• Resources Recycling
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• v.9 no.5
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• pp.22-27
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• 2000

Iron oxide produced form the pickling process at the cold rolling mill in iron & steelmaking industry, use for raw material of electronic an colorant product. Recently, decreasing of the chlorine content in iron oxide is demanded at the market. In this study, under the field test of the spray roaster and the screw conveyer for dechlorination, the experiments of the chlorine content in iron oxide were investigated. From the results of experiment, the chlorine content in iron oxide can be reduced to 1,100 ppm from the spray roaster and, 383 ppm from the screw conveyer.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.225-230
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• 2004

A cold ＆ hot rolling coil production line of iron nill consists of a kind of coherent automatic process, but an automatic labelling process still had technical difficulties in the automation of its process. The reason for difficulties in building an automatic process is that quantitative data for each rolled coil from every shipping is not easy to receive from the previous process. it is not possible to apply for a general and simple purpose robot that is actually worked through a taught position to the process because the size and direction of the coi1 has differed on every shipping. From these reasons. we introduce a robot vision system to accept an expected variable situation and to ensure the stability and flexibility of the process. This paper examines a study applied for similar cases and finds the position and direction of relied coil using the moment invariant algorithm proposed by Hu. In addition. the camera calibration and position error compensation algorithm is applied by the analysis of the relationship of transition in a space coordinate system. The construction of a robot vision system proposed by this paper is a more intellectual system than that of the automatic labelling system. which is already used to the Daihen steel nill of NEW JAPAN steel mill co. Ltd in Japan, and shows a better independent operation in the field of production.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.305-310
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• 2012

Planetary gear box is a power transmitter having very high gear ratio in compact volume. The planetary step-down gear box converts high speed and low torque into low speed and high torque, which is widely used in constructional and industrial machinery field. And, the planetary step-up gear box does vice versa working, which is used as main gear box of large sized wind mill system. The large sized planetary gear box must be performed the normal-opposite rotation test as a its durability test for achieving the reliability. The large sized planetary gear box is composed by triple gear trains of sun gear, carrier, and ring gear. If input power is supplied into one of them and the other is fixed, and then another becomes the output part. In this paper, we designed a new test equipment which can do rapid normal and opposite rotational change with only small displacement by supplying test power using the above rotation (driving) characteristics and hydraulic cylinder and link, and also compared and analyzed with existing method through various experiments.

• Journal of Technologic Dentistry
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• v.25 no.1
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• pp.21-28
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• 2003

The purpose of this study was to process bio-active glass ceramic composite, reinforced with sapphire fibers, by hot press. Also to study the interface of the matrix and the sapphire fiber, and the mechanical properties. Glass raw materials melted in Pt crucible at 1300$^{\circ}C$ during 3.5 hours. The melt was crushed in ball mill and then crushed material, ground and sieved to $<40{\beta}{\mu}m$. Sapphire fibers cut (30mm) and aligned. Powder and fibers hot pressed. The micrographs show good bonding between the matrix and the fiber and no porosity in the glass matrix. This means ideal fracture phenomena. Glass is fractured before the fiber. This is indication of good fracture strength. EDXS showing aluminum rich phase and crystalline phase. Bright field image of the matrix showing crystalline phase. Also diffraction pattern of TEM showing the crystalline phase and more than one phase. Strength of the samples was determined by 3 point bend testing. Strength of the 10vol% sample was approximately 69MPa, while strength of the control sample is 35MPa. Conclusions through this study as follow: 1. Micrographs show no porosity in the glass matrix and the interface. 2. The interface between the fiber and the glass matrix show no gaps. 3. Fracture of the glass indicates characteristic fiber-matrix separation. 4. Presence of crystalline phase at high processing temperature. 5. Sapphire is compatible with bioactive glass.

• Korean Journal of Materials Research
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• v.27 no.2
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• pp.82-88
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• 2017

Ink-jet printing techniques with ceramic ink, which contains ceramic pigments as colorant, are in increasingly use in the ceramic industry. Generally, ceramic pigments that are produced by conventional method show diameters of several micrometers; these micrometer sized particles in the ink-jet printing process can cause undesirable behavior such as print head nozzle clogging. To prevent this problem, a particle size reduction process is required. In this study, CMYK (cyan, magenta, yellow, black) pigments were synthesized via solid state method. Each pigment particle was milled to submicron size by an attrition mill. The effects of micronizing on the morphology, mechanical property, crystal structure and color property of the CMYK ceramic pigments were investigated by field emission scanning electron microscopy (FE-SEM), particle size analysis (PSA), X-ray diffraction (XRD) and CIE $L^{\ast}a^{\ast}b^{\ast}$.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.254-259
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• 1993

For the production of mycoplasma-free jujube trees from mycoplasma-infected trees in vitro micrografting visas carried out using apical meristems of in vitro grown plantlets as scions. The rootstocks were hypocotyl segments of in vitro germinated seedlings of Zizyphus jujuba Mill. which is widely used as rootstocks in the field grafting. Ten percent of scions showed normal growth and grew into plants. The presence of mycoplasma was tested using transmission electron microscopy and fluorescence microscopy. Mycoplasma was not found in the tissues of scion parts and seedlings, whereas it was found in in vitro grown plantlets. This suggests that the production of mycoplasmaa-free jujube trees is possible by the in vitro micrografting technique.

