• Title/Summary/Keyword: size of the angle

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Electrolyzed Water Cleaning for Semiconductor Manufacturing (전리수를 이용한 반도체 세정 공정)

  • 류근걸;김우혁;이윤배;이종권
    • Journal of the Semiconductor & Display Technology
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    • v.2 no.3
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    • pp.1-6
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    • 2003
  • In the rapid changes of the semiconductor manufacturing technologies for early 21st century, it may be safely said that a kernel of terms is the size increase of Si wafer and the size decrease of semiconductor devices. As the size of Si wafers increases and semiconductor device is miniaturized, the units of cleaning processes increase. A present cleaning technology is based upon RCA cleaning which consumes vast chemicals and ultra pure water (UPW) and is the high temperature process. Therefore, this technology gives rise to environmental issue. To resolve this matter, candidates of advanced cleaning processes have been studied. One of them is to apply the electrolyzed water. In this work, electrolyzed water cleaning was compared with various chemical cleaning, using Si wafer surfaces by changing cleaning temperature and cleaning time, and especially, concentrating upon the contact angle. It was observed that contact angle on surface treated with Electrolyzed water cleaning was $4.4^{\circ}$ without RCA cleaning. Amine series additive of high pKa (negative logarithm of the acidity constant) was used to observe the property changes of cathode water.

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Ohmic Contact Properties of Nonpolar GaN Grown on r-plane Sapphire Substrate with Different Miscut Angle

  • Shin, Dongsu;Park, Jinsub
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.314.1-314.1
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    • 2014
  • The properties of Ni/Au Ohmic contacts formed on nonpolar a-plane GaN grown on r-plane sapphire substrate with different tilt angles are investigated using current-voltage (I-V) measurements. To investigate the effects of pattern direction and size on Ohmic contact properties of a-plane GaN, transmission line method (TLM) patterns are formed either along c-axis and m-axis on nonpolar GaN surface with different size. I-V measurement results show that the size of TLM pattern and formation direction of electrode have an effect on the electrical properties of a-plane GaN. The large sized patterns show the relatively lower sheet resistance compared to the small sized patterns. In addition, the sheet resistance of a-plane GaN along m-axis shows lower values than that along the c-axis. Finally, the effects of miscut angle of r-sapphire substrate ($0.2^{\circ}$, 0.4oand $0.6^{\circ}$) on electrical properties of a-plane GaN will be discussed.

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PHASE VARIATION IN DOPPLER SIGNAL FOR VARIOUS OPTICAL PARAMETERS

  • Son, Jung-Young;Kim, Myung-Sik;Oh, Myung-Kwan
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.629-632
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    • 1989
  • The scattered light intensity from a spherical particle passing through the cross-over region of two coherent laser beams, varies periodically. Photodetection of this light beams produces a periodic signal of varying amplitude. The phase of the signal varies with the particle size and refractive index, the beam crossing angle and wavelength, and the position and size of the scattered ligth collecting aperture. In this paper the phase variation with respect to the particle absorptive index of retraction, collecting lens size and beam crossing angle is calculated using both Mie scattering theory and reflection theory. The two theories show good agreement in phase predictions, especially for large absorptive indices and for small collection lenses. Both theories predict phase to be inversely proportional to the beam crossing angle.

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Pool-Boiling Critical Heat Flux of Water on Small Plates: Effects of Surface Orientation and Size

  • Yang, Soo-Hyung;Baek, Won-Pil;Chang, Soon-Heung
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.337-342
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    • 1996
  • The pool-boiling critical heat flux (CHF) of water on small flat plates has been experimentally investigated focusing on the effects of the inclination angle and size of the heated surface under near atmospheric pressure. The second-phase experiment was accomplished to find out the general CHF behavior for over-all inclination angles from -90$^{\circ}$ to 90$^{\circ}$using two plate-type test sections (30$\times$150 mm and 40$\times$150 mm) submerged in a slightly subcooled water pool. Test results generally confirm the first-phase findings and show little effect of inclination angle for inclined upward-facing cases. CHF position moves to lower position with the increase of the heater characteristic size and inclination angle(from -30$^{\circ}$to 60$^{\circ}$).

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A Study on Dust Collection Efficiency of Axial-vane Type Cyclone for Oil Mist (오일미스트용 축상 유입식 사이클론의 집진효율에 관한 연구)

  • Yi, Chung-Seob;Shin, Hae-Joong;Lee, Chi-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.415-420
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    • 2012
  • Dust collecting performance of axial-vane type cyclone for oil mist was analyzed in this study. For predicting cut diameter size of cyclone, the number and angle of vane (${\beta}_2{^{\prime}}$) was calculated by CFD. As the result, ${\beta}_2{^{\prime}}$ was decreased as the number of vane was increased and the angle of inclination (${\beta}_2{^{\prime}}$) decreased, and it cause strong swirl flow. Therefore, it could be confirmed that as the number of vane was increased and the angle of inclination was decreased, cut diameter size was decreased. Also, by verifying the results of CFD through experiment, the cut diameter size could be 2 ${\mu}m$ at 4 $m^3/min$ of flow rate.

