• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
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• pp.149-152
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• 1999

A new process for deinking of colored offset newsprint, i.e. enzyme treatment in cooperation with ultrasonic wave was developed in the present study. The physical characteristics such as fiber length, coarseness, crystallinity index of the deinked pulps were investigated and the sugar residues released from the treatment were analyzed. It was found that colored offset newsprint could be deinked effectively by cellulase treatment when ultrasonic wave was applied. The brightness increased by 5% ISO over that of control experiment and the pigment content was reduced markedly. Though the ultrasonic wave had little effect on the strength and crystallinity of the pulp, the treatment of enzyme combined with ultrasonic wave reduced the coarseness and fiber length to some extent. It was also found that ultrasonic wave could accelerate the hydrolysis of cellulose and hemicellulose during the cellulase treatment.

• 펄프종이기술
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• 제45권5호
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• pp.44-48
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• 2013

Ultrasonic treatment of KOCC was tried to explore the possibility for improvement of KOCC quality as a raw material for making industrial packaging paper and paperboard. The effect of pH, stock consistencies and treatment times on the ultrasonic response of KOCC were investigated. WRV, apparent density, tensile index and burst index were improved as pH of KOCC slurry is increased. However highest tear index and stiffness were obtained at pH 8. It was also found that the highest WRV and strength properties could be obtained at 0.5% of KOCC consistency during ultrasonic treatment. WRV and most strength properties were improved with ultrasonic treatment time. It was found that ultrasonic treatment can be used as a useful mean for KOCC modificaton.

• Journal of the Korean Wood Science and Technology
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• 제32권3호
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• pp.25-32
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• 2004

This research work explored physical and mechanical properties of impregnated sawdust boards from three softwood species (P, densifora, L. kaemferi, and P. koraiensis) with phenol-formaldehyde (PF) resin by various vacuum treatment methods of combining pressure, vacuum, and ultrasonic waves. Simultaneous vacuum and ultrasonic wave treatments with no pressure resulted in the greatest increase in resin content, density, dimensional changes (thickness and length), bending strength, and hardness of impregnated board. This result seemed to be attributed to the ultrasonic wave treatment.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.121.1-121.1
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• 2014

Recently, much attention has been given to plasma production under liquid and its applications [1]. However, most of plasma production techniques reported so far utilize high voltage dc, ac, rf or microwave power [2], where damage to discharge electrodes and small discharge volume are remained issues. As an alternative of plasma production method under liquid, we have proposed pulsed microwave excited plasma using slot antenna, where damage to the slot electrode can be minimized and plasma volume can be increased. We have also reported improvement of treatment efficiency with use of reduced-pressure condition during the discharge [3]. To realize low pressure conditions in liquid, various alternative technique can be considered. One possible technique is simultaneous injection of microwave power and ultrasonic wave. Ultrasonic wave induces pressure fluctuation with the wave propagation and is so far used for cavitation production in the water. We propose utilization of reduced pressure induced by ultrasonic cavitation for improvement of the plasma production. Correlation between the plasma production and the ultrasonic power will be discussed.

• Journal of Oral Medicine and Pain
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• 제16권1호
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• pp.103-111
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• 1991

This study was performed to observe the effect of micro-wave diathermy and ultrasonic-wave diathermy on the craniomandibular disorder patients. 19 patients were classified into 12 acute and 7 chronic groups according to the duration of 6 months. They were treated with micro-wave diathermy and ultrasonic-wave diathermy for 2 weeks and pain, maximum comfortable opening, active range of motion were checked before and after therapy. Electromyographic activities of temporal and masseter muscles were also measured at physiologic rest position, clenching and mastication before and after therapy. The obtained results were as follows : 1. After treatment, pain were reduced and active range of motion and maximum comfortable opening were increased. 2. Temporoal and masseter muscle activities of post-treatment in rest position, clenching and mastication were lower than those of pre-treatment. 3. In rest position, temporal and masseter muscle activities of pre-treatment on affected sides were higher than those on unaffected sides, but there were no differences in muscle activities between affected ad unaffected sides on clenching and mastication in pre and post-treatment respectively. 4. There were no significant differences in active range of motion, pain and maximum comfortable opening between acute and chronic groups in pre and post-treatment but there were significant differences between pre-treatment and post-treatment in acute and chronic groups respectively. 5. Muscle activities of masseter and temporal muscles in acute and chronic patients were reduced in rest position after treatment.

