Spectrometry: Theory rind Applications in Geosciences (이차이온질량분석기의 원리와 지질학적 응용)

  • 최변각
    • The Journal of the Petrological Society of Korea
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    • v.10 no.3
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    • pp.222-232
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    • 2001
  • Secondary ion mass spectrometry (SIMS) uses focused high-speed primary ions to produce secondary ions from sample surface that are analyzed through a mass filter. SIMS is often called as ion microprobe, since it offers a micrometer-scale spatial resolution. Although the precision and accuracy of SIMS are not as good as many conventional mass spectrometers, it has several advantages such as small sample-size requirement, high spatial resolution and capability of in-situ analysis. In the field of geochemistry/cosmochemistry, SIMS is widely used for (1) stable isotope geochemistry of H, C, O, S, etc., (2) geochronology of U/Th-bearing minerals, (3) lateral distribution of trace elements in a mineral, and (4) discovery of presolar grains and investigation of their isotopic compositions.

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Performance Improvement of Mowse Scoring Method for Protein Identification (단백질 동정을 위한 Mowse 스코어링 방법의 성능 개선)

  • Jung, Min-A;Kim, Chi-Yeon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.10
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    • pp.1880-1885
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    • 2007
  • In this paper, we propose the method that improve the performance of the Mowse. Mowse is the tool of the peptide mass fingerprinting that is used the identification of protein. In Mowse, frequency factor matrix is generated to regular interval for protein and peptide mass and the value of each elements is calculated to frequency of peptide. We propose new method for calculation of exact scoring value maintaining same size of matrix. The proposed method is that decide interval of matrix considering distribution of protein database. That is, interval of matrix is decided to small in many value of protein mass and is decided to large in few value of protein mass. We present the performance result both Mowse scoring method and the proposed scoring method.

A Study on the Removal Characteristics of Indoor Air Pollutants using the Air Cleaning System (실공간에서 공기정화시스템을 이용한 실내 오염 입자 제거 특성에 관한 연구)

  • Koo, Jeong-Hwan;Kim, Seong-Chan;Kim, Jang-Woo;Lee, Ju-Yong;Lee, Jae-Keun;Kang, Tae-Wook;Lee, Kam-Gyu
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.532-537
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    • 2000
  • The purpose of this study is to determine the performance of a commercial air cleaner in removing tobacco smoke indoors. Following injection of tobacco smoke in a room, decay rates for particle concentrations were obtained far mass concentration at each point. The size distribution of the tobacco smoke particles was approximately $1.266{\mu}m$ in mass median diameter with a geometric standard deviation of 1.313. The air cleaner consisted of an electrostatic filtration unit and a fan operated at a flow rate of 5.98 CMM. The collection efficiency for $>1\;{\mu}m$ was more than 99%. Without air cleaner operation, tobacco smoke concentration ratio in room decreased to 30% of initial values within 30 minutes and with air cleaner operation, decreased to 90% of initial values in the test chamber, volume $51.27\;m^3$. Without air cleaner operation, tobacco smoke concentration ratio in room decreased to 10% of initial values within 30 minutes and with air cleaner operation, decreased to 30-70% of initial values in the test chamber, volume $149.2\;m^3$.

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Combustion Behavior in a Solid Fuel Ramjet Combustor (고체 램제트 추진기관 연소실에서의 연소 현상)

  • Lee, T. H.
    • Journal of the Korean Society of Propulsion Engineers
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    • v.3 no.3
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    • pp.25-30
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    • 1999
  • An experimental investigation was conducted to explore the effects of air mass flux on the combustion efficiency and particle size distributions in a solid fuel ramjet using a fuel grain highly loaded with boron carbide. Particle distributions were measured at the grain exit and at the nozz1e entrance using a Malvern 2600 HSD. Combustion efficiency increased with decreasing air mass flux. In general, the particle distribution was trimodal or quadrimodal with node peaks at approximately 4, 15, and 25$\mu\textrm{m}$ and possibly one at less than 2$\mu\textrm{m}$. The larger particles were the result of surface agglomeration, primarily within the recirculation region. Higher inlet air temperature produced higher combustion efficiencies, apparently the result of enhanced combustion of the larger boron carbide particles that burn in a diffusion controlled regime.

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ChlorophyII and suspended sediment specific absorption coefficient in the sea.

