Tension conditions

FIG. 16 Effect of LAS/AES ratio on dishwashing foam stability and interfacial tension. Conditions 46°C, 0.05% concentration, 50 ppm hardness, Keen soil. (From Ref. 33.)... 

A special holder was designed and realized to host the LPG straight without bending and under similar tensional conditions during both coating procedure and subsequent sensor testing to minimize the effects of the LPG cross-sensitivity to other environmental parameters. 

Uniaxial tensile criteria can lead to gross inaccuracies when applied to situations where combined stresses lead to failure in multiaxial stress fields. Often one assumes that combined stresses have no influence and that the maximum principal stress governs the failure behavior. An improved approach applied to biaxial tension conditions relies upon a pragmatic biaxial correction factor which is applied to uniaxial data,... 

Because we are modeling the stress-strain behavior of tissues in which all tissues are under internal tension conditions where the stress is a function of time, then this element is not particularly useful for even superficial modeling of the stress-strain behavior of ECMs. The other element is a spring in parallel with a dashpot, termed the Voigt or Kelvin element. In... 

Ackerberg3 determined that, the oxidation, which is trifling at a polished platinum anode, is quantitative under the same conditions at, a platinized anode. Salsser3 investigated the electrolysis of oxalic, acid, as to the tension conditions and oxidation action, in sulphuric-acid and in aqueous solutions at polished (bright) and platinized anodes. 

The effect of stress state on the maximum algebraic stress concentration for various orientations of the ellipse (ft) is shown in Figure 4 for an ellipticity R = 0.1. The uniaxial tension condition = 0) generates the highest stress concentration. Equal biaxial tension ( = 45°) generates the same stress concentration for any ellipse orientation p. This is because the stress state is planar isotropic, and any pair of orthogonal axes can be chosen as the external principal axes. Consequently the orientation p is without effect. 

A general model that considers nonequilibrium oxygen tension conditions between the erythrocytes and plasma has been derived. The rate of oxygen transport between the erythrocyte and plasma is assumed to be a function of the difference between the equilibrium and dynamic oxygen dissociation curves, and the rate of oxygen transfer to the tissue is based on the oxygen tension difference between the plasma and tissue. The three-lump model can be written as follows,... 

When a geotextile subjected to concentrated forces normal to the plane is kept under pre-tensioned conditions, the distribution and magnitude of these forces result in the puncture failure. In general, a biaxial tensile failure simulates puncture failure more appropriately than uniaxial tensile tests. The puncture properties of geotextiles are significantly affected by the fabric and soil parameters. ... 

In materials with high anisotropy in the grain boundary energy and, thus, with faceted grain boundaries, the angles between boundaries may not be uniquely defined by an interfacial tension condition because of torque on facets. ... 

For t = 0 or i=N, this equation should be modified. The Rouse model used no tension boundary condition, equivalent to setting Xn+ 1 = Xn and x i = Xq. However, these conditions for the ID motion inside the tube will lead to an escape from the tube after the Rouse time since the tube length will fluctuate in the range from 0 to i/Nb, with 0 being the most probable value. To prevent this, it was argued that a constant tension condition... 

A constant tension condition is equivalent to a constant distance between monomers at the ends tb - -... 

Parameter Cto represents failure stress in tension condition and ffco and cTcu are initial yield and ultimate stresses in compression condition. As it shown in Fig. 3, when the brittle specimen is unloaded from any point on the strain softening branch of the stress-strain curves, the unloading response is weakened and the elastic stiffness of the material appears to be damaged (or degraded). The degradation... 

Mr. Marangoni the spreading out of a liquid drop on another liquid is a phenomenon of tension condition of its production. Soap film crossed by liquid streams. Experiment which shows that the tension is modified on the common surface of two liquids in contact. 160bis... 

Each of the main facility types, e.g. steel jacket, gravity structure, tension leg and floating platform, have different options for decommissioning. The main factors which need to be considered and which will impact on costs are type of construction, size, distance from shore, weather conditions and the complexity of the removal, including all safety aspects. The following options are available ... 

Princen and co-workers have treated the more general case where w is too small or y too large to give a cylindrical profile [86] (see also Refs. 87 and 88). In such cases, however, a correction may be needed for buoyancy and Coriolis effects [89] it is best to work under conditions such that Eq. 11-35 applies. The method has been used successfully for the measurement of interfacial tensions of 0.001 dyn/cm or lower [90, 91]. 

