• Title/Summary/Keyword: sonication

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Ultrasound-Aided Monolayer Assembly of Spherical Silica Nanobeads (초음파 방법을 이용한 실리카 나노비드의 단층 정렬에 관한 연구)

  • Yoon, Sang-Hee;Yoon, Seo Young;Lee, Jin Seok
    • Journal of the Korean Vacuum Society
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    • v.22 no.6
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    • pp.298-305
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    • 2013
  • Uniform silica nanobeads were synthesized by St$\ddot{o}$ber method and assembled in the form of monolayer on glass substrate using sonication method. Before the assembly of silica nanobeads, glass substrates were treated with molecular linkers, such as CP-TMS and PEI, and nanobeads were dispersed in toluene. In attachment test, SO (sonication without stacking) method and SS (sonnication with stacking) method was used and sonication time was controled. After the experiment, microbalance was use to measure deviation between before and after the attachment experiment then calculate percent of coverage. Minutely observe with SEM (Scanning Electron Microscopy) then select the most close-packed and monolayer assembled cover glass and calculate DOC (Degree of Coverage). In SO method, DOC increased very sharply and reach over 140 percent point, also got lots of multi-layer region. On the other hand, in SS method DOC increased slower than SO method but more close-packed and monolayer assembled.

Sonication Effects on Froth Flotation for Deinking from Old Newspaper(ONP) (폐신문지(廢新聞紙)(ONP)로부터 부유선별(浮遊選別)을 이용한 잉크분리(分離)시 초음파처리(超音波處理) 효과(效果))

  • Lim, Gwang Il;Hwang, In Sung;Kim, Joung Woon;You, Kwang Suk;Ahn, Ji Whan;Han, Choon
    • Resources Recycling
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    • v.21 no.5
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    • pp.44-49
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    • 2012
  • In this study, the sonication method was applied to remove ink from old newspaper(ONP) using flotation. Results indicated increased whiteness and effective residual ink concentration (ERIC) with longer disintegration. Therefore 58% of whiteness and 182.9 ppm ERIC were obtained for 30 minutes of disintegration time without the change in yield. Longer disintegration than 30 minutes had no effects on whiteness without the application of ultra-sonication. On the other hand, higher than 58% of whiteness was achieved in 2 minutes of disintegration when the ultra-sonication was applied. The highest whiteness (59.32 %) was obtained by applying sonication for 20 minutes and froth flotation with kerosene as a collector under the alkaline condition (pH 11).

A Comparison of Sonication and Microwave-assisted Extraction Method for Speciation of Arsenic in Fish Tissue, DORM-2 (어류중 비소의 종분화 분석을 위한 초음파 추출법과 마이크로파 추출법의 비교)

  • Yoon, Cheol-Ho;Park, Yong-Chul;Hong, Jong-Ki
    • Analytical Science and Technology
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    • v.16 no.2
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    • pp.134-142
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    • 2003
  • Comparison of a microwave-assisted extraction with sonication extraction was performed for arsenic speciation in fish tissue with chromatographic separation and inductively coupled plasma mass spectrometry detection. The detection limits of arsenicals with ultrasonic nebulizerand cross-flow nebulizer were shown to be similar. The arsenicals investigated were arsenobetaine (AsB), arsenite [As(III)], dimethylarsine acid (DMA), monomethylarsonic acid (MMA), arsenate [As(v)], and phenylarsonic acid (PAA). Quantitative extraction of arsenicals from dogfish muscle, DORM-2, standard reference material of NRCC (National Research Council of Canada) was achieved using 50% (v/v) methanol-water in both extraction methods. Extraction efficiency of arsenobetaine in both methods is greater than 82% with RSDs on replicates of less than 5%. The concentrations of AsB determined in extract of microwave assisted extraction and sonication methods were $14.18{\pm}0.42mg\;kg^{-1}$ and $13.54 {\pm}0.84mg\;kg^{-1}$, respectively. And the concentrations of DMA were $0.45{\pm}0.06mg\;kg^{-1}$ and $0.44{\pm}0.06mg\;kg^{-1}$, respectively.

Crystal development and growth mechanism by pretreatment process for zinc crystalline glaze (아연 결정유약 전처리 공정을 통한 결정생성 및 성장의 mechanism)

  • Lee, Chiyoun
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.27 no.1
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    • pp.34-41
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    • 2017
  • In this study, the effect on the zinc nuclei crystallization caused by changes preprocessing of the zinc crystalline glaze preparation has been studied. The mechanism of the nuclei formation in the crystalline glaze and development of the nuclei by studying the preprocessing step was explained. The preprocessing step was improved by altering mixing process of the materials prior to sintering: number of sieving dispersion process and ultra-sonication prove tests with various duration of sonication. According to the result, the sieving and sonication of the starting materials facilitated the interface reactions of $ZnO-SiO_2$ from $680^{\circ}C$ where low temperature willemite is formulated, and altered Si bonding for the easier bonding between Zn-Si. In other words, solely sieving was enough to accelerate the formation of willemite in low temperature. When the particles were distributed evenly by sonication, the willemite formation was even more significant.