  • Ahn, Yu-Hwan;Moon, Jeong-Eon
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.399-403
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    • 1998
  • Absorption coefficient per mass unit of particles, specific absorption coefficient, is one of main parameters in developing algorithms for ocean color remote sensing. Specific absorption coefficient of chlorophyll (a$^*_{ph}$) and suspended sediment (SS) were analyzed by "wet filter technique" and "Kishino method" for data sets observed in the Yellow and Mediterranean Seas. A new data-recovering method for the filter technique was also developed using spectrum slopes. This method recovered the baseline of spectrum that was often missed in the Kishino method. High a$^*_{ph}$($\lambda$) values in the oligotrophic Mediterranean Sea and low values in the Yellow Sea were observed, spanning over the range of 0.02 to 0.12 $m^2$/mg, at the chlorophyll maximum absorption wavelength 440nm. The empirical relationship between a$^*_{ph}$ and chlorophyll concentration was found to fit a power function, which was slightly different from that proposed by Bricaud et ai. (1995). Absorption specific coefficients for suspended sediment (a$^*_{SS}$) didn't show any relationship with concentrations of suspended sediment. However, the average value of a$^*_{SS}$ at 440nm was close to the specific absorption coefficient of soil (loess) measured by Ahn (1990). The more-pronounced variability of a$^*_{SS}$ than a$^*_{ph}$ perhaps can explain more wide range of size-distribution for SS, which were determined by their specific gravity and agitation of water mass in the sea surface.

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Occurrence of scutica-like ciliate (SLC) and its control during the mass seed production of the Japanese scallop, Patinopecten yessoensis (참가리비 (Patinopecten yessoensis) 대량 종묘생산시의 Scutica-like ciliate 발생 및 대책)

  • Jo, Q-Tae;Bang, Jong-Deuk;Kim, Su-Kyeong;Rahman, Mohamad M.;Gong, Yong-Geun;Kim, Dae-Kwon;Lee, Joo-Seok
    • Journal of fish pathology
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    • v.21 no.3
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    • pp.167-174
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    • 2008
  • Few studies on parasitic scutica-like ciliates (SLCs) influencing larval growth and survival during the seed production of the Japanese scallop, Patinopecten yessoensis have been performed in spite of relatively high magnitude of their infectious damage to the larvae. In the mass seed production of the scallop, SLCs were never infectious during D-larval stage which lasted 6 to 7 days. Indeed, the infection first occurred in 2 to 4 days after first umbo-staged larvae. A regular selection of active larvae in swimming behavior kept larval SLC infection low throughout the culture compared to unselected control (P<0.05) in which all the larvae alive were contained. Higher infection frequencies of the unselected control resulted in lower larval survivals and wider range of larval size distribution that drove larval attachment rate lower. To the worse, the nursery spats from the higher SLC infection exhibited a retarded growth and elevated occurrence of abnormal scallop.

Physicochemical Properties of Asian Dust Sources

  • Ma, Chang-Jin;Kasahara, Mikio;Tohno, Susumu;Kim, Ki-Hyun
    • Asian Journal of Atmospheric Environment
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    • v.2 no.1
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    • pp.26-33
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    • 2008
  • In order to fully understand the chemical properties of Asian dust particles, especially their transformation and aging processes, it is desirable to investigate the nature of original sands collected at local source areas in China. This study presents the detailed properties of sands collected at four different desert regions (Yinchuan, Wuwei, Dulan, and Yanchi) in China. Most of sands have irregular shape with yellowish coloration, whereas some of them show peculiar colors. The relative size distribution of sands collected at Yinchuan, Wuwei, and Dulan deserts exhibits monomodal with the maximum level between 200 and $300{\mu}$, whereas that of Yanchi desert is formed between 100 and $200{\mu}$. The mass concentration ratio of each element to that of Si (Z/Si) determined by PIXE analysis has a tendency towards higher Z/Si ratios for soil derived elements. It was possible to visually reconstruct the elemental maps on the surface of individual sands by XRF microprobe technique. In addition, the multielemental mass concentration could be quantitatively calculated for numerous spots of desert sands.