In detergency, for separation of an oily soil O from a solid fabric S just to occur in an aqueous surfactant solution W, the desired condition is 730 = 7wo+7sw. Use simple empirical surface tension relationships to infer whether the above condition might be met if (a) 73 = 7w. (6) 70 = 7W, or (c) 73 = 70. 

A drop of surfactant solution will, under certain conditions, undergo a fingering instability as it spreads on a surface [27, 28]. This instability is attributed to the Marongoni effect (Section IV-2D) where the process is driven by surface tension gradients. Pesach and Marmur have shown that Marongoni flow is also responsible for enhanced spreading... 

It is quite clear, first of all, that since emulsions present a large interfacial area, any reduction in interfacial tension must reduce the driving force toward coalescence and should promote stability. We have here, then, a simple thermodynamic basis for the role of emulsifying agents. Harkins [17] mentions, as an example, the case of the system paraffin oil-water. With pure liquids, the inter-facial tension was 41 dyn/cm, and this was reduced to 31 dyn/cm on making the aqueous phase 0.00 IM in oleic acid, under which conditions a reasonably stable emulsion could be formed. On neutralization by 0.001 M sodium hydroxide, the interfacial tension fell to 7.2 dyn/cm, and if also made O.OOIM in sodium chloride, it became less than 0.01 dyn/cm. With olive oil in place of the paraffin oil, the final interfacial tension was 0.002 dyn/cm. These last systems emulsified spontaneously—that is, on combining the oil and water phases, no agitation was needed for emulsification to occur. 

Surface waves at an interface between two innniscible fluids involve effects due to gravity (g) and surface tension (a) forces. (In this section, o denotes surface tension and a denotes the stress tensor. The two should not be coiifiised with one another.) In a hydrodynamic approach, the interface is treated as a sharp boundary and the two bulk phases as incompressible. The Navier-Stokes equations for the two bulk phases (balance of macroscopic forces is the mgredient) along with the boundary condition at the interface (surface tension o enters here) are solved for possible hamionic oscillations of the interface of the fomi, exp [-(iu + s)t + i V-.r], where m is the frequency, is the damping coefficient, s tlie 2-d wavevector of the periodic oscillation and. ra 2-d vector parallel to the surface. For a liquid-vapour interface which we consider, away from the critical point, the vapour density is negligible compared to the liquid density and one obtains the hydrodynamic dispersion relation for surface waves + s>tf. The temi gq in the dispersion relation arises from... 

The separation of two surfaces in contact is resisted by adhesive forces. As the nonnal force is decreased, the contact regions pass from conditions of compressive to tensile stress. As revealed by JKR theory, surface tension alone is sufficient to ensure that there is a finite contact area between the two at zero nonnal force. One contribution to adhesion is the work that must be done to increase surface area during separation. If the surfaces have undergone plastic defonnation, the contact area will be even greater at zero nonnal force than predicted by JKR theory. In reality, continued plastic defonnation can occur during separation and also contributes to adhesive work. 

An important part of solving any differential equation is the specification of the boundary conditions. In the present case these can correspond to tension or shear and can be solved to give either a modulus or a compliance. 

Table 3.5 Rouse Theory Expressions for the Modulus (entries labeled 1) and Compliances (entries labeled 2) for Tension and Shear Under Different Conditions ...

The choice of the solvent also has a profound influence on the observed sonochemistry. The effect of vapor pressure has already been mentioned. Other Hquid properties, such as surface tension and viscosity, wiU alter the threshold of cavitation, but this is generaUy a minor concern. The chemical reactivity of the solvent is often much more important. No solvent is inert under the high temperature conditions of cavitation (50). One may minimize this problem, however, by using robust solvents that have low vapor pressures so as to minimize their concentration in the vapor phase of the cavitation event. Alternatively, one may wish to take advantage of such secondary reactions, for example, by using halocarbons for sonochemical halogenations. With ultrasonic irradiations in water, the observed aqueous sonochemistry is dominated by secondary reactions of OH- and H- formed from the sonolysis of water vapor in the cavitation zone (51—53). 

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