• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.38-41
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• 2001

The combustion characteristics of the disilicides molybdenum system have been studied experimentally. The pertinent reaction parameters that control self-propagating high temperature synthesis reactions have been examined. These include reactant particle size, powder mixing and compaction, reaction stoichiometry, diluents. The influence of experimental variables on integrity, uniformity, structure, and related material properties will be discussed. Formation mechanism of $MoSi_2$ during SHS might be different and depending on experimental conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.38-41
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• 2001

The combustion characteristics of the disilicides molybdenum system have been studied experimentally. The pertinent reaction parameters that control self-propagating high temperature synthesis reactions have been examined. These include reactant particle size, powder mixing and compaction, reaction stoichiometry, diluents. The inf1uence of experimental variables on integrity, uniformity, structure, and related material properties will be discussed. Formation mechanism of MoSi$_2$ during SHS might be different and depending on experimental conditions.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.231-238
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• 2006

The physical properties of seven perlites different in particle size distribution were investigated to develop perlite bag culture in Korea. Particle sizes of 1.0-2.8mm and larger than 2.8 mm were rather evenly distributed in S-1 (1.2-5 mm), S-2 (0.15-5 mm) and S-5 (parat No.1). Larger particles were less in S-3 (1-3 mm), S-4 (Parat No.2), S-6 (OTAVI) and S-7 (Agroperl B-3). S-4, S-6 and S-7 contained lots of particles less than 1 mm in size. Total porosity was similar among substrates with the value of $59{\sim}62%$. Container capacity was between 35-40% regardless of substrates except in S-2 with 27.7%. Water content, which was about 60% at 0 kPa, was decreased sharply at 4.90 kPa regardless of substrates, which meant the easily available water was plenty in any kind of perlite tested. Substrates, S-1, S-2 and S-3 with different particle size distribution, were investigated to evaluate for perlite bag culture. Six tomatoes (Licopersicon esculentum Mill. cv. Rokkusanmaru) were planted in a perlite bag of 40 liters with the dimension of 120cm in length and 34cm in width. The amount of nutrient solution supplied and its drainage dependent on daily integrated radiation didn't show any regular trend during the growth. Roots in the bag were distributed evenly in S-1 and S-2 than in S-3. Plant grown in S-1 showed the highest total and marketable yield of 8,628 and 7,759 kg/10a, respectively. The number of small size fruits and malformed fruits were more in S-3. Consequently, S-1 with the particle size distribution of 1.2-5 mm is suggested as desirable substrate for perlite bag culture.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.5
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• pp.471-479
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• 2006

Automatic transfer equipments of manufacturing and process line trend toward big size as LCD glass is big size, heavy weight. The conventional stocker uses rotational motor and mechanical power converter device as travel axis of stocker crane and then frequent maintenances by complex structure and mechanical friction are required. Also it has problem to minimize the particle generation. To solve these problems, this paper verified the performance of permanent magnet(PM) excited transverse flux linear motor(TFLM) that is big power density per unit volume applied for travel axis of 7 generation stocker that is being big size, high power, long distance by the experiment based on proposed control algorithm, controller and power converter device.

• Journal of Powder Materials
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• v.26 no.6
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• pp.502-507
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• 2019

Macro-porous carbon foams are fabricated using cured spherical phenolic resin particles as a matrix and furfuryl alcohol as a binder through a simple casting molding. Different sizes of the phenolic resin particles from 100-450 ㎛ are used to control the pore size and structure. Ethylene glycol is additionally added as a pore-forming agent and oxalic acid is used as an initiator for polymerization of furfuryl alcohol. The polymerization is performed in two steps; at 80℃ and 200℃ in an ambient atmosphere. The carbonization of the cured body is performed under Nitrogen gas flow (0.8 L/min) at 800℃ for 1 h. Shrinkage rate and residual carbon content are measured by size and weight change after carbonization. The pore structures are observed by both electron and optical microscope and compared with the porosity results achieved by the Archimedes method. The porosity is similar regardless of the size of the phenolic resin particles. On the other hand, the pore size increases in proportion to the phenol resin size, which indicates that the pore structure can be controlled by changing the raw material particle size.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.461-462
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• 2008

