Wall moving

As the external pressure on the chest wall becomes larger than its internal pressure during the passage of a blast wave, the chest wall moves inward, thus causing injury. Because the inward motion takes time, the duration of the blast wave is important. Results of animal tests indicate that overpressure is only important for long durations, and impulse is important for relatively short durations (White et al. 1971). 

No physical interpretation of the criterion was provided, but it can be regarded as the ratio of the square of the velocity of a gravity-driven "free fall bubble," of diameter equal to the flame thickness, to the square of the laminar flame speed. This leads to the conclusion that quenching occurs when a flame element quenched at the wall moves ahead of the flame, as observed and as described by Jarosinski et al. [4] (see Fig. 5 in the paper referred to) for downward propagating flames in tubes. 

Fig. 3. Mixing in the cavity flow. The flow is time periodic with the upper and lower walls moving alternately for a fixed time period (Leong and Ottino, 1989).

The French drain (also called a channel drain or floating slab) is a construction feature that appears to provoke strong reaction from its defenders and detractors alike. French drains are only a concern in basement foundations. This slab detail is a standard feature in new houses in parts of the country as varied as New York and Colorado, but in other places it is virtually unknown. French drains are used in areas with expansive soils, such as parts of Colorado, to protect the slab from damage if the wall moves. In central New York State, the main function of the French drain is to drain away water that may seep down the walls. One national builder has discontinued and now prohibits the use of French drains in houses because of the potential for radon problems. This builder states that French drains also have been found to significantly increase indoor moisture levels. 

Figure 8.6 Average stretching (5,) for operational modes of a conventional extrusion and the chaotic mixing. The j/-axis is logarithmic. The top wall moving curve corresponds to a conventional single-screw extruder with a rotating screw. The results are shown for an /r/FF aspect ratio of one and a period of 4 s...

Figure 18 Possible mechanism for arranging octahedral coordination around an impurity atom located on the interior of a grain, (a) Shifts of the atoms are indicated by the arrows, (b) Resulting structure. With this mechanism the oxygen stoichiometry becomes larger than 7. The twin walls move as a consequence of the rearrangement of the oxygen atoms and cross-twinning becomes possible.

FIGURE 9.5 Movement of a domain wall. The broken lines illustrate the domain wall, which separates two domains with magnetic moments lined up in opposite directions. The moments twist to align with the applied field, H, and the wall moves in the direction of the arrow. 

Figure 2.4b shows, conceptually, the velocity distribution in steady turbulent flow through a straight round tube. The velocity at the tube wall is zero, and the fluid near the wall moves in laminar flow, even though the flow of the main body of fluid is turbulent. The thin layer near the wall in which the flow is laminar is called the laminar sublayer or laminar film, while the main body of fluid where turbulence always prevails is called the turbulent core. The intermediate zone between the laminar sublayer and the turbulent core is called the buffer layer, where the motion of fluid may be either laminar or turbulent at a given instant. With a relatively long tube, the above statement holds for most of the tube length, except for... 

An analysis of the temperature distribution in a mold (Fig. 4.54) at the final moment of filling for two reactive systems with different values of G shows that the temperature along the central line increases monotonically downstream (at distance x) from the inlet nozzle. At high values of the gelation criterion, the temperature at locations close to the injection nozzle is maximum near the mold wall. Moving down stream, the position of the temperature maximum shifts to the center, except at the frontal zone. Here the temperature is nearly constant, because the major part of the... 

A polyester foam with a negative Poisson s ratio has been reported by Lakes. Its cells consist of reentrant faces. Figure 19.4 shows a cell with 24 faces. When the cell is extended its sides are moved inward and when it is compressed the walls move outward. The negativity of v increases with 9. 

The origin of the nonlinearity and hysteresis in the films is most likely due to displacement of domain walls [4], If domain walls move in a medium with a random distribution of pinning center, the response of the material can be described, in the first approximation by Rayleigh relations. We next demostrate how optical interferometry can be sued to verify whether this particular model applies to the investigated pzt thin film. In the case of the converse piezoelectric effect, when the driving field E is varied between — Eo and Eo, the piezoelectric strain x is hysteretic and can be expressed by the following Rayleigh relations ... 

Initially, at t — to, the walls and disks touch with no force, FN — 0, Fig. E4.2(a). The walls move toward each other at a constant velocity, v. At time t — to + At the walls have each moved a distance v At. Since the disturbance cannot travel beyond a single disk as assumed by the model, both disks maintain their initial positions during this time interval. Thus, overlaps are created at points A and C, Fig. 4.2(b), given by... 

Fig. E4.2 Soft-sphere DEM model for two disks being compressed by two confining walls moving in opposite direction with a velocity v. [Reprinted by permission from P. A. Cundall and O. D. L. Strack, A Distinct Element Model for Granular Assemblies, Geotechnique, 29, 47-65 (1979).]...

Fig. 7.12 The flow pattern (bottom) is generated in a cavity filled with glycerin with the walls moving continuously in opposite directions. The flow pattern (top) has two elliptic and one hyperbolic point. [Reprinted by permission from J. M. Ottino, The Mixing of Fluids, Set Am., 20, 56-67, 1989.]...

Q4 The pleura are serous membranes one layer (the visceral pleura) firmly adheres to the surface of the lung and the other (the parietal pleura) adheres to the inner surface of the thoracic wall and diaphragm. The two pleural membranes lie very close together, separated only by a thin him of fluid. This lubricates the pleural surface, allowing the two layers to smoothly slide over each other as the thoracic wall moves. 

A 70-year-old woman with a history of mastectomy developed syncope which lasted a few seconds. She had taken tamoxifen 10 mg bd for 10 years and had no history of allergic reactions. Doppler ultrasound showed aortic stenosis and coronary angiography was performed using 150 ml of iopromide (a non-ionic contrast medium, iodine 370 mg/ml). She had visual hallucinations (spiders on the wall, moving curtains) 30 minutes after the injection of iopromide. The symptoms resolved 72 hours later without any specific treatment. Neurological and psychiatric examinations were normal, as were brain MRI and Doppler ultrasound of the carotid and vertebral arteries. 

The results of measurements by the microscopic method show that the electrophoretic mobility of the particles varies with the distance from the wall of the cell particles close to the wall move in a direction opposite to that in which those in the center migrate. In any event, the results show an increase in velocity from the walls to the center of the cell. The explanation of this fact lies in the electro-osmotic movement of the liquid a double layer is set up between the liquid and the walls of the cell and under the influence of the applied field the former exhibits electro-osmotic flow. For the purpose of obtaining the true electrophoretic velocity of the suspended particles it is neceasary to observe particles at about one-fifth the distance from one wall to the other. A more accurate procedure is to make a series of measurements at different distances from the side of the cell and to apply a correction for the electro-osmotic flow. The algebraic difference of the corrected electrophoretic velocity and the speed of the particles near the walls gives the electro-osmotic mobility of the liquid in the particular cell. If the solution contains a protein which is adsorbed on the surface of the walls of the vessel and on the particles, it is possible to compare the electrophoretic and electro-osmotic mobilities in one experiment reference to the significance of such a comparison was made on page 532. 

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