• Journal of Biosystems Engineering
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• v.31 no.5 s.118
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• pp.389-394
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• 2006

The characteristic of moisture absorption of granular fertilizer was measured at several different opening sizes on the top cover of a hopper in a humid weather. The size of the opening was to represent the degree of looseness of sealing of the top cover of the hopper. The application distribution was characterized by the scattering distance of granular fertilizer with different degree of moisture absorption in a pneumatic granular fertilizer applicator. The moisture absorption rates were 12.92 and 12.26 mg of moisture an hour for one gram of each granular fertilizers of NPK 22-12-12 and 21-17-17, respectively. The moisture absorption increased linearly as the opening size increased. The median value of the scattering distance distribution decreased with time of absorption, however, it decreased very slowly after three hours of absorption.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.367-373
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• 2020

Most of the spatial scattered dose caused by the scattered rays generated by the collision between the object and X-rays is relatively easily absorbed by the human body as electromagnetic waves in the low energy region, thereby increasing the degree of radiation exposure. Such spatial scattering dose is also used as an indicator of the degree of radiation exposure of radiation workers and patients, and there is a need for a method to reduce exposure by reducing the spatial scattered dose that occurs indirectly. Therefore, in this study, a lead-free radiation shielding sheet was proposed as a way to reduce the spatial scattering dose, and a Monte Carlo (MC) simulation was performed based on a chest X-ray examination. The absorbed dose was calculated and the measured value and the shielding rate were compared and evaluated.

• Journal of radiological science and technology
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• v.4 no.1
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• pp.63-71
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• 1981

The metal-plates(Aluminium. Copper, Lead) of change the variation thickness have been penetrated by the collimated beam($450mm{\times}4mm{\phi}$) of Gamma-ray from $^{192}Ir$. Then, the scattered $\gamma$-ray dose in variable angle and the directly transmitted $\gamma$-ray dose were measured using the electrometer of ionization chamber. The results were summarized as follows: 1. Obtained the mass attenuation coefficients of $Al;0.0937cm^2g^{-1},\;Cu;0.0937cm^2g^{-1},\;pb;0.244cm^2g^{-1}$. 2. Total intensity of front scattered $\gamma$-ray follow the order of Al>Cu>pb. 3. The scattered $\gamma$-ray intensity with the lager angle of scattering was saturated after increase rapidly, and the scattering angle of the more larger was decreased. 4. The scattered $\gamma$-ray intensity through plates of aluminium or copper was saturated after increase with thicker scatterer, and the intensity was decreased at the more thicker. But the variation of scattered $\gamma$-ray dose in the lead plate made the fewest than Al and Cu. 5. The ratio of the scattered $\gamma$-ray dose and the directly transmitted $\gamma$-ray dose was saturated after increase with the thicker scatterer, and the scatterer of the more thicker was decreased. Degree of total intensity in these ratios was followed the order of Cu>Al>Pb.

• Journal of Korean Society of Forest Science
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• v.57 no.1
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• pp.14-19
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• 1982

Fines in high-yield sulfite pulp have much higher water retention value as compared with fines in Stone groundwood pulp. Therefore, they are apt to adhere partially or entirely onto the fiber surface during the paper making. This tendency is greatly enhance with decrease of the pretreated yield and increase of the water retention value of fines. Fines, which adhere onto the fiber surface in paper, contribute to the light scattering of the paper. Accordingly, the specific scattering coefficient of fines in high-yield sulfite pulp is considerably lower than that of fines in stone groundwood pulp, which hardly adhere onto the fiber surface. The fact that high-yield sulfite pulp is inferior to stone groundwood pulp in opacity is explained on the basis of the high degree of swelling of fined in addition to the softening of fiber fraction.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.33.2-34
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• 2016

The unification model of active galactic nuclei invokes the presence of a thick molecular torus that hides the broad emission line region from a line of sight toward observers with low latitude. It is expected that the illuminated side of the molecular torus may be photodissociated by strong far UV radiation from the central AGN, forming an H I region with a high neutral column density. We propose that the Rayleigh scattering optical depth of this HI region can be significant for most broad $Ly{\alpha}$ line photons with the Doppler factor not exceeding 104 km s-1. Rayleigh scattered $Ly{\alpha}$ photons can be characterized by strong linear polarization depending on their scattering optical depth. We performed Monte Carlo simulations of polarized radiative transfer of $Ly{\alpha}$ adopting simple scattering geometries relevant to the unification model of AGN. We find that for a low torus the Rayleigh scattered $Ly{\alpha}$ is polarized in the direction parallel to the symmetry axis with the polarization degree dependent on wavelength. In the case of a high torus, the core part of $Ly{\alpha}$ is polarized in the direction perpendicular to the symmetry axis whereas the wing part is parallelly polarized. We conclude that careful spectropolarimetry around $Ly{\alpha}$ can be useful in testing the AGN unification model.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.4
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• pp.581-586
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• 1998

