• Title/Summary/Keyword: Size distributions

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A Study on Behavior of Heavy Metals during Waste Incineration (폐기물 소각시 중금속 성분의 거동에 관한 연구)

  • 박용이;허철구
    • Journal of Environmental Science International
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    • v.5 no.6
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    • pp.785-799
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    • 1996
  • The incineration tests of mixed industrial wastes using the stoker type incinerator are carried out to investigate the partitioning characteristics of heavy metals during incineration. The results obtained from this study are as follow. The partitioning characteristics of heavy metals throughout this incinerator are found that, at given condition of $700^{\circ}C$, the elements with the relatively high boiling point such as Cr, Cu and Pb are partitioned into a bottom ash, a fry ash captured tv cyclone, and a flue gas stream, 67~88%, 2~19% and 6~16% of initial amount entering the incinerator, respectively, but the Cd and Hg of 75~81% is vaporized into the flue gas. It appears that the partitioning characteristics according to the particle size of ash is different between the bottom ash and the fly ash. For bottom ash, the fraction of partitioning into 75${\mu}{\textrm}{m}$ oversized particles is reatively high. For fly ash, the characteristics of distributions with the particle size can not be clearly shown.

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Collection Efficiency of Nano Particles by Electrostatic Precipitator using Dielectric Barrier Discharge (배리어 유전체 방전을 이용한 전기 집진부에서의 나노 입자 집진 효율)

  • Kang, Suk-Hoon;Byeon, Jung-Hoon;Ji, Jun-Ho;Hwang, Jung-Ho
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1435-1440
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    • 2003
  • Although Dielectric Barrier Discharge (DBD) in air has been applied to a wider range of aftertreatment processes for HAPs(Hazardous Air Pollutants), due to its high electron density and energy, its potential use as precharging dust particles is not well known. In this work, we measured size distributions of bimodal aerosol particles and estimated collection efficiency of the particles by electrostatic precipitator(ESP) using DBD as particle charger. To examine the particle collection with DBD charger, nano size particles of NaCl($20{\sim}100$ nm) and DOS($50{\sim}800$ nm) were generated by tube furnace and atomizer, respectively. For experimental conditions of 60 Hz, 11 kV, and 60 lpm, the particle collection efficiency for the hybrid system comprising DBD charger and ESP was over 85 %, based on the number of particles captured.

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Measurements of Droplet Sizes and Velocities with Optimum Probability Density Function in a Transient Liquefied Butane Spray (액상부탄 간헐분무의 액적 크기 및 속도 측정과 최적 확률분포 연구)

  • Kim, J.H.;Kim, J.W.;Koo, J.Y.
    • Journal of ILASS-Korea
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    • v.5 no.1
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    • pp.30-40
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    • 2000
  • The characteristics of liquefied butane spray are expected to be different from conventional diesel fuel spray, because a kind of flash boiling spray is expected when the back pressure is below the saturated vapor pressure of the butane(0.23MPa at 298K). The ambient pressure was held at a pressure above(0.37MPa) and below(0.15MPa) the fuel vapor pressure. The axial velocities, radial velocities, and size distributions in butane sprays were measured with PDPA(Phase Doppler Particle Analyzer) system. The PDPA measurement showed a smaller SMD at the 0.15MPa chamber pressure, compared to the 0.37MPa case. Log-hyperbolic density function for the droplets size distribution can be fitted to the experimental results of a liquefied butane spray.

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Automatic Extraction of Particle Streaks for 3D Flow Measurement

  • Kawasue, Kikuhito;Ohya, Yuichiro
    • 제어로봇시스템학회:학술대회논문집
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    • 1999.10a
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    • pp.270-273
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    • 1999
  • Circular dynamic stereo has special advantages as it enables a 3-D measurement using a single TV camera and also enables a high accurate measurement without a cumbersome calibration. Annular particle streaks are recorded using this system and the size of annular streaks directly concerns to the depth from TV camera. That is, the size of annular streaks is inversely proportional to the depth from the TV camera and the depth can be measured automatically by image processing technique. Overlapped streaks can be processed also by our method. The flow measurement in a water tank is one of the applications of our system. Tracer particles are introduced into the water in a flow measurement. Since the tracer particles flow with water, three-dimensional velocity distributions in the water tank can be obtained by measuring the all movement of tracer particles. Experimental results demonstrate the feasibility of our method.

