• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.19-23
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• 2001

The paper presents the development of separating system from the slash with solid and liquid. The materials of filter are used rice chaffs, which are widely found in the agricultural village. The performance of separator is experimentally shown through new developed measurement apparatus. The flow rates of the system are evaluated by changing the inlet pressure of slash, thickness of filter and size of particle concentration of rice chaffs. In this work the optimal design parameters can be obtained for the separator for solid and liquid. And in the results rice chaffs filter improve the performance of separator solid and liquid.

• Journal of ILASS-Korea
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• v.2 no.1
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• pp.46-51
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• 1997

In this study, spray characteristics of the pressure swirl atomizer have teen investigated. Four atomizers with the different orifice diameter and five tangential ports with the different inlet number were fabricated. For the purpose of the measurement of the mean drop sine, Malvern particle sizer was used. And also discharge coefficient was measured and spray cone angle was measured by using shadow graphy method. As a result when the injection pressure was increased, mean drop size was decreased. And the dominant factor which influence on the spray characteristics of pressure swirl atomizer was orifice diameter.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.481-484
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• 2006

The purpose of this study is to present the recycling method of reject-ash. The reject-ash, a significant portion of the pulverized fuel ash produced by coal-fired power plants and rejected from the ash classifying process, has remained unused due to its high carbon content and large particle size. This study compared reject-ash with fly-ash by physical properties, the properties of fresh & harden concrete with cement replacement ratio of reject-ash and fly-ash, 0, 5, 10, 15, 20, 25(wt. %). The loss of ignition of the reject-ash is similar to fly-ash and is suited to the KS L 5405. When the replacement ratio of reject-ash is increasing the air content of reject-ash concrete is lowly decreased. The results of the compressive strength measurement of reject-ash tends to decrease by increasing the replacement ratio.

• KIEAE Journal
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• v.7 no.4
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• pp.135-140
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• 2007

In this study we settled the trouble of the MgO board of existence by this research. We changed the wooden one of the main ingredient of a board to a perlite and a mineral particle in the aluminum hydroxide group and proceeded with a study to physical character and fire resistance efficiency improvement. The result yellowing phenomenon could be improved and it was possible to reduce size decrease of pin hole and the frequency of occurrence. We found out that the in case of absorbed amount added 5~8% corresponding to the weight decreases the acrylic group emulsion suddenly. So this product is improved with the bending strength and water-resistance. After behavior stop time measurement of a mouse for experiments was measured at the time of a gas harmful effect test, an improved MgO board appeared more highly for an average of 138 seconds compared with a board of existence.

• Journal of the Korean Ceramic Society
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• v.33 no.8
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• pp.863-870
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• 1996

Fabricated modified PZT system for pyroelectric IR sensor were analyzed and characterized for dielectric piezoelectric and pyroelectric properties. Particle size and distribution of source powders were controlled by attrition milling process. 0.05PSS+yPT+(0.95-y)PZ+0.4 wt%MnO2 system was fabricated and investigated sintering density crystal structure and micro-structure through sintering conditions sintering temperature and sintering atmosphere. The poled sintered system of y=0.11 showed the lowest dielectric constant. The dielectric constants were increased with increasing y-mole ratio. The pyroelectric properties of modified PZT systems which were assembled to TO-5 package were measured by IR measurement system average out-voltage of 0.05PSS+0.1PT+0.84PZ+ wt%MnO2 was 3V.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1697-1705
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• 1991

본 연구에서는 층류 확산화염내의 매연 분포에 관하여 좀 더 명확히 알아보고 자 화염의 높이방향 뿐만이 아니라 반경 방향으로도 매연을 열영동 포집하여 보았다. 한편, 화염 내에 삽입되는 Fig.1(a)와 같은 프로브에 매연 입자들이 열영동 현상에 의 하여 포집되려면 순간적인 돈도 구배가 필요하다. 따라서 화염내에서의 프로브 체류 시간을 조절할 수 있도록 Fig.1(b)와 같은 공압 장치(pneumatic device)를 만들어 실 험했다.

• Journal of the Korean Society of Visualization
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• v.10 no.3
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• pp.11-15
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• 2012

Inertial migration phenomena of phytoplankton in pipe flows were investigated using a digital holography technique. As the Reynolds number increases, the microorganisms suspended in a pipe flow are focused at a certain radial position which is called equilibrium position or pinch point. In this study, the effects of the size of microorganism and Reynolds number in the range of 1 < Re < 78 on the inertial migration were investigated and the results are compared with those for solid particles under similar experimental conditions. As a result, the equilibrium position for the elastic microorganisms is not so distinct, compared to the solid particles. This results from deformation of elastic body shape caused by shear-gradient of surrounding flow.

• Economic and Environmental Geology
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• v.20 no.3
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• pp.159-168
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• 1987

Some physico-chemical properties such as surface area, moisture content, cation exchange capacity, swelling rate, pH, viscosity and liquid limit have been determined for evaluation of Cabentonite deposit occurring in four localities; Yonil, Gampo, Haseo and Pohang, in Gyeongsang-do. Montmorillonite contents can be derived from surface area measurement. Enhancement of liquid limit values and swelling volume were observed in the samples which had higher exchangeable Na ion and finer particle-size distribution. Identical results were observed even in the Na-exchanged samples. This suggests that aggregation effects have a great influence on physico-chemical properties. Aggregation of montmorillonite were controlled not only burial depth but also composition of exchangeable cation. Consequently, sample occurred in Yonil area where has the greatest burial depth in the area show somewhat lower physico-chemical properties than those of samples occurred in the other localities. However, the basic test applied in this study provides very useful preliminary information relating to its commercial potential.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.48-53
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• 2010

Roadside measurement of ultrafine particles, black carbon, and NOx was carried out to investigate air pollution at a junction area contaminated with vehicle emissions in Seoul from March 19 to 23, 2007. Diurnal variation of ultrafine particles, black carbon, and $NO_x$ concentrations at a roadside showed minimum at around 2-4 a.m. and two peak modes during the morning and evening rush hours. Since these pollutants might be mainly emitted from vehicles, the roadside was highly contaminated with vehicles.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.531-533
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• 2000

In compared with air insulated switchgear, GIS has a high efficiency and confidence So the transformer substation can be reduced the size to 1/10. Insulation method using $SF_6$ gas has a very excellent insulation characteristics for high pressure equipment but has a characteristics that insulation heredity is changed for internal unequal electric field. So analysis of electromagnetic field in GIS is very important basic data for structure design and trouble diagnosis process. In compared with established method, SNM in this paper observes variation of the electromagnetic field with real time and get result very similar to measurement. In order to know the variation of electromagnetic field distribution for transient response for time and position, variations are observed when the spacer is bonded and metal particles are moving fast.