Transverse slip

Since in all these lamellar clusters the best slip system lies parallel to the interface, any applied stress cannot activate slip in them but can, at best, initiate slip only on other inclined planes with slip directions lying parallel to the interface. In HDPE these alternative slip systems are the (010) [001] chain-slip system and the (100) [010] transverse-slip system, with these having plastic-shear resistances of 15.6 MPa and 12.2 MPa, respectively, compared with the shear resistance of the (100) [001] primary slip system of only 7.2 MPa (Bartczak et al. 1992). 

Following the same approach employed in equation (5), the transverse slip associated with rope rotation in the slip zone is given by... 

For polyamide 6 crystals the slip systems are (001) [010] chain slip at 16.24 MPa, (100)[010] chain slip at 23.23 MPa and (001)[100] transverse slip [71]. Relatively little attention was paid to the plastic deformation of other semicrystalline polymers [98,110]. In particular, there are only a few papers [111,112] describing the investigations of the yield behavior and plastic resistance of oriented iPP. 

Belt route another problem is to find the routes of the shoulder and lap belts on the dummy, with the evidence that these routes may often change during a crash, corresponding to transverse slip not modelled in Madymo. Another reason to treat this problem analytically is that we wanted to simulate earlier tests, where the connecting points of the strap on the dummy were not known. Therefore, we chose to model the route and calculate geometrical characteristics of the belt with a pre-processor, in the initial position of the dummy. It is explained below how to control this parameter. 

In addition to elastic turbulence (characterised by helical deformation) another phenomenon known as sharkskin may be observed. This consists of a number of ridges transverse to the extrusion direction which are often just barely discernible to the naked eye. These often appear at lower shear rates than the critical shear rate for elastic turbulence and seem more related to the linear extrudate output rate, suggesting that the phenomenon may be due to some form of slip-stick at the die exit. It appears to be temperature dependent (in a complex manner) and is worse with polymers of narrow molecular weight distribution. 

Check slip areas for longitudinal and transverse cracks and sharp notches. Check tool Joints for wear, galls, nicks, washes, fins, fatigue cracks at root of threads, or other items that would affect the pressure holding capacity or stability of the Joint. 

Fig. 8—Comparison of film and pressure profiles with Venner and Holmes results (for a moving transversal ridge, slip=0.0). (a) Venner s result [40] (b) Holmes result [41] and (c) present result.

Slip is not always a purely dissipative process, and some energy can be stored at the solid-liquid interface. In the case that storage and dissipation at the interface are independent processes, a two-parameter slip model can be used. This can occur for a surface oscillating in the shear direction. Such a situation involves bulk-mode acoustic wave devices operating in liquid, which is where our interest in hydrodynamic couphng effects stems from. This type of sensor, an example of which is the transverse-shear mode acoustic wave device, the oft-quoted quartz crystal microbalance (QCM), measures changes in acoustic properties, such as resonant frequency and dissipation, in response to perturbations at the surface-liquid interface of the device. 

Figure 4. Theoretical trends for —(storage) and dissipation as the inner slip is varied between no slip (0) and strong slip (1) for a coated transverse shear acoustic wave device in water. The thickness of the film is 5 nm. The solid line displays the decrease in storage, and the dashed line shows the change in dissipation.

Oldham discovered that there are actually two kinds of seismic vibrations, one called P (or "primary," because it travels faster and arrives first) and the other called S (or "secondary," because of its later arrival at the same station). The compressional motion of the P waves can be transmitted through most substances, although the speed at which the wave moves decreases as the stiffness of the medium decreases. In contrast, the transverse motion of S waves cannot be transmitted through a liquid, because the loosely bonded molecules in a liquid slip past each other too easily. S waves are observed to disappear at the top of the core. Then, at a depth of approximately 5100 km, the P wave velocity abruptly increases and there is a hint of the reappearance of an S wave. From such observations, Danish geophysicist Inge Lehman hypothesized in 1936 that the core was stratified, with an outer liquid portion and an inner solid portion. The existence of molten metal at core pressures requires some light element to act as antifreeze. 

Rope represents a very useful form of fibrous product. A rope or cord consists of a bundle of fibers. The fibers may be continuous or they may be made of staple fibers, i.e. short, fine fibers. The tensile strength of a rope comes from the strength of individual fibers and the friction between them. The interliber friction prevents their slip past one another. Quite obviously, a rope or a cord has very anisotropic properties. It is strong in tension along the axis direction but not in the transverse or radial direction. Strength in compression is also very poor. 

Fig. 7 Sequential micrographs of the evolution of the damage in a SiO 4.5 wt.% P film deposited on an Al substrate subjected to a tensile test (system C, Figure 6). The black arrows show the tensile direction, (a) Networks of primary and secondary cracks perpendicular to the tensile axis (e = 11%). The white arrows show a secondary crack which stops when getting close to primary cracks, (b) decohesion and buckling of the strips of film. Slip lines are observed on the Al surface under the buckled strips, and (c) transverse rupture of the buckled zones along the directions of maximum shear of the substrate (e = 19%).

We consider fully developed incompressible laminar flow, considering slip at the walls, inside a circular micro-tube or a parallel plates micro-channel subjected to a pressure gradient dp/dz that varies in an arbitrary functional form with the time variable. The velocity field is represented by u(r,t), which varies with the transversal coordinate, r, and time, t. The related time-dependent axial momentum equation (z-direction) is then written in dimensionless form as ... 

At the impermeable wall boundaries of the solution domain, normally a no slip boundary condition is employed. This is achieved by setting the transverse fluid velocity equal to that of the surface and setting the normal velocity to zero. Since the normal velocity at the wall is known, the value of pressure at the wall boundary is not required to be known. For species concentrations or temperatures, any of the following conditions can be specified at the wall boundaries ... 

Either of the boundary-value problems can be uniquely solved numerically if any positive value of the slip velocity U = Unix, 1) would be prescribed on the common boundary z = 1. However, this value is physically suited if it secures the continuity of the transversal velocity and the shear stress. The conjugation boundary condition... 

Figure 10. Chemotaxis-detection system in a Zigmond chamber. Top a transverse section. Bottom a plan view. A concentration gradient is formed between the covei slip and the partition wall [p] separating two wells (Cl and C2). See text for details. (Taken with permission from Giojalas et al. (57].]...

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