• Journal of the Korean institute of surface engineering
• /
• v.50 no.3
• /
• pp.192-197
• /
• 2017

A 6-way-cross consisting of a 2.75-inch CF flange was used as a main chamber on a PFEIFFER VACUUM TMP station based on a 67 l / sec turbo molecular pump and a diaphragm pump to produce a magnet array with a volume ratio of 5.5: 1.A 1-inch diameter copper target and graphite target were fabricated using MDX-1.5K from Advanced Energy Industries, Inc as a DC power supply. Ion current density of copper target and graphite target was measured by unbalanced magnetron sputtering. The basic pressure condition was $6.3{\times}10^{-7}mbar$ and the process pressure was Ar 50 sccm at $1.0{\times}10^{-2}mbar$ (7.5 mTorr) in the Ar atmosphere. Therefore, the relative density of copper ions reaching the substrate with the measured ion current density was derived.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.26 no.4
• /
• pp.425-429
• /
• 2017

During ultrasonic welding, plastic deformation, elastic hysteresis, and friction generate heat at the contact portions of the two materials to be welded, theoretically analyzing and experimentally measuring the temperature at the welded part are very important for identifying the heat affected zone. However, the welding temperature during ultrasonic welding wherein welding is performed in less than a second is a challenge. We investigated the effects of welding conditions such as welding time, welding pressure, and the ultrasonic vibration amplitude of horns on the temperature of welded surface of a Ni sheet of thickness 0.1 mm. We used a horn with a resonance frequency of 40 kHz and an ultrasonic welder. The temperature was measured using a intrared sensor, and its characteristics were investigated. Experimental results showed that increase in welding time and pressure and ultrasonic vibration amplitude of horns generally caused the increase in surface temperature of the weld.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.35 no.3
• /
• pp.36-46
• /
• 1993

The purposes of this study are to develop three-layered Green-Ampt infiltration model considering temporal variation of physical properties of soil and to evaluate the model with field experiment on bare-tilled and soybean-growing soil plots under natural rainfalls. Infiltration tests were conducted on a sandy loam soil. The model has three-layered soil profile including a surface crust, a tilled layer, a subsoil and considers temporal variation of porosity, hydraulic conductivity, capillary pressure head on a tilled layer by natural rainfalls and canopy density variation of crop. Field measurement of porosity, average hydraulic conductivity and average capillary presure head on a tilled layer were conducted by soil sampler and air-entry permeameter at regular intervals-after tillage. It was found that temporal variation of porosity and average hydraulic conductivity might be expressed as a function of cumulative rainfall energy and average capillary pressure head might be expressed as a function of porosity of a tilled soil. The model was calibrated by an optimization technique, Hooke and Jeeves method using hourly surface runoff data. With the calibrated parameters, the model was verified satisfactorily.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.9 no.2
• /
• pp.57-65
• /
• 1985

In the experiment with a basic material for the design of summer wear that comfort can be obtained in temperature, to get individual differences, clothing styles (slacks, skirt), material differences(T/C, cotton), and the contrast between when naked and dressed, when two healthy females were dressed four kinds of summer wear as an object of experiment under the regular warm temperature environmental condition (24, 28, 32, $36^{\circ}C$, $60\pm10\%$ RH), the measurement of physiological, phychological change was taken and the result goes as follow; 1. Mean skin temperature rose by clothing, body weight loss decreased below $32^{\circ}C$, thermal sensation changed toward low temperature by $2\~3^{\circ}C$. 2. Mean skin temperature, body weight loss, the lowest blood pressure above $32^{\circ}C$, under-clothing temperature, and thermal sensation increased when in slacks to be compared with when in skirt. 3. Ambient temperature had a great effect on mean skin temperature, body weight loss, respiration, clothing surface temperature, under-clothing temperature and humidity, thermal sensation, etc. 4. It was admitted that pulse, thermal sensation, comfort show different individuality. 5. It was recognized that the lowest blood pressure, clothing surface temperature, under. clothing humidity differ according to the kinds of clothing. 6. A comfortable ambient temperature in clothing summer wear was about $27\~28^{\circ}C$.

