• Title/Summary/Keyword: Stripping

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ORTHODONTIC TREATMENT USING AIR-ROTOR STRIPPING WITH ESSIX ANTERIOR ANCHOR (Air Rotor Stripping with Essix Anterior Anchor를 이용한 교정치료)

  • Yang, Kyu-Ho;Kim, Sug-Eui;Choi, Nam-Ki
    • Journal of the korean academy of Pediatric Dentistry
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    • v.26 no.1
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    • pp.119-125
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    • 1999
  • Conventional interproximal stripping using abrasive strips is normally limited to the anterior teeth. The strips must be forced between the contact points of the teeth creating patient discomfort and the risk of cutting gingival tissue. Air-rotor stripping(ARS) with Essix anterior anchor enables the clinician to remove a precise amount of interproximal enamel to create space, primarily in the buccal quadrants, for aligning or retracting teeth. In selected cases, ARS can resolve significant differences in ratios of tooth site to arch length, and the technique can become an alternative to extraction or expansion. ARS can create substantially more space than that is usually obtained by conventional interproximal stripping, and it can be done at any time during treatment without discomfort to the patient and without adversely affecting the function of the dentition, interocclusal relations, or tooth form.

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Selective transport of Cadmium by PVC/Aliquat 336 polymer inclusion membranes (PIMs): the role of membrane composition and solution chemistry

  • Adelung, Sandra;Lohrengel, Burkhard;Nghiem, Long Duc
    • Membrane and Water Treatment
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    • v.3 no.2
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    • pp.123-131
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    • 2012
  • This study investigated the extraction and stripping performance of PIMs consisting of PVC and Aliquat 336. Extraction and stripping of three representative heavy metals - namely $Cd^{2+}$, $Cu^{2+}$, and $Zn^{2+}$ - by the synthesized membranes were evaluated as a function of sodium chloride concentration and under different stripping solutions (0.01 M $HNO_3$, Milli-Q water, 0.01 M HCl and 0.01 M NaOH), respectively. Results reported here indicate that the formation of negatively charged metal chloride complex species was responsible for the extraction of the target metal to PIMs. Experimental results and thermodynamic modeling of the speciation of chloro metal complexes further confirm that the extraction selectivity between $Cd^{2+}$, $Cu^{2+}$ and $Zn^{2+}$ can be controlled by regulating the chloride concentration of the feed solution. An acidic solution without any chloride was the most effective stripping solution, followed by Milli-Q water, and a diluted hydrochloric acid solution. On the other hand, the stripping of metals from PIMs did not occur when a basic stripping solution was used.

Stripping Method of Ring Laser Gyroscope Based on Measurement Model of Dither Motion (디더 운동 측정치 모델 기반 링레이저 자이로 스트리핑 방법)

  • Kim, Cheon-Joong;Shim, Kyu-Min
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.4
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    • pp.531-536
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    • 2014
  • There are trapping and stripping methods as the technique to remove the dither motion from RLG(Ring Laser Gyro) output. V/F converter output of angular sensor to measure the dither motion is used in stripping method. But bias and scale factor error is always included in V/F converter output and is a critical limiting factor for the wide application of stripping method to RLG. Therefore there have been many researches to solve this problem. The method to accurately estimate the bias and scale factor error of V/F converter using measurements of the angular sensor acquired at data sampling rate of INS is presented in this paper. To this end, stripping technique based on model of dither motion is newly applied.

Performance Evaluation of the MAC Protocols for WDM Metro Ring with Wavelength-Shared Nodes Connecting Broadband Access Networks (대역 액세스 망을 연결하는 파장 공유 노드 기반 WDM 메트로 링의 MAC 프로토콜 성능 평가)

