• 보일러설비
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• s.64
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• pp.106-107
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• 1999

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.3
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• pp.152-155
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• 2018

Ultrasonic wave technologies have been widely used in ultrasonic washing machines, ultrasonic surgery, ultrasonic welding machines, ultrasonic sensors, and medical instruments. Ultrasonic surgery can be realized through the cavitation effect of ultrasonic waves. In this study, piezoelectric ceramics were manufactured to achieve the optimum design of a piezoelectric vibrator in a handheld generator for ultrasonic surgery. The best specimen showed the excellent piezoelectric properties of kp＝0.624, Qm＝1,531, and $d_{33}=356pC/N$. Numerical modeling based on the finite element method was performed to find the resonance frequency, the anti-resonance frequency, and the displacement properties of the handheld ultrasonic generator. Maximum displacement was observed in the six-step piezoelectric vibrator at $6.36{\mu}m$.

• Polymer(Korea)
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• v.37 no.3
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• pp.316-322
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• 2013

In this study, poly(ethylene terephthalate) (PET) was treated with fluorination and ultrasonic washing treatment for hydrophilic modification of PET film. We measured the change of surface modified PET film surface characteristics using contact angle, surface free energy, FE-SEM, AFM and XPS. After direct fluorination and ultrasonic washing treatment, the water contact angle was measured to be $10.81^{\circ}$, 85% reduction compared to the untreated PET film. Total surface free energy has been measured to be $42.25mNm^{-1}$, 650% increase compared to the untreated PET film. Also RMS roughness has been measured to be 1.965 nm, 348% increase compared to the untreated PET film. Hydrophilic functional group C-OH bond concentration has increased approximately 3 times. These results are attributed to the hydrophilic functional group and cavitation due to chemical etching. From this result, it was suggested that the fluorination-ultrasonic washing treatment method could be useful to make PET film surface hydrophilic.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.51-60
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• 2020

This study was conducted to investigate changes in pesticide residues in eggplant and lettuce during washing and cooking processes after application with azoxystrobin. Eggplant was processed with running washing, steaming, and stir-frying, and lettuce was processed with soaking washing, running washing, soaking and running washing, ultrasonic cleaning, and blanching. The limit of quantitation of GC analysis of azoxystrobin was 0.01 mg/kg and the recovery rate was 84.7-109.5%. The azoxystrobin processing factors (PFs) and reduction rates in eggplant and lettuce were calculated and the results were as follows. In the case of eggplant, the azoxystrobin PF and reduction rate of running washing were 0.29 and 71.1%, respectively, those of steaming were 0.32 and 68.0%, respectively, and those of stir-frying were 0.24 and 75.7%, respectively. In the case of lettuce, the azoxystrobin PF and reduction rate of soaking washing were 0.25, 75.3%, those of running washing were 0.61 and 38.9%, respectively, those of soaking and running washing were 0.32, 68.0%, those of ultrasonic cleaning were 0.47 and 53.1%, respectively, and those of blanching were 0.26 and 73.6%, respectively. It could be identified that pesticide residues in eggplant and lettuce can be effectively reduced through washing and cooking processes and that most of pesticide residues were removed when cooking processes were undergone after washing. Therefore, azoxystrobin PFs after washing and processing can be provided as basic data for risk assessment.

• Textile Coloration and Finishing
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• v.13 no.3
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• pp.180-187
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• 2001

Generally, polyester microfiber has much greater dye uptake than that of regular ones. In spite of high dye up-take visual shade depth of dyed fabric decreases with smaller denier, which results in poor washing fastness of dyed fabric. In this study, in order to investigate the washing fastness, polyester microfiber fabric was dyed by using two type of disperse dyes and treated with 3 different reduction clearing methods. The reduction clearing methods in this study are normal alkaline reduction clearing, $N_2$ gas replacement method, and ultrasonic treatment during reduction clearing. The results were as followings ; The most important factors affecting the washing fastness of polyester artificial suede fabric were found to be the reduction clearing method, the chemical structure of used disperse dyes and the structure and denier of fibers. It was also obtained that the heat treatment of dyed fabric decreased the washing fastness due to the dye migration from inner phase to surface.

• Resources Recycling
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• v.3 no.3
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• pp.32-49
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• 1994

Hydration process is one of the basic carbonation system. Limestone sludge produced in Pohang Iron & Steel Co., Ltd. We tested for identify of hydration characteristics. The result obtained in this study can be summarized as follows; 1. The classify of limestone sludge is type of ground calcium carbonate(-3mm+325mesh)and the major mineral of calcite, and further more high grade(CaO 51%), fine powder(15~22$\mu\textrm{m}$). 2. Limestone sludge mixed two process sludge, first one is washing process sludge and the other one is wet collect kiln dust. The composition rate is about 8:2. Wet collect kiln dust is major mineral of calcite, too. But the sludge is assumed to one by quick lime, slaked lime and unreacted natural limestone. So, the ideal process is dividing of the washing process sludge and wet collect kiln dust. 3. We manufactured of slaked lime from limestone sludge. To investigate the effect of hydration reactor, the experiments was done with various reactor type as magnetic stirrer, shaking incubator and ultrasonic vibration reactor, respectively. Generally, ultrasonic vibration reactor is excellent hydration for limestone sludge and produced very fine slaked lime powder with ideal distribution. 4. The optimum condition is 10% pulp density, when the manufacture of fine slaked lime powder by ultrasonic vibration reactor. And hydration times to compare the results of the study with ultrasonic vibration reactor of generalized most short time(5~10 min). 5. Finally, the dispersive characteristics of slaked lime powder measured 1~5 $\mu\textrm{m}$ from limestone sludge were compared with those of natural limestone ones(10~20$\mu\textrm{m}$), in order to check applicability of slaked lime with hydration process from limestone sludge.

