• Journal of Chest Surgery
• /
• v.24 no.8
• /
• pp.802-806
• /
• 1991

Primary neoplasms of the ribs and sternum are rare. Most primary bony chest wall neoplasms are malignant, and chondrosarcoma is the most common malignancy in this location The etiology of chondrosarcoma is unknown. Definitive diagnosis of chondrosarcoma can only be made pathologically. The natural history of chest wall chondrosarcoma is one of slow growth and local recurrence. Most tumors of the sternum require wide resection and reconstruction procedures, with potentially serious postoperative problems. Advances in chest wall reconstruction primarily through refinement in muscle transposition and clarification of the functional anatomy and blood supply of trunk muscles, has resulted in a more aggressive resection of the these tumors . Recently we experienced a case with chondrosarcoma of the sternum. A 56 year-old man was admitted to our hospital due to painless, slowly enlarging mass at the left sternoclavicular junctional area. The chest radiograph strongly suggested an underlying cartilaginous neoplasm owing to the appearance of typical flocculent and curvilinear calcifications within the lesion. On CT of the chest, the tumor exhibited a scalloped or lobulated contour, hypodensity of the nonmineralized component in comparison to adjacent muscle, and characteristic stippled cartilaginous matrix mineralization, also typical for cartilaginous neoplasm. The patient underwent wide resection of the chest wall tumor include with a 2-3cm margin of normal tissue on all sides and the thoracic skeletal defect was reconstructed with polytetrafluoroethylene [Gore-Tex] soft-tissue patch. Soft tissue reconstructive procedure was done with the pectoralis major muscle transposition. The patient had an uneventful postoperative course and discharged without adjuvant treatment such as radiation and chemotherapy.

• 한국초전도학회:학술대회논문집
• /
• v.10
• /
• pp.125-127
• /
• 2000

We report high pressure synthesis of Sr$_{0.9}$Sm$_{0.1}$CuO$_2$. Powder x-ray diffraction showed that the synthesized compounds have infinite layer structure as a major component. Slow heating at the first stage of heating processes after pressurization resulted in several larger grains. The largest grain was found to have the longest edge length of about 100 micrometer. Through magnetic property measurement in superconducting state, we found that pinning in this compound has substantial difference from that of La doped infinite layer, which has no unpaired spin at Sr site.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.1
• /
• pp.63.4-64
• /
• 2018

High resolution spectroscopy of the yellow symbiotic star AG Draconis is performed with the Canada-France-Hawaii Telescope to analyse the line profiles of Raman scattered O VI broad emission features at $6825{\AA}$ and $7082{\AA}$ with a view to investigating the wind accretion process from the mass losing giant to the white dwarf. These two spectral features are formed through inelastic scattering of O $VI{\lambda}{\lambda}32$ and 1038 with atomic hydrogen. We find that these features exhibit double-component profiles with red parts stronger than blue ones with the velocity separation of ~ 60 km s-1 in the O VI velocity space. Monte Carlo simulations for O VI line radiative transfer are performed by assuming that the O VI emission region constitutes a part of the accretion flow around the white dwarf and that Raman O VI features are formed in the neutral part of the slow stellar wind from the giant companion. The overall Raman O VI profiles are reasonably fit with an azimuthally asymmetric accretion flow and the mass loss rate ~ 4 ${\times}$ 10^{-7} M_sun yr^{-1}. We also find that additional bipolar neutral regions moving away with a speed ~ 70 km s^{-1} in the directions perpendicular to the orbital plane provide considerably improved fit to the red wing parts of Raman features.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.2
• /
• pp.301-305
• /
• 2010

Cutting procedures where qualities are determined by various demand factors largely influences shipbuilding productivity. Particularly, defects in cutting shapes and cutting surface results in delay for post shipbuilding stages such as in welding and assemblage lines which could become factors for reduced economic viability of the project. Existing cutting procedures utilize fossil fuels such as propane or ethylene as the main fuel component and these methods applied particularly to ship plate cutting gives relatively slow cutting speed and generates large quantities of harmful and sometimes poisonous polluting fumes of which warrants an urgent need to look for alternative cutting methods. Recent introduction of hydrox gas generated by electrically dissociating water into hydrogen and oxygen components to be utilize as an alternative cutting fuel has resulted not just in visible improvement on cutting quality and speed over the existing methods but it has also been welcomed as an environmentally friendly clean fuel source. This paper has been prepared to serve as the basis for accommodating this environmentally friendly hydrox gas cutting method into actual working environment by observing and recording hydrox gas cutting thermal characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.7 s.178
• /
• pp.1841-1846
• /
• 2000

