• Tuberculosis and Respiratory Diseases
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• v.77 no.6
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• pp.251-257
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• 2014

Background: Transbronchial lung biopsy (TBLB) is a valuable diagnostic tool for peripheral pulmonary lesions. The diagnostic yield of TBLB reportedly ranges from 41%-60%. Many studies demonstrated the various factors that influence the yield of TBLB, including size, location, and distance from the carina or pleura. However, no study has evaluated the effects of the bronchoscope diameter. We evaluated whether the bronchoscope diameter affected the diagnostic yield of TBLB. Methods: We reviewed records from 178 patients who underwent TBLB using bronchoscopes of two different diameters (5.7 mm, thick outer diameter, Olympus BF-200; 4.9 mm, thin, BF-260). The fluoroscopic guidance rates, yield of TBLB and flexible bronchoscopy (FB) were compared between the two groups. Additionally, we compared the results of the procedures with respect to diagnosis, distance from the pleura, and size of the lesion. Results: The results of fluoroscopic guidance, TBLB, and FB yield using thin diameter bronchoscope were significantly better than those obtained with a thick diameter bronchoscope (p=0.021, p=0.036, and p=0.010, respectively). Particularly, when the distance from the pleura was ${\leq}10mm$, success rates for fluoroscopic guidance and FB with thin bronchoscope were higher (p=0.013 and p=0.033, respectively), as compared to with thick bronchoscope. Conclusion: A thinner diameter bronchoscope increased the yield of bronchoscopy, and bronchial washing in conjunction with TBLB was useful in the diagnosis of peripheral pulmonary nodules.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.27-35
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• 1991

An interstitial radiofrequency needle electrode system was constructed for interstitial heating of brain tissue. Radiofrequency electrodes with Thermotron RF 8 were tested in an agar phantom and in a normal canine brain to determine how variations in physical factors affected temperature distributions. Temperature distributions were checked after heating with 1 mm diameter needle electrode implants on the corners of 1 and 2 cm squares in a phantom and plot isotherms for various electrodes arrangement. We observed that the 1 cm square array would heat a volume with a 1.25 cm radius circular field cross section to therapeutic temperatures ($90\%$ relative SAR using Tm) and the 2 cm square array with a 1.75 cm radius rectangular field with central inhomogeneity. With 2 cm long electrode implants, we observed that the 1 cm square array would heat a 3 cm long sagittal section to therapeutic temperature ($90\%$ relative SAR using Tm). We found that radiofrequency electrodes could be selected to match the length of the heating area without affecting its performance. The histopathological changes associated with RF heating of normal canine brains have been correlated with thermal distributions. RF needle electrode heating was applied for 50min to generate tissue temperatures of $43^{\circ}C$. We obtained a quarter of the heated tissue material immediately after heating and sacrificed at intervals from $7\sim30$days. The acute stage (immediately after heating) was demonstrated by liquefactive necrosis, pyknosis of neuronal element in the gray matter and by some polymer-phonuclear leukocytes infiltration. The appearance of lipid-laden macrophages surrounding the area of liquefaction necrosis was demonstrated in all three sacrificed dogs. Mild gliosis occurring around the necrosis was demonstrated in the last sacrificed (Days 30) canine brain.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1453-1458
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• 2011

This paper dealt with the measurement and analysis of electromagnetic waves generated by partial discharges in insulation oil to develop insulation diagnostic techniques for power transformer. Two types of narrow-band monopole antennas with the resonant frequency of 500 MHz and 1 GHz were designed and fabricated. We simulated defects which consist of a needle electrode with curvature radius of 10 ${\mu}m$ and a plane electrode with diameter of 60 mm in insulation oil. From the experiment, the maximum output voltage of the fabricated antennas was measured; 620 $mV_{max}$ for 500 MHz resonant frequency and 920 $mV_{max}$ for 1 GHz resonant frequency.

