• Title/Summary/Keyword: relaxation

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Ultrasonic Absorption Measurements of Bovine Serum Albumin Solutions in the Frequency Range 200 kHz to 3 MHz (주파수 200 kHz-3 MHz영역에 대한 알부민용액의 초음파 흡수측정)

  • Bae, Jong-Rim
    • The Journal of the Acoustical Society of Korea
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    • v.25 no.1E
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    • pp.14-19
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    • 2006
  • Ultrasonic absorption and velocity spectra in bovine serum albumin (BSA) aqueous solutions have been measured at $20^{\circ}C$ over the frequency range 0.2-3 MHz in the pH range 1.5-13.2. The high-Q ultrasonic resonator and pulse-echo overlap methods were used. At acid pH's, excess absorption over that of pH 7 was explained by double relaxation. The pH dependences of the relaxation frequency and maximum absorption per wavelength, showed that the relaxation at about 200 kHz was related to the expansion of molecules and that about 3 MHz resulted from the proton transfer reaction of carboxyl group. At alkaline pH's, the excess absorption was explained by double relaxation. The relaxation at about 300 kHz was associated with a helix-coil transition, and that about 3 MHz was attributed to the proton transfer reaction of phenolic group. The rate constants and volume changes associated with these processes were estimated.

Real Time Estimation of the Left Ventricular Diastolic Relaxation Rate using Intraventricular Pressure Waveform (압력 파형을 이용한 좌심실 확장 이완율의 실시간 추정)

  • Chun, H.G.;Kim, H.C.;Sohn, D.W.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.415-419
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    • 1997
  • The left ventricular relaxation rate is used as a golden standard which describes the left ventricular diastolic unction. So far, to get the rate of relaxation one should calculate the data after full recording, that is, off-line method. Therefore one cannot get the rate of relaxation in real-time while changing loading condition or infusing drug. But real time monitoring of the relaxation rate is necessary while changing loading condition or infusing drug to control the mechanics of heart and to get more information. We propose a new criterion to get the left ventricular relaxation rate and a real time algorithm. By comparison, it was turned out that our criterion outperforms others criterion.

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Analysis of Thermal Relaxation Time of Tissues Subject to Pulsed Laser Irradiation (초단파 레이저 조사시 티슈 열완화 시간 분석)

  • Kim, Kyung-Han;Lee, Jae-Hoon;Suh, Jeong
    • Laser Solutions
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    • v.12 no.2
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    • pp.17-25
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    • 2009
  • Two methodologies for predicting thermal relaxation time of tissue subjected to pulsed laser irradiation is introduced by the calculation the optical penetration depth and by the investigation of the temperature diffusion behavior. First approach is that both x-axial and y-axial thermal relaxation times are predicted and they are superposed to achieve the thermal relaxation time (${\tau}_1$) for two-dimensional square tissue model. Another approach to achieve thermal relaxation time (${\tau}_2$) is measuring the time required for local temperature drop until $e^{-1}$ of the maximum laser induced heating.

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Effects of Some Autonomic Drugs on the Intramural Nervous System of Isolated Jejunum of Chiken Pretreated with Reserpine (몇가지 자율신경성약물(自律神經性藥物)이 Reserpine 처리(處理) 병아리의 척출공장(剔出空腸) 내재성신경(內在性神經)에 미치는 영향(影響))

  • Lee, Chang Eop
    • Korean Journal of Veterinary Research
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    • v.14 no.2
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    • pp.207-210
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    • 1974
  • Pharmacological investigation was performed in chickens which were pretreated with reserpine. Transmural stimulations were given to the isolated jejunum of chickens and studied the responses and the effects of dibenamine, propranolol, atropine and tetrodotoxin on them. The results obtained were summerized as follows: 1. Three different patterns of response were obtained from the isolated jejunum of non-treated chickens after giving them transmural stimulation. The first pattern was contraction followed by relaxation, the second pattern was contraction only and the third pattern was relaxation only. 2. The transmural stimulation of the jejunum preparations evoked relaxation while the periarterial stimulation evoked contraction in the reserpinized chick. 3. The relaxation response to the transmural stimulation was not affected by the pretreatment with dibenamine, propranolol and atropine. 4. The relaxation response to the transmural stimulation was abolished by tetrodotoxin. The results obtained in these studies indicate that the relaxation response to the transmural stimulation is due to non-adrenergic inhibitory fibers.