To examine the effect of acid fog on the corrosion fatigue behavior in structural steel, fatigue tests under acid fog atmosphere were carried out in comparison with distilled water. The corrosive c omponents contained in acid fog pile up the corrosion products on crack face and show a crack branching and crack tip blunting. Therefore, due to these workings crack growth rate was reduced by decreasing the effective stress range in crack tip rather than under distilled water. Also the effect of sulfuric acid, which is the main component of acid fog, and testing speed on fatigue crack growth were examined. It was found that corrosion behavior was remarkably dependent upon pH and Hz rather than components of acid fog. According as pH and testing speed decrease below a specific value, crack growth was accelerated in comparison with distilled water. This reveals that due to liquid having strong acidity and slow speed of test the crack face dissolution was promoted, so crack closure was disturbed in the process of stress descent.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.6C
• /
• pp.575-581
• /
• 2006

In this paper, we first define one-dimensional component symbol error function (ODSEF) from the exact expression of the pairwise error probability of orthogonal space-time block codes (OSTBC). Using the ODSEF and the general bit error probability (BEP) expression for quadrature amplitude modulation (QAM) introduced by Cho and Yoon, the exact closed form expressions for the BEP of linear OSTBCs with QAM in slow-varying Rayleigh fading channel are derived.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2008.09a
• /
• pp.126-132
• /
• 2008

Cutting procedures whose qualifies are determined by various variables largely influences shipbuilding productivity. Particularly, defects in cutting shapes and cutting surface results in delay of the post shipbuilding stages such as welding and assemblage process. Because cutting procedures are influenced by various numbers of requirements according to the plate thickness, cutting precision can be maintained when the cutting conditions are appropriate. Existing cutting procedures utilize fossil fuels such as propane or ethylene as the main fuel component. Especially, when fossil fuel is applied to thick plate cutting, this process gives relatively slow cutting speed and generates large quantities of harmful polluting fumes. Recently, hydrogen-oxygen mixed gas generated by electrically dissociating water into Hydrogen and oxygen components is welcomed as an alternative fuel source. Also recent results report that alternative cutting fuel improves the cutting Dualities and speed. This paper presents that cutting characteristics and optimum cutting condition of hydrogen-oxygen mixed gas.

• Journal of the Korean Society of Tobacco Science
• /
• v.25 no.1
• /
• pp.27-33
• /
• 2003

This study was conducted to determine the changes of nitrogen compounds in lamina and midrib during the curing process with the different curing methods, such as priming and stalk-cut curing. After KB 108 burley tobacco was cultivated by the different fetilization levels such as standard and 20% higher, only the tips and leaf were harvested. Though the contents of total alkaloid and total nitrogen were similar in lamina, midrib showed a very low contents of those components by the different curing method and fertilization levels. The content of nitrate-nitrogen in lamina increased during a middle of curing process, and then these compound was decreased during an end of curing process by stalk-cut curing method. Nitrate-nitrogen contents in the lamina by the priming curing showed a high level caused by rapid drying process during an end of curing process. That component in midrib was 5-6 times higher than that of lamina. The contents of ammonia-nitrogen in the lamina and midrib were increased during a curing process. Though those amount in tips showed a similar by a different fetilization and curing method, midrib of stalk-cut curing showed a slow increasing during a curing process.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.18 no.5
• /
• pp.514-520
• /
• 2009

Titanium is one of the most attractive materials due to their superior properties of high specific strength and excellent corrosion resistance. The applications in aerospace and medical industries demand machining process more frequently to obtain more precise products. Machining of titanium is faced with strong challenges such as increased component complexity i.e. airframe components manufacturing processes. The machining cost on titanium have traditionally demanded high cutting tool consumable cost and slow machining cycle times. Similarly, the high wear of the cutting tools restricts the cutting process capabilities. Titanium screws applied to fasten parts In the several corrosion environment. In the thread cutting of titanium alloys, the key point for successful work is to select proper cutting methods and tool materials. This study suggests a guidance fur selecting the cutting methods and the tool materials to improve thread quality and productivity. Some experiments investigate surface roughnesses, cutting forces and tool wear with change of various cutting parameters including tool materials, cutting methods, cutting speed. As the results, the P10 type insert tip was assured of the best for thread cutting of Ti-6Al-4V titanium alloy. Also the initial depth of infeed was desirable to use the value below 0.5mm as the uniform cutting area method is applied.

• Journal of the Korea Safety Management & Science
• /
• v.19 no.4
• /
• pp.149-155
• /
• 2017

This study is analyzed combustion phenomena based on the environmental energy facility incinerator. It is assumed that combustible components of waste are composed of carbon and hydrogen, and the combustion process of fuel is by setting as multi-component / multistage reaction. As the combustion chamber is burned, the high temperature environment is achieved, also the heat transfer accompanied by the turbulent flow and the generation of NOx, a pollutant, are interpreted to predict the thermal and fluid characteristics and pollution emissions of the grate incinerator. As the result of internal flow analysis, the slow flow around the ash chute and the mixing effect due to the complicated turbulence around the combustion chamber were predicted to show excellent performance. It is shown to the internal average temperature was about $1024^{\circ}C$, around the about $1000^{\circ}C$ homogeneous temperature distribution. Due to the sudden temperature decrease in the boiler, the flue gas temperature at the outlet was estimated to be about $220^{\circ}C$.