• Journal of Welding and Joining
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• v.27 no.4
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• pp.67-72
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• 2009

In this paper, arc characteristics of V groove joints using pulsed GMA welding were found out. The bevel angles of $22.5^{\circ}$ and $30.0^{\circ}$ were chose to make the V groove configuration with the groove angles of $45^{\circ}$ and $60.0^{\circ}$, respectively. In the experiment, the arc current waveform measurement and the high speed photography were taken to investigate the arc characteristics for a single-beveled asymmetric workpiece. Consequently, the welding current was changed abnormally around the edge of groove. As the arc moved close to the groove face, the welding current was increased rapidly because the welding arc was affected by the inclined surface. Also the welding current waveforms were measured for the double-sided symmetric workpiece to verify the previous measurements for the single-beveled workpiece, and similar current waveforms were found.

• Journal of the Korean Institute of Navigation
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• v.11 no.2
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• pp.73-88
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• 1987

It is well known that the height of tank metacenter above the centroid of fluid in a tank is given by i/v where I is the inertia moment of free surface and v is the fluid volume. It is supposed in this formula that the inclination of ship is small and that the free surface of fluid do not touch the top and the bottom of tank. It the inclination of ship is large, the height of tank metacenter may be possibly greater than that given by i/v. The height of tank metacenter is smaller than i/v when the free surface of fluid touch the top or the bottom of tank. The reasonable method to calculate the height of tank metacenter is presented in this paper and prepared in FORTRAN program by FUNCTION EFFRES. The approximate formula was also developed and given by $g_m=(1+\frac{2}{1}tan^2\theta)[1-EXP\{-12(\frac{\alpha(1-\alpha)k}{tan\theta})^{1.25}\}]\frac{i}{v}$ where $g_m$ is the distance from the centroid of fluid to the tank metacenter, $\theta$ is inclined angle of ship, $\alpha$ is the ratio of filled volume to tank capacity and k is the ratio of the depth to the width of tank. The values calculated by the approximate formula given in this paper were compared with the exact values from the computer program and proved out to be sufficiently precise for practical use.

• Journal of the korean academy of Pediatric Dentistry
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• v.7 no.1
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• pp.33-40
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• 1980

The author observed the eruption pattern of the mandibular premolars. For this study the author took 406 cases of oblique cephalographs of 6 to 12 year old children. The measurement were with regard to the vertical and horizontal dimensional changes and tooth axis changes to the occlusal plane. The following results were obtained. 1. At stage V the tooth axis of 1st premolar inclined mesially to the occlusal plane, as the tooth erupt toward vertically the angulation changed that at stage X the tooth axis almost right angle to the occlusal plane. 2. The distance from the root apex of premolars to the lower border of mandible were slightly increased to the stage VII, while after stage VII rapid increasing appeared. At stage X the distance of 1st premolar was more longer than 2nd premolar. 3. The distance from the mesial surface of 1st molar to the mesial surface of premolars were decreased slightly to the stage VII, but this distances were decreased rapidly after stage VII. 4. The distance between distal surface of 1st premolar and mesial surface of 2nd premolar was almost constant before stage VIII, at stage IX this distance was little presented because the premolars were contacted.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.79-88
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• 2020

This paper propose the method to drive a solar panel cleaning robot efficiently on an inclined panel using vacuum pad pressure. In this method, the rubber pads using the vacuum pressure are used to attach robot body to the panel surface. By applying the linkage mechanism to the vacuum pads, it was possible to reduce robot weight and power consumption and to prevent slipping of the robot. In addition, the use of solenoid valves, proximity sensors, and encoders to detect movement of the robot body and the control of the pad pressure dedicate to the driving of the robot on an inclined panel. In order to move the robot forward, the operation sequence of multiple solenoid valves was completed, and the six vacuum pads mounted to both legs were accurately controlled to form vacuum and atmospheric pressure in right order so that the robot could move forward without slipping. At last, it was confirmed through experiments that straight-forward moving and rotational movement could be performed up to 36 degrees of inclination angle of solar panel.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.11
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• pp.1485-1495
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• 1997