  • So Won-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.1 s.343
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    • pp.111-120
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    • 2006
  • In this paper, a node architecture of WDM metro network for connecting broadband access networks to converge wire/wireless networks. In consideration of the proposed node architecture and network requirements we proposed and evaluated medium access control protocols. We review WDM related technologies of sub-carrier multiplexing and optical components in order to resolve the bottleneck between optical backbone networks md access networks, and a access node architecture sharing common wavelength is introduced. Source-stripping (SS) MAC protocol Is evaluated under the proposed functional node architecture. DS+IS (Destination-Stripping and Source-Stripping) and DS+IS (Destination-Stripping and Intermediate-Stripping) MAC protocols are described to increase the slot-reuse factor which is low on SS MAC protocol. The key function of new MAC protocols regards the optical switch module of proposed node architecture and helps intermediate or source access nodes for dropping slots to destinations of different wavelength group. Thus, slot-reuse factor increases as the MAC protocols reduce the unnecessary ring-rotation of transferred slots. We use a numerical analysis to expect bandwidth efficiency and maximum throughput by slot-reuse factor Throughput network simulation, the verification of throughput, queuing delay, and transmission fairness are compared among MAC protocols.

Vacuum Stripping of $CO_2$ from Aqueous MEA Solutions Using PDMS-PE Composite Membrane Contactor (MEA 수용액으로부터 PDMS-PE 복합막 접촉기를 이용한 이산화탄소 감압탈거)

  • Kim, Jeong-Hoon;Ahn, Hyo-Seong;Kim, Jeong-Hoon
    • Membrane Journal
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    • v.22 no.1
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    • pp.46-53
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    • 2012
  • Low-temperature carbon dioxide stripping by a vacuum membrane stripping technology was studied as a substitute for the stripping process in a conventional aqueous amine process. Composite membranes with $5{\mu}m$ thickness of PDMS (polydimethylsiloxane) dense layer on a PE (polyethylene) support layer were prepared by a casting method and used as a membrane contactor for $CO_2$ stripping. Aqueous amine solutions of 30 wt% MEA (monoethanolamine) were used as absorbents. $CO_2$ flux was examined under various operating conditions by varying the vacuum pressure (60~360 mmHg (abs.)), stripping temperature ($25{\sim}80^{\circ}C$), $CO_2$ loading (0.5~0.7). $CO_2$ stripping flux increased with increasing temperature and $CO_2$ loading as well as decreasing vacuum pressure. PDMS-PE composite membrane has stability for vacuum stripping process compared with PTFE porous membrane.

Analysis of Arsenic(III) by the Cathodic Stripping Voltammetry (음극 벗김 전류법을 이용한 비소(III) 분석에 관한 연구)

  • Yun, Young Ja;Lee, Hyung Sook;Ko, Weon Bae;Kim, Chung Hee
    • Analytical Science and Technology
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    • v.5 no.4
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    • pp.417-423
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    • 1992
  • The effects of metal ions on the arsenic(III) stripping peak were examined by the cathodic stripping voltammetry. The reduction stripping peak potential and current of arsenic(III) value were -0.79V(vs. Ag/AgCl). $0.86{\mu}A$ by using 0.1N-hydrochloric acid solution. When 10 times of Cu(II) was added to the solution, the reduction stripping peak potential of arsenic(III) was the value of -0.84V(vs. Ag/Cl), which showed a good agreement with theoretical value -0.84V(vs. Ag/Cl) by using 0.1N hydrochloric acid solution. Lead(II) and copper(II) increased the stripping peak heigh of arsenic(III), Among them, the copper(II) extremely enhanced it.

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Stripping of High-Dose Ion-Implanted Photoresist Using Co-solvent and Ultra-sonication in Supercritical Carbon Dioxide (초임계이산화탄소 내에서 공용매 및 초음파를 이용한 고농도이온주입 포토레지스트의 제거)

  • Kim, Seung-Ho;Lim, Kwon-Taek
    • Clean Technology
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    • v.15 no.2
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    • pp.69-74
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    • 2009
  • A high-dose ion-implanted photoresist (HDIPR) was stripped off from the surface of a semiconductor wafer by using a mixture of supercritical carbon dioxide and a co-solvent. The additional ultrasonication improved the stripping efficiency remarkably and thus reduced the stripping time by supplying physical force to the substrate. We investigated the effect of co-solvents, co-solvent concentration, and stripping temperature and pressure on the stripping efficiency. The wafer surfaces before and after stripping were analyzed by scanning electron microscopy and by an energy dispersive X-ray spectrometer. The HDIPR could be stripped off completely in 3 min with 10%(w/w) acetone/sc$C0_2$ mixture at 27.6 MPa and 343 K.

