• Journal of Life Science
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• v.11 no.4
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• pp.316-320
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• 2001

Sonication tremendously improves the efficiency of Agrobacterium infection by introducing small and uniform fissures and channels throughout the targeted tissue. Using shoot tips of cotton as explants, the effect of sonication treatment and virulence genes in Agrobacterium tumefaciens on transformation efficiency was investigated. The pat gene which encodes resistance to the herbicide, glufosinate, was used as a selectable marker. Transformation efficiency was evaluated on th basis of survival rates of cocultivated shoot tips on selection medium containing 2.5 mg/l gulfosinate-ammonium(ppt) adn 25. mg/l Clavamax. Sonication from 5 to 15 second has a positive effect on shoop tip survival. However, whil virE as well as virG or vir GN54D showed an enhancement in transformation efficiency, virE,. virG resulted in the most significant enhancement. Overall, the combination of additional virG/virE gene and sonication treatment resulted in the most significant increase in transformation efficiency.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.75-81
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• 2007

This research was conducted to estimate the effect of sonication and reducing agent addition on soil washing of heavy metals-contaminated soil. Sonication trained in soil washing did not significantly increased extraction efficiency of heavy metal compared to soil washing only. The extraction efficiency of sonication trained in soil washing was 12% increased for Pb in 0.01M EDTA leaching solution. Pb and Cd showed higher extraction efficiency in case of reducing agent treatment with mechanical shaking than that with sonication. However, the extraction efficiency of Cu and Zn in case of reducing agent treatment with sonication was over 2 times higher than that in with soil washing. Therefore, application of reducing agent addition with sonication or mechanical shaking should be decided differently for pretreatment of soil washing, according to the kind of heavy metal. It was estimated that sonication after adding reducing agent could increase removal efficiency of Zn or Cu-contaminated soil and shorten the treatment time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.843-848
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• 1996

As the first step of studies related to production of chitooligosaccharides by physical methods, chitosan solution were sonicated with 20 kHz and various treatment effects were examined to present fundamental data of sonicated chitosan solution. Intrinsic viscosity of chitosan solution sharply decreased from 3.76 dl/g to 2.90 dl/g until 5 minutes of sonication and then slowly decreased. With low volume of chitosan solution, sonication was very effective and temperature of chitosan solution slightly affected the efficiency of sonication. In case of changing the solvent, no significant differences were observed on the effect of sonication, however, acetate buffer had highest sonication effect among various solvents. The sonication effect was increased as the increasement of the value of pH, on the contrary, ionic strength and type of counterions showed no effect on sonication. With these results, we assumed that optimal sonication treatment would be as follows, solution volume was $10\~20\;ml$, temperature range was $20\~30^{\circ}C$, pH value of solution was 4.5 and type of solvent was acetate buffer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.415-418
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• 2004

The effects of sonication and vacuum infiltration on transformation efficiency was investigated by using immature embryos of Korean wheat as explants. Two Agrobacterium tumefaciens strains, KYRT1 and EHA105, carrying pCAMBIA 1305.1 were used. Transformation efficiency was demonstrated by the detection of $\beta-glucu-ronidase$ (GUS) activity. GUS expression showed clear difference among Korean wheat cultivars. Geurumil showed higher GUS expression efficiency $79.1\%$ compared with other cultivars. The effects of the duration of vacuum infiltration and sonication treatment showed a tendency high GUS expression efficiency by their combination. In comparison with other Agrobacterium strains, KYRT1 showed high efficiency in most Korean cultivars.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.893-906
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• 2011

