• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.1-6
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• 2015

Transmission of a tracked vehicle designed for multiple functions such as steering, gear-shifting, and braking is a core component of heavy vehicle to which the power is transferred based on combined technology of various gears, bearing, and fluid machineries. Robustness and durability of transmission, however, have been issued due to a large number of driving units and sub-components inside its body. The bevel gears are major components for the transmission of power in a transmission. Increasing the tooth surface roughness and chamfering of the bevel gears, especially, we aim to improve the quality of transmission. In this study, design structural evaluation is conducted on bevel gears of transmission for tracked vehicle using the ROMAX-DESIGNER program. By doing so, design safety of the bevel gears has been evaluated based on the gear strength theory of ANSI/AGMA 2003 B97 standard.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.598-605
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• 2001

The study that has been conducted is the consideration of the durability of dye, antibacterial activity, and deodorizing effects of cotton and silk textiles dyed with a botanical dying material that has been used in various ways over the years as Korean diet and folk remedies, the pomegranate. 1. The results of the K/S value of dying according to the types of mordants of textiles dyed with pomegranate extract the following have been discovered: The increase of K/S value of dying of the silk textiles appear to be higher than that of the cotton textiles. Next, silk textiles that have been treated with FeSO$_4$.7$H_2O$ appear to be at the highest. 2. The results of the color change measurement show a difference of color can be noticed according to the types of mordant. As opposed to those textiles that had been only scured textiles, all of the dyed textiles appeared to turn yellow. 3. Textiles that had been treated with $K_2$Cr$_2$O(sub)7 recorded the highest durability according to the colorfastness to light results. In the case of the cotton textiles colorfastness to washing, all appeared to show exceptional results of 3rd class or higher, excluding the textiles that had been treated FeSO$_4$.7$H_2O$. However silk textiles recorded relatively low classes of below 3rd to 4th class. For the colorfastness to washing of pollution, the results for both the cotton and silk textiles were excellent at class 4-5. The results of colorfastness to perspiration, colorfastness to rubbing, and colorfastness to dry cleaning showed comparatively exceptional results of 3rd to 4th class or higher when it came to dyed textiles. 4. According to the measurements of antibiosis, dyed textiles that had been treated with SnCl$_2$.2$H_2O$ appeared to show an exceptional bacterium decrease of approximately 70%. 5. According to the deodorizing measurements, dyed silk textiles appeared to have a higher deodorizing effect than cotton textiles. As for cotton textiles, those that had been treated with FeSO$_4$.7$H_2O$ and in the case of dyed silk textiles those that had been treated SnCl$_2$.2$H_2O$ recorded the highest deodorizing effect.

• Journal of Chest Surgery
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• v.45 no.6
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• pp.390-395
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• 2012

Background: Conventional open repair is a suboptimal therapy for blunt traumatic aortic injury (BTAI) due to the high postoperative mortality and morbidity rates. Recent advances in the thoracic endovascular repair technique may improve outcomes so that it becomes an attractive therapeutic option. Materials and Methods: From August 2003 to March 2012, 21 patients (mean age, 45.81 years) with BTAI were admitted to our institution. Of these, 18 cases (open repair in 11 patients and endovascular repair in 7 patients) were retrospectively reviewed and the early perioperative results of the two groups were compared. Results: Although not statistically significant, there was a trend toward the reduction of mortality in the endovascular repair group (18.2% vs. 0%). There were no cases of paraplegia or endoleak. Statistically significant reductions in heparin dosage, blood loss, and transfusion amounts during the operations and in procedure duration were observed. Conclusion: Compared with open repair, endovascular repair can be performed with favorable mortality and morbidity rates. However, relatively younger patients who have acute aortic arch angulation and a small aortic diameter may be a therapeutic challenge. Improvements in graft design, delivery sheaths, and graft durability are the cornerstone of successful endovascular repair.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.41-50
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• 2000

Cement-bonded particleboard is being used as outdoor siding material all over the world, because this composite particularly bears a light weight, high resistance against fire, decay, and crack by cyclic freezing and thawing, anti-shock property, and strength enhancement. Construction systems are currently changing into a frame-building style and wooden houses are being constructed with prefabrication type. Therefore, they require a more durability at outdoor-exposed sides. In this study, the cement hydration property for Korean pine particle, Japanese larch particle and face- and middle layer particles (designated as PB particle below) used in Korean particleboard-manufacturing company was investigated, and the rapid manufacturing characteristics of cement-bonded particleboard by supercritical $CO_2$ curing was evaluated. Korean pine flour showed a good hydration property, however, larch flour showed a bad one. PB particle had a better hydration property than larch flour. The addition of $Na_2SiO_3$ indicated a negative effect on hydration, however, $MgCl_2$ had a positive one. Curing by supercritical $CO_2$ fluid gave a conspicuous enhancement in the performances of cement-bonded particleboards compared to conventional curing. $MgCl_2$ 3%-added PB particle had the highest properties, and $MgCl_2$ 1%-added Korean pine particle had the second class with the conditions of cement/wood ratio of 2.7, a small fraction-screened particle and supercritical curing. On the contrary, the composition of non-hammermilled or large fraction-screened particle at cement/wood ratio of 2.2 was poorer. Also, the feasibility for actual use of 3%-added, small PB particle-screened fraction was greatest of all the conventional curing treatments. Relative superiority of supercritical curing vs. conventional curing at dimensional stability was not so apparent as in strength properties. Through the thermogravimetric analysis, it was ascertained that the peak of a component $CaCO_3$ was highest, and the two weak peaks of calcium silicate hydrate and ettringite and $Ca(OH)_2$ were present in supercritical treatment. Accordingly, it was inferred that the increased formation of carbonates in board contributes to strength enhancement.