• Journal of the Korean institute of surface engineering
• /
• v.24 no.3
• /
• pp.119-124
• /
• 1991

Recently, the trend of research in hard coating is concentrate on developing the process of ionization rate under low operating pressure, to get the thin film with high adhesion and dense microstructures. In this study ionization rate enhancement type PVD process using permanent magnet is developed, which enhances the ionization rate by confining the plasma suppressing the wall loss of electron. By the result to investigate the characteristic of glow discharge, the ionization rate of this process is enhanced about twice as high as that of triod BARE process (about 26%), and more dense TiN microstructures are obtained in this process. Cylindrical ion energy analyzer is made and attached in front of a quadrupole mass filter for the analysis of the energy distribution of reactive gas and activated gas ions from the plasma zone. To analyze the operation mechanism of ion energy analyzer, computer simulation is performed by calculation the electric field environment using finite element method. By these analyses of ion energy distribution of outcoming ions from the plasma zone, it is found that magnetic field enhances ion kinetic energy as well as ionization rate. The other results of this study is that the foundation of feed-back system is constructed, which automatically control the partial pressure of reactive gas. In can be possible by recording the data of mass spectrum and ion energy analysis using A-D converter.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.11
• /
• pp.1230-1233
• /
• 2004

The ITO thin films were prepared by the FTS(Facing Targets Sputtering) system. The ITO thin films are deposited by changing the input current and working gas pressure. Then, electric characteristics, transmittance and surface roughness of ITO thin films were measured by Hall effect measurement, UV-VIS spectrometer and AFM. As a result, the ITO thin film was fabricated with resistivity 6xl0$^{-4}$ Ωㆍcm, carrier mobility 52.11 $\textrm{cm}^2$/Vㆍsec, carrier concentration 1.72 x $10^{20}$ $cm^{-3}$ transmittance over 85 % of ITO film at working gas pressure 1 mTorr and input current 0.6 A.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05c
• /
• pp.124-130
• /
• 2003

Zinc Oxide(ZnO) thin films on Si (100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance. To analyze a crystallographic properties of the films, $\theta/2\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity. and surface roughness highly depended on $Ar/O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of $9{\times}10^7{\Omega}cm$ was obtained at a working pressure of 10 mTorr with $Ar/O_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with $Ar/O_2$=50/50 showed the excellent roughness value of $28.7{\AA}$.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.7
• /
• pp.26-31
• /
• 2003

In this paper, supersonic jets impinging on axisymmetric cone were investigated to obtain fundamental design data for jet deflector case of example being VTOL/STOL or rocket launch. It was of interest to study flow phenomena such as shock interactions and separation induced by shear layer. Experiments were conducted to obtain schlieren flow visualization and measurement of surface pressure. Numerical results are compared with the experimental result. The dominant feature of the flow is the shock pattern induced by the interaction between the cone shock and the barrel shock. This pattern can take a wide variety of forms depending on the structure of the free jet and strongly influences the form of the surface pressure distributions.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.11 no.6
• /
• pp.50-57
• /
• 2007

Pressure Sensitive Paint(PSP) means a reacting paint in pressure. PSP can measure continuous pressure field by analyzing the oxygen quantity using optical method. The surface pressure of down stream after the sonic jet that injected transversely into the supersonic freestream was measured by PSP technique. Moreover the effect of various rectangular shaped cavities in front of the jet was measured by PSP technique. A comparison of the PSP results with conventional pressure tap and CFD indicates good agreement. Until now, the results of numerical analysis were compared with the discrete points such as the results of pressure tap. In this study, the whole region pressure was measured using PSP technique and its results were similar to CFD. Therefore, the flow phenonenon of cavity downstream was clearly grasped.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.34 no.11
• /
• pp.1824-1835
• /
• 2010

This study develops tight-fitting torso patterns for performance garments by taking into account the skin deformation generated directly from a 3D scan during arm movements. The skin deformation caused during the arm movements was scanned after scanning the skin surface stamped with a circle. To create a torso pattern in response to skin deformation, the ratio and direction of the skin deformation were first measured and analyzed so that the 3D human body could be segmented. After translating, the 3D skin surface was segmented into 2D flat patterns, designing nude patterns and reducing them as well as tight-fitting shirts: the skin deformation segment shirts were made in response to the skin deformation. The features of the fabric deformation and the garment pressure were analyzed and evaluated. In comparison with a clothing construction segment shirt, the diameter of the skin deformation segment shirt was smaller as well the ratios of extension and reduction was less. The garment pressure of the skin deformation segment shirt was higher. The skin deformation segment shirt fitted more tightly compared to a clothing construction segment shirt as it covered the body more thoroughly and was as comfortable as the other shirts with less fabric deformation made as the body moved.