Quasi-static conditions

As for the mechanical response of thin lipid films, surface pressure(fl)-surface area(A) characteristics of lipid monolayer at air/water interface have been well studied under quasi-static conditions. It has been established that different phases are observed for the ensemble of lipid molecules in a two-dimensional arrangement, similarly to the gas, liquid, and solid phases and some other intermediate phases as in three-dimensional molecular assemblies. 

Rgure 1.10. Condition of mptur-ing in quasi static-conditions for (a) a simple shear flow and (b) a pure elongational flow. (Adapted from [139].)... 

Figure 1.21. Comparison of the critical capillary number for simple shear, when the shear is applied in quasi-static conditions or suddenly.

SFM s can be also classified according to static and dynamic operating modes. Under quasi-static conditions, the microscope measures the instantaneous response of the cantilever when it interacts with the sample. Dynamic SFM enables separation of the elastic and inelastic component in the cantilever deflection when the sample surface is exposed to a periodically varying stress field. The dynamic modes are useful for investigation of viscoelastic materials such as polymers and results in additional improvements in the signal-to-noise ratio. 

In quasi-static conditions, it has been established both theoretically [7, 12] and experimentally [6, 12] that a drop breaks when the applied stress a overcomes the product of the critical capillary number Cacr and the Laplace pressure... 

High rate fracture parameters are important in the assessment of structural integrity, particularly in applications where there is a risk of rapid crack propagation. Linear elastic fracture mechanics provide a method for assessing fracture parameters under quasi-static conditions but under impact conditions various dynamic effects make both experimental measurement and analysis difficult. 

Investigation of nucleation in superheated light and heavy water in quasi-static conditions has revealed their anomalous behavior, which is manifested in the fact that superheat temperatures achieved in experiments at different pressures have proved to be much lower than theoretical ones, and the character of the dependence J p,T) is different from other, for instance cryogenic, liquids. ... 

When the reaction rate is slow, the main component should be absorbed not in a flow but rather under quasi-static conditions in the reactor upstream of the chromatographic column. For example, Janak and Novak [42], in the analysis of trace components in butadiene-1,3, provided for absorption of the main component by maleic anhydride... 

Figure 10. Thermodesorption of liquids from the surface of the sample A5 under quasi-static conditions.

Now, by virtue of the quasi-static conditions, the electric field may be derived from a scalar potential d)... 

Cyclic chip formation refers to the periodic chip formation process of birth, growth, and final breaking of chips. The study of cyclic chip formation is important because in practice chip formation is rarely a imiquely defined process that can be represented by a quasi-static condition, but rather a cyclically repeated application of a time-dependent process involving chip formation, chip-form development, and chip fracture. Even if the cycles are not exactly repeatable, they indicate the history of chip formation and trace back important information to connect with the process mechanics. One of the earliest discoveries of cyclic chip formation in turning operations was reported by Jawahir (1986). This work was followed by an extensive experimental analysis... 

MIP membranes from nylon had a rather symmetric pore morphology, but had been applied in binding experiments also at very low flux. Identical moderate binding capacities had been observed for batch equilibrium sorption ( static ) and filtration ( dynamic ), but this can be explained by the protocol whereTho had been accumulated over a very long filtration time, i.e., under quasi- static conditions [36]. 

Bursting pressure of a containment in quasi-static conditions ... 

Taking the reference pressure at z=L, and assuming quasi-static conditions, we obtain the following expression for p(r,6)... 

Under quasi-static conditions, according to (6.9) and neglecting prestress spring stiffnesses for a first approximation (which gives T3 = 0), the strain Ss of Terfenol-D in an unloaded actuator is ... 

The surfactant molecules move toward the cathode by electrophoresis when dc voltage is applied. Under static or quasi-static conditions, we assume current density i is proportional to electric field E,... 

Solutions have been obtained for the cyclic variation of film thickness and pressure under conditions representative of the ankle joint in level walking. A single-elded roughness model of the form depicted In Figure 2 has been adopted and results are presented for an undeformed sinusoidal roughness profile of amplitude 1 and wavelength 1 mn. Detailed consideration of the Influence of wave amplitude and roughness upon film thickness under quasi-static conditions has been reported elsewhere by the authors (8). 

We consider the system model depicted in Figure 5.2, which describes the self-cleaning mechanism through the following sub-models (1) droplet model, (2) substrate surface model, and (3) particle-droplet interaction model. Since quasi-static conditions are considered in this work, it is convenient to treat the droplet as a hydrostatic bulk and a deformable liquid membrane. The latter is modeled using the stabilized FE formulation introduced by Sauer [15], which captures the in-plane equilibrium of the membranes due to constant surface tension. The multi-scale nature of self-cleaning surfaces can be mathematically modeled as 2D sinusoidal functions as done by Bittoun and Marmur [19], and Iliev and Pesheva [20],... 

We consider a rigid spherical contaminant particle of radius and density initially resting on a substrate smface and interacting with a liquid droplet under quasi-static conditions (see Figme 5.4). Four forces are involved in this interaction particle weight F, contact line force hydrostatic force F, and buoyancy force F, defined as follows ... 

Based on the sub-models described above, we present two numerical examples (1) wetting of droplets on a rough surface, and (2) adhesion of contaminant particles to a droplet surface. Quasi-static conditions are considered in both examples. We distinguish the parameters for the substrate surface in the first example (6, y, V, p) from those for the... 

Figure 3 shows the load (P) - load line displacement (5) records obtained from fracture tests at room temperature and at quasi-static conditions (low loading rates) of propylene homopolymer, PPO, and thee controlled-rheology PPs. The mechanical response for all the materials presented clearly elastic-plastic behaviour and this justifies the use of the EPFM multiple specimen method to evaluate the fracture behaviour. In addition, all the curves deviated from linearity and at a certain deflection level, sudden instability occurred and the specimen broke in two halves. The difference in stiffness is due to the different initial crack lengths. 

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