• Title/Summary/Keyword: Focused ultrasound

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Effect of Drying Time and Additives regarding the Physical Properties of Vegetable Fatty Acid Soap (식물성 지방산 비누의 물리적 특성에 대한 건조시간과 첨가물의 효과)

  • Lee, Sung-Hee;Lee, Ki-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.4032-4038
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    • 2014
  • Vegetable fatty acid solid soap requires a drying process for moisture evaporation and hardness after being manufactured through saponification. Although the soap is manufactured by mixing additives mainly from natural ingredients, existing studies have focused primarily on the usability of vegetable solid soap. Consequently, research into the physical properties of vegetable fatty acid solid soap mixed with natural ingredients has been unsatisfactory. Therefore, this study attempted to compare and observe the changes in the physical properties (pH, surface tension, critical micelle concentration, and cleansing power) of solid soap in accordance with the drying period and additives (tea tree E.O and $TiO_2$) using pH paper, the Du Nouy measurement method, sedimentation method, and ultrasound washer. Regardless of the mixture with additives, vegetable fatty acid solid soap showed the same pH, and there was no change in the pH while maintaining pH 8 beginning from the $2^{nd}$ weeks to $12^{th}$ weeks of drying. In addition, as a result of measuring the surface tension and CMC, regardless of the drying period, only the soap added with $TiO_2$ showed an even value of 62.5mg/L, whereas the other soap specimens showed a decline in CMC to 25mg/L on the fourth week of drying. As a result of measuring the detergency, the removal efficiency of vegetable fatty acid solid soap mixed with tea tree E.O and $TiO_2$ and dried for four weeks was 4.50~4.65%, which was higher than that of the vegetable fatty acid solid soap without additives (3.62~3.92%).

Finite Element Simulation of Laser-Generated Ultrasound and Interaction with Surface Breaking Cracks (유한요소법을 이용한 레이저 유도 초음파와 표면 균열과의 상호작용 모델링)

  • Jeong, Hyun-Jo;Park, Moon-Cheol
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.3
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    • pp.259-267
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    • 2004
  • A finite element method is used to simulate interaction of laser-based ultrasounds with surface breaking tracks in elastic media. The laser line source focused on the surface of semi-infinite medium is modeled as a shear dipole in 2-D plane strain finite elements. The shear dipole-finite clement model is found to give correct directivity patterns for generated longitudinal and shear waves. The interaction of surface waves with surface breaking cracks (2-D machined slot) is considered in two ways. Both the source and receiver are fixed with respect to the cracks in the first case, while the source is moving in another case. It is shown that the crack depth tested in the range of 0.3-5.0mm $({\lambda}_R/d=0.21{\sim}3.45)$ can be measured using the corner reflected waves produced by the fixed laser source. The moving laser source is found to cause a large amplitude change of reflected waves near crack, and the crack whose depth is one order lower than the wavelength ran be detected from this change.

Risk Analysis of Factors for Metabolic Diseases according to the Epicaridal Adipose Tissue Thickness - which Focused on the Presented Subjects with Asymptomatic Screening Purposes (심장외막의 지방두께에 따른 대사질환의 위험도 분석 - 무증상의 검진목적으로 내원한 대상자를 위주로)

  • Kim, Sun-Hwa;Kim, Jung-Hoon;Kim, Changsoo
    • The Journal of the Korea Contents Association
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    • v.16 no.7
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    • pp.476-483
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    • 2016
  • Epicardial adipose tissue(EAT) is metabolically active endocrine organ that secretes several hormones in fat thickness is a risk factor for cardiovascular disease and metabolic disorders. This study was to measure and then using ultrasound epicardial adipose tissue thickness, abdominal subcutaneous fat thickness in the target group correlates and general blood properties and characteristics, and presents a local thickness for prediction of metabolic disorders. Results epicardal adipose tissue of the average thickness measured in each of the subjects was 8.890mm, 4.783mm, 4.777, 6.147mm in each section. Showed the epicardial adipose tissue in correlation with the average thickness of the risk factors age, BMI, SBP, LDH, LDL, TC is a positive correlation relationship(p<0.05) in each section. In particular, the thickness of the metabolic disorders epicardial adipose tissue thickness, abdominal subcutaneous compared to subjects that do not have the risk subjects with a risk factor for fat significantly higher(p<0.05). It showed the most reliable that can be cut-off value of 8.950mm obtained with 66.7 % sensitivity and 80 % specificity for predicting the risk of metabolic disorders.