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Fuzzy Relaxation Based on the Theory of Possibility and FAM

  • Uam, Tae-Uk;Park, Yang-Woo;Ha, Yeong-Ho
    • Journal of Electrical Engineering and information Science
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    • v.2 no.5
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    • pp.72-78
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    • 1997
  • This paper presents a fuzzy relaxation algorithm, which is based on the possibility and FAM instead of he probability and compatibility coefficients used in most of existing probabilistic relaxation algorithms, Because of eliminating stages for estimating of compatibility coefficients and normalization of the probability estimates, the proposed fuzzy relaxation algorithms increases the parallelism and has a simple iteration scheme. The construction of fuzzy relaxation scheme consists of the following three tasks: (1) definition of in/output linguistic variables, their term sets, and possibility. (2) Definition of FAM rule bases for relaxation using fuzzy compound relations. (3) Construction of the iteration scheme for calculating the new possibility estimate. Applications to region segmentation an ege detectiojn algorithms show that he proposed method can be used for not only reducing the image ambiguity and segmentation errors, but also enhancing the raw edge iteratively.

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A Study on Spin-Lattice Relaxation of Methyl Protons in 2,6-Dichlorotoluene and N-Methyl Phthalimide

  • Lee, Jo-Woong;Lim, Man-Ho;Rho, Jung-Rae
    • Bulletin of the Korean Chemical Society
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    • v.12 no.1
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    • pp.47-51
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    • 1991
  • Spin-lattice relaxation of methyl protons in 2,6-dichlorotoluene and N-methyl phthalimide, each dissolved in CDCl$_3$, has been studied at 34$^{\circ}$C and the contribution from spin-rotation interaction to the relaxation process has been separated from that due to dipole-dipole interactions among methyl protons. The results show that the spin-rotational contributions to the initial rate of relaxation in 2,6-dichlorotoluene and N-methyl phthalimide amount to 18 and 31%, respectively, of the total relaxation rate at 34$^{\circ}$C. The method of separating the spin-rotational contribution from that of dipolar interactions adopted in this paper is based on the well known fact that in an A$_3$ spin system such as methyl protons in liquid phase dipolar relaxation mechanism gives non-exponential decay of the z-component of total magnetization of protons while the random field fluctuation such as spin-rotational mechanism causes exponential decay.

Effects of Two Music Therapy Methods on Agitation and Anxiety among Patients Weaning off Mechanical Ventilation: A Pilot Study

  • Park, Jong Yoen;Park, Soohyun
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.26 no.2
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    • pp.136-143
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    • 2019
  • Purpose: The feasibility and differential effects of two music therapy methods (interventions with preferred music vs. classical relaxation music) were done to examine the effects on agitation and anxiety in patients weaning off mechanical ventilation. Methods: This pilot study was conducted using a crossover design. Six patients listened to preferred music choices and classical relaxation music. Anxiety scores were measured using the Richmond Agitation Sedation Scale (RASS), State-Trait Anxiety Inventory (STAI), and visual analog scale (VAS). Results: Patients showed a significant decrease in agitation and anxiety after both the preferred and classical relaxation music interventions. The difference in the effects of preferred music and that of classical relaxation music was not significant. As for feasibility, patients exhibited a change in agitated behaviors after the music interventions by not trying to take off medical devices and quietly listening to the music, and by smiling and moving lips along with the lyrics while listening. Conclusion: Music interventions which centered on either patients' preferences or classical relaxation music to enhance relaxation, helped reduce agitation and anxiety during the mechanical ventilation weaning process.