We investigated the effect of mechanical back side damage in Czochralski grown silicon wafer. The intensity of mechanical damage was evaluated by minority carrier recombination lifetime by laser excitation/microwave reflection photoconductivity decay method, degree of X-ray diffuse scattering, X-ray section topography, and wet oxidation/preferential etching methods. The data indicate that the higher the mechanical damage intensity, the lower the minority carrier lifetime, and the magnitude of diffuse scattering and X-ray excess intensity increased proportionally, and it was at Grade 1:Grade 2:Grade 3=1:7:18.4 that the normalized relative quantization ratio of excess intensity in damaged wafer was calculated, which are normalized to the excess intensity from sample Grade 1.

• Journal of Mechanical Science and Technology
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• v.15 no.9
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• pp.1311-1318
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• 2001

It is necessary to diagnose accurately the characteristics of soot formation and oxidation in a diesel engine. Whereas past measurement techniques for soot concentration give limited information for soot, laser-based two-dimensional imaging diagnostics have a potential to provide temporally and spatially superior resolved measurements of the soot distribution. The technique using laser sheet beam has been applied to an optically accessible diesel engine for the quantitative measurement of soot. The results provided the information for reduction of soot from the diesel engine. Both LIS (Laser Induced Scattering) and LII (Laser Induced Incandescence) techniques were used simultaneously in this study. The images of LIS and LII showed the quantitative distribution of the soot concentration in the diesel engine. In this study, several results were obtained by the simultaneous measurements of LIS and LII technique. The diameter and number density of soot in combustion chamber of the test engine were obtained from ATDC 20 degree to 110 degree. The soot diameter increased about 37% between ATDC 20 degree and 110 degree. The number density of soot, however, decreased significantly between ATDC 40 degree and 70 degree.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.8
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• pp.1191-1199
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• 2003

This paper describes to observe the combustion process of only one droplet cluster. In this study, liquid fuel was atomized by ultrasonic wave to form an acoustically levitated droplet cluster. In order to elucidate the detailed structure of burning process of the droplet cluster, laser tomography method was applied. Time-series planar images of fuel droplets were processed and diameter of the each droplet was calculated based on the Mie-scattering theory. Using these data, the modified droplet group combustion number was estimated in time-series. As the result, when the internal droplet group combustion occur, the modified group combustion number dose not decrease monotonically, but show a tow-staged decreasing process. In all case of combustion process, combustion reactions were measured two types that combustion speed was fast and slow. It was casued by difference of concentration degree and droplet size distribution.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.666-670
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• 2006

It has been considered that scattered sounds have a positive effect on a hearing impression of a sound filed. This study investigates the degree and the quality of a scattered sound field by using the acoustical parameters and autocorrelation function(ACF) of impulse responses. The acoustical parameters and fine structure of the ACF of an impulse response were used for the evaluation of the scattered sound field. The relationship between the scattering coefficient of surfaces with various hemisphere diffuser configurations and the acoustical parameters and ACF parameters of impulse responses was investigated.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.94.1-94.1
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• 2013

Whistler mode chorus waves, which are observed outside the plasmasphere of the Earth's magnetosphere, play a major role in accelerating and scattering energetic electrons in the radiation belts. In this study we developed a predicting scheme of the global distribution of chorus by using the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellite data. First, we determined global spatial distributions of chorus activity, and identified fit functions that best represent chorus intensities in specific L-MLT zones. Second, we determined the specific dependence of average chorus intensity on preceding solar wind conditions (e.g., solar wind speed, IMF Bz, energy coupling degree) as well as preceding geomagnetic states (as represented by AE, for example). Finally, we combined these two results to develop the predicting functions for the global distribution and intensity of chorus. Implementing these results in the radiation belt models should improve the local acceleration effect by chorus waves.