• Elastomers and Composites
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• v.38 no.2
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• pp.103-121
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• 2003

The application of powerful ultrasound to rubber recycling is a very recent field of study. An ultrasonic field creates high frequency extension-contraction stresses by acoustic cavitation. The breakdown of rubber network occurs primarily around pulsating cavities due to the highest level of strain produced by high-power ultrasound. Stronger reductions of cross-link density were observed at a higher pressure, indicating an important role of pressure during ultrasonic recycling. Visible bubbles were observed during ultrasonic treatment as a proof of acoustic cavitation. Shearing effect has a significant influence on improving the efficiency of ultrasonic treatment. After the ultrasonic treatment, the cross-link densities of NR/SBR blends were lower than those of NR and SBR due to the reduced degree of unsaturation and chemical reactions. Carbon black fillers increase the probability of bond scission during ultrasonic treatment, due to the restricted mobility. The mechanical properties of ground tire rubber (GRT)/HDPE blends were improved by ultrasonic treatment and dynamic revulcanization. Ultrasonic treatment of GRT in the presence of HDPE matrix was found to give better mechanical properties due to the chemical reactions between rubber and plastic phases.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.4
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• pp.36-44
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• 1997

This experiment was mainly performed with a mechanical treatment using ultrasound. We got the following conclusions : At seven minutes-ultrasonic treatment using nonionic surfactant, yield, brightness and residual ink contents were superior to other treatment, but several strength properties were decreased. On the other hand anionic surfactant was considerably low ink removal efficiency. For ultrasonic treatment using nonionic surfactant, yield and brightness were dropped when temperature was over 4$0^{\circ}C$, but were observed to be insensitive to the pulp consistency and flotation time. In the case of nonionic surfactant, tensile and burst strength were improved when ultrasonic treatment was used comparing to non-treatment, and nonionic surfactant was generally better than anionic surfactant in terms of tensile and burst strength regardless of ultrasound conditions. Several properties were decreased when anionic surfactant was used in comparison with nonionic surfactant except yield, therefore, anionic surfactant. was not proper to be used in this condition.

• Transactions on Electrical and Electronic Materials
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• v.14 no.5
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• pp.268-272
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• 2013

The aim of this study was to develop an ultrasonic tooth-whitening apparatus using piezoelectric transducers, which enhance bleaching efficiency by applying ultrasound, while performing a teeth whitening procedure. For this purpose, an ultrasonic transducer was designed and manufactured, and the effects of reduction in the whitening material's concentration and in the whitening treatment time through using the ultrasound cavitation phenomenon were confirmed. Also, the validity of this study was investigated by comparing the whitening performance with a commercialized optical whitener, through color comparison. The results revealed that the ultrasound whitener produced color values that were enhanced by as much as double that of the conventional LED light whitening method. Even when the operational time was reduced by half, the ultrasound method showed superior performance by over 54% compared to the conventional light whitener, revealing that the ultrasound method showed a remarkable treatment reduction effect.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.1
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• pp.50-58
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• 2011

Ultrasound-guided intervention is very safe and useful for the treatment of shoulder pain. Injection techniques vary according to the diseases causing shoulder pains. This review tried to describe various methods of the ultrasoundguided intervention around the shoulder joint.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1511-1514
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• 2009

Liquid whole egg (LWE) was subjected to high hydrostatic pressure (HHP), a consecutive combination of nisin and HHP (nisin-HHP), or a consecutive combination of ultrasound and HHP (ultrasound-HHP), and functional properties of processed LWE were compared to those of raw LWE. Little changes in foaming and emulsifying properties were observed by the application of HHP alone and the combined process of nisin and HHP. In contrast, ultrasound-HHP combination resulted in significant changes in color, foaming, and emulsifying properties. The maintenance of functional properties after HHP treatment agreed with expectation, because the HHP processing condition had been selected where minimal rheological changes had occurred.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.522-529
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• 2009

