• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.3
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• pp.254-259
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• 2014

A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter ${\times}$ 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the $D_2O$ heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.13-19
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• 2010

The purpose of this study was to compare the microshear bond strength of a self-etching primer adhesive to dentin prepared with different diamond points, carbide burs and SiC papers, and also to determine which SiC paper yield similar strength to that of dentinal surface prepared with points or burs. Fifty-six human molar were sectioned to expose the occlusal dentinal surfaces of crowns and slabs of 1.2 mm thick were made. Dentinal surfaces were removed with three diamond points, two carbide burs, and three SiC papers. They were divided into one of eight equal groups (n = 7); Group 1: standard diamond point(TF-12), Group 2: fine diamond point (TF-12F), Group 3: extrafine diamond point (TF-12EF), Group 4: plain-cut carbide bur (no. 245), Group 5: cross-cut carbide bur (no. 557), Group 6 : P 120-grade SiC paper, Group 7: P 220-grade SiC paper, Group 8: P 800-grade SiC paper. Clearfil SE Bond was applied on dentinal surface and Clearfil AP-X was placed on dentinal surface using Tygon tubes. After the bonded specimens were subjected to uSBS testing, the mean uSBS (n = 20 for each group) was statistically compared using one-way ANOV A and Tukey HSD test. In conclusion, the use of extrafine diamond point is recommended for improved bonding of Clearfil SE Bond to dentin. Also the use of P 220-grade SiC paper in vitro will be yield the results closer to dentinal surface prepared with fine diamond point or carbide burs in vivo.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.339-347
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• 1996

Background : Transthoracic fine needle aspiration and biopsy(TNAB) has become a frequently used technique in the investigation of the intrathoracic lesions because of its safety, reliability, and accuracy. Method : Data on 125 patients who underwent TNAB from 1990 through 1994 were studied to determine the diagnostic sensitivity, accuracy and complications of this procedure as related to lesion type and location. Results : 1. The over-all diagnostic sensitivity of TNAB was 61.6%(77 of 125 patients). 2. The diagnostic yields were as high as 89.9% for malignant lesions, but a specific diagnosis of benign lesions were obtained only in 30% of benign lung lesions. 3. The correlation between results of TNAB cytology and of final histology was as high as 88.2%. 4. Lung lesions that were greater than 3cm in size had a higher proportion of correct diagnosis(73.3%) as compared with lesions 3cm or less in size(38.1%). But there was no significant difference between the central and peripheral lung lesions. 5. There were no serious complications to TNAB. In 12.8% of the procedures a pneumothorax developed, indicating a chest tube in 1.6% of the procedures. In 2 cases, minimal hemoptysis developed which did not require treatment. Conclusion : In our experience, TNAB represents a minor and safe procedure, which permits a direct approach to localized malignant lung lesions with a high degree of accuracy.

• Korean Institute of Interior Design Journal
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• no.36
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• pp.14-21
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• 2003

The Propose of this research was to consider how the New Media Architecture was applied to contemporary architecture according to the analysis of the design method process of Toyo Ito. Sendai Mediatheque by Toyo Ito stands as one of the most symbolic statement In New Media architecture. The four principal architectural elements of the Mediatheque are the digital image, the continuous space, the tube, and the skin facade. The digital image express forms of communication, person-to-person and person-to-thing, and they vary according to the media utilized on each level. The three skin elements of the Mediatheque are a double skin of MPG, skin of louvers, skin of fine-floor decking. The tubes act as columns while enveloping light, air, water, electricity the passage of people, as well as the means of transferring material. The thirteen tubes of different sizes prevent the erection of wall and suggest places instead of rooms. Instead of being limited to certain specified actions in clearly defined rooms, people are free to choose places for their actions in the continuous space.

• Journal of radiological science and technology
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• v.16 no.1
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• pp.101-106
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• 1993

In order to assure safety of both patient and operator, and to provide uniform quality radiographs, it is necessary to perform periodic calibration of diagnostic X-ray equipment. A basic parameter of diagnostic equipment's and its image sharpness is the size(and shape the energy distribution) of the focal spot as viewed along the central X-ray beam. This size determines the resolution possible with the equipment and also determines the heat characteristics of an anode. A fine focus tube gives high resolution but causes high local heating of target. In past, the pin-hole and star pattern image measurement for evaluation of resolution have been widely used, but it produced blurring and inaccuracy of image. So newly inverted Ug-meter has advantage in more convenient measurement method and less out-put bias than other image measurement. The authors intended to compare measured focal size between Ug-meter and focal spot test tool, changed state from setting to now of units.

