Stability concept

A joint Russian and American team of physicists created two new super heavy elements—115 and 113—that provide more support for the island of stability concept. The experiments were conducted between July 14 and August 10 in 2003, but the results of the experiments were not published until February 2004. The experiments were conducted in the Joint Institute of Nuclear Research (JINR) in Dubna, Russia, and also involved the scientists of the Lawrence Berkely National Laboratory located at Berkeley, California. Only four atoms of two isotopes of ununpentium (element 115) were produced, and the results were published in a peer-reviewed scientific journal. Following is the nuclear reaction that produced these four atoms ... 

It was therefore appropriate that the first attempt to produce lattice stabilities for non-allotropic elements dealt with Cu, Ag and Zn (Kaufman 1959b). It is also significant that, because of the unfamiliarity of the lattice stability concept, this paper did not appear as a mainstream publication although the work on Ti and Zr (Kaufman 1959a) was published virtually at the same time. It was also realised that Ae reliability of metastable melting points derived by extrapolation were best... 

The heart of the acid-stabilization concept is a consequence of the thermodynamics of reaction (1) if X forms strong bonds with M + (i.e. if X acts as a strong Lewis base), then disproportionation of M," will be strongly driven by the favorable change in enthalpy. Weak Lewis bases ( non-coordinating anions) would therefore be expected to be beneficial for the stability of sub-valent species. In other words, the thermodynamic stability of M "+ in a given system would be expected to increase upon the addition of a Lewis acid, which is stronger than the... 

To satisfy the bond-stabilization concept, it appears essential to reclassify the inorganic azides. Hence, five classes are identified here and are listed in Figure 1 as normal azides, mixed azides, hetero azides, azido complexes, and metalorganic azides. 

Professor Viejo Dinosaurio wishes to utilize this reaction as the basis for a laboratory demonstration that would illustrate both autothermal operation of a CSTR and reactor stability concepts. He plans to use a well-insulated reactor with an effective liquid volume of 1.0 L. The feed is to consist of a mixture of the hydroperoxide (HP), acetone (A), and acid catalyst at 25°C. Initial concentrations of hydroperoxide and acetone are 0.5 and 1.0 mol/L, respectively. The following property values are available the standard heat of reaction at 25°C (estimated) = -60.5 kcal/g-mol and the heat capacity per liter of fluid (estimated) = 406 cal/(L-°C). This value may be taken as independent of the fraction conversion. 

Utilization of Small Molecule Stabilization Concepts for Tailoring the Properties of Nanodispersions... 

The stability concept is also useful in establishing the maximum supersaturation that can occur for both pure components and multicomponent mixtures. Suppose we are given a mixture of Ci and nC that has a fixed bubblepoint pressure at a given temperature. If the pressure of this mixture at the given temperature is lowered from a pressure above to a pressure below the bubblepoint, the gas phase may not appear if the pressure reduction is carried out rapidly. However, there is a theoretical limit for the pressure at which the gas phase will appear no matter how fast is the pressure reduction. This maximum supersaturation can be calculated from the stability limit to be discussed in this chapter. In the last part of this chapter, we will present methods that can be used in calculating the critical point of complex... 

It has been mentioned in chapter VI, 8, p, 263 that Stern s correction results in a lower potential drop in the diffuse double layer (9 instead of The potential in the diffuse layer, instead of being oply dependent on the amount of potential-determining ions, now also depends upon the total electrolyte concentration and is lower, the higher the electrolyte content. This explains why in several cases a sort of critical u-potential has been found and it shows how in the refinements of the double layer theory of stability, conceptions of the older theories (like discharge by adsorption of counter ions) again play a role. 

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