• Journal of Forest and Environmental Science
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• v.23 no.2
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• pp.73-78
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• 2007

Ultrasonic deinkings of white ledger were carried out to confirm whether the ink removal efficiency and pulp qualities can be improved by the ultrasonic deinking. The effects of conventional pulping and ultrasonic treatment of white ledger on the ink particle size distribution and ink removal coefficient were compared. The physical properties of paper, energy consumption and effluent qualities were measured. The ultrasonic treatment of white ledger resulted in the ink particle size distribution suitable for flotation. The ink removal efficiency, brightness, breaking length and effluent quality were improved by the ultrasonic deinking. It is expected that the competitiveness of ultrasonic deinking system can be improved by the optimization of treatment condition.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.5
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• pp.239-245
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• 2022

The purpose of this study is to evaluate the degree of microstructural change of materials using ultrasonic nonlinear parameters. For microstructure change, isothermal heat-treated ferritic 2.25Cr steel and low-cycle fatigue-damage copper alloy were prepared. The variation in ultrasonic nonlinearity was analyzed and evaluated through changes in hardness, ductile-brittle transition temperature, electron microscopy, and X-ray diffraction tests. Ultrasonic nonlinearity of 2.25Cr steel increased rapidly during the first 1,000 hours of deterioration and then gradually increased thereafter. The variation in non-linear parameters was shown to be coarsening of carbides and an increase in the volume fraction of stable M6C carbides during heat treatment. Due to the low-cycle fatigue deformation of oxygen-free copper, the dislocation that causes lattice deformation developed in the material, distorting the propagating ultrasonic waves, and causing an increase in the ultrasonic nonlinear parameters.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.5
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• pp.818-823
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• 2013

In the process of sterilization during the manufacture of beverages, both the treatment time and the temperature influence the beverage taste and flavor. Therefore, to improve the beverage quality, a nonthermal sterilization method is preferred to a high-temperature one. A nonthermal method, ultrasonic treatment by shock waves from cavitation, has been known to have a sterilizing effect. In this study, to observe the effect of ultrasonic frequency and treatment time on beverage quality, batch type ultrasonic equipment was fabricated and tested. Further, to evaluate the applicability of this ultrasonic method to an in-situ process, flow type ultrasonic heptagonal equipment was fabricated and then used to perform a sterilization experiment. Subsequently, the sterilizing effect was measured under ultrasonic and low-temperature ($55^{\circ}C$) treatments. Based on the obtained results, ultrasonic sterilization technology that can be applied for treatments at flow rates of up to 3 L/min was developed.

• Fashion & Textile Research Journal
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• v.11 no.2
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• pp.337-343
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• 2009

This study systematically investigated a method for extraction of safflower (Carthamus tinctorius Linnaeus) colorants by ultrasonic treatment. Compared to pigments productivity and cell wall structures of safflower after general and ultrasonic method, the ultrasonic method showed high extraction efficiency of safflower pigments due to destruction of safflower cell wall caused by high vibration energies. Microscopic analysis confirmed the hypothesis that the ultrasonic treatment of safflower caused its cell wall structure loosened and made efficient extraction of safflower pigments. And also, LC-MS/MS analysis revealed that productivities of the yellow and red safflower pigments by ultrasonic method were 21.9% and 14.6% higher, respectively, than those of pigments extracted by general method. The ultrasonic extracted yellow and red colorants could be used to dye not only natural fibers like cotton, silk and wool, but also synthetic fiber like nylon, and generally gave a better color tone than the general extracted colorants from safflower due to the affinities of red and yellow colorant on different fibers. As the yellow and red colorant were extracted by ultrasonic treatment in water, the K/S value on of 550/440nm of cotton and rayon was increased but in the case of silk and wool the change of this value was almost not detected. Finally, this technique might provide a solution to establish reproducibility and standardization for the extraction and dyeing methods on fabrics.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.810-815
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• 2010

Ultrasonic sludge pre-treatment has been studied to enhance the performance of anaerobic digestion by increasing sludge hydrolysis which is regarded as the rate-limiting-step of anaerobic digestion. In this study, the effect of ultrasonic pre-treatment on sludge hydrolysis (solubilization) and methane production was investigated. Sludge solubilization efficiency increased with ultrasonic energy input. However, it is uneconomical to apply more than 720 kJ/L as the solubilization efficiency per energy input declines afterwards. Volatile fatty acids concentration increased after the ultrasonic sludge hydrolysis. Anaerobic batch digestion showed that methane volume reached 64.7 and 84.5 mL after 18 days of incubation with the control sludge and ultrasonically hydrolyzed sludge, respectively. Methane production potential, maximum methane production rate, and the lag time of modified Gompertz equation were changed from 70 mL, 6.4 mL/day, and 1.2 days to 89 mL, 9.6 mL/day, and 0.5 day, respectively, after the ultrasonic sludge treatment. The results proved that ultrasonic pre-treatment contributed significantly not only for the methane production but also for the reduction of anaerobic digestion time which is critical for the performance of anaerobic sludge digestion.

