Test Method for Interfacial Tension of Electrical Insulating Oils of Petroleum Origin Against Water by the Drop-Weight Method

10.1520/d2285 ◽  
2008 ◽  
Author(s):  
2008 ◽  
Vol 195 (8) ◽  
pp. 889-924 ◽  
Author(s):  
Boon-Beng Lee ◽  
Pogaku Ravindra ◽  
Eng-Seng Chan

1982 ◽  
Vol 10 (2) ◽  
pp. 72
Author(s):  
R Horstman ◽  
KA Peters ◽  
BM Schindler ◽  
RL Meltzer ◽  
M Bruce Vieth ◽  
...  

INDIAN DRUGS ◽  
2014 ◽  
Vol 51 (09) ◽  
pp. 36-39
Author(s):  
B. U Hadkar ◽  
◽  
N. B. Sanghavi

The drop weight method was used to determine the interfacial tension between organic liquid and solutions of different concentrations of the surfactant, sodium lauryl sulphate (SLS), using Hadkar factor. Two experiments were performed to determine the interfacial tension. In the first experiment the drop weight method was used to determine the interfacial tension between water or aqueous surfactant solutions and benzene (liquid lighter than water) using Hadkar factor H1. In the second experiment the drop weight method was used to determine the interfacial tension between water or surfactant solutions and carbon tetrachloride (liquid heavier than water) using Hadkar factor H2. The plot of interfacial tension between benzene or CCl4 and SLS solutions versus concentration of surfactant solution was used to determine the critical micelle concentration (CMC) of the surfactant. The results were in good agreement with the reported values of CMC for SLS showing the utility of Hadkar factor in the determination of CMC of surfactants.


Author(s):  
S. Xu ◽  
R. Bouchard ◽  
W. R. Tyson

This paper reports results of tests on flow and ductile fracture of a very high toughness steel with Charpy V-notch absorbed energy (CVN energy) at room temperature of 471 J. The microstructure of the steel is bainite/ferrite and its strength is equivalent to X80 grade. The flow stress was determined using tensile tests at temperatures between 150°C and −147°C and strain rates of 0.00075, 0.02 and 1 s−1, and was fitted to a proposed constitutive equation. Charpy tests were carried out at an initial impact velocity of 5.1 ms−1 using drop-weight machines (maximum capacity of 842 J and 4029 J). The samples were not broken during the test, i.e. they passed through the anvils after significant bending deformation with only limited crack growth. Most of the absorbed energy was due to deformation. There was little effect of excess energy on absorbed energy up to 80% of machine capacity (i.e. the validity limit of ASTM E 23). As an alternative to the CVN energy, the crack tip opening angle (CTOA) measured using the drop-weight tear test (DWTT) has been proposed as a material parameter to characterize crack propagation resistance. Preliminary work on evaluating CTOA using the two-specimen CTOA test method is presented. The initiation energy is eliminated by using statically precracked test specimens. Account is taken of the geometry change of the specimens (e.g. thickening under the hammer) on the rotation factor and of the effect of strain rate on flow stress.


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