• Agricultural and Biosystems Engineering
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• v.6 no.2
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• pp.65-69
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• 2005

A windheat generation system with a Savonius windturbine was developed and the performance was evaluated through field tests. The system consisted of a heat generation drum, heat exchanger, water storage tank, and two circulation pumps. Frictional heat is created by rotation of a rotor inside the drum containing thermo oil, and was used to heat water. In order to estimate the capacity of this windheat generation system, weather data was collected for one year at the site near the windheat generation system. Wind Power from the savonius wind turbine mill was transmitted to the heat generation system with an one-to-three gear system. Starting force to rotate the savonius wind turbine and the whole system including the windheat generation system were 1.0 and 2.5 kg, respectively. Under the outdoor wind condition, maximum speed of the rotor in the drum was 75rpm at wind speed 6.5 m/sec, which was not fast enough to produce heat for greenhouse heating. Annual cumulative hours for wind speeds greater than 5 m/sec at height of 10, 20, 30 m were 190, 300 and 1020 hrs, respectively. A $5^{\circ}C$ increase in water temperature was achieved by the windheat generation system under the tested wind environment.

• Journal of the Korean Society of Food Culture
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• v.30 no.5
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• pp.502-544
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• 2015

This study researched a document regarding 'Pyeon (tteok)' on 25 Jong-ga ancestral ritual foods through "Jong-ga Ancestral ritual formalities and food", published during 2003~2008 by the National Research Institute of Cultural Heritage of Cultural Heritage Administration. A after about 10 years, the transmission process of the setting and recipe was compared and analyzed in 2015 by directly visiting 4 Jong-ga. This research classified regions into 7 Gyeonggi, 4 Chungcheong, 2 Honam, and 12 Yeongnam, and classified hakpa, Gyeonggi, Chungcheong, Honam region into 13 Gihohakpa, Yeongnam region into 12 Yeongnamhakpa. The important analysis standard of Jong-ga ancestral ritual food was the region and hakpa, which appeared to considerably influence 'Pyeon' setting style, which represents and symbolizes family and recipe. Gihohakpa Jong-ga, which is an academic tradition that pursues practical interests, seems to highly regard practicality to adapt to changes along with the period. On the contrary, Yeongnamhakpa Jong-ga, which highly regards self-sufficiency living base and moral justification, seems to be highly conservative. Increase in Jong-ga, which utilizes mill, is the result of adaptation to the period environment such as Jongbu aging and lack of labor, etc.

• Journal of the Korean Ceramic Society
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• v.38 no.12
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• pp.1110-1114
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• 2001

We report the mechanochemical effect of an Fe(NO$_3$)$_3$$.$9H$_2$O-Al(OH)$_3$sample as catalytic precursor mixed-ground by mixer mill on the growth of carbon nanotubes using thermal chemical vapor deposition method. From and TEM observations, carbon products grown on a ground catalyst were more uniform than those grown on an unground catalyst and most of them were identified as carbon nanobubes. Also, it was observed that field emission properties of products on ground catalyst were superior to those of unground catalyst.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.53-53
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• 2008

Piezoelectric transformers have been widely used such as DC-DC convertor, invertor, Ballast, etc. Because, the y have some merits compared with electro-magnetic transformers such as step-up ratio, high efficiency, small size and lg hit weight, etc. Piezoelectric transformer require high electromechanical coupling factor kp in order to induce a large out put power in proportional to applied electric field. And also, high mechanical quality factor Qm is required to prevent mechanical loss and heat generation. In general, PZT system ceramics should be sintered at high temperatures between 1200 and $1300^{\circ}C$ in order to obtain complete densification. Accordingly, environmental pollution due to its PbO evaporation. Hence, to reduce its sintering temperature, various kinds of material processing methods such as hot pressing, high energy mill, liquid phase sintering, and using ultra fine powder have been performed. Among these methods, liquid phase sintering is basically an effective method for aiding densification at low temperature. In this study, In order to comparis on low temperature sintering and solid state sintering piezoelectric transformers, rosen type transformers were fabricated u sing two PZT ceramics compositions and their electrical properties were investigated.