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Preparation of Microporous Glasses by the Phase-Separation Technique and Their Salt-Rejection Characteristics (상분리법에 의한 다공질유리의 제조 및 탈염특성)

  • 현상훈;김계태
    • Journal of the Korean Ceramic Society
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    • v.23 no.5
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    • pp.93-101
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    • 1986
  • Microporous glasses were prepared from the 50 $SiO_2-44$ $B_2O_3-6$ $Na_2O$(wt%) parent glass by the phase eparation technique and were characterized by SEM, BET, and Gas Adsorption methods to investigate the possiblity of their use as salt-rejection membranes for reverse osmosis. The conditions of the phase separation for the possible glass membranes were optimized for the given parent glass. The temperature and duration of heat-treatment were desired to be lower(853K) and shorter (1/2~1 hr) respectively. The specific surface areas of porous glasses prepared in this study were about 80~120$m^2$/g and their pore size distribution had a unimodal shape(peak pore radius less than 15$\AA$) It was suggested that the porous glass obtained in this work could be effective for salt-rejection in point of pore size distributions but the way to increase its surface area for the high flux must be studied.

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A four-variable plate theory for thermal vibration of embedded FG nanoplates under non-uniform temperature distributions with different boundary conditions

  • Barati, Mohammad Reza;Shahverdi, Hossein
    • Structural Engineering and Mechanics
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    • v.60 no.4
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    • pp.707-727
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    • 2016
  • In this paper, thermal vibration of a nonlocal functionally graded (FG) plates with arbitrary boundary conditions under linear and non-linear temperature fields is explored by developing a refined shear deformation plate theory with an inverse cotangential function in which shear deformation effect was involved without the need for shear correction factors. The material properties of FG nanoplate are considered to be temperature-dependent and graded in the thickness direction according to the Mori-Tanaka model. On the basis of non-classical higher order plate model and Eringen's nonlocal elasticity theory, the small size influence was captured. Numerical examples show the importance of non-uniform thermal loadings, boundary conditions, gradient index, nonlocal parameter and aspect and side-to-thickness ratio on vibrational responses of size-dependent FG nanoplates.

Empirical Statistical Power for Testing Multilocus Genotypic Effects under Unbalanced Designs Using a Gibbs Sampler

  • Lee, Chae-Young
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.11
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    • pp.1511-1514
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    • 2012
  • Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

Gasoline Spray Characteristics Impinging onto the Wall Surface in Suction Air Flow

  • Kim, Woo-Tae;Kang, Shin-Jae;Park, Byung-Joon
    • Journal of Mechanical Science and Technology
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    • v.14 no.12
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    • pp.1376-1385
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    • 2000
  • This study investigates spray characteristics before and after wall impingingment of gasoline spray in suction air flow. For this study, a rectangular model intake port was made of acrylic glass, and suction air was generated by using the forced air blower contrariwise. The injector for this study was a pintle-type port gasoline injector in which an air-assist adaptor is installed to supply assisted air. A PDPA system was employed to simultaneously measure the size and velocity of droplets near the wall. Measured droplets are divided into "pre-impinging droplets"with positive normal velocity and "post-impinging droplets"were negative normal velocity for the suction flow. The velocities, size distributions and Sauter mean diameter(SMD) of pre-and post-impinging droplets for varions injection angles and air-assists are comparatively analyzed.

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A Batch Arrival Queue with Bernoulli Vacation Schedule under Multiple Vacation Policy

  • Choudhury Gautam;Madan Kailash C.
    • Management Science and Financial Engineering
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    • v.12 no.2
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    • pp.1-18
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    • 2006
  • We consider an $M^x/G/1$ queueing system with Bernoulli vacation schedule under multiple vacation policy. where after each vacation completion or service completion the server takes sequence of vacations until a batch of new customer arrive. This generalizes both $M^x/G/1$ queueing system with multiple vacation as well as M/G/1 Bernoulli vacation model. We carryout an extensive analysis for the queue size distributions at various epochs. Further attempts have been made to unify the results of related batch arrival vacation models.

A Batch Arrival Queue with a Random Setup Time Under Bernoulli Vacation Schedule

  • Choudhury, Gautam;Tadj, Lotfi;Paul, Maduchanda
    • Management Science and Financial Engineering
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    • v.15 no.2
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    • pp.1-21
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    • 2009
  • We consider an $M^x/G/1$ queueing system with a random setup time under Bernoulli vacation schedule, where the service of the first unit at the completion of each busy period or a vacation period is preceded by a random setup time, on completion of which service starts. However, after each service completion, the server may take a vacation with probability p or remain in the system to provide next service, if any, with probability (1-p). This generalizes both the $M^x/G/1$ queueing system with a random setup time as well as the Bernoulli vacation model. We carryout an extensive analysis for the queue size distributions at various epochs. Further, attempts have been made to unify the results of related batch arrival vacation models.