• Journal of Forest and Environmental Science
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• 제23권2호
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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.

• 산경연구논집
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• 제9권12호
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• pp.23-29
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• 2018

Purpose - The purpose of this study is to apply a cost effective ultrasonic odor reduction method that generated micro-bubbles using ejector to the Southeast Asian wastewater market. Research design, data, and methodology - A leather maker located in Ansan-city, Gyunggi-do, South Korea was sampled from the collection tank to select experimental materials. Experimental setup consisted of circulating water tank-air ejector-ultrasonic device, and circulating wastewater. Sample analysis was performed by CODcr, T-N, T-P, and turbidity by the National Environmental Science Institute. Results - Experimental results show that it is most effective in removing odors when the frequency range of ultrasonic wave is 60~80 Khz and the output is 200 W. It showed that the concentration of complex odor dropped from a maximum of 14,422 times to a minimum of 120 times. Also, analysis of ammonia and hydrogen sulfide in specific odor substances has shown that they were reduced from 1.5 ppm to 0.4 ppm and from 0.6 ppm to 0.1 ppm, respectively. Conclusions - It is possible to shorten more than 12 hours in the treatment of micro-organisms. It can be seen that the processing time of odor after ultrasonic treatment in the pre-treatment facility is reduced by 25% when compared to the resultant micro-organisms after the chemical treatment, that is, the time of the bio-treatment of micro-organisms. Based on the results, it was confirmed that the pre-treatment method using the ultrasonic and the air ejector device of the experiment shows the effect of reducing the water pollutants and odor more effectively in a relatively short time than the conventional advanced oxidation method.

• 한국염색가공학회지
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• 제32권4호
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• pp.274-280
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• 2020

This study compared the mechanical properties of bamboo fiber composites and kenaf fiber composites through physical treatment (ultrasonic treatment). Kenaf, a composite of PP reinforced with bamboo fiber, was made using injection molding technology. PP was used as a binder and the ultrasonic treatment time of bamboo and kenaf was increased by 30 minutes to compare and study various mechanical properties of bamboo and kenaf composites through physical treatment. Interfacial properties such as internal cracks and internal structure of the wave cross section were confirmed using a scanning electron microscope (SEM). As a result of the ultrasonic treatment, most of the characteristics were fragile as the ultrasonic treatment time was increased, and it was confirmed that the natural characteristics of the twisted fibers had a great influence on the characteristics of the composite material.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 추계 기술심포지움
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• pp.138-140
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• 2001

Fluxless flip chip bonding using plasma & ultrasonic wave was investigated in order to evaluate the effect of plasma & ultrasonic treatment on the bondability of the Sn-3.5wt%Ag solder bumped die to TSM-coated glass substrate. The $Ar+10%H_2plasma$ was effective in removing tin oxide on solder surface. The die shear strength of the plasma-treated Si-chip is higher than that of non-treated specimen but lower than that of specimen bonded with flux. The die shear strength with the bonding load at 25W ultrasonic power increased to 0.8N/bump for all bonding temperature but decreased above 1.0N/bump.

• 대한기계학회논문집A
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• 제23권7호
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• pp.1215-1222
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• 1999

It is advantageous to use an NDE method to assess the mechanical properties of materials since the conventional method is time-consuming and sometimes requires cutting of sample from the material/component. This paper shows that the ultrasonic and the Barkhausen noise(BHN) methods can be used to accurately characterize forged reactor vessels. The attenuation coefficient of the ultrasonic wave was changed with heat treatment temperature and condition[as-quenched, tempered, PWHT]. The RMS[root mean square] voltage of Barkhausen noise depended on heat treatment temperature and conditions. The fracture appearance transition temperature(FATT) can be predicted using nondestructive evaluation methods.