Voids discontinuous

Holidays Application defect whereby small areas are left uncoated. Syn misses, skips, voids, discontinuities, and vacations. 

The reflection tomograms (c) show the axial hole in the Plexiglas specimen, but also a real discontinuity in the A/5i -alloy. The internal discontinuity is located 6 mm from the edge, 50° from the axial hole and its dimension is about 1-2 mm. This may be an inclusion or a porosity (void). Multiple reflections from the measurement were ignored in the calculation of the Plexiglas tomogram (left). This is seen as a bright circle. 

This work presents two procedures of quantitative evaluation of the material discontinuities, using the eddy current method. One of the procedures concerns the long surface or subsurface crack-type discontinuities in a flat conductive body. The second procedure allows a quantitative evaluation of short discontinuities, such as voids, inclusions etc. 

Palygorskite and sepioHte minerals are 2 1 layered phyUosiHcates that differ from the above mentioned clays because the octahedral sheets have significant intracrystalline void space caused by discontinuous octahedral layers. The basal tetrahedral unit is connected to an adjacent inverted basal tetrahedral creating a void space or channel. Charge deficits are balanced by hydrated cations in the intracrystalline space. 

Select steels with minimum voids or discontinuities. 

To reduce heat transfer by conduction, an insulant should have a small ratio of solid volume to void. Additionally, a thin-wall matrix, a discontinuous matrix or a matrix of elements with minimum point contacts are all beneficial in reducing conducted heat flow. A reduction in the conduction across the voids can be achieved by the use of inert gases rather than still air. 

With nondestructive ultrasonic test back and forth scanning of a specimen is accomplished with ultrasonics. This NDT can be used to find voids, delaminations, defects in fiber distribution, etc. In ultrasonic testing the sound waves from a high frequency ultrasonic transducer are beamed into a material. Discontinuities in the material interrupt the sound beam and reflect the energy back to the transducer, providing data that can be used to detect and characterize flaws. It can locate internal flaws or structural discontinuities by the use of high frequency reflection or attenuation (ultrasonic beam). 

Annular flow. In annular flow there is a continuous liquid in an annulus along the wall and a continuous gas/vapor phase in the core. The gas core may contain entrained droplets—dispersed mist—while the discontinuous gas phase appears as bubbles in the annulus. This flow pattern occurs at high void fractions and high flow velocities. A special case of annular flow is that where there is a gas/vapor film along the wall and a liquid core in the center. This type is called inverse annular flow and appears only in subcooled stable film boiling (see Sec. 3.4.6.3)... 

As both phases occupy the full flow field concurrently, two sets of conservation equations correspond to these two phases and must be complemented by the set of interfacial jump conditions (discontinuities). A further topological law, relating the void fraction, a, to the phase variables, was needed to compensate for the loss of information due to model simplification (Boure, 1976). One assumption that is often used is the equality of the mean pressures of the two phases, ... 

Saturation (v) is the volume fraction of the total void volume occupied by a specific fluid at a point. Saturation values can vary from zero to 1 with the saturation of all fluids equal to 1. Residual saturation (Sr) is the saturation at which the NAPL becomes discontinuous and immobile due to capillary forces. Residual saturation is dependent upon many factors, including pore size distribution, wettability, fluid viscosity and density ratios, interfacial surface tension, gravity and buoyancy forces, and hydraulic gradients. 

Wallis points out that, from continuity considerations and bubble dynamics, the cocurrent flow of uniformly dispersed bubbles as a discontinuous phase in a liquid can always be made to occur in any system and for any void volume. (This is not true for countercurrent flow.) Coalescence of bubbles may occur, of course, and if this coalescence is sufiiciently rapid, a developing type of flow is observed, usually from bubble to slug flow. Because of this behavior, the particular flow pattern observed in bubble flow is quite dependent on the previous history of the two-phase mixture. This would be true for both horizontal and vertical flow. 

In its ultimate form, AIDECS is intended to be an inspection device which will provide a high resolution, three-dimensional scan profile of an entire expl charge in an artillery shell. It is designed to perform a differential measurement which, with an appropriately small inspection volume element, will not only identify the presence of discontinuities in the expl (such as voids, cracks, annular rings, base separations and inclusions), but is also to provide data about their size, three-dimensional location and orientation... 

This ref pertains to a US patent for a nondestructive testing method and app for determining the presence of voids, cracks or discontinuities in solid substances by the use of radioactive gases as a tracer. Although developed specifically for use with large solid proplnt rocket motors, composed mainly of active ingredients such as ammonium perchlorate imbedded in an inert binder, the method is claimed to be applicable to other solids as well... 

Other NDT Methods. Radiography (x-ray) inspection can be used to detect voids or discontinuities in the adhesive bond. This method is more expensive and requires more skilled experience than ultrasonic methods. The adhesive must contain some metal powder or other suitable filler to create enough contrast to make defects visible. This method is applicable to honeycomb sandwich structures as well as metal and nonmetal joints. 

Dispersed discontinuities Occur in A1 and Mg alloy castings. Appear as tiny voids scattered in parts or throughout the castings. Gas porosity and shrinkage porosity in A1 alloys are examples of this flaw... 

In real-time, shallow earth profiles of dielectrical discontinuities related to subsurface conditions such as moisture content lithology, bedding, voids, fractures, man-made objects. Can be used to detect buried plastic containers artd areas of excavation boundaries. 

However, it was qnickly realized during the introduction of this technique that an IPR having a hydrophobic region to interact with the stationary phase was prone to adsorb onto the reversed phase chromatographic bed because (1) the fuU impact of the reagent was felt after many void volumes of the column were displaced, (2) if the analyte and the IPR carried the same charge status, analyte retention decreased upon introduction of the IPR in the eluent, and (3) when the presence of IPRs in the eluent was discontinued, the previous eolumn retentive behavior was not restored promptly. The IPR adsorption could be measured and modeled via the adsorption isotherm [6]. 

A common form of discontinuity occurring in a solid dielectric is one where cracks or voids are present. The relative permittivity will then simply be reduced, depending on the amount and distribution of the enclosed space or air. A much more serious type of heterogeneity, however, is one where a relatively conductive component is mixed in an insulator. Common instances of this occur where a material is contaminated with metallic particles or droplets... 

Due to the composite nature of boron fibers, complex internal stresses and defects such as voids and structural discontinuities result from the presence of a... 

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