• Journal of Energy Engineering
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• v.20 no.2
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• pp.84-89
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• 2011

In this study, individual(alkaline, ultrasonic) and combined(alkaline+ultrasonic) pretreatment effect on sewage sludge solubilization was investigated. COD solubilization rates increased with the dose of NaOH added: solubilization reached 27.6%. Additional alkaline agents did not increase solubilization further. Ultrasonic pretreatment achieved 33~39% solubilization when 140 W/L amplitude. In(alkaline(pre-treatment)+ultrasonic (after-treatment)) treatment, solubilization increased as the combined intensity in creased($70.4{\pm}9.4%$). SCOD rising rate(0.076) was achieved.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.3
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• pp.251-260
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• 2001

Damage Profess of CFRP laminates under monotonic tensile test was characterized by the correlation between Acoustic Emission(AE) and Ultrasonic Test(UT). The amplitude distribution of AE signal from a specimens is an aid to the determination of the extent of the different fracture mechanism such as matrix crack, debonding, fiber pullout and fiber fracture as load is increased. In addtion, the characteristics of ultrasonic amplitude attenuation are useful lot analysis of the different type of fracture mechanism. Different orientation of carbon fiber reinforced plastic specimens were used to investigate the AE amplitude range and ultrasonic amplitude attenuation. Finally, loading-unloading tests were carried out to check Felicity effect. During the tests, ultrasonic amplitude attenuation was investigated at the same time and compared with AE parameters. The result showed that two parameters of both AE and UT could be effectively used for analysis of fracture mechanism in CFRP laminates.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.561-567
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• 2004

The influence of ultrasound frequency, dissolved gases, and initial concentration on the decomposition of sodium dodecylbenzene sulfonate(DBS) aqueous solution was investigated using ultrasound generator with 200 W ultrasound power. The decomposition rates at three frequencies(50, 200, and 600 kHz) examined under argon atmosphere were highest at 200 kHz. The highest observed decomposition rate at 200 kHz occurred in the presence of oxygen followed by air and argon, helium, and nitrogen. The effect of initial concentration of DBS on the ultrasonic decomposition was decreased with increasing initial concentration and would depend upon the formation of micelle in aqueous solution. It appears that the ultrasound frequency, dissolved gases, and initial concentration play an important role on the sonolysis of DBS. Sonolysis of DBS mainly take place at the interfacial region of cavitation bubbles by both OH radical attack and pyrolysis to alkyl chain, aromatic ring, and headgroup.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.96-102
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• 2009

The effect of ultrasonic and alkaline pre-treatments on waste activated sludge (WAS) disintegration was investigated for improved anaerobic digestion. As WAS was treated by either methods, longer capillary suction time (CST) was required due to the break-up of cell walls, and its supernatant demonstrated increase in soluble chemical oxygen demand (SCOD), protein content and turbidity. Ultrasonic process combined with alkaline pre-treatment demonstrated higher SCOD and protein content in the supernatant as compared with ultrasonic pre-treatment only. However, the degree of disintegration (DDCOD) of WAS decreased with increasing solid concentration as both WAS disintegration methods employed simultaneously.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.1031-1040
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• 2021

In this study, the actual condition of ultrasound examination was conducted for radiological technologist working across the country. The measuring tool of the study was a questionnaire, and it was targeted to radiological technologist engaged in ultrasound examination at medical institutions located across the country from February 01 to July 31, 2021. In consideration of the COVID-19 situation, 431 questionnaires suitable for research were analyzed using the SPSS/PC Ver 18.0 program using email and SNS in a non-face-to-face manner. The general characteristics of study subjects, ultrasound examination job characteristics, and job satisfaction factors were analyzed using descriptive statistics. As a result of analyzing the job characteristics of radiological technologist who perform ultrasound examination as overall job satisfaction, the overall job satisfaction was 3.30 ± 0.56. The job satisfaction level of radiological technologist performing ultrasound examinations was higher than the average of 3.0 points, indicating a higher job satisfaction level than the average. Since insurance coverage for ultrasound examinations started, many radiological technologists have been very interested in ultrasound examination work. Therefore, the Korean radiological technologists of Association and radiological technolgists engaged in ultrasound examination more attention and effort should be put into strengthening professionalism.

• Applied Chemistry for Engineering
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• v.29 no.5
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• pp.503-509
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• 2018

In this study, we used the ultrasonic extraction process as a method to extract antioxidant substances from kudzu, and measured the content of iso-flavonoids puerarin, daidzein, daidzin contained in kudzu. The response surface methodology which is a statistical analysis method for optimizing the extraction amount of iso-flavonoids from the kudzu and the process condition for maximizing the yield was applied. It is the final objective of this study to effectively derive the condition of the process that matches the target response with a minimum number of experiments and analyze the effect of each process condition on the response. In the response surface methodology, the central composite design was applied and the optimum condition was analyzed, and the three independent variables were set to ultrasonic irradiation time, volume ratio of ethanol/ultrapure water, ultrasonic irradiation power. Using the response surface methodology, the optimum conditions with the maximum extraction yield and the content of iso-flavonoids were evaluated as ultrasonic irradiation time (24.75 min), ethanol / ultrapure water volume ratio (39.75 vol%), ultrasonic irradiation power (592.36 W). The overall satisfaction level appears as high as 0.8938, which is recognized at a significance level within 5%. As a result of analyzing the optimization process, it was confirmed that the ultrasonic irradiation time is the factor that most affects the responses.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.802-805
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• 2011