Hydrogen Plasma Characteristics for Photoresist Stripping Process in a Cylindrical Inductively Coupled Plasma

  • Yang, Seung-Kook;Cho, Jung Hee;Lee, Seong-Wook;Lee, Chang-Won;Park, Sang-Jong;Chae, Hee-Sun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.4
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    • pp.387-394
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    • 2013
  • As the feature size of integrated circuits continues to decrease, the challenge of achieving an oxidation-free exposed layer after photoresist (PR) stripping is becoming a critical issue for semiconductor device fabrication. In this article, the hydrogen plasma characteristics in direct plasma and the PR stripping rate in remote plasma were studied using a $120{\Phi}$ cylindrical inductively coupled plasma source. E mode, H mode and E-H mode transitions were observed, which were defined by matching the $V_{rms}$ and total impedance. In addition, the dependence of the E-H mode transition on pressure was examined and the corresponding plasma instability regions were identified. The plasma density and electron temperature increased gradually under the same process conditions. In contrast, the PR stripping rate decreased with increasing proportion of $H_2$ gas in mixed $H_2/N_2$ plasma. The decrease in concentration of reactive radicals for the removal of PR with increasing $H_2$ gas flow rate suggests that NH radicals have a dominant effect as the main volatile product.

Evaluation of Moisture Susceptibility of Asphalt Mixtures Using Boiling Water Test (보일링 시험을 통한 아스팔트 혼합물의 수분민감성 평가)

  • Kim, Jun;Park, Dae-Wook;Vo, Viet Hai;Kim, Hyeok-Jung;Park, Jun-Sang
    • International Journal of Highway Engineering
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    • v.17 no.1
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    • pp.77-82
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    • 2015
  • PURPOSES : The purpose of this paper is to evaluate the moisture susceptibility of asphalt mixtures containing developed liquid anti-stripping agents using the boiling water test as a screening test. METHODS : The boiling water test was used to evaluate the moisture susceptibility of asphalt mixtures containing different anti-stripping agents. The tensile strength ratio was calculated to compare the moisture susceptibility of the asphalt mixtures after indirect strength tests were performed. Additionally, image analysis techniques were used to calculate and analyze the quantity of stripped area in the asphalt mixtures. RESULTS : In general, the asphalt mixtures containing anti-stripping agents showed a higher resistance of anti-stripping based on the boiling water test and tensile strength ratio. CONCLUSIONS : The boiling water test can be used to differentiate the resistance of moisture susceptibility of asphalt mixtures, except for asphalt mixtures containing hydrated lime. The boiling water test can be used as a screening test for asphalt mixtures before conducting time consuming and expensive indirect tensile strength tests.

Regeneration of $FeCl_3$ from a Spent Etching Solution Containing Nickel by Solvent Extraction (니켈 함유 에칭폐액으로부터 용매추출에 의한 $FeCl_3$의 재생)

  • Lee, Kyoung-Joo;Lee, man-Seung;Oh, Young-Joo
    • Proceedings of the Korean Institute of Resources Recycling Conference
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    • 2004.05a
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    • pp.218-226
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    • 2004
  • Solvent extraction and stripping experiments were conducted to separate iron from a spent $FeCl_3$ etching solution containing nickel. In the extraction, PC88A, MIBK and Alamine336 were tested as an extractant in various diluents. Alamine336 salt in toluene led to the highest extraction percentage of iron. Stripping percentage of iron from the loaded organic by Alamine336 increased with decreasing HCl conentration of stripping solution and with increasing volume ratio of aqueous to organic. In the operation of bench scale mixer-settler, 7 extraction stage with 1.0M Alamine336 salt in toluene and 10 stripping stage with 0.01M HCl solution resulted in a stripped solution with 133g/L of iron and in a raffinate with most of nickel together with a small amount of iron when the flow rate ratio of organic to aqueous was 7.

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