Void, voids

Translation Change void voids void, A. void, A. 

For pure water voids, void nucleation is instantaneous. For air-water voids, air void nucleation or entrapment has already occurred during lay-up or at the beginning of the cure cycle. 

Polymer Engineering and Science 41, No.3, March 2001, p.575-83 IZOD IMPACT STRENGTH OF A PRODUCT MOLDED OF POLY(VINYL CHLORIDE)/ IMPACT MODIFIER CONTAINING VOIDS (VOID MOD)... 

For the screening test phase, three replicate specimens of each combination of independent variables were made, and each of the indicator or control tests was run on the specimens of sulfur-asphalt concrete. These indicator tests (dependent variables) included bulk specific gravity, air voids, voids in the mineral aggregate (VMA), resilient modulus, Hveem stability, Marshall stability, and Marshall flow. Table II presents the range of dependent variables determined during the screening test for the AAS system mixtures. 

For weak scale adherence and low substrate ductility, through-scale cracking is accompanied by a delamination and spalling of the scale. This was observed to a large extent on Fe-doped NiAl specimens after bending at RT (Fig. 6).The weak adherence in this case was caused by a pronounced formation of interfacial voids. Void formation at the oxidc-metal interface has often been observed for NiAl. It was studied in more detail by Brumm and Grabke in [32. ... 

It consists of a specimen production 100 mm (or 101 mm) in diameter, compacted with an impact Marshall compactor, using a Marshall apparatus for stability and flow determination as well as for volumetric property determination (air voids, voids in the mineral aggregate [VMA] and voids filled with asphalt [bitumen] [VFA]). 

The mix design is based on the volumetric properties of the mix and particularly on air voids (void content) and the presence of stone-on-stone contact. The specimens are compacted by a gyratory compactor or another compactor providing equivalent compacted density. 

Total void content = air voids + voids filled with water. 

The volumetric properties of the asphalt such as air voids, voids in the mineral aggregate and voids filled with bitumen are calculated from the compacted asphalt specimens obtained from the site. The calculations for the determination of the volumetric properties are carried out according to CENEN 12697-8 (2003), ASTM D 3203 (2011) or AASHTO T 269 (2011). 

PA matrix with PP, FVA particles and 4,2% carboxylized PP as modifier, deformed matrix strands around voids, voids due to debonding between PA and PP or FVA ... 

All injection-moulded thermoplastics are prone to sink marks and voids in areas where sudden changes in section thickness occur, or over ribs and bosses. Semi-crystalline polymers such as PP are more prone to sinks and voids. Voids occur when the external skin of the moulding is rapidly cooled and becomes sufficiently rigid to support the contraction of the underlying melt. Sinking or surface depression occurs in localised thick sections where internal mass contains sufficient heat to keep the polymer in molten stage and erystallises slowly producing sink marks. 

It is believed that, in addition to the driving force acting on voids, void growth also depends strongly on the properties of the thermoplastic matrix. Hence, it is necessary to examine the properties of the polymer matrix in thermal deconsolidation. Amorphous thermoplastics become brittle below T, then... 

Volume defects consist of inclusions or precipitates of a second phase material or voids. Voids can be formed by vacancy clusters or from the nucleation of bubbles from dissolved gases or from components with high vapor pressures. Such defects can range in size from microscopic to gross. Bear in mind that not all such defects are unwanted. Many are purposely introduced into the final solid to tailor certain electrical, optical, and magnetic properties, or to serve as strengthening mechanisms. These topics are discussed in later chapters. 

Note There are two types of hollows, entrapped air and voids. Voids are vacuole hollows, formed by the shrinkage of the moulding compoimd (see sink marks ). Distinguishing between the two is very hard, because of their similar appearance. The following hints might be helpful ... 

Reactivity due to voids (%) Void fraction core average %)... 

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