• Title/Summary/Keyword: Ultrasound technology

Search Result 495, Processing Time 0.031 seconds

Effects of Ultrasound and Ascorbic acid Cotreatment on Browning of Fresh-cut 'Tsugaru' Apples (초음파 및 Ascorbic acid 병용처리가 신선절단 '쓰가루' 사과의 갈변에 미치는 영향)

  • Cho, Jeong-Seok;Jeong, Moon-Cheol;Moon, Kwang-Deog
    • Food Science and Preservation
    • /
    • v.19 no.3
    • /
    • pp.323-327
    • /
    • 2012
  • The effects of ultrasound and ascorbic acid cotreatment on the browning inhibition and microbial growth of fresh-cut Tsugaru apples were investigated. The prepared samples were dipped in distilled water (Cont) or 1% (w/v) ascorbic acid solution (AA) and were then ultrasonicated in distilled water (US) or 1% (w/v) ascorbic acid solution (AA+US). The samples were then packed in a 0.04mm polypropylene bag ($20{\times}15$ cm) and were stored at $10^{\circ}C$ for eight days. The AA+US treated samples showed high $L^*$ and low $a^*$, $b^*$ values as well as inactivated PPO activity. The growth of the total aerobic bacteria also inhibited the AA+US treated samples more. The physicochemical properties were not different among all the samples. It was demonstrated in this paper that the ultrasonication treatment with ascorbic acid prevented the enzymatic browning of and microbial growth in fresh-cut Tsugaru apples.

Sonochemical Oxidation Reactions in 300 kHz Sonoreactor for Various Liquid Height/Volume Conditions (다양한 액상 수위/부피 조건에서의 300kHz 초음파 캐비테이션 산화반응 분석 연구)

  • Lee, Seongeun;Son, Younggyu
    • Journal of Korean Society on Water Environment
    • /
    • v.38 no.5
    • /
    • pp.211-219
    • /
    • 2022
  • In this study, the effect of liquid height/volume on sonochemical oxidation reactions was investigated in 300 kHz sonoreactors. The gas mixture of Ar/O2 (50:50) was applied in two modes including saturation and sparging, and zero-order reaction (KI dosimetry) and first-order reaction (Bisphenol A (BPA) degradation) were used to quantitatively analyze sonochemical oxidation reactions. For the zero-order reaction, the highest sonochemical oxidation activity was obtained for the liquid height of 5𝛌, and the lowest height for both the gas saturation and sparging conditions. In addition, the sparging did not enhance the sonochemical oxidation activity for all height conditions except for 50𝛌, where very low activity was obtained. It was found that in sonochemiluminescence (SCL) images the sonochemical active zone was formed adjacent to the liquid surface for the gas sparging condition due to the formation of the standing wave field while the active zone was formed adjacent to the transducer at the bottom due to the blockage of ultrasound. For the first-order reaction, the highest activity was also obtained at 5𝛌 and the comparison based on the reactant mass was not appropriate because the concentration of the reactant (BPA) decreased significantly as the reaction time elapsed. Consequently, it was revealed that the determination of optimal liquid height (ultrasound irradiation distance) based on the wavelength of the applied ultrasound frequency was very important for the optimal design of sonoreactors in terms of reaction efficiency and reactor size.

Diagnostic Value of Endorectal Ultrasound in Preoperative Assessment of Lymph Node Involvement in Colorectal Cancer: a Meta-analysis