The present study investigates heat/mass transfer around film cooling jets and circular cylinders to compare the characteristics of each other. Experiments are conducted to obtain the detailed heat/mass transfer coefficients of flat plate with injections through an array of holes and for flows around an array of protruding circular cylinders using the naphthalene sublimation technique. The inclination angles of cylinders are set to the same ones of jets; a, the angle between the jet and the surface is fixed at 30 deg. through the whole experiments and .betha., the angle between the projection of the jet on the surface and the direction of main stream is adjusted to 0 deg., 45 deg. and 90 deg. to investigate the effect of variation of injection angles. The influence of blowing rates of jets and those of cylinder length to diameter ratios are also investigated. The results indicate that the increase of angle .betha. influences the spanwise uniformity of heat/mass transfer remarkably for both jets and cylinders, but that variation of cylinder length to diameter ratios has weaker effects on heat/mass transfer coefficients than that of blowing rates.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.991-995
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• 2004

Immobilized sensor spots were applied for online measurement of dissolved $O_2$, in test tubes. Oxygen transport was quantified at varied shaking frequency and filling volumes. The k$_{L}$ a increased with increasing shaking frequency and decreasing filling volume. In non-baffled tubes the maximum $k_{L}a$ value was $70h^{-1}$, equivalent to a maximum $O_2$ transfer capacity of 15mMh^{-1}$. Monitoring of the hydrodynamic profile revealed that the liquid bulk rotated inside the tube with an inclined liquid surface, whereby the angle between the surface and tube wall increased with increasing shaking frequency. The $k_{L}a$ clearly correlated to the surface area. Placement of four baffles into the tubes improved the oxygen transfer up to 3-fold. The highest increase in $k_{L}a$ was observed at high filling volume and high shaking frequency. The maximum $k_{L}a$ in baffled tubes was $100 h^{-1}$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.4
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• pp.1-9
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• 2002

There is the high possibility of crack initiation from mechanical joints, which are widely used in aircraft fuselages, due to the development of stress concentration and contact pressure. In this paper, the mixed-mode stress intensity factors at the surface and deepest points of an inclined quarter elliptical corner crack in mechanical joints are analyzed by the weight function method. The coefficients included in the weight function are obtained by finite element analyses for reference loadings. Critical angle at which mode I stress intensity factor becomes maximum is determined by analyzing the variation of stress intensity factors along incline angle of crack and the effects of the amount of clearance and crack depth on the critical angle are investigated.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.6
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• pp.699-705
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• 1985

Heat transfer characteristics in terms of the tube wall-temperature and the enthalpy have been investigated utilizing ribbed (rifled) tubes in order to enhance heat transfer performance. Considerations were given for the cases of smooth tubes in order to compare with the case of ribbed tubes. The tilt angle of the experimental tubes are from 0.deg. to 90.deg. , in order to simulate the boiler water tubes having 15.deg.-90.deg. inclined angle in boiler nose and studded tubes (burner zones), Natural convection and forced convection (Re=1810) conditions were considered in the experiments. The experimental results for the effect for the tube inclination through a natural convection and forced convection are presented and it is shown that ribbed tubes permit an appreciable increase in heat transfer coefficients and consequently it means substantial reductions in boiler water wall tubes and heat exchanger surface areas.

• International Journal of Air-Conditioning and Refrigeration
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• v.10 no.3
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• pp.147-152
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• 2002

When a liquid is supplied through a nozzle onto a relatively non-wetting inclined solid surface, a narrow rivulet forms. There exist several regimes of rivulet flow depending on various flow conditions. In this paper, the fundamental mechanism behind the transition of a linear rivulet to a droplet flow is investigated. The experiments show that the droplet flow emerges due to the necking of a liquid thread near the nozzle. Based on the observation, it is argued that when the retraction velocity of a liquid thread exceeds its axial velocity, the bifurcation of the liquid thread occurs, and this argument is experimentally verified.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1485-1495
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• 2003

We investigate the triboelectrostatic separation of polyvinylchloride (PVC) from mixed plastics in the laboratory scale triboelectrostatic separation system. The flow and electric fields in the precipitator are obtained from the numerical solution of finite volume method. Using these flow and electric fields, we solved the particle motion equation considering the inertia, drag, gravity and electrostatic forces acted on the particles. The particle trajectories are obtained using a Lagrangian method as a function of different important variables such as Reynolds number, Stokes number, electrostatic force, electric charge and electric field distribution, inclined angle of plane electrodes, particle rebounding, particle charge decay rate after impact on the electrode surface, etc., in order to determine the optimal design conditions. The present predicted results for the cumulative yield represent well the experimental ones.