Ambient temperature effect in concrete dam foundation seepage

2020 ◽  
pp. 107754632096693
Author(s):  
Jun Dai ◽  
Zhao-Dong Xu ◽  
Pan-Pan Gai ◽  
Xiao Yan

Experimental results show that mechanical behaviors of viscoelastic dampers are greatly affected by ambient temperature. Neglecting the ambient temperature effect will lead to an inaccurate seismic evaluation on viscoelastically damped structures. This study investigates the ambient temperature effect on the seismic performance of viscoelastically damped structures. An efficient algorithm is proposed to solve the seismic response of viscoelastically damped structures at different ambient temperatures based on the time–temperature correspondence. Numerical simulations of a ten-story viscoelastically damped steel frame under historical earthquakes are presented to illustrate the ambient temperature effect on the seismic performance. The results show that the natural frequency decreases with the increase in ambient temperature, whereas the damping ratio change with ambient temperature greatly depends on the viscoelastic damper properties. The seismic displacement reduction, in general, decreases with the increase in ambient temperature. The seismic acceleration reduction with ambient temperature is affected by the viscoelastic damper properties, structural parameters, and earthquakes together.


1989 ◽  
Vol 12 (10) ◽  
pp. 659-663 ◽  
Author(s):  
D.H. Tang ◽  
P.S. Malchesky ◽  
S. Omokawa ◽  
M. Matsushita ◽  
C.R. Davies ◽  
...  

Plasma perfusion with the anion exchange resin BR-601 is an effective method to treat patients with hepatic failure and hyperbilirubinemia. To assess the temperature dependency of bilirubin sorption in vitro, isotherm studies with human pathologic plasmas and an albumin-bilirubin solution were carried out. Results showed that BR-601 was more effective at 37°C and 42°C than at 4°C and 25°C for sorbing bilirubin. Therefore, plasma sorption at near physiologic temperature would be expected to be more efficient for plasma treatment than sorption at ambient temperature.


2018 ◽  
Vol 27 (12) ◽  
pp. 1850182 ◽  
Author(s):  
W. Petchmaneelumka ◽  
A. Rerkratn ◽  
A. Luangpol ◽  
V. Riewruja

In this paper, a circuit technique to compensate the temperature effect in the output signal of the linear variable differential transformer (LVDT) is presented. The realization technique is based on the proposed feedback configuration to minimize the active component used in the circuit. The subtraction and sum schemes are provided instead of the error detector used in the traditional feedback loop. The feedback signal is obtained from two secondary winding signals of LVDT. The proposed feedback technique requires only the proportional control action to minimize the error caused by the variation of the ambient temperature. The sensitivity of LVDT is unaffected from the proposed compensation technique. The performances of the proposed technique are discussed in detail and confirmed by experimental implementation using the commercial devices. The maximum percentage error can be reduced from 6.52% of the LVDT output signal without temperature compensation to 0.05% of the proposed technique for the ambient temperature varied from 25[Formula: see text]C to 70[Formula: see text]C. The purpose of the proposed technique is emphasized in terms of high performance, simple configuration and low cost.


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