Propagation from

In UltraSIM/UlSim the ultrasonic sound propagation from a virtual ultrasonic transducer can be simulated in ray tracing mode in any isotropic and homogeneous 3D geometry, including possible mode conversions phenomenons, etc. The CAD geometry for the simulation is a 3D NURBS surface model of the test object. It can be created in ROBCAD or imported from another 3D CAD system. 

By using this method, the mati ix is propagated from a very small... 

Below a certain critical temperature, which varies with pressure and stoichiometry, cool flames for several hydrocarbons propagate from the wall inward above this temperature, they propagate from the center of the vessel (78). This transition is interpreted as evidence for a changeover from a predominantly heterogeneous preflame mechanism to a homogeneous one. 

Example 2 (Shock Reflection from a Lower Z Interface). Figure 2.17 represents a shock wave propagation from left to right in material A. When the... 

When an isotropic material is subjected to planar shock compression, it experiences a relatively large compressive strain in the direction of the shock propagation, but zero strain in the two lateral directions. Any real planar shock has a limited lateral extent, of course. Nevertheless, the finite lateral dimensions can affect the uniaxial strain nature of a planar shock only after the edge effects have had time to propagate from a lateral boundary to the point in question. Edge effects travel at the speed of sound in the compressed material. Measurements taken before the arrival of edge effects are the same as if the lateral dimensions were infinite, and such early measurements are crucial to shock-compression science. It is the independence of lateral dimensions which so greatly simplifies the translation of planar shock-wave experimental data into fundamental material property information. 

We assume that in (4.38) and (4.39), all velocities are measured with respect to the same coordinate system (at rest in the laboratory) and the particle velocity is normal to the shock front. When a plane shock wave propagates from one material into another the pressure (stress) and particle velocity across the interface are continuous. Therefore, the pressure-particle velocity plane representation proves a convenient framework from which to describe the plane Impact of a gun- or explosive-accelerated flyer plate with a sample target. Also of importance (and discussed below) is the interaction of plane shock waves with a free surface or higher- or lower-impedance media. 

Moulded plastics will also have crack initiation sites created by moulding defects such as weld lines, gates, etc and by filler particles such as pigments, stabilisers, etc. And, of course, stress concentrations caused by sharp geometrical discontinuities will be a major source of fatigue cracks. Fig. 2.72 shows a typical fatigue fracture in which the crack has propagated from a surface flaw. 

The flame propagation direction affects the type of flame arrester selected. An end-of-line or in-line deflagration flame arrester used for the protection of an individual tank may be of a unidirectional design because the flame will only propagate from the atmosphere towards the tank interior. A bidirectional flame arrester design, however, is needed for an in-line application in a vapor recovery (vent manifold) system because the vapors must be able to flow from the tank interior into the manifold, or from the manifold into the tank interior. Consequently, flame may propagate in either direction. 

A deflagration or detonation flame arrester fails hy definition if any flame propagates from the unprotected to the protected side. Failures can result for a numher of reasons, some of which are listed helow ... 

Monomer A is polymerized initiated with a pair of radicals formed by thermolysis of an active site of macroinitiator. Since growing chain A propagates from the residual segment of the initiator, polymer A thus formed retains unreacted active sites in the chain end. 

A deflagration is a slow burning exothermic reaction similar to the combustion explosion, but which propagates from the burning gases into the unreacted material at a velocity that is less than the speed of sound in the unreacted material. Most (not all) explosions are deflagrations. 

Lower Flammability (Explosive) Limits (LF.J, trr I FT.) The lowest percentage concentration at which a flash or flame can develop and propagate from the source of ignition when in contact with a source of ignition in a combustible material. 

In the case of crystalline polymers it may be that solvents can cause cracking by activity in the amorphous zone. Examples of this are benzene and toluene with polyethylene. In polyethylene, however, the greater problem is that known as environmental stress cracking , which occurs with materials such as soap, alcohols, surfactants and silicone oils. Many of these are highly polar materials which cause no swelling but are simply absorbed either into or on to the polymer. This appears to weaken the surface and allows cracks to propagate from minute flaws. 

Being able to construct an e xplicit solution to a nonlinearly separable problem such as the XOR-problem by using a multi-layer variant of the simple perceptron does not, of course, guarantee that a multi-layer perceptron can by itself learn the XOR function. We need to find a learning rule that works not just for information that only propagates from an input layer to an output layer, but one that works for information that propagates through an arbitrary number of hidden layers as well. 

Although head addition occurs during PVC polymerization to the extent of ca 1%, it is now thought that PVC contains few, if any, head-to-head linkages (<0.05%).61-6- Propagation from the radical formed by head addition is not competitive with a unimolecular pathway for its disappearance, namely, 1,2-chlorine atom transfer (see Scheme 4.8). 

The interaction matrix can be built following Le Louam and Tallon, 2002. We assume narrow fields approximation for the propagation from the turbulent layers, i.e. phase perturbations by the turbulent layers simply add at the level of the pupil. It also means that scintillation is negligible. A point x, y) in the turbulent layer at altitude h is projected onto the pupil at (rcpupii, 2/pupii) ... 

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