VISCOELASTICITY OF SWOLLEN NETWORKS AS PROBED BY LIGHT INTENSITY FLUCTUATION SPECTROSCOPY

Author(s):  
K.L. Wun
2020 ◽  
Vol 59 (03) ◽  
pp. 1
Author(s):  
Shihao Yin ◽  
Wenyao Liu ◽  
Enbo Xing ◽  
Ziwen Pan ◽  
Yu Tao ◽  
...  

1988 ◽  
Vol 66 (9) ◽  
pp. 1232-1238 ◽  
Author(s):  
D. Bose ◽  
T. Kobayashi ◽  
R. A. Bouchard ◽  
L. V. Hryshko

Scattered light intensity fluctuation (SLIF) of coherent light by a strip of ventricular muscle during diastole is believed to be due to asynchronous cellular motion within the myocyte as a result of spontaneous release of Ca from the sarcoplasmic reticulum. Previous studies have shown a correlation between inotropic agents, such as ouabain and elevated extracellular Ca or decreased extracellular Na, and SLIF. The purpose of this study was to see if this correlation could be extended to other inotropic agents. The digitalis genin, ouabagenin, produces inotropy by increasing intracellular free Ca. In toxic concentrations the drug produces abnormal aftercontractions by spontaneous Ca release from the sarcoplasmic reticulum. On the other hand, the Ca channel agonist BAY k 8644 is also positively inotropic, but its effect is associated with a decrease in Ca release from the sarcoplasmic reticulum, manifested by conversion of "rest potentiation" to "rest depression." The effects of these inotropic agents on the power spectra of SLIF were dissimilar. Both frequency and amplitude of SLIF were increased after ouabagenin (1 μM), but these changes were most marked after the onset of toxicity, at which time contractility was decreased, rather than during the positive inotropic response. In contrast, BAY k 8644 (1 μM) decreased SLIF at all levels of inotropic response. The β-adrenoceptor stimulant drug, dobutamine, and the adenylate cyclase activator, forskolin, produced minimal increase in SLIF at inotropic concentrations but caused a large increase in SLIF only after the onset of toxicity. These results suggest that SLIF is a better indicator of intracellular Ca overload and toxic oscillatory contractions in the presence of an inotrope and not of increased inotropy, per se.


2017 ◽  
Vol 2 (2) ◽  
pp. 96-101
Author(s):  
Lakhdar Amer ◽  
Messaoud Hamouda ◽  
Chellali Benachiba

In order to reduce the electric consumption for high intensity discharge lamps (HID), the use of high frequencies electronic ballasts represents both a solution and many advantages such as, the decrease in the congestion, low costs and weak losses, approximately 10%. However it is not regarded as perfectly reliable, this is due in a great part to the appearance of Acoustic Resonances inside the arc tube which can result in low frequency light flicker and even lamp destruction. Experimentally we used a HID lamp of 50 W and we determined, light flicker frequencies and the arc motion frequencies using a photodiode which detects the light intensity fluctuation and a camera to record the arc motion. The experiment was done in the Department of Mechanical Engineering and Production, Hamburg University of Applied Sciences.


Author(s):  
Amer Lakhdar ◽  
Hamouda Messaoud ◽  
Benachiba Chellali ◽  
Marcus Wolff

<p>In order to reduce the electric consumption for high intensity discharge lamps, the use of high frequencies electronic ballasts represents both a solution and many advantages such as the decrease in the congestion and low costs. However, high frequency operation is not regarded as perfectly reliable due to the appearance of acoustic resonances inside the arc tube, which can result in low frequency light flicker and even lamp destruction. Here we experimentally determined light flicker frequencies using a photodiode which detects the light intensity fluctuation for a high intensity discharge lamp of 50W. Additionally, the arc motion frequencies<strong> </strong>are determined with the aid of a camera. The results obtained are compared with those of a lamp of the same type but with different power (35W).</p>


2012 ◽  
Vol 10 (4) ◽  
pp. 042801-42804 ◽  
Author(s):  
Guojie Tu Guojie Tu ◽  
Yu Wang Yu Wang ◽  
Fengzhong Dong Fengzhong Dong ◽  
Hua Xia Hua Xia ◽  
Tao Pang Tao Pang ◽  
...  

2019 ◽  
Vol 27 (21) ◽  
pp. 30700 ◽  
Author(s):  
Jian Chen ◽  
Zhenhui Du ◽  
Tao Sun ◽  
Jinyi Li ◽  
Yiwen Ma

2018 ◽  
Vol 47 (4) ◽  
pp. 401001 ◽  
Author(s):  
王惠琴 WANG Hui-qin ◽  
李源 LI Yuan ◽  
胡秋 HU Qiu ◽  
包仲贤 BAO Zhong-xian ◽  
曹明华 CAO Ming-hua

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