Criteria boron

Proposed boron criteria for the protection of natural resources and human health... 

Table 29.10 Proposed Boron Criteria for the Protection of Natural Resources and Human Health...

Boron criteria recommended for the protection of sensitive species include ... 

A serious limitation of such boron criteria is the lack of provision for difference in soils, irrigation management, and climate. Soils differ in their capacity for adsorbing boron, and irrigation and rainfall characteristics likewise exert an effect on the distribution of available boron in soils. Additional details are presented in discussions of criteria for irrigation water quality by Bernstein (41) and Rhoades (42). 

Figure 2-44 Hoffman Failure Criterion for Boron-Epoxy (Data from Pipes and Cole [2-25])...

The second special case is an orthotropic lamina loaded at angle a to the fiber direction. Such a situation is effectively an anisotropic lamina under load. Stress concentration factors for boron-epoxy were obtained by Greszczuk [6-11] in Figure 6-7. There, the circumferential stress around the edge of the circular hole is plotted versus angular position around the hole. The circumferential stress is normalized by a , the applied stress. The results for a = 0° are, of course, identical to those in Figure 6-6. As a approaches 90°, the peak stress concentration factor decreases and shifts location around the hole. However, as shown, the combined stress state at failure, upon application of a failure criterion, always occurs near 0 = 90°. Thus, the analysis of failure due to stress concentrations around holes in a lamina is quite involved. 

Although a number of factors affect structural evolution in sol-gel processing, many of the observed trends can be explained on the basis of the stability of the M-O-M bond in its synthesis environment. Structures which form in solution are the products of a successive series of hydrolysis, condensation and restructuring reactions. M-0-M bonds which are unstable with respect to hydrolysis and alcoholysis are absent. In borates this criterion precludes gelation for systems with insufficient fractions of 4-coordinated borons. In silicates... 

Boron does not meet Glassman s criterion for vapor-phase combustion of the metal. Thus, the boron surface remains coated with a vitreous B203 layer and boron consumption becomes extremely slow consequently, boron is not burned efficiently in propulsion devices. 

This volume follows the organizational patterns initiated in Volumes X and XI. Syntheses are grouped according to interest area, using this criterion, we have placed in Vol. XII a chapter on Metal Complexes of Molecular Nitrogen and one on Significant Solids. More traditional chapter headings such as Nonmetal Systems and Boron Compounds also fit appropriately under the criterion of interest areas. 

The electrochemical properties of the clathrochelate Ca-nonsymmetric FeDnD 3-n(BX)2 and Ca-nonsymmetric FeD3(BX)(BY) tris-dioximates and their dependence on electronic characteristics of the substituents in the dioximate fragments and ones at capping atoms are discussed in Refs. 64 and 68. Table 36 lists the E1/2 and the Tomes criterion values for these complexes. As seen from this table, the oxidation process for most of the boron-capped iron(II) clathrochelates is reversible or quasi-reversible. 

Physically safer as a mechanistic criterion is reversible inhibition by boronic acids, RB(0H)2, which add the active site serine to form tetrahedral species [RB(0H)20Ser] , which mimic the tetrahedral intermediate/transition state. They also mimic the tetrahedral intermediates in aspartic protease action, however, and are therefore not as definitive. 

The detailed description of the AdNDP method and its application to boron clusters, prototypical aromatic hydrocarbons, gold clusters, metalloorganic complexes, and inorganic complexes containing metal clusters as the building blocks can be found elsewhere [58-64]. The AdNDP analysis allows us to introduce a new aromaticity criterion. A chemical species should be considered aromatic if there is a... 

The existing analysis for the uncontrolled depressurisation of all steam generators is based on a scenario where neider main steam header separation nor steam generator isolation occurs, enabling all steam generators to blow down through the ruptured main steam line (i.e. the isolation valve on the ruptured line fails to close), however the faulted SG is automatically isolated on feed side by the logic. For this scenario, the analysis was finalised to include safety injection termination criterion for boron concentration. 

Vega-Boggio, J. and Vingsbo, O. (1976) Application of Griffith criterion to fracture of boron fibers. J. Mater. Sci., 11 2242-2246. 

The acceptance criterion for GSI 022 is that new plants shall minimize the consequences of inadvertent boron dilution events by meeting the intent of SRP Section 15.4.6. Specifically, when performing a safety analysis to evaluate the consequences of an inadvertent boron dilution, plant designers should consider (1) design limits for maximum RCS pressure and minimum DNBR, (2) moderate frequency events in conjunction with a single failure or operator error and their possible effects on fuel integrity and radiological dose calculations, (3) and time limits specified for each mode of plant operation, if operator action is required to terminate an inadvertent boron dilution. 

A second criterion of aromaticity, electrophilic aromatic substitution, is also seen in the reaction between furan and acetic anhydride (in the presence of a boron trifluoride-etherate Lewis acid catalyst) Scheme 8.104. 

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