• Advances in pediatric surgery
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• v.1 no.2
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• pp.177-180
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• 1995

A 2-day-old male (Premie, Large for gestational age(LGA), Intrauterine period(IUP) 33 weeks, birth weight 2,955 gram) was transferred with marked abdominal distention, bilious return via the orogastric tube, respiratory difficulty, and generalized edema (hydrops fetalis). He was born by cesarean section to a 36 year-old mother. Antenatal ultrasonogram at IUP 31 weeks demonstrated multiple dilated bowel loops suggestive of intestinal obstruction. There was no family history of cystic fibrosis. Simple abdominal films disclosed diffuse haziness and suspicious fine calcifications in the right lower quadrant. Barium enema demonstrated a microcolon. Sweat chloride test was not available in our institution. At laparotomy, there noted 1) a segmental volvulus of the small bowel with gangrenous change, associated with meconium peritonitis, 2) an atresia of the ileum at the base of the volvulus, and 3) the terminal ileum distal to the volvulus was narrow and impacted with rabbit pellets-like thick meconium. These findings appeared to be very similar to those of a complicated meconium ileus. In summary, the ileal atresia and meconium peritonitis seemed to be caused by antenatal segmental volvulus of the small intestine in a patient with probable meconeum ileus.

• International Journal of Aeronautical and Space Sciences
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• v.12 no.2
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• pp.149-155
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• 2011

The viscous flow in an axisymmetric nozzle was analyzed while accounting for the mesh sizes in both in the free stream and the boundary layer. The Navier-Stokes equations were resolved using the finite volume method in order to determine the supersonic flow parameters at the exit of the converging-diverging nozzle. The numerical technique in the aforementioned method uses the flux vector splitting of Van Leer. An adequate time stepping parameter, along with the Courant, Friedrich, Lewis coefficient and mesh size level, was selected to ensure numerical convergence. The boundary layer thickness significantly affected the viscous flow parameters at the exit of the nozzle. The best solution was obtained using a very fine grid, especially near the wall at which a strong variation of velocity, temperature and shear stress was observed. This study confirmed that the boundary layer thickness can be obtained only if the size of the mesh is lower than a certain value. The nozzles are used at the exit of the shock tube in order to obtain supersonic flows for various tests. They also used in propulsion to obtain the thrust necessary to the displacement of the vehicles.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.302-310
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• 2012

Bio assay of mercury and cadmium ions were searched using voltammetric analysis using DNA doped carbon nanotube paste electrodes (DCP). The square-wave stripping voltammetryic optimized results indicated working ranges of 1-10.0 $ngL^{-1}$ and 20-100 $ugL^{-1}$, Hg(II) Cd(II) within an accumulation time of 120 seconds, in 0.1-M phosphate buffer solutions of pH 6.3. The relative standard deviations of 5 $ngL^{-1}$ Hg(II) and Cd(II) that observed were 0.14 and 0.22% (n=12), respectively, using optimum conditions. The low detection limit (S/N) was pegged at 0.1 $ngL^{-1}$ ($4.9{\times}10^{-11}M$) Hg(II) and 0.2 $ngL^{-1}$ ($1.77{\times}10^{-10}M$) Cd(II). The developed methods can be applied to assays in biological fish kidneys and water samples.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.7.2-7
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• 1982

Foreign body in the esophagus is not uncommom in the otolaryngological field, but esophageal perforation followed by pneumothrax due to esophageal foreign body is very rare. Authors recently experienced such a case developed in 1 year old male baby. This baby had been treated at local clinic for 2 weeks prior to admission under the impression of U.R.I.. Thereafter foreign body in the esophagus (fine wire pin) with left pneumothorax was detected by chest X-ray and the body was transfered to our hospital. Closed chest tube was inserted on left and under the general anesthesia, foreign body was removed by esophagoscopy. He was discharged on 16th postoperative day uneventfully.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.326-333
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• 2003

In the measurement using DMA and CPC in series, there is some time delay for particles classified in DMA to detect in CPC. During this time, the DMA time-response changes due to the velocity profile of sampling tube and the diffusion of particles in the volume that exists between the DMA exit and the detector of ultra-fine CPC. This is called mixing effect. In the accelerated measurement methods like the TSI -SMPS, the size distribution is obtained from the correlation between the time-varying electrical potential of the DMA and the corresponding particle concentrations sampled in DMA. If the DMA time -response changes during this delay time, this can cause the error of a size distribution measured by this accelerated technique. The kernel function considering this mixing effect using the residence time distribution is proposed by Russell et al. In this study, we obtained a size distribution using this kernel to compare to the result obtained by the commercial accelerated measurement system, TSI -SMPS for verification and considered the errors that result from the mixing effect with the geometric mean diameters of originally sampled particles, using virtually calculated responses obtained with this kernel as input data.