  • Li, Li;Chen, Shi;Wang, Ke;Huang, Jiao;Liu, Li;Wei, Sheng;Gao, Hong-Yu
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.8
    • /
    • pp.3485-3491
    • /
    • 2015
  • Background: Nodal invasion by colorectal cancer is a critical determinant in estimating patient survival and in choosing appropriate preoperative treatment. The present meta-analysis was designed to evaluate the diagnostic value of endorectal ultrasound (EUS) in preoperative assessment of lymph node involvement in colorectal cancer. Materials and Methods: We systematically searched PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) databases for relevant studies published on or before December 10th, 2014. The sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR) and area under the summary receiver operating characteristics curve (AUC) were assessed to estimate the diagnostic value of EUS. Subgroup analysis and meta-regression were performed to explore heterogeneity across studies. Results: Thirty-three studies covering 3,016 subjects were included. The pooled sensitivity and specificity were 0.69 (95%CI: 0.63-0.75) and 0.77 (95%CI: 0.73-0.82), respectively. The positive and negative likelihood ratios were 3.09 (95%CI: 2.52-3.78) and 0.39 (95%CI: 0.32-0.48), respectively. The DOR was 7.84 (95%CI: 5.56-11.08), and AUC was 0.80 (95%CI: 0.77-0.84). Conclusions: This meta-analysis indicated that EUS has moderate diagnostic value in preoperative assessment of lymph node involvement in colorectal cancer. Further refinements in technology and diagnostic criteria are necessary to improve the diagnostic accuracy of EUS.

Evaluation of Ultrasound for Prediction of Carcass Meat Yield and Meat Quality in Korean Native Cattle (Hanwoo)

  • Song, Y.H.;Kim, S.J.;Lee, S.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.15 no.4
    • /
    • pp.591-595
    • /
    • 2002
  • Three hundred thirty five progeny testing steers of Korean beef cattle were evaluated ultrasonically for back fat thickness (BFT), longissimus muscle area (LMA) and intramuscular fat (IF) before slaughter. Class measurements associated with the Korean yield grade and quality grade were also obtained. Residual standard deviation between ultrasonic estimates and carcass measurements of BFT, LMA were 1.49 mm and $0.96cm^2$. The linear correlation coefficients (p<0.01) between ultrasonic estimates and carcass measurements of BFT, LMA and IF were 0.75, 0.57 and 0.67, respectively. Results for improving predictions of yield grade by four methods-the Korean yield grade index equation, fat depth alone, regression and decision tree methods were 75.4%, 79.6%, 64.3% and 81.4%, respectively. We conclude that the decision tree method can easily predict yield grade and is also useful for increasing prediction accuracy rate.

Blood Flow in an Aortic Bifurcation Model: Pulsed Doppler Ultrasound and Laser Doppler Anemometry Studies (대동맥분기에서의 혈액유동: 맥도플러초음파 및 레이저도플러계측기를 사용한 연구)

  • Kim, Young-H.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1992 no.11
    • /
    • pp.43-46
    • /
    • 1992
  • $\underline{In\;vitro}$ velocity measurements were made using both the pulsed Doppler ultrasound (PDU) machine and laser Doppler anemometer (LDA) system in order to investigate the flow characteristics near the aortic bifurcation. Velocities measured from the PDU machine was in good agreement with those from the LDA. The flow in the daughter branches was three-dimensional with a secondary flow. The oscillating wall shear stress with this secondary fluid motion is well correlated with the localization of the atherosclerosis.

  • PDF

Polydispersity and Particle Size Distribution of Polystyrene Latex Prepared by Ultrasound Induced Emulsion Polymerization (초음파에너지가 도입된 유화중합공정에서 Polystyrene Latex의 분산도 및 입자분포 특성)

  • Kim, Won-Il;Hong, In-Kwon
    • Elastomers and Composites
    • /
    • v.33 no.2
    • /
    • pp.110-116
    • /
    • 1998
  • A new technology was introduced to the emulsion polymerization. It is the ultrasonic activation method which replaced a chemical initiator and the environmentally benign process. In this study, free radicals were produced by a pulse type ultrasound energy irradiation, then polystyrene latex was polymerized without chemical initiator. With ultrasonic energy density, the degree of polymerization, average molecular weight, and particle size were increased, but the polydispersity index for the molecular weight and the particle size were decreased. The optimum condition of emulsifier concentration and temperature was found to be 1.0 wt.% SDS and $40^{\circ}C$, respectively. As a result, the emulsion polymerization process without chemical initiator was proved to be comparable to common latex properties such as average molecular weight, molecular weight distribution, particle size, etc.