• Journal of the Korean Ceramic Society
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• v.53 no.1
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• pp.7-12
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• 2016

In this paper, we have developed a simple, new and economical carbonation method to synthesize a pure form of aragonite needles using dolomite raw materials. The obtained aragonite Precipitated Calcium Carbonate (PCC) was characterized by XRD and SEM, for the measurement of morphology, particle size, and aspect ratio (ratio of length to diameter of the particles). The synthesis of aragonite PCC involves two steps. At first, after calcinated dolomite fine powder was dissolved in water for hydration, the hydrated solution was mixed with aqueous solution of magnesium chloride at $80^{\circ}C$, and then $CO_2$ was bubbled into the suspension for 3 h to produce aragonite PCC. Finally, aragonite type precipitated calcium carbonate can be synthesized from natural dolomite via a simple carbonation process, yielding product with average particle size of $30-40{\mu}m$.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.593-597
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• 1987

Mesothelioma is a primary tumor of the pleura. There are two forms of mesotheliomas; diffuse form and localized form. The majority of localized mesotheliomas are benign, but the tumor with pedicle recur at 20% after removal of it. Malignant localized fibrous mesothelioma is differential diagnosed pathologically and clinically with diffuse mesothelioma. Symptoms of localized mesothelioma are generally related to the size of the tumor. We presented one case of malignant localized fibrous mesothelioma. The patient was 32 years old female and chief complaints were dyspnea and dry cough. Sputum cytology and needle lung biopsy were not able to diagnose definitely the tumor. Explothoracotomy was carried out for definite tissue biopsy. At the time of operation, huge adult head size mass was in the right thoracic cavity. The surface of the mass was nodular, multilobular and had hard consistency. Pedicle was formed above first rib and its diameter was 4.5cm. There was no adhesion except to RUL. Frozen biopsy suggested mesothelioma. Extirpation of the mass, right upper lobectomy. and partial pleurectomy were carried out.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.301-303
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• 2009

This paper presents a basic data of the surface discharge characteristics of solid dielectric in various gas including $SF_6$ and environmentally friendly gas as Dry-Air and $N_2$ gas. Used electrodes are needle and plane. Used solid dielectric which is installed between the electrodes is made of epoxy resin and is disc form of 100[mm] diameter and 2, 3[mm] thickness. AC In same condition, we can obtain different surface dielectric strength. Increased pressure and thickness caused increased surface dielectric strength.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.101-102
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• 2008

SF6 widely used as insulating gas is rising as the environment problem. For decreasing this greenhouse gas, electrical breakdown characteristics of vacuum with air are studied in non-uniform field. The gap of needle to plane was 0.5mm. The pressure of vacuum the range of 10^-4${\sim}$10^-5torr. The diameter of a plane made of the stainless steel is 150mm. As a result of the experiment, the breakdown voltage is increased about degree of vacuum increased. The electrode material influenced breakdown voltage in vacuum.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.366-367
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• 2008

SF6 widely used as insulating gas is rising as the environment problem. For decreasing this greenhouse gas, electrical breakdown characteristics of vacuum with air are studied in non-uniform field. The gap of needle to plane was 0.5mm, 0.8mm. The pressure of vacuum the range of 10^-4-10^-5torr. The diameter of a plane made of the stainless steel is150mm. As a result of the experiment, the breakdown voltage is increased about electrode gap distance increased. The electrode material influenced breakdown voltage in vacuum.

• Laser Solutions
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• v.10 no.1
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• pp.11-17
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• 2007

We presented the proper laser processing conditions for the capillary line marking, which could be applied for the fabrication of injection needles. With changing the parameters such as lamp current, duty cycle and beam amplification factor of beam expander, we evaluated the processing performance considering amount of dross, processing efficiency and processed linewidth in the sample. We could carry out the proper line marking at the condition of 70% lamp current, duty cycle of 7-10% and 6-times amplification of beam diameter. To perform efficient line processing, the utilization of duty cycle of 12% at 80% lamp current was also preferred.

• Journal of the Korean Society of Visualization
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• v.11 no.3
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• pp.12-16
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• 2013

The impact and spreading behaviors of silicon dioxide nanoparticle colloidal suspension droplets were quantitatively visualized using a high-speed imaging system. Millimeter-scale droplets were generated by a syringe pump and a needle. Droplets of different velocity were impacted on a non-porous solid surface. Images were consecutively recorded using a CMOS high-speed camera at 5000 fps (frames per second) for millimeter-scale droplets. Temporal variations of droplet diameter, velocity and maximum spreading diameters were evaluated from the sequential images captured for each experimental condition. Effects of Reynolds number, Weber number, and particle concentration were investigated experimentally.