Tensile strength of liquids

The tensile strength of a pure liquid is determined by the attractive intermolecular forces which maintain its liquid state the calculated tensile strength of water, for example, is in excess of -1000 atmospheres (7). In practice however, the measured threshold for initiation of cavitation is never more than a small fraction of that. Indeed, if the observed tensile strengths of liquids did approach their theoretical limits, the acoustic intensities required to initiate cavitation would be well beyond that generally available, and no sonochemistry would be observed in homogeneous media Cavitation is initiated at a nucleation site where the tensile strength is dramatically lowered, such as small gas bubbles and gas filled crevices in particulate matter, which are present in the liquid. 

Tail s compressibility formula, 66, 68 Tammann s internal pressure theory, 70 tangent to plane curve, 245 tangent plane to conicoid, 432 Tate s drop-weight law, 182, tears of strong wine, 137 Telang s viscosity formula, 91 tensi-eudiometer, 232 tensile strength of liquid, 203 tensimeter, 232 hypsometer, 234 tension tube, 277... 

FLOBERG, L. On the tensile strength of liquids, Trans. Machine Element Division,... 

The experimental tensile strengths of liquids were reported by Briggs who employed a "Z-shaped capillary tube, open at both ends, rotating in the Z plane about an axis passing throu the center of the Z and perpendicular to the plane. The liquid menisci are located in the bent-back short arms of the Z. The speed of rotation is increased gradually until the liquid in the capillary breaks." " ... 

Thus the hysteresis loop should close at a relative pressure determined by the tensile strength of the liquid adsorptive, no matter whether the pore system extends to finer pores than those characterized by or not. 

The most direct test of the tensile strength hypothesis would be to compare the value of Tq calculated from the closure point of the isotherm by Equation (3.61) with the tensile strength of the bulk liquid determined directly. Unfortunately, experimental measurement of the tensile strength is extremely difficult because of the part played by adventitious factors such as the presence of solid particles and dissolved gases, so that the values in the literature vary widely (between 9 and 270 bar for water at 298 K, for example). 

It is, however, possible to calculate the tensile strength of a liquid by extrapolation of an equation of state for the fluid into the metastable region of negative pressure. Burgess and Everett in their comprehensive test of the tensile strength hypothesis, plot the theoretical curves of T /T against zjp, calculated from the equations of state of van der Waals, Guggenheim, and Berthelot (Fig. 3.24) (7], and are the critical temperature and critical... 

The best formulation proved to be one based on a liquid containing 88 % EBA, 5% n-ethylhexyl syringate and 7% n-hexyl vanillate. Cements prepared from these liquids set in 5-5 to 6-5 minutes with a compressive strength of 66 MPa and tensile strength of 6 to 7 MPa. 

Skinner, Molnar Suarez (1964) studied the cement-forming potential of 28 liquid aromatic carboxylic acids with zinc oxide. Twelve yielded cohesive products of some merit. Of particular interest were cements formed with hydrocinnamic, cyclohexane carboxylic, p-tertiary butyl-benzoic, thiobenzoic and cyclohexane butyric acids. One of these cements is on the market as a non-eugenol cement. It is very weak with a compressive strength of 4 0 MPa, a tensile strength of 11 MPa and a modulus of 177 MPa, and is only suitable as a temporary material (Powers, Farah Craig, 1976). 

Transition Zone III is of utmost importance, since the formation of dry spots is accompanied by a dramatic change in the heat transfer mechanism. In such units as gas-fired boilers, the dry spots may cause the tube wall temperature to approach the temperature of the heating gas. However, before the tube wall temperature reaches a steady-state value, the tensile strength of the tube wall is reduced, and rupture may occur. This phenomenon, called burn-out, may also occur at any point along the tube wall if the wall heat flux qmt is large enough so that a vapor film forms between the tube wall and the liquid surface. 

Consider two equal spheres held together by a liquid bridge, as shown in Fig. 4. Two forces contribute to the tensile strength of the bond in an additive fashion the pull due to surface tension at solid-liquid-gas contact line directed along the liquid surface and the negative capillary pressure or the... 

When an electrostatic field is applied so rapidly that flow phenomena cannot occur (or in the case of a solid, which does not flow), breakup may not occur until the electrostatic stress exceeds the tensile strength of the liquid. Schultz and Branson (S2) and Schultz and Wiech (S3) claim that this is the case in their liquid atomization studies. For this case, at breakup,... 

Figure 5.5 Volumetric density of compressed hydrogen gas as a function of gas pressure including the ideal gas and liquid hydrogen. The ratio of the wall thickness to the outer diameter of the pressure cylinder is shown on the right-hand side for steel with a tensile strength of 460 MPa. A schematic drawing of the pressure cylinder is shown as an inset.

Another way of explaining why tiny suspended particles should be important for boiling is that these motes represent cracks or imperfections in the liquid structure. The tensile strength of the liquid will be reduced because of these flaws. 

Commercial hydroxypropyl cellulose has been melt-spun from a liquid-crystalline melt at 180 °C to produce fibres with an orientation factor (fc) of 0.6 even at zero take-up stress and 0.7 at higher take-up stresses, a tensile strength of 80 MPa, Young s modulus of 3 GPa and extension at break of 2 to 5 % 71). 

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