The effect of ultrasound pretreatment on sludge degragability was investigated at different condotions: ultrasonic frequency(28, 40, 50kHz), intensity(10, 25, 50W), sonication time(10, 20, 30, 60min). Total suspended solid(TSS) and soluble chemical oxygen demand(SCOD) concentration were measured for the evaluation of pretreatment efficiency. The pretreated sludge was used as the feedstock for anaerobic digestion process. Biogas production and volatile suspended solid(VSS) removal were determined for evaluating the process performance. 1. TSS concentration of the sludge decreased at a constant rate as sonication operation was applied. The degradation rate of TSS increased when ultrasound frequency was decreased from 50kHz to 28kHz and intensity was increased from 10W to 50W. Efficiency of TSS degradation per input energy increased as ultrasonic frequency and intensity were decreased. At the frequency of 28 and 40kHz, SCOD concentration rapidly increased during the initial 30min of sonication time, and then it gradually increased. At 50kHz, SCOD concentration constantly increased for 60min of the sonication time. The SCOD production rate increased with increasing intensity under all ultrasound frequencies. 2. The optimum condition of ultrasound treatment was 28kHz, 50W and 60min for maximizing the biogas production, methane fraction, VSS removal. The highest values in biogas production, methane fraction in biogas, VSS removal were 370ml, 70%, 2.45g, respectively. Methane production rate per input energy increased at ultrasonic frequency and intensity decreased. 3. When raw sludge was pretreated at the condition of ultrasonic frequency of 28 and 40kHz in series, sequential-frequency sonication, intensity of 50W and 60min, biogas production, methane fraction, VSS removal were about the same that of 28kHz single-frequency sonication. When sequential-frequency sonication of 28 and 50kHz was applied in series, biogas production, methane fraction, VSS removal were 356 ~ 423ml, 69 ~ 71%, 2.41 ~ 2.78g, respectively. The pretreatment efficiency of 28-50kHz sequential-frequency sonication which sonication time of 28kHz and 50kHz was 40min and 20min was higher than that of 28kHz single-frequency sonication.

• Journal of the Mineralogical Society of Korea
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• v.23 no.1
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• pp.85-91
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• 2010

The various forms of heavy metals in soil environments have been studied by sequential extraction method. We tested conventional Tessier sequential extraction and new ultrasound-sonication extraction methods, and compared their extraction efficiency. Total As, Cd, Cu, Pb, and Zn contents of the target soil (NIST SRM 2710 Montana Soil), by three methods (USEPA Method 3050B, KBSI Method, and ultrasound-sonication method) were all consistent with the certified values. Sequential extraction efficiency along with step-wise extraction values was similar in both Tessier method and ultrasound-sonication method. The ultrasound-sonication method took about 3 hours to complete whole procedure while the Tessier sequential extraction method took around 12 hours. Ultrasound-sonication method was estimated as one of the best methods with a relatively short application time and no requirement of high temperature treatment.

• 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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.307-316
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• 2016

Objectives: In general, NIOSH method 5506 is most widely used for the occupational exposure measurement of PAHs, but 2-4 ring PAHs have poor desorption efficiency, especially for a filter. The purpose of this study was to determine a method to increase the desorption efficiency of 16-PAHs using an ultrasonic extraction procedure. Methods: Test samples prepared spiked XAD-2 tubes and PTFE filters in the range of $0.01-1.0{\mu}g/mL$ for desorption efficiency study. Four different extraction solvents, acetonitrile, acetone, tetrahydrofuran and dichloromethane, were tested in order to select the most suitable solvent for the extraction of the 16 PAHs. The addition of dimethyl sulfoxide and sonication time were considered in order to determine the method with the highest extraction efficiency. All samples were made in three sets and analysis was replicated seven times by HPLC. Results: Acetonitrile and acetone were the optimized as an extraction solvent and desorption efficiency of 2-ring PAHs such as naphthalene, acenaphthylene were increased 3~19% with dimethyl sulfoxide for XAD-2. Acetone was the best extraction solvent for PTFE filter and the desorption efficiency was increased 3~13% for 2- to 4-ring PAHs. The optimum sonication time was 60 minutes and desorption efficiency increased with extraction time. Conclusions: As a result, the best extraction solvent was acetone with dimethyl sulfoxide for ultrasonic extraction procedure and the desorption efficiency of this method was better than NIOSH 5506's. This study could be applied as a method for occupational exposure measurement of PAHs.

• Journal of Biosystems Engineering
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• v.32 no.2 s.121
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• pp.121-129
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• 2007

This study was conducted to elucidate extraction efficiency by microwave technique in comparison with sonication technique for extraction of insecticide residue in pear. In the analysis of the extraction efficiency of microwave for a pear spiked with imidacloprid, the extraction efficiency by microwave power of 300 W with extraction temperature of $80^{\circ}C$, heating time of 1 to 3 minute was shown to be similar with the extraction time 20 minutes by sonication. The optimal condition. in consideration of economical condition and treatment time, for microwave extraction of imidacloprid in the pear were 300 watts of power supply, $100^{\circ}C$ of extraction temperature, 1 minute of heating time and 10 mL of acetone volume. A new microwave vessel was developed to rapidly process the sample of the insecticide imidacloprid residues in the pear. This vessel was designed to include a reaction chamber and a filtration equipment, and a gathering chamber. The system could curtail a pretreatment time to 21 minutes than sonication and 7.9 minutes than the previous microwave vessel.

• 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.