  • PDF

An Improved Protocol on the Synthesis of Thiazolo[3,2-a]pyrimidine Using Ultrasonic Probe Irradiation

  • Tan, Sian Hui;Chuah, Tse Seng;Chia, Poh Wai
    • Journal of the Korean Chemical Society
    • /
    • v.60 no.4
    • /
    • pp.245-250
    • /
    • 2016
  • An improved protocol on the synthesis of thiazolo[3,2-a]pyrimidine-6-carboxylate derivatives are reported. Previously, the thiazolo[3,2-a]pyrimidine-6-carboxylate derivatives were prepared in a two-step procedure. Under the improved procedure, the thiazolo[3,2-a]pyrimidine-6-carboxylate derivatives was readily prepared in a one-step reaction. This procedure was found to be more efficient than the previous protocol and also compared to the ultrasound bath and conventional heating methods in terms of yield and reaction time.

Indoor Positioning System for Moving Objects on an Indoor for Blind or Visually Impaired Playing Various Sports

  • Lee, Young-Bum;Lee, Myoung-Ho
    • Journal of Electrical Engineering and Technology
    • /
    • v.4 no.1
    • /
    • pp.131-134
    • /
    • 2009
  • We have proposed an indoor positioning system for moving objects and/for the blind or visually impaired to play various sports. [ for a blind or visually impaired playing various sports.] This system consists of a wireless heart rate monitor, wireless sensor network and / 4 ultrasound satellites [ configuration with four ultrasound satellite modules) at the corners of the room. This system provides / the real-time measurement of the location and heart rate of the person in the room[ non-invasive measurement method of the heart rate and the location of a person in real time ], and will help the [a] blind or visually impaired enjoy sports more easily.

In-situ fatigue monitoring procedure using nonlinear ultrasonic surface waves considering the nonlinear effects in the measurement system

  • Dib, Gerges;Roy, Surajit;Ramuhalli, Pradeep;Chai, Jangbom
    • Nuclear Engineering and Technology
    • /
    • v.51 no.3
    • /
    • pp.867-876
    • /
    • 2019
  • Second harmonic generation using nonlinear ultrasonic waves have been shown to be an early indicator of possible fatigue damage in nuclear power plant components. This technique relies on measuring amplitudes, making it highly susceptible to variations in transducer coupling and instrumentation. This paper proposes an experimental procedure for in-situ surface wave nonlinear ultrasound measurements on specimen with permanently mounted transducers under high cycle fatigue loading without interrupting the experiment. It allows continuous monitoring and minimizes variation due to transducer coupling. Moreover, relations describing the effects of the measurement system nonlinearity including the effects of the material transfer function on the measured nonlinearity parameter are derived. An in-situ high cycle fatigue test was conducted using two 304 stainless steel specimens with two different excitation frequencies. A comprehensive analysis of the nonlinear sources, which result in variations in the measured nonlinearity parameters, was performed and the effects of the system nonlinearities are explained and identified. In both specimens, monotonic trend was observed in nonlinear parameter when the value of fundamental amplitude was not changing.

The development of dyeing process by ultrasonics wave for clean technology (초음파를 이용한 피혁의 친환경 염색공정 기술 개발)

  • Kim, W.J.;Kim, H.H.;Kim, S.C.;Park, K.S.
    • Clean Technology
    • /
    • v.10 no.1
    • /
    • pp.19-25
    • /
    • 2004
  • The leather was fixed with various colors through the dyeing process in leather manufacturing. During the dyeing process, the amount of 30~50% dyestuff which were not bonded with leather drained with waste water. These dyestuff raise lots of environmental problems, so technology for improving the fixing effect, levelling effect and penentration effect with the use of small amount of dyestuff has been required. Also, insufficient color fastness level 2~3 grade for common natural leather needs to be improved at the same time. Accordingly, the use of ultrasound(us) in dyeing process has decreased the amount of dyestuff and obtained the smooth permeability effect. So, we could find that the reduction of amount of dyestuff in wastewater led to decrease in environmental trouble caused by leather waste water with severe contamination degree and improved fastness up to 0.5 grades.

  • PDF