Delamination analysis of multilayered beams with non-linear stress relaxation behavior

  • Victor I., Rizov
    • Coupled systems mechanics
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    • v.11 no.6
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    • pp.543-556
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    • 2022
  • Delamination of multilayered inhomogeneous beam that exhibits non-linear relaxation behavior is analyzed in the present paper. The layers are inhomogeneous in the thickness direction. The dealamination crack is located symmetrically with respect to the mid-span. The relaxation is treated by applying a non-linear stress-straintime constitutive relation. The material properties which are involved in the constitutive relation are distributed continuously along the thickness direction of the layer. The delamination is analyzed by applying the J-integral approach. A time-dependent solution to the J-integral that accounts for the non-linear relaxation behavior is derived. The delamination is studied also in terms of the time-dependent strain energy release rate. The balance of the energy is analyzed in order to obtain a non-linear time-dependent solution to the strain energy release rate. The fact that the strain energy release rate is identical with the J-integral value proves the correctness of the non-linear solutions derived in the present paper. The variation of the J-integral value with time due to the non-linear relaxation behavior is evaluated by applying the solution derived.

The Effect of Submerged Relaxation Exercise on Muscle Tone in Persons With Hemiparesis (수중이완운동이 편마비 환자의 근긴장도에 미치는 영향)

  • Chun, Seung-Chul;Yoon, Seoung-Ic;Oh, Duck-Won;Shim, Jae-Hun;Lee, Gyu-Wan;An, Chang-Sik
    • Physical Therapy Korea
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    • v.13 no.3
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    • pp.84-91
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    • 2006
  • The purpose of this study was to investigate the effect of submerged relaxation therapy for the spasticity on the affected side in three subjects with post-stroke hemiparesis. A single-subject alternating design with multiple baselines across individuals was employed in this study. Each subject alternately participated in a range of motion exercises on the mat and in the pool, and relaxation exercises in the pool. The muscle tone of the affected side was measured using the tone assessment scale (TAS). Measurements were made immediately and one hour following the intervention. The findings showed a therapeutic effect of submerged relaxation exercise on reducing spasticity for all subjects. The effect of submerged relaxation exercise on decreasing muscle tone was maintained for one hour measurements after the submerged relaxation exercise, although the mean TAS score assessed one hour after intervention was higher than that assessed immediately. The results of this study suggest that submerged relaxation exercise has a positive effect on decreasing spasticity on the affected side in persons suffering from post-stroke hemiparesis. Future research on submerged relaxation exercise should focus on objective evaluation and functional the aspects relevant to activities of daily living.

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Effects of CT Contrast Medium on the Relaxation Rate of MR Contrast Medium (CT 조영제가 MR 조영제의 이완율에 미치는 영향)

  • Kwon, Soon-Yong;Kang, Chung-Hwan;Jeong, Hyeon Keum;Park, Jin Seo;Kim, Seong-Ho
    • Journal of radiological science and technology
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    • v.41 no.2
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    • pp.103-107
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    • 2018
  • In MR, the iodine CT contrast medium reduces the T1 and T2 relaxation times of the substance, resulting in a change in signal intensity. This study aimed to measure the relaxation rate of MR contrast medium with or without diluting CT contrast medium and analyzed the effect of CT contrast medium. Undiluted Gadoteridol solution was diluted with saline to prepare MR contrast medium phantoms with various levels of Gadoteridol concentrations. Moreover, undiluted Iomeprol was mixed with the prepared MR contrast medium phantoms at 1:1 ratio to make MR contrast medium phantoms with containing CT contrast medium for the experiment. T1 and T2 mappings were conducted to quantitatively evaluate the relaxation time and relaxation rate of these phantoms. The results showed that the T1 and T2 relaxation time and relaxation rate of MR contrast medium diluted with CT contrast medium were significantly (p<0.05) shorter than those of MR contrast medium not diluted with CT contrast medium. The results of this study imply that, when MR contrast medium shall be used after injecting CT contrast medium, CT contrast medium should be discharged enough. Moreover, it would be desirable to conduct CT test after taking MRI test in order to reduce the effects of CT contrast medium on MR contrast medium.