• Progress in Superconductivity
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• v.10 no.2
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• pp.99-102
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• 2009

We report our development of the fabrication process of sub-micron scale $Al-AlO_x-Al$ tunnel junction by using electron-beam lithography and double-angle shadow evaporation technique. We used double-layer resist to construct a suspended bridge structure, and double-angle electron-beam evaporation to form a sub-micron scale overlapped junction. We adopted an e-beam insensitive resist as a bottom sacrificing layer. Tunnel barrier was formed by oxidation of the bottom aluminum layer between the bottom and top electrode deposition, which was done in a separate load-lock chamber. The junction resistance is designed and controlled to be 50 $\Omega$ to match the impedance of the transmission line. The junctions will be used in the broadband shot noise thermometry experiment, which will serve as a link between the electrical unit and the thermodynamic unit.

• Composites Research
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• v.19 no.4
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• pp.23-30
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• 2006

In the development of a cryogenic propellant tank, the proper selection of adhesives to bond composite and metal liner is important for the safety of operation. In this study, 3 types of adhesives were tested for the ability to bond CFRP composites developed for cryogenic use and aluminum alloy (Al 6061-T6) for lining the tank using double-lap joint specimens. The double-lap joint specimens were tested inside an environmental chamber at room temperature and cryogenic temperature ($-150^{\circ}C$) respectively to compare the bond strength of each adhesive and fracture characteristics. The material properties with temperature of component materials of double-lap joints were measured. In addition, ABAQUS was used for the purpose of analyzing the experimental results.

• Journal of Sensor Science and Technology
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• v.8 no.5
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• pp.368-376
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• 1999

This paper predicts the changes in the spring constant, the resonant frequency, the electrostatic force, and the displacement of a resonant structure due to non-ideal anisotropic RIE etching process. First, a $6\;{\mu}m$ thick polysilicon was etched by RIE and the anisotropy of the etched structure was measured as a function of a RF power, a $Cl_2$ flow rate and a chamber pressure. In the experimental results, an anisotropy was decreased as the RF power, the $Cl_2$ flow rate, or the chamber pressure was increased. A comb actuator's operation characteristic was predicted depending on the anisotropy variations in RIE etching. Comb actuators with three different support beam structures were investigated : fixed-fixed, crab-leg, and double crab-leg. As the RIE etch anisotropy becomes non-ideal, i.e. the cross section becomes rather a trapezoidal than a rectangular shape, it decreases spring constant, resonant frequency and electrostatic force of a comb actuator but it increases the displacement of the mass. Among the three structures, the comb actuator with double crab-leg support beams is more influenced by anisotropy variation in RIE etch than other two.

• Journal of Chest Surgery
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• v.18 no.2
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• pp.241-249
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• 1985

Twenty-one patients with Double Chambered Right Ventricle [DCRV] associated with Ventricular Septal Defect [VSD] were treated by open heart surgery under cardiopulmonary bypass with moderate hypothermia in the Department of Thoracic and Cardiovascular Surgery, Hanyang University Hospital between June 1982 and October 1984. The following results were obtained 1. The symptoms and physical signs, specific for DCRV, could not be identified. 2. The radiologic findings on simple chest X-ray, specific for DCRV, could not be identified. 3. Electrocardiographic findings, specific for DCRV, could not be identified. 4. Cardiac catheterization was found to be the most important diagnostic method, revealing pressure gradient between proximal chamber and distal chamber in the right ventricle. The average pressure gradient between two chambers showed 48.1523.29 mmHg[varying from 15mmHg to 94mmHg]. 5. Cardiac angiography was found to visualize the anomalous muscle bundles in right ventricle [in 17 cases, 81%] but the evidence of pressure gradient between two chambers within right ventricle is considered necessary for the diagnosis of DCRV. 6. Via surgical observation, anatomical and pathologic findings of the anomalous muscle bundles, associated DCRV were identified. 7. As the direct pressure was measured on the operating table before and after surgery, the average pressure gradient across the muscle bundles showed 40.5219.75mmHg [varying from 16 to 89mmHg] preoperatively and 8.909.72mmHg [varying from 0 to 32mmHg] postoperatively, indicating significant surgical correction of the obstruction present. 8. The presence of anomalous muscle bundles, dividing the right ventricle into two separated chambers, and the presence of the pressure gradient over 15mmHg are considered necessary for the diagnosis of DCRV.