To supply safe drinking water to areas lacking in water supply and drainage system, such as rural area and military bases in proximity to Demilitarized Zone, effective method for treating organic contaminants such as MTBE is required. This study focuses on seeking optimal conditions for effective degradation of MTBE using a bath type ultrasound reactor. Effectiveness of MTBE degradation by ultrasound is dependent on the frequency, power, temperature, treatment volume, initial concentration, catalyst, etc. In this study the degradation rate of MTBE by ultrasound was proportional to power/unit volume ratio and removal is relatively more efficient for 0.1 mM than for 1 mM of MTBE solution. Efficiency of ultrasound treatment for 1 mM MTBE solution was enhanced under bath temperature of $30^{\circ}C$ compared to $4^{\circ}C$, but the temperature effect was negligible for 0.1 mM MTBE solution. Also for 0.1 mM MTBE solution, effect of catalyst such as $TiO_2$ and $Fe^0$ on treatment speed was negligible, and zeolite even increases the time taken for the degradation. Under these specific experimental conditions of this study, the most determinant factor for degradation rate of MTBE in solution was frequency and power of ultrasound. The results have shown that a continuous ultrasound reactor system can be used for small scale remediation of organically polluted groundwater, under optimal conditions.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.1
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• pp.17-24
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• 2005

Local treatment for tumors has developed from extended radical surgery to function preserving surgery on the basis of modern biology. With the development of minimally invasive technique, it changed to be minimal-invasive surgery. And nowadays technical revolution made non-invasive surgery possible with appearance of several kinds of non-surgical knives such as gamma knife, cyber knife, and HIFU (high intensity focused ultrasound) knife. In this article, history, HIFU machine and treatment procedure, histological change and its mechanism, clinical applications, advantage, disadvantage, and future prospect of extracorporeal high intensity focused ultrasound therapy using HIFU knife will be reviewed.

• Clinics in Shoulder and Elbow
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• v.25 no.1
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• pp.57-64
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• 2022

Background: There are various conservative treatment options for lateral epicondylitis (LE). The aim is to evaluate pain, daily functioning, and complications after ultrasound-standardized autologous blood injections in patients with LE. Methods: For this prospective cohort study, consecutive patients (>18 years) diagnosed with LE were included. Autologous blood was injected using a medical device containing an injection disposable with 12 small needles (Instant Tennis Elbow Cure [ITEC]) device. Patient-Rated Tennis Elbow Evaluation (PRTEE), subjective elbow score (SES), palpation and provocation pain, satisfaction, and complications of treatment were measured at baseline and two months after treatment. Paired t-tests and Fisher's exact tests were used for calculating the difference between pre- and post-treatment outcomes. Results: Fifty-five elbows were analyzed. Mean time between pre- and post-treatment was 11.1 weeks (standard deviation [SD], 8.9 weeks). The mean PRTEE score decreased from 68.2 (SD, 15.7) before surgery to 53.2 (SD, 25.9; p<0.001) after. The mean SES improved from 36.9 (SD, 20.8) to 51.7 (SD, 27.4; p<0.001). Despite this improvement, only 44.7% of patients showed relevant clinical improvement in PRTEE, and 37.3% showed significant clinical improvement based on SES. Four patients reported a complication and the injection disposable failed three times. Conclusions: Ultrasound-standardized autologous blood injection using the ITEC device is not an effective tool in reducing symptoms related to LE. This study showed that only half of all patients experienced a positive effect. In this heterogeneous cohort of patients, we showed no added value of ultrasound standardization.

• Journal of Acupuncture Research
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• v.39 no.2
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• pp.105-114
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• 2022