$BaMgAl_{10}O_{17}$:Mn, $Eu^{2+}$ green phosphors has been synthesized by the solid state reaction. Green phosphors of nano-size were manufactured in short time by shake method. which were easily manufactured respectively general method. Green phosphors of nano size were control additive, size of $ZrO_3$ ball, shake time and weight of ball in toluene. In result that green phosphors were obtained particle size of 140nm~150nm. The characteristics of fired samples were obtained by 365nm and 380nm excitation source under ultraviolet. In result that the highest PL intensity were observed in wavelength of 365nm.

• Journal of Powder Materials
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• v.30 no.4
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• pp.297-304
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• 2023

Iron oxide (Fe₂O₃) nanoclusters exhibit significant potential in the biomedical and pharmaceutical fields due to their strong magnetic properties, stability in solutions, and compatibility with living systems. They excel in magnetic separation processes, displaying high responsiveness to external magnetic fields. In contrast to conventional Fe2O3 nanoparticles that can aggregate in aqueous solutions due to their ferrimagnetic properties, these nanoclusters, composed of multiple nanoparticles, maintain their magnetic traits even when scaled to hundreds of nanometers. In this study, we develop a simple method using solvothermal synthesis to precisely control the size of nanoclusters. By adjusting precursor materials and reducing agents, we successfully control the particle sizes within the range of 90 to 420 nm. Our study not only enhances the understanding of nanocluster creation but also offers ways to improve their properties for applications such as magnetic separation. This is supported by our experimental results highlighting their size-dependent magnetic response in water. This study has the potential to advance both the knowledge and practical utilization of Fe₂O₃ nanoclusters in various applications.

• Journal of Environmental Science International
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• v.8 no.2
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• pp.183-187
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• 1999

The purpose of this study is providing basic data to control the air pollutants from solid waste incinerator. Incinerating the waste wood, the electrostatic precipitator had the best collection efficiency. The leather incineration had the same collection efficiency as synthetic resin incineration. And the coarse particle collection efficiency was high. As you know in correlation of leather incineration. pollutants produced a from incinerator are mostly fine particles. If the scrubber used only in the process produced a lot of fine particles. It is adequate to use the above control devices, together with high efficiency collector like bag-filter. To select the adequate control devices, it is required to investigate the size distribution before establishing control devices.

• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.47-56
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• 1997

This paper presents the vibration control of an engine mount featuring an ER(electro-rheological) fluid. The Bingham properties of the ER fluid to be employed to the ER engine mount are experimentally obtained through Coeutte type viscometer. The ER engine mount is devised ant its governing equation is derived. After evaluating the performance of the ER engine mount on the basis of the mathematical model, the novel type of the ER engine mount is then designed and manufactured. The electric field-dependent transmissibility of the ER engine mount is evaluated by changing the particle concentration and the electrode gap size. To investigate the control performance of the ER engine mount, neuro-control algorithm is adopted. It is shown that the proposed ER engine mount has prominent capabilities of controlling the damping force by tuning the electric fields and excellent vibration isolation performance.

• Asian Journal of Atmospheric Environment
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• v.8 no.2
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• pp.89-95
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• 2014

There have been a lot of efforts to keep permissible emission standards and to reduce the amount of emitted air pollutants. There are several air pollution control equipments, however, wet scrubber is used to remove particulate matters and gaseous pollutants simultaneously, even if it has low collection efficiency in the particle size less than $5.0{\mu}m$. To overcome this problem, we introduced a spray tower scrubber with an electrospray system which a high voltage was indirectly applied. We found that collection efficiency of fine particles in the electrospray system was improved by increasing electrical field strength and the ratio of liquid-gas flow rate (from 41% to 84% for $0.3{\mu}m$ particles). In addition, a number of small droplets generated from an electrospray system led high collection efficiency, resulting from electrostatic attraction between droplets and particles and higher collision frequency. Therefore, we can conclude that the introduction of an electrospray system is quite effective to increase the particle removal efficiency of a spray tower scrubber.