• Journal of Biosystems Engineering
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• v.13 no.4
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• pp.9-19
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• 1988

The threshing of head-feed combine may be accomplished mainly by the action of impact between threshing teeth and rice. In this study, it was attempted to assess threshing performance characteristics of head-feed threshing teeth. And the characteristics of threshing teeth will be applied to the method which could analyze the time and order of impact between teeth and the rice, which was used as a basis for predicting the threshing performance and determining the optimum design parameters. The results of the study are summarized as follows: 1. About 50% of threshed material were threshed by the beginning 7 impacts on the rice bundle. Threshing torque decreased until 25 impacts and did not change thereafter. 2. There was significant difference in the threshability according to the shape of threshing teeth. The triangular-shaped tooth was the most efficient in threshability ratio and the semicircle-shaped tooth was the lowest. There was no significant difference in specific energy requirement for the varied teeth design. Torn-head ratio being generated by the semicircle-shaped and the triangular-shaped teeth in series was less than that by a single tooth with the triangular-shaped and the double setting of the triangular-shaped. Chaff generation ratio by the triangular-shaped and the semicircle-shaped teeth was less than the others tried. 3. The triangular-shaped teeth in series, which was newly designed for this study, showed an intermediate characteristics between the double setting of the triangular-shaped and the semicircle- shaped teeth. Threshability ratio of the triangular-shaped teeth in series was higher than that of the semicircle and lower than the double setting of the triangular-shaped tooth. Torn-head generation ratio for it was about same as that of the semicircle. Chaff being generated by the triangular-shaped teeth in series was about same as the double setting of the triangular-shaped teeth. 4. About 40% of threshed grains which passed through concave were concentrated under the threshing tooth and the rest of grains displayed a skew distribution toward the inlet of threshing chamber.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.1-7
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• 2013

Pneumatic cylinders are widely used to actuators in automatic equipments because they are relatively inexpensive, simple to install and maintain, offer robust design and operation, are available in a wide range of standard sizes and design alternatives. This paper presents a comparative study among the dynamic characteristics of meter-out and meter-in speed control of pneumatic cushion cylinders with a relief valve type cushion mechanism. Because of the nonlinear differential equations and a requirement for simultaneous iterative solution in a mathematical model of a double acting pneumatic cushion cylinder, a computer simulation is carried out to investigate pressure, temperature, mass flow rate in cushion chamber and displacement and velocity time histories of piston under various operating conditions. It is found that the piston velocity and pressure response in meter-in speed control are more oscillatory than with meter-out those when pneumatic cushion cylinders are driven at a high-speed. In meter-out speed control, the effective area of the flow control valve is larger than that of meter-in, and the supply pressure has to be much higher than the pressure required to move the load because it has also to overcome the back pressure in cushion chamber.

• Journal of Chest Surgery
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• v.18 no.2
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• pp.273-278
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• 1985

The case of a patient with abnormal position of the atrial septum resulting in a left atrium with two atrioventricular valves and a disconnected right atrium is presented with review of related articles. Anatomic details showed atrial situs solitus and a left sided cardiac apex. The right atrium received both venae cavae and a coronary sinus. No AV valve was found in the right atrium, and the floor of this chamber was placed above the posterior wall of right ventricular chamber. The atrial septum with secundum ASD was displaced to right anteriorly at its lower portion and inserted to right of tricuspid annulus. The tricuspid and mitral valve configuration was that of so-called partial ECD, i.e. mitral cleft with large anterior mitral leaflets. The ventricular septum was intact and both ventricular chambers were equally well developed with normal relationships. Surgical repair of this anomaly was performed by resecting the abnormally positioned lower part of the atrial septum, repairing the cleft of the anterior mitral leaflet, and septating the atrium for diverting the systemic and pulmonary venous blood to RV and LV, respectively.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.231-236
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• 2020

A water reforming reaction high-speed turning incinerator test facility was prepared. The reforming reaction chamber and the combustion chamber were directly connected. The incinerator and dust collecting device were integrated and made into a double bulkhead type air cooling structure. The blower is built into the dust collector to improve spatial efficiency. An axial flow type multi-stage dust collector was applied by collecting dust by using a plurality of dust collecting bins attached to the side of the dust collecting part. As a result of measuring dioxin among the exhausted gases, results below the standard value were obtained. As a result of measuring exhaust gas and heavy metals, results were obtained below the environmental standard.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.171-176
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• 2006

An experimental study on a fuel-rich gas generator was carried out. Thirty seven double-swirl injectors with recess number of 1.5 were distributed and installed in the injector head, which significantly influences the combustion performance. In the paper, the characteristics of combustion stability are inspected by the parametric varations such as changing length and diameter of a combustion chamber and installing a turbulence ring. The experimental results show that as a resonant frequency took place in a high region, the amplitude of the dynamic pressure generally diminished, however, the combustion instability could not be suppressed perfectly.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.20-24
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• 2002

We have from water samples of Kwalim, Dochang, and Mulwang reservoirs in Kyonggi-Do, where cyanobacteria blooming occurred. Isolated microbes which have lytic activity for cyanobacteria. Water samples were smeared on the Anabaena cylindrica lawn and incubated in light chamber at $28^\circ{C}$, under 3000 lux for 13 days. A fungus having cyanobacterial lytic activity was isolated from the samples of Dochang reservoir. The isolate was identified as Cryptococcus laurentii by Vitek system. From the culture of the isolate, four major extracellular protein bands (29, 35.2, 40.9, 51.1 kDa) have been detected and the 29 kDa protein band was more thickly appeared in the culture with cyanobacteria.