A Study on Airborne Coal Dust Concentration at each Work Site in Coal Briquet Factory (연탄제조 공장의 작업장별 석탄분진의 농도에 관한 연구)

  • 신대윤;오정룡;강공언
    • Journal of Environmental Health Sciences
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    • v.18 no.1
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    • pp.6-11
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    • 1992
  • This study was carried out to investigate exposure level, size distribution, and respirable mass fraction of airborne coal dust and heavy metal concentration of respirable coal dust at each work site in coal briquet factory from July 1991 to September 1991. Geometric mean of total dust concentration was 10.88mg/m$^{3}$ at storage shop, 8.22mg/m$^{3}$ at pulverize shop, and 3.79mg/m$^{3}$ at rotary press shop, respectively, but those at storage and pulverize shop were higher than TLV. Geometric mean of respirable coal dust concentration wat 1.03mg/m$^{3}$ at storage shop, 0.78mg/m$^{3}$ at pulverize shop, and 0.55mg/m$^{3}$ at rotary press shop, respectively, which were lower than TLV Aerodynamic 50% cutoff diameter of the suspended coal dust was 5$\mu$m at rotary press shop and 6.8$\mu$m at storage shop, ranged to thoracic particulate defined by ACGIH, and deposited in the region of repiratory system. The mass fraction rate of respirable dust to the total coal dust was 26.2% at rotary press shop, 18.8% at storage shop, and 13.8% at pulverize shop, respectively. Heavy metal concentrations of the respirable coal dust were 0.028mg/m$^{3}$ ib Fe, 0.0081mg/m$^{3}$ in Cu, and 0.0039mg/m$^{3}$ in Pb.

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A Study on the Purchasing Practice and Size Fitness of Ready-made Clothes for Male College Students according to Body Types (한국 남자대학생의 체형에 따른 기성복 구매실태 및 치수적합도 조사)

  • Lim, Jiyoung
    • Fashion & Textile Research Journal
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    • v.15 no.6
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    • pp.942-949
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    • 2013
  • This study was performed to investigate purchasing practice and size satisfaction in order to offer basic data to establish marketing strategy and produce ready-made clothes for the male college students according to their body type. For data analysis, crosstabs, factor analysis and one-way ANOVA were used. Results were as follows; first, this study considered the somatotype distribution of male college students. The results showed that inverted triangle -shaped torso was the ideal somatotype in all the classified four actual somatotypes. Second, people in standard body types significantly considered price and appearance such as design, color, pattern and price while people in triangle-shaped torso placed the most importance in the practicality and wearability. People with inverted triangle-shaped torso was found to significantly consider the perceptual quality such as brand, a/s and fashion. Third, this study considered the wearing satisfaction of ready-to-wear. The respondents placed more emphasis on the practicality and wearability as their actual somatotypes were not ideal for them. Fourth, the examination of the difference in size fitness depending on clothing by somatotype when wearing ready-to-wear showed that breast on the top was small when wearing it in the remaining somatotypes except for standard somatotype. The upper body showed better size fitness in triangle-shaped torso. There is a difference in fitness according to somatotypes classified by the form factors even though they have the same body mass index.

Variations and Trends in Concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in Air (대기 중 다환방향족 탄화수소류의 오염도 변화 특성)

  • Chung, Yong;Park, Seong-Eun;Hwang, Man-Sik;Hong, Ji-Yeon
    • Environmental Analysis Health and Toxicology
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    • v.13 no.1_2
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    • pp.43-53
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    • 1998
  • Ambient air levels of polycyclic aromatic hydrocarbons(PAHs) are of concern because of their potential for adverse health effects including transformation of some of these substances to mutagens and carcinogens by mammalian microsomal enzyme system. Airbone particulate samples were collected by a conventional high-volume sampler and by an Anderson cascade impactor on 2 to 3 days in each month over a period of 1 year at a representative site of the heavy traffic area of Seoul from beptember 1994 to August 1995. Ten individual PAHs in sizable air particulates of each stage of two months were separated and analyzed by gas chromatography/mass spectrometry. As a results of analysis, the gross concentrations of PAHs in the fine and coarse particles were higher in the winter month than in the spring, followed in descending order by in the fall and summer. In a study of dependency of 10 PAHs compounds on size distribution of particles at heavy traffic area found that about 85% of the total PAHs content was associated with particles less than 2.0um (fine particles) in diameter of winter sampling period. while 79% were associated with this size fraction during summer period. In according to the mean concentrations of the 10 PAHs in 7 size classification from < 0.38 to> 10.1, the 'size was the smaller, PAHs concentration was the higher. Thus it was found that PAHs concentration was greatly affected by air particle size. Annual mean benzo(a)pyrene equivalents was 5.88ng/m$^3$ and obtained by applying, toxic equivalency factor developed by Nisbet and Lagoy.

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