Defects defined

This seems to imply that the associated distortion of the cage is only large for one atom (not two as for the type a structures) and therefore possibly better accomodated by the defects defined in Table 4. It must be concluded that either structures b and c are chemically unrealistic or there is a subtle, but significant, stabilisation provided by a complete geometry optimisation. 

Note Commonly, the term mass defect, defined as the difference between the exact mass and the integer mass, is used to describe this deviation. [3] Application of this concept leads to positive and negative mass defects, respectively. In addition, the association of something being defective with certain isotopic masses can be misleading. 

In spite of what has been said above, it is nevertheless important to realize that the properties of intermetallic systems are by no means completely characterized by their ideal crystal structures alone. Such systems, more than any others, often display the defects defined as faults in chapter 9, and frequently it is to these faults that many of the technically most important properties, such, for example, as hardness and strength, are to be ascribed. Faults of this type are on a scale intermediate between atomic dimensions and those accessible to microscopic study, and therefore constitute a peculiarly difficult field of investigation. They have, nevertheless, been the subject of much work in recent years but it would be inappropriate here to give an account of this work, the interest of which is primarily physical rather than chemical. 

Superscript. The superscript denotes the effective electric charge on the defect, defined as the difference between the real charge of the defect species and that of the species that would have occupied that site in a perfect crystal. The superscript is a prime for each negative charge, a dot for every positive charge, or an x for zero effective charge. 

Fig. 31.3 shows as an example a typical potential map as measured by the scanning Kelvin probe for an iron/adhesive interface activated with 0.5 m NaCl during cathodic undermining in a humid air atmosphere (at about 95% r.h.). The samples for this type of measurement are prepared with a defect area of about 20 mm which is free of the adhesive, adjacent to the adhesive film, and filled with an electrolyte solution the measurement with the SKP is performed above the adhesive film starting from the border of the defect defined as x=0 pm. 

Standard deviation of the lateral positions of defective units, the lateral encumbrance, t, of kink defects (defined in Fig. 25) was esteemed to be about 1.6 A, in a good agreement with the lateral encumbrance of the kink model proposed in [105] by Petraccone, Allegra and Corradini. 

Levine and Muenke (1991) reported the case of a pregnant lead worker who sustained brief, early, and quite elevated workplace exposure and delivered an infant with virtually aU of the characteristic defects defining the VACTERL association seen with other human cases, where Pb was not explicitly identified as present. VACTERL refers to collective vertebral anomalies, anal artresia, cardiac defect, renal anomalies, and limb anomalies only tracheoesophageal fistula was absent. A striking feature of these birth defects was their similarity to high-dose birth defects found in various test animal species, a urorecto/caudal pattern of malformations. 

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