• Journal of the Korean Society for Heat Treatment
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• v.4 no.3
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• pp.54-62
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• 1991

The effect of tempering temperature on the ultrasonic propagation velocity at SCM 440 steel quenched from $870^{\circ}C$ and $1000^{\circ}C$ has been studied by metallurgical and crystallographical observation. The measurements of ultrasonic velocity were made on the specimen by appling an immersion ultrasonic pulse-echo technique with a constant frequency of 10 MHz. The quenched microstructure of this steel was a lath martensite. As the tempering temperature was increased, the martensite was transformed into the tempered martensite composed of cementite and carbide. The ultrasonic velocity increased with increasing the tempering temperature. It was thought that these were resulted from the microstructural transformation. The change of ultrasonic propagation velocity with quenching and tempering heat treatment was resulted from microstrain due to the change of internal stress. Considering these results concerning to the change of ultrasonic propagation velocity. the phenomena of microstructural transformation were estimated. Consequently, it was thought that the degree of quenching and tempered heat treatment of steel could be nondestructively evaluated with the change of ultrasonic propagation velocity.

• Journal of the Korean Home Economics Association
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• v.45 no.10
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• pp.13-20
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• 2007

A new method for competent extraction of safflower (Carthamus tinctorius Linnaeus) colorants by using ultrasonic device was developed. When comparing to general extraction method, the ultrasonic method showed high extraction efficiency of safflower pigments. Ultrasonic method gave a higher extraction yield of red and yellow safflower pigments than using general method. It is supposed that the extraction efficiency is to be attributed to high vibration energies from ultrasound and finally induced physical changes of the pigments. Furthermore, this study explored the effects of ultrasonic treatment into the extracted safflower pigments on dyeing of cotton fabrics. Ultrasonic treatment into the extracted pigments exhibited significantly improved dyeing properties for the cotton fabrics.

• Journal of Environmental Health Sciences
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• v.21 no.3
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• pp.102-106
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• 1995

This study was performed to examine factors affecting the decompostion of nondegradable polluants(trichloroethylene(TCE), phenol) using ultrasonic irradiation. The TCE and phenol, which are major hazard compounds causing environmental pollution, were not decomposable pollutants by conventional treatment. The results show that the oxidation and reduction reaction of ultrasound produced $H_2O_2$, $H^+$ and $OH^-$ radical, which decomposed pollutants of TCE and phenol in water. It was confirmed that the ultrasonic irradiation showed an excellent removal efficiency for the nondegradable pollutants than any other processes, utilized in the treatment of organic compounds in the industrial wastewater. Conclusively, these results suggest that ultrasonic irradiation may be highly useful for the treatment of wastewaters contaminated organic pollutants, which is difficult to treat economically by conventional process.

• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.76-84
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• 1995

This study was performed to examine the factors influenced on the decomposition of nondegradable organic pollutants( Tricholoroethylene,Benzene ) in aqueous by ultrasonic irradiation. The TCE( Tricholoroethylene ) and Benzene are major hazard compounds causing environmental Pollution and not decomposable substances by conventional treatment. The results shows that the oxidation and reduction reaction of ultrasonic Irradiation was formed the H$_{2}$O$_{2}$ , H$^{+}$ and OH$^{-}$ radical, and then theses was decomposed pollutants of TCE and Benzene in aqueous. We were conformed that the ultrasonic irradiation was excellent in removal efficiency of the nondegradable organic substances any other than processes and utilized the treatment of organic compounds in the industrial wastewater. Conclusively, these results suggest that ultrasonic irradiation may be extremely useful for the treatment of wastewater contaminated organic pollutants, which is difficult to treat economically by conventional treatment.

• Textile Coloration and Finishing
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• v.14 no.4
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• pp.214-222
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• 2002

In order to give a silk-like touch to PET fabrics, the PET fabrics were treated with NaOH alkaline solution in various conditions. In alkaline treatment, the liquor flow type pilot weight reduction apparatus with magnetostrictive ultrasonic transducer was used for the study. The weight loss of PET fabrics hydrolyzed in 4% and 6% NaOH solution, at $95^\circ{C}$ and $99^\circ{C}$ for 60min. with ultrasonic application showed 3.7~4.6% higher than that of treated fabric without ultrasonic application. From the difference of specific weight loss, the treatment condition of the maximum of hydrolyzation effect appeared at $95^\circ{C}$ in $4^\circ{C}$ and at $90^\circ{C}$ in 6% NaOH solution, respectively. During the alkali hydrolysis of PET fabrics, the decomposition rate constant(k) increased exponentially with the treatment temperature and were not related with ultrasonic cavitation. The activation energy$(E_a)$ in decomposition of PET fabrics were 21.06kcal/mol with ultrasonic application and 21.10kcal/mol without ultrasonic application. The ultrasonic application gave a little higher value of the activation entropy$(\Delta{S}^\neq)$ and a little lower value of Gibbs free energy$(\Delta{S}^\neq)$ compared with not used ultrasonic apparatus.