Spray Characteristics on Shape of Twin Fluid atomizer by Internal Mixing Chamber Type (내부혼합형 2유체 분사노즐의 형상에 따른 분무특성)

  • 윤수환;정대인;하종률
    • Journal of Advanced Marine Engineering and Technology
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    • v.18 no.4
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    • pp.43-52
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    • 1994
  • I investigated experomentally the spray characteristics to the operating conditions and the shapes of internal mixing twin fluid atomizer. The wide variations of air per liquid ratio are conducted to predit the influences of the Sauter mean diameter(SMD), spray angle, distribution of drop size, the flowing condition of gas and length, flowing, area of gas and liquid, and diameter, number and place of the orifice. In this experiment, air per liquid raio, mixing chamber length per diameter, orifice diameter, and the flowing area ratio of gas and fluid influences greatly on SMD, spray angle, distribution of drop size and intermittent fluctuation region.

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An Experimental Study on Passive Earth Pressure of 3-Dimension (3차원 수동토압에 관한 실험적 연구)

  • 김기동;이상덕
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.489-496
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    • 1999
  • The safety of a structure can be improved by applying the three dimensional passive earth pressure. Because the three dimensional passive earth pressure is much larger than the two dimensional passive earth pressure and it is determined by the size(width B and height H) and the wall frictional angle of the resistant wall. Therefore, the three dimensional passive resistance behavior was studied through the model tests in sandy ground, where the size of the resistant wall and the wall frictional angle were varied. The results show that three dimensional passive earth pressure is 1.1∼3.4 times larger than that of the two dimensional value depending on the wall size and the wall friction.

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Airway size in malocclusions with hyperdivergent skeletal pattern (개방교합성 골격헝태를 갖는 부정교합자의 기도크기)

  • Kwak, So-Yeong;Kim, Hyo-Young;Jeon, Young-MI;Kim, Jong-Ghee
    • The korean journal of orthodontics
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    • v.33 no.4 s.99
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    • pp.293-305
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    • 2003
  • The pharynx have significant locations and functions because it forms a part of the unit in which respiration and deglutition are carried out. Because of the closed relationship between the pharynx and the dentofacial and craniofacial structure, many studies are carried out on this subjects. The purpose of this study were to compare the airway size including pharynx, soft palate, tongue and hyoid bone between normal and hyperdivergent skeletal pattern and to evaluate the change of those size in different age. The sample of this study were consisted of 51 subjects in normal group, 52 subjects in hyperdivergent group. Each was divided into two subgroups by age , child group(9-l2yr old) and adult group(18yr old over). The lateral cephalometric radiographs were taken and the distance, angle and ratio of the facial skeleton, pharynx, soft palate, tongue and hyoid bone were measured and evaluated statistically. The result obtained were summarized as follows : 1 SN-Mn angle, FMA, and Pal-Mn angle were significantly larger in child group than adult group, but the lower anterior facial height(LAFH) and facial height ratio(FHR) were significantly smaller in child group than adult group. Occlu-Mn angle was significantly steep in hyperdivergent group than normal, but not significantly different between child group and adult group. 2. Hyperdivergent group and child group had the stronger correlation between SN-Mn angle, FMA, Pal-Mn angle, LAFH and FHR and airway size than normal group and adult group. Hyperdivevgent child group had significant negative correlation between SN-Mn angle, FMA, Pal-Mn angle and sagittal skeletal dimension of nasopharynx and sagittal depth of nasopharyngeal lumen. Significant positive correlation were seen between LAFH and vertical measurement of airway. 3. There was no difference of the linear measurement of airway size between hyperdivergent group and normal group. 4. Adult group had smaller posterior pharyngeal wall, target nasopharyngeal depth longer nasopharyngeal height and longer pharyngeal length than child group. 5. The sagittal measurement of hyoid bone had no difference between child group and adult group. But adult group had larger vertical measurement of hyoid bone than child group.

Some Relations Between the Geometric Parameters and Internal Flow Field Characteristics in Multiblade Fan/Scroll System (다익 홴/스크롤 시스템의 형상변수와 내부 유동장 특성과의 관계)

  • Maeng, Joo-Sung;Yoo, Dal-Hyun;Lee, Kwang-Ho;Park, ln-Gyu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.9
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    • pp.1139-1147
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    • 2000
  • This paper describes that the size of inactive zone can be directly applied to design multiblade fan/scroll system. From the experimental studies using a five hole pitot tube and smoke test, it is found that the size of inactive zone has linear relations with the mean velocity of impeller inlet and cut-off angle gives a great influences to the fan efficiency. For the practical design, a function related with geometric parameters(i.e. inner radius, cord length, cut-off clearance and cut-off angle) of fan/scroll system is suggested. By using these formulas, the size and distribution of inactive zone can be predicted without the measurements through the full domain, it can be possible to use them to know the efficiency improvement for new model designed.

A Study on the Variation of Collar Edge and Height according to the Angles of Collar Roll Line - Based on the Open Collar - (칼라 꺾임선(線) 눕힘각도(角度) 변화(變化)에 따른 외곽치수(外廓値數) 및 스탠드량 변화(變化)에 관(關)한 연구(硏究) - 오픈 칼라를 중심(中心)으로 -)

  • Lim, Ja-Young
    • Journal of Fashion Business
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    • v.9 no.2
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    • pp.143-159
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    • 2005
  • This study was done to provide basic data for clothing design and thus to contribute to the academic development at the clothing and textile area and collar roll line lay down angle variation at collar width on the open collar. The study was composed as tallows: 1. The variation at collar outer wall size increase collar roll line lay down angle size the more Increase. 2. The outer wall and stand height size increase aware at variation collar width at the more Increase. It is desirable that this study will be at help to enchancement of life style in garments and promotion of garments industury by developing the archetype basic collar pattern suitable to Korean women's garments.