Detection of a Surface-Breaking Crack Using the Surface Wave of a Laser Ultrasound (레이저 초음파의 표면파를 이용한 표면결함 측정)

  • Park, Seung-Kyu;Jung, Hyun-Kyu;Baik, Sung-Hoon;Lim, Chang-Hwan;Joo, Young-Sang;Kang, Young-June
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.2
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    • pp.84-89
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    • 2006
  • A laser ultrasonic inspection system is a non-contact inspection device which generates and measures ultrasounds by using laser beams. A laser ultrasonic inspection system provides a high measurement resolution because the ultrasonic signal generated by a pulse laser beam has a wide-band spectrum and the ultrasonic signal is measured from a small focused spot of a measuring laser beam. In this paper, we have investigated the detection techniques of a surface-breaking crack by using the laser ultrasonic surface waves. A crack acts as a low pass filter whose cut-off frequency is lowered in proportion to the depth of a crack. And, the center frequency value of a spectrum is decreased in proportion to the depth of a crack. In this paper, we extracted the crack information by using the frequency attenuation from the normalized transfer function spectrum of a surface-breaking crack. Also, we effectively measured the crack depth by using the decreasing value of the center frequency from a crack passed ultrasonic signal. The proposed measuring techniques of crack depths provided more precise information than the amplitude measuring technique.

Use of Imaging and Biopsy in Prostate Cancer Diagnosis: A Survey From the Asian Prostate Imaging Working Group

  • Li-Jen Wang;Masahiro Jinzaki;Cher Heng Tan;Young Taik Oh;Hiroshi Shinmoto;Chau Hung Lee;Nayana U. Patel;Silvia D. Chang;Antonio C. Westphalen;Chan Kyo Kim
    • Korean Journal of Radiology
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    • v.24 no.11
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    • pp.1102-1113
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    • 2023
  • Objective: To elucidate the use of radiological studies, including nuclear medicine, and biopsy for the diagnosis and staging of prostate cancer (PCA) in clinical practice and understand the current status of PCA in Asian countries via an international survey. Materials and Methods: The Asian Prostate Imaging Working Group designed a survey questionnaire with four domains focused on prostate magnetic resonance imaging (MRI), other prostate imaging, prostate biopsy, and PCA backgrounds. The questionnaire was sent to 111 members of professional affiliations in Korea, Japan, Singapore, and Taiwan who were representatives of their working hospitals, and their responses were analyzed. Results: This survey had a response rate of 97.3% (108/111). The rates of using 3T scanners, antispasmodic agents, laxative drugs, and prostate imaging-reporting and data system reporting for prostate MRI were 21.6%-78.9%, 22.2%-84.2%, 2.3%-26.3%, and 59.5%-100%, respectively. Respondents reported using the highest b-values of 800-2000 sec/mm2 and fields of view of 9-30 cm. The prostate MRI examinations per month ranged from 1 to 600, and they were most commonly indicated for biopsy-naïve patients suspected of PCA in Japan and Singapore and staging of proven PCA in Korea and Taiwan. The most commonly used radiotracers for prostate positron emission tomography are prostate-specific membrane antigen in Singapore and fluorodeoxyglucose in three other countries. The most common timing for prostate MRI was before biopsy (29.9%). Prostate-targeted biopsies were performed in 63.8% of hospitals, usually by MRI-ultrasound fusion approach. The most common presentation was localized PCA in all four countries, and it was usually treated with radical prostatectomy. Conclusion: This survey showed the diverse technical details and the availability of imaging and biopsy in the evaluation of PCA. This suggests the need for an educational program for Asian radiologists to promote standardized evidence-based imaging approaches for the diagnosis and staging of PCA.

Evaluation of Present Curriculum for Devlopment of Dept. of Radiological Science Curriculum (방사선학과 교육과정 개선을 위한 현 교육과정 평가)

  • Kang, Se-Sik;Kim, Chang-Soo;Choi, Seok-Yoon;Ko, Seong-Jin;Kim, Jung-Hoon
    • The Journal of the Korea Contents Association
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    • v.11 no.5
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    • pp.242-251
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    • 2011
  • A curriculum of study demands a change as period of time and society evolve. Therefore, at this point where changes are required, this study is to analyze and evaluate the curriculums which will enhance and improve current studies as a preceding stage. The research was based on the survey by groups of education experts and 19 universities with current curriculum of study in radiologic science, and their references. The study was focused on the scope of work by radiologic technologist, change of college systems, academic research about radiologic science, and the improvement and the future of radiologic science field in perspective to globalization and the digital era. In terms of work scope, angiography and interventional radiology at 6 to 8 schools, fluoroscopy at 4 schools, ultrasound and practices at 6 schools, magnetic resonance image at 2 schools were found to be unestablished. The basic medical subjects, humuan physiology, human anatomy and practices, medical terminology courses were set up at most schools; however, pathology at 5 schools, image anatomy at 6 schools, clinical medicine at 11 schools were yet opened. Among the basic science and engineering subjects, general biology and its practices at 11 schools, general physics and its practices at 14 schools, and general chemistry and its practices at 8 schools were established which is about a half from a total number of schools. Only 4-5 schools established digital subjects such as, health computer, computer programming, PACS which are the basic major subjects. In order to provide academic improvement in radiologic science, digitalized education and globalization, and basis for future-oriented education for the field of radiologic science, including expanded scope of work, it is acknowledged that curriculums that are opened and run at each school need to be standardized. Therefore, the need for introduction of certificate for the radiologic science education courses are suggested.