• Journal of Acupuncture Research
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• v.29 no.2
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• pp.9-14
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• 2012

Objectives : This study was designed to evaluate the pesticide residue of herb medicine through high density ozone water cleaning system. Materials and Methods : We purchased ginseng(Panax ginseng) on market and sprayed pesticides (Diazinon) on ginseng. We analyzed pesticide residue according to washing methods(untreated, ozone water cleaning, ultrasonic cleaning, Water cleaning). As a result of each washing methods, in ozone water cleaning method pesticide residue was much less remained than in Ultrasonic Cleaning method and water cleaning method. Conclusions : High density ozone water cleaning is the best method for removing pesticides of herbal medicine.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.2_2
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• pp.389-395
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• 2024

The purpose of this study was to evaluate the effect of different washing solvents and washing methods on the flexural strength of 3D printed temporary resin. A bar(25 × 2 × 2 mm) was produced with a layer thickness of 50 ㎛ using an LCD-type 3D printer and divided into 15 groups(n = 10, each) according to washing solution(IPA; 99% isopropyl alcohol, TPM; 93% Tripropylene glycol monomethylether, ETL; Ethanol, TWC; Twin 3D Cleaner, and DNC; DIO navi Cleaner) and washing method(Dip; Dip washing, Ultra; Ultrasonic washing, and Auto; Automated washing). All groups were washed for 5 minutes, and post-cured for 5 minutes using a UV LED light curing machine. The Flexural strength was measured using a three-point bending test using a universal testing machine. For statistical analysis, one-way ANOVA, Tukey HSD post hoc test, Kruskal-Wallis test and post-hoc by Bonferroni-Dunn test(𝛼=.05) were performed depending on whether the normality test was satisfied. In all washing solvents except TPM and DNC, the Dip group showed the lowest flexural strength values, while the Auto group showed the highest flexural strength values except for DNC. Additionally, the washing solution showed completely different flexural strength values depending on the washing method.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.255-258
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• 1997

In order to determine the removal efficiency of pesticide residues on apples by ultrasonic cleaner, apples(Fuji var.) were artificially treated by dipping in water solution of fenitrothion EC, chlorpyrifos EC and phenthoate EC. The treated apples were washed by the ultrasonic cleaner with water, 30% ethanol solution or 0.2% detergent solution, respectively. The removal efficiency of fenitrothion, chlorpyrifos and phent-hoate by ultrasonicated washing in water for 0.5min. was 39.2%, 32.0% and 50.4%, respectively, but there was a tendency to decrease the removal efficiency of the pesticide residues as the duration of ultrasonicated washing period is increased. The maximum removal efficiency of the pesticide residues washed in the detergent solution was observed by ultrasonicated washing the samples for 5min. and it was recorded as 33.5% ; fenitrothion, 30.1% ; chlorpyrifos and 48.3% ; phenthoate, respectively. However it's appeared that the longer the ultrasonicated washing period in 30% ethanol solution the more pesticides from the apples were removed and the maximum removal efficiency of the pesticides was recorded as 66.2%(fenitrothion ; washed for 15min.), 41.7%(chlorpyrifos ; washed for 10min.), 74.2%(phenthoate ; washed for 10min.).

• Journal of Technologic Dentistry
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• v.43 no.3
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• pp.84-92
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• 2021

Purpose: The purpose of this study was to compare the dimension safety evaluation between a general ultrasonic cleaner and an ultrasonic cleaner equipped with UV-C (ultraviolet-C). Methods: An edentulous model was prepared. A denture base and an occlusal rim were fabricated, and scanning was performed. After scanning, a denture base and full arch artificial teeth were designed. The full arch artificial teeth were printed using a three-dimensional printer (n=10). The residual resin was washed with alcohol and then scanned (reference data). The printed specimens were classified and cleaned using a general ultrasonic cleaner (GU group) and an ultrasonic cleaner equipped with UV-C (UC group). After each washing, a rescan was performed (scan data). Reference data and scan data were superimposed using overlapping software. Data were statistically analyzed using the Mann-Whitney test (α=0.05). Results: In the deviation values of full arch artificial teeth, the GU group showed a high deviation of 18.02 ㎛ and the UC group showed a low deviation of 15.02 ㎛. The two groups demonstrated a statistically significant difference (p<0.05). Conclusion: Full arch artificial teeth prepared using photopolymerized resin were deformed according to the temperature of water generated in the ultrasonic cleaner. It is judged that there is no deformation according to the UV-C ultrasonic cleaner.