Background: The objective structured clinical examination (OSCE) is used in the colleges of Korean Medicine, but few studies have validated the OSCE evaluation criteria or post-education questionnaires. Diagnostic ultrasound is used in Korean medicine treatment including acupuncture, acupotomy, and pharmacopuncture to increase the safety and efficacy of treatment. We aimed to develop and validate a OSCE checklist and questionnaire for diagnostic musculoskeletal ultrasound training. Methods: A OSCE checklist and rubric for diagnostic ultrasound training, and questionnaire was developed using literature research. Eight expert panelists verified each draft item in a single-round survey. Items with a content validity ratio (CVR) < 0.75 were excluded or modified to reflect the experts' opinions. Results: The OSCE checklist and rubric for diagnostic ultrasound training focusing on volar wrist and carpal tunnel syndrome included: 15 items revised according to CVR and expert opinions, the pre-examination procedure, structures to be identified by ultrasound, scans with 2 diagnostic criteria for carpal tunnel syndrome, an explanation of the exam results, and the post exam procedure. The questionnaire consisted of 15 items, including the overall evaluation of training, the effect of the OSCE, and the perception of the ultrasound. All 6 self-evaluation items were not revised, as they had a CVR of ≥ 0.75. Conclusion: An ultrasound OSCE for scanning the volar wrist and diagnosing carpal tunnel syndrome was developed using 15 validated tasks, 15 survey questions about ultrasound training, and 6 questions for self-evaluation. These results may be used in the future for education in diagnostic ultrasound.

• Physical Therapy Korea
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• v.9 no.1
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• pp.81-96
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• 2002

The purpose of this research was to determine the effects on the healing of fibular fractures in rabbits of low-intensity pulsed ultrasound (50 $mW/cm^2$ and 500 $mW/cm^2$) applied for periods of 4, 14 and 24 days following fibular osteotomy. Thirty-six male Japanese white rabbits were randomly divided into three groups of twelve for three treatment protocols: (1) ultrasound treatment at intensities of 50 $mW/cm^2$ and 500 $mW/cm^2$ until the 4th day following fibular osteotomy, (2) ultrasound treatment at intensities of 50 $mW/cm^2$ and 500 $mW/cm^2$ until the 14th day following fibular osteotomy, and (3) ultrasound treatment at intensities of 50 $mW/cm^2$ and 500 $mW/cm^2$ until the 24th day following fibular osteotomy. The low-intensity pulsed ultrasound was applied to only one fibula of each rabbit (these served as the experimental group). The other fibula of each rabbit served as the control group. The selection of which fibula was to be treated was made randomly. The animals were sacrificed on the 4th, 14th and 24th day after the start of ultrasound treatments. Percent of trabecular bone area and fibular radiography were carried out to compare the degree of fibular bone healing. A microscope was also used to determine any histologic changes. For statistical differences in radiological changes due to length of treatment period (4, 14 and 24 days respectively), the Wilcoxon signed-ranks test was used to compare the experimental and control groups. For statistical differences in fracture healing due to differences in ultrasound intensity, radiological studies were compared using the Mann-Whitney Test. And, to compute percentage differences in areas of trabecular bone, Two-way analysis of variance (ultrasound intensity x each group) was used. Experiment results were as follows: 1. In animals sacrificed on the 4th day, no difference was found in the radiological studies of the fibulae in the experimental and control groups (p>.05). However, experimental groups showed more rapid bone repair than control group. 2. Both radiographic and percent of trabecular bone area studies showed significant differences in rabbits sacrificed after 14 days. Fracture healing was significantly increased in the experimental group (p<.05) 3. In the animals sacrificed on the 24th day, histologic study showed rapid bone repair but fibular radiologic studies did not show statistical differences between the two groups (p>.05). 4. On the 14th day, bone union on radiograph was significantly more rapid in the treatment group with pulsed ultrasound of 50 $mW/cm^2$ than the group with 500 $mW/cm^2$ (p<.05). Histologic studies showed that both the 14 and 24 days groups had more rapid bone repair in animals treated with 50 $mW/cm^2$ ultrasound intensity than those treated with 500 $mW/cm^2$ intensity. In conclusion, it has been shown that the low-intensity pulsed ultrasound has a positive effect on bone fracture healing in the early stage and the range of pulse ultrasound from 50 $mW/cm^2$ to 500 $mW/cm^2$ is effective for fracture healing. Further study is needed to investigate the influence of pulsed ultrasound on delayed union and non-union in bone fractures and also for the clinical use of low-intensity pulsed ultrasound for bone healing in humans.