scholarly journals Evaluation of Time-Dependent Deformation of High Modulus CFRP under a Constant Temperature Condition.

1992 ◽  
Vol 18 (5) ◽  
pp. 192-200
Author(s):  
S. TAKADA ◽  
K. TSUKUI ◽  
S. YOSHIOKA ◽  
A. HIJIKATA
Keyword(s):  
Constant Temperature ◽  
Time Dependent ◽  
High Modulus

The Effects of Forced Convection on the Power Dissipation of Constant-Temperature Thermal Conductivity Sensors

1997 ◽  
Vol 119 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Y. Huang ◽  
H. H. Bau
Keyword(s):  
Thermal Conductivity ◽  
Forced Convection ◽  
Constant Temperature ◽  
Power Dissipation ◽  
Peclet Number ◽  
Asymptotic Theory ◽  
Time Dependent ◽  
Péclet Number ◽  
Theoretical Predictions ◽  
On Line

The effect of forced convection on the power dissipation of cylindrical and planar, constant temperature, thermal conductivity detectors (TCDs) is investigated theoretically. Such detectors can be used either for on-line continuous sensing of fluid thermal conductivity or for determining the sample concentrations in gas chromatography. A low Peclet number, asymptotic theory is constructed to correlate the TCD’s power dissipation with the Peclet number and to explain experimental observations. Subsequently, the effect of convection on the TCD’s power dissipation is calculated numerically for both time-independent and time-dependent flows. The theoretical predictions are compared with experimental observations.

Improving Temperature Probe Calibration Accuracy in Constant Temperature Baths With a Novel Data Processing Method

2019 ◽  
Author(s):  
Mustafa Koz ◽  
Thomas Visalli
Keyword(s):  
Data Processing ◽  
Constant Temperature ◽  
Sampling Rate ◽  
Processing Method ◽  
Time Dependent ◽  
Calibration Data ◽  
Temperature Probe ◽  
Data Processing Method ◽  
Probe Calibration ◽  
The Stability

Abstract The accuracy of temperature probe calibration in a constant temperature bath is governed by the stability and uniformity of the bath. In the available literature, there have been efforts in designing baths with better stability and uniformity. This work is distinguished from the previous efforts by presenting a novel data processing method that improves the calibration performance without the need to improve the inherent qualities of the bath. The stability limitation is addressed by filtering out the time dependent components of temperature readings, and then the resulting calibration performance becomes limited only by the uniformity. This work provides the theory and guidelines for filtering the time dependent signal components such as sampling rate and duration based on the stability of the bath. The method is experimentally validated by applying it to a baseline bath and the results are compared to those from a high-end bath. As a figure of merit, the probability of obtaining a calibration value within ±0.75 mK of the high-end bath is reported. In a calibration scenario in which the uncertainty is predominantly governed by the stability, only 10% of the calibration values are within the aforementioned limits with the conventional method. With the application of the novel method, all of the calibration data meets the criterion.

A note on the stability of an infinite fluid heated from below

1967 ◽  
Vol 29 (3) ◽  
pp. 461-464 ◽  
Author(s):  
J. L. Robinson
Keyword(s):  
Growth Rate ◽  
Temperature Profile ◽  
Constant Temperature ◽  
Temperature Difference ◽  
Rate Of Change ◽  
Time Dependent ◽  
Initial Value ◽  
Horizontal Boundary ◽  
Boundary Case ◽  
The Stability

The problem of the stability of a fluid with time-dependent heating has been investigated by Morton (1957), Lick (1965) and Foster (1965). Morton and Lick assumed that the rate of change of the temperature profile is small compared with the growth rate of the disturbances (quasi-static assumption). This assumption is invalid near the onset of instability (as defined by ∂/∂t = 0), and Foster has therefore used an initial-value approach.In this paper the range of validity of the quasi-static assumption is discussed, and results of a time-scaled analysis and calculations based on this are compared with the work of Foster; the agreement is found to be good. We restrict our attention to a semi-infinite fluid initially at a constant temperature; at time t = 0 a temperature difference ΔT is applied at the (lower) horizontal boundary (case (A) of Foster).

EXELFS Studies of Carbon Fibers

1990 ◽  
Vol 48 (2) ◽  
pp. 72-73
Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely
Keyword(s):  
Carbon Fibers ◽  
Energy Analysis ◽  
Electron Excitation ◽  
Complex Structures ◽  
High Modulus ◽  
Promising Technique ◽  
X Ray ◽  
Fine Structures ◽  
X Ray Absorption

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.

Autonomous self-healing polyisoprene elastomers with high modulus and good toughness based on the synergy of dynamic ionic crosslinks and highly disordered crystals

2020 ◽  
Vol 11 (41) ◽  
pp. 6549-6558
Author(s):  
Yohei Miwa ◽  
Mayu Yamada ◽  
Yu Shinke ◽  
Shoichi Kutsumizu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Self Healing ◽  
High Modulus ◽  
Disordered Crystals ◽  
Ionic Crosslinks

We designed a novel polyisoprene elastomer with high mechanical properties and autonomous self-healing capability at room temperature facilitated by the coexistence of dynamic ionic crosslinks and crystalline components that slowly reassembled.

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