본 연구는 갑상선암 초음파 수검의도에 영향을 미치는 요인들을 규명하기 위해 시도하였다. 자료는 2010년 12월 13일부터 2011년 1월 31일까지 한 종합병원 건강검진센타에 내원한 검진자 205명을 대상으로 설문 및 면접조사로 도출하였다. 연구결과 첫째, 보건의료에 따른 갑상선암 초음파수검의도는 수검의도가 있는 응답자의 경우 본인의 건강이 양호하다는 85.5%로 건강이 양호하지 못하다의 14.5%보다 유의하게 높았다($X^2$=6.73 p<.01). 둘째 갑상선암 초음파수검의도의 영향요인은 본인이 건강하다는 사람이 그렇지 않은 사람에 비해 2.53배 수검의도가 유의하게 높았다(95% Cl=1.39-12.7) 따라서 홍보를 통한 초음파검진에 대한 국민적 호응을 유도하는 것이 갑상선암의 조기발견을 위한 초음파검진 정책을 효율적으로 운영하는 대안이 될 것이다.

• The Journal of the Acoustical Society of Korea
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• v.42 no.5
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• pp.429-440
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• 2023

This study explores recent research trends and potential applications of ultrasound optical imaging-based multimodal technology. Ultrasound imaging has been widely utilized in medical diagnostics due to its real-time capability and relative safety. However, the drawback of low resolution in ultrasound imaging has prompted active research on multimodal imaging techniques that combine ultrasound with other imaging modalities to enhance diagnostic accuracy. In particular, ultrasound optical imaging-based multimodal technology enables the utilization of each modality's advantages while compensating for their limitations, offering a means to improve the accuracy of the diagnosis. Various forms of multimodal imaging techniques have been proposed, including the fusion of optical coherence tomography, photoacoustic, fluorescence, fluorescence lifetime, and spectral technology with ultrasound. This study investigates recent research trends in ultrasound optical imaging-based multimodal technology, and its potential applications are demonstrated in the biomedical field. The ultrasound optical imaging-based multimodal technology provides insights into the progress of integrating ultrasound and optical technologies, laying the foundation for novel approaches to enhance diagnostic accuracy in the biomedical domain.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.252-252
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• 2022

최근 기존의 전통적인 부유사채집기를 활용한 유사량 측정방법의 대안으로 지속적인 유량측정을 목적으로 활용되고 있는 횡방향 초음파도플러유속계의 초음파산란도를 활용하여 부유사농도를 측정에 대한 연구가 수행되고 있다. 하지만, 하천에서 횡방향 초음파도플러유속계를 활용한 유사량 측정 연구는 현장에서 측정된 자료를 기반으로 분석이 수행되기 때문에 통제된 유사 조건에서의 유사의 농도 및 입도분포에 대한 사전 정보를 바탕으로 정밀한 분석의 어려움이 있다. 이에 본 연구에서는 안동하천실험센터 순환수로에서 균일한 입도를 가지고 있는 황토를 활용하여 주입량에 따른 초음파산란도의 변화와 동시에 측정된 LISST(laser in-situ scattering and transmissometry)의 부유사 농도와 입도 자료를 활용하여 유사공급에 따른 3Mhz의 단일 주파수를 사용하는 횡방향 초음파도플러유속계의 초음파산란도를 활용한 부유사농도 및 평균입경의 측정에 대한 연구를 수행하였다. 측정결과, 유사공급에 따라서 초음파산란도를 활용하여 부유사농도가 증가하는 경향을 나타내고 있었으며, 횡방향 초음파도플러유속계로부터 측정된 셀별 초음파산란도를 활용하여 부유사농도의 공간적인 분포의 분석이 가능함을 확인할 수 있었다. 그리고 유사감쇄계수를 활용하여 LISST로부터 측정된 평균입경과의 관계식을 개발하여 유사공급에 따른 평균입경의 변화를 측정할 수 있을 것으로 나타났다. 추후, 통제된 조건에서의 다양한 입도분포에 따른 실험을 통해 횡방향 초음파도플러유속계의 초음파산란도를 활용한 부유사농도 측정 정확도를 개선과 유사감쇄계수를 통해 평균입경을 측정하는데 활용이 될 것으로 판단된다.

• Journal of radiological science and technology
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• v.30 no.4
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• pp.357-363
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• 2007

The breast cancer occurrence have been increase yearly. Consequently the effort for early discovery or prevention is necessary. The study investigated the age distribution rate and a disease distribution occurrence rate in the breast medical examination of Ulsan city area. Breast medical examination distribution ratio it preferred the breast ultrasound with mamography 38.8% breast-ultrasonogrphy 61.2% to be investigated. The disease categories distribution was various from breast-ultrasound medical examination and it was investigated with becomes ramification. The reading find was many most infiltrating duct carcinoma from 40 age stage. The ductal carcinoma in situ was many from 50 age stage. The most many disease was investigated HP(Heterogenous dense nodule or mass parenchyma pattern) with 29.2%. Also the breast abscess or mastitis disease is confirmed only the breast-ultrasonography examination, even from the outside disease it was investigated with the fact that the breast-ultrasound raises the discrimination.