The Early Detection of the Spore Using Sonication and Fluorescent Dye in the Field (현장에서 초음파 파쇄와 형광시약을 이용한 포자의 조기 탐지)

  • Ha, Yeon-Chul;Choi, Ki-Bong
    • KSBB Journal
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    • v.26 no.4
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    • pp.305-310
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    • 2011
  • This study was carried out to establish the optimum condition of cell disruption with a sonicator for the detection of the spore, Bacillus anthracis ${\Delta}$-sterne for the purpose of developing automatic fluorometer. The efficiency of sonication on the ${\Delta}$-sterne spore disruption was very weak. The ${\Delta}$-sterne spore with zirconia bead showed greater disruption than the ${\Delta}$-sterne spore alone when sonificated. The volumn of the zirconia bead added in the spore solution has little effect on the disruption efficiency. The detection limit of the ${\Delta}$-sterne spore with zirconia bead and the ${\Delta}$-sterne spore alone was $10^6$ CFU/mL and $5{\times}10^7$ CFU/mL respectively, when sample was sonicated for 20 seconds with a sonicator probe of 13 mm diameter.

Characteristics of deodorization for malodorants in aqueous solution by sonication

  • Yoo, Young-Eok;Maeda, Yasuaki
    • Journal of Environmental Science International
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    • v.13 no.2
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    • pp.167-173
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    • 2004
  • A aqueous solution of malodorants (i.e., n-valeraldehyde, n-valeric- acid, 2-methylisoborneol, and trimethylamine) was exposed to 200KHz ultrasound with a power of 6.0W/$\textrm{cm}^2$ per unit volume in a sonochemical reactor under room temperature and atmospheric pressure condition. The concentration of malodorants decreased with irradiation time, indicating pseudo-first-order kinetics. The removal efficiency of malodorants was about from 50% to 96% decomposed after 90 minutes sonication. At the deodorization, it was determined by triangle odor bag(TOB) method for odor sensory measurement, and it indicated that over 60% of relative odors were deodorized with degradation by the sonication.

Separation of Single-Walled Carbon Nanotubes by Length and Diameter (단일벽 탄소 나노튜브의 길이와 지름에 따른 분류)

  • Oh Young-Seok;Lee Dock-Jin;Chang Yyun-Seok;Choi Jae-Boong;Kim Young-Jin;Baik Seung-Hyun
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.3 s.180
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    • pp.171-178
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    • 2006
  • The sonication mettled is widely used with surfactants to suspend individual single-walled carbon nanotubes in solution, and it is well known that sonication-induced tube cutting occurs. Recently, it is found out that ultrasonicated nanotubes yield simultaneous separation by tube length and diameter. Nanotubes that have been cut shortest possess the greatest enrichments of large-diameter species. In this study, single-walled carbon nanotubes are cut using a ball milling method. Similar fracture behavior is observed fur the ball milled nanotubes: i.e., large diameter tubes are cut shorter. The ability to separate carbon nanotubes by diameter and length will contribute to tile development of nanotube-based applications.

Comparative Sonophotocatalysis and Photocatalysis for Chloroform Degradation (Sonophotocatalysis와 Photocatalysis를 이용한 Chloroform의 광산화)

  • Park, Jae-Hong;Cho, Il-Hyoung
    • Journal of Korean Society on Water Environment
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    • v.21 no.3
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    • pp.263-266
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    • 2005
  • Comparison between photocatalysis (UV+$TiO_2$) and sonophotocatalysis (Sonication+UV+$TiO_2$) were performed in lab-scale experiments for the treatment of chloroform. The effect of operational parameters, i.e., initial chloroform concentration, $TiO_2$ concentration, UV light intensity and sonication time on the degradation rate of aqueous solution of chloroform has been examined. The optimal conditions for photocatalysis and sonophotocatalysis processes were determined: initial chloroform concentration was 25 mg/L, the concentration of $TiO_2$ was 200 mg/L and UV light intensity was $6.630 mW/cm^2$, respectively. The optimal sonication time on sonophotocatalysis process was 90 min. Under the optimal conditions, sonophotocatalysis was effective for inducing faster degradation of the chloroform.

ON THE SONO-VOLTAMMETRY CURVES OF POLYCRYSTALLINE PLATINUM ELECTRODE IN SULFURIC ACID SOLUTION

  • Chiba, Atsushi;Kobayashi, Katsuyoshi;Yamashita, Tsugito
    • Journal of the Korean institute of surface engineering
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    • v.32 no.3
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    • pp.366-371
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    • 1999
  • The volumetric curve was characterized by current functions of large amplitude and formation peak potential of adsorption oxygen (O(a)) was disappeared with sonication. The reduction peak potential of O(a) shifted about 0.05 V to noble direction in saturated $N_2$ and air systems with addition of $Cl^{-1}$ ion and sonication. The formation and ionization potentials of adsorption hydrogen (H(a)) had not been confirmed, and were not changed with sonication.

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Optimization of Conditions for High Concentration of Eleutheroside E and Chlorgenic Acid Components of Acanthopanax koreanum Stem Extract

  • Kim, Sung Gi;Yang, Byung Wook;Lee, Jae Bum;Kim, Sa Hyun;Ko, Sung Kwon
    • Biomedical Science Letters
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    • v.26 no.4
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    • pp.319-326
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    • 2020
  • This study was conducted to develop a new functional material by optimizing the conditions for high concentrations of chlorogenic acid and eleutheroside E in Acanthopanax koreanum stem. The total phenolic compound content was the highest in the 20 hours sonication Acanthopanax koreanum stem extract (UAK-20). In addition, eleutheroside E, a typical functional ingredient of Cortex Acanthopanacis, in the 20 hours treated Acanthopanax koreanum stem extract showed the highest content at 1.646%. However, another functional ingredient, chlorogenic acid, showed the highest content of 2.625% in 1 hour treated Acanthopanax koreanum stem extract. Therefore, it is considered that the optimal conditions for high concentrations of total phenolic compound and eleutheroside E are 20 hours sonication Acanthopanax koreanum stem extract.