Determination of Dynamic Bulk Modulus of Elastomers Using Pressure Measurement

1993 ◽  
Vol 66 (5) ◽  
pp. 749-753 ◽  
Author(s):  
B. P. Holownia ◽  
E. H. James

Abstract A novel method of determining dynamic bulk modulus of elastomers, by measurement of pressure changes of the fluid in which the specimen is immersed, was successful in principle. The frequency range covered was between 100 Hz and 1200 Hz which was limited by the power of the oscillator used.

1957 ◽  
Vol 30 (2) ◽  
pp. 449-459
Author(s):  
J. E. McKinney ◽  
S. Edelman ◽  
R. S. Marvin

Abstract An apparatus has been developed for the direct measurement of the real and imaginary parts of the dynamic bulk modulus of solid and liquid materials over the frequency range of 50 to 10,000 cps. Piezoelectric crystals serving as driver and detector, together with the sample and a confining liquid, are contained in a cavity small compared with the wavelength of sound at these frequencies. Static pressure is superposed to eliminate the effect of small air bubbles. The complex compliances of the sample, confining liquid, and the cavity, are additive in this region, where the compliance is pure dilatation. The dynamic compliances of several natural rubber-sulfur mixtures were obtained in a preliminary evaluation of the behavior of the apparatus.


Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4264 ◽  
Author(s):  
Sae June Park ◽  
John Cunningham

We investigate the use of finite-element simulations as a novel method for determining the dielectric property of target materials in the terahertz (THz) frequency range using split-ring resonator (SRR) sensing elements integrated into a planar Goubau line (PGL) waveguide. Five such SRRs were designed to support resonances at specific target frequencies. The origin of resonance modes was identified by investigating the electric field distribution and surface current modes in each SRR. Red-shifts were found in the resonances upon deposition of overlaid test dielectric layers that saturated for thicknesses above 10 µm. We also confirmed that the SRRs can work as independent sensors by depositing the analyte onto each individually. The relation between the permittivity of the target material and the saturated resonant frequency was obtained in each case, and was used to extract the permittivity of a test dielectric layer at six different frequencies in the range of 200–700 GHz as an example application. Our approach enables the permittivity of small volumes of analytes to be determined at a series of discrete frequencies up to ~1 THz.


1986 ◽  
Vol 59 (2) ◽  
pp. 223-232 ◽  
Author(s):  
B. P. Holownia ◽  
A. C. Rowland

Abstract The measurement of the dynamic bulk modulus of elastomers by the direct method using ESPI has been achieved within the frequency range of 50–1000 Hz. The two types of Nitrile rubbers tested show that the dynamic bulk modulus increases with frequency, but the rate of increase depends on the type of rubber used. A novel method of measuring the phase angle using ESPI was successful in principle, although the resolution error on the oscilloscope prevented definite conclusions being reached regarding its variation with frequency.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.


Food Control ◽  
2020 ◽  
pp. 107766
Author(s):  
Xiaoling Zheng ◽  
Wusheng Fu ◽  
Kuicheng Zheng ◽  
Bo Gao ◽  
Lishan Lin ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document