Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Rules limitations

It should be noted that in the cases where y"j[,q ) > 0, the centroid variable becomes irrelevant to the quantum activated dynamics as defined by (A3.8.Id) and the instanton approach [37] to evaluate based on the steepest descent approximation to the path integral becomes the approach one may take. Alternatively, one may seek a more generalized saddle point coordinate about which to evaluate A3.8.14. This approach has also been used to provide a unified solution for the thennal rate constant in systems influenced by non-adiabatic effects, i.e. to bridge the adiabatic and non-adiabatic (Golden Rule) limits of such reactions. [Pg.893]

P I H I P >. It ean be shown (H. P. Kelly, Phys. Rev. 131, 684 (1963)) that this differenee allows non-variational teehniques to yield size-extensive energies. This ean be seen in the MPPT/MBPT ease by eonsidering the energy of two non-interaeting Be atoms. The referenee CSF is = Isa 2sa Isb 2sb the Slater-Condon rules limit the CSFs in P whieh ean eontribute to... [Pg.489]

The traditional methods for measuring the swelling degree [100] are, as a rule, limited due to the difficulties in quantitative separation of the swollen gel from the outer solution because of extremely low strength of the former. These difficulties can be avoided by measuring the dimensions of a regular shape sample directly in an excess of liquid [19, 101,102], The other example is the modified volumetric method recently developed by us especially for SAH [103],... [Pg.111]

In the previous regulations, bleached kraft mills were divided into four subparts and unbleached kraft mills were divided into three subparts. As a result, the remaining preCluster Rules limits (i.e., BPT for BOD5, TSS, and pH, and BAT and PSES for pentachlorophenol and trichlorophenol) for the four previous bleached kraft mill subparts now exist as four segments. Likewise, the remaining preCluster Rules limits for the three previous unbleached kraft subparts now exist as three segments. [Pg.889]

It is tempting to place significance on the relative magnitudes of the saturation indices calculated for various minerals and then to relate these values to the amounts of minerals likely to precipitate from solution. The data in Table 6.6, however, suggest no such relationship. Thirteen minerals are supersaturated in the initial fluid, but the phase rule limits to ten the number of minerals that can form only two (dolomite and quartz) appear in the final phase assemblage. [Pg.93]

Figure 4.4 Frequency-domain representation of the dynamically controlled decoherence rate in various limits (Section 4.4). (a) Golden-Rule limit, (b) Anti-Zeno effect (AZE) limit (c) Quantum Zeno effect (QZE) limit. Here, F,( ) and G(w) are the modulation and bath spectra, respectively and F are the interval of change and width of G( ), respectively and is the interruption rate. Figure 4.4 Frequency-domain representation of the dynamically controlled decoherence rate in various limits (Section 4.4). (a) Golden-Rule limit, (b) Anti-Zeno effect (AZE) limit (c) Quantum Zeno effect (QZE) limit. Here, F,( ) and G(w) are the modulation and bath spectra, respectively and F are the interval of change and width of G( ), respectively and is the interruption rate.
The Rydberg state which is optically prepared in a typical ZEKE experiment is usually directly coupled to the continuum [45c, 57]. Other considerations being absent, it should decay promptly, possibly with a stable, trapped component. The point is that the initially prepared state is also directly coupled to many other states, due both to external perturbations [37] and to intramolecular coupling [3b]. The conclusion that the initial state has two components, one that decays promptly and one that is trapped, is thus only valid in zero order (so-called golden rule limit). One needs to allow for the coupling terms represented by V and U. [Pg.639]

Structure C has 10 electrons surrounding nitrogen, but the octet rule limits nitrogen to 8 electrons. Structure C is incorrect. [Pg.13]

There are no hard and fast rules limiting the number of businesses that a company can be in. The only constraints are that it should be distinctive in each of them, and that its portfolio should not incorporate too many dissimilar businesses. [Pg.44]

A court order has vacated the OSHA Air Standards set in 1989 and contained in 29CFR 1910.1000. OSHA has decided to enforce only pre-1989 air standards. We have elected to include both the Transitional Limits that went into effect on December 31,1992, and the Final Rule limits that went into effect September 1,... [Pg.1964]

After the solvent-laden material is desolventized, it is conveyed to the meal DC. The material entering the DC is typically at the DT exit temperature of 108°C and contains 18-20% moisture. The primary purposes of the DC are to reduce the moisture in the meal to within trading rule limits and to lower the meal temperature prior to storage. [Pg.2501]

This complex has an electron count matching a nido structure, but it adapts the butterfly structure expected for arachno. This is one of the many examples in which the structure of metal clusters is not predicted accurately by Wade s rules. Limitations of Wade s rules are discussed in R. N. Grimes, Metal-lacarboranes and Metallaboranes, in G. Wilkinson, F. G. A. Stone, and W. Abel, eds.. Comprehensive Organometallic Chemistry, Vol. 1, Pergamon Press, Elmsford, NY, 1982, p. 473. [Pg.584]

The American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value — time-weighted average (TLV — TWA) is 5000 ppm and the ACGIH short-term exposure limit (STEL) is 30 000 ppm the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) — TWA is 500 ppm (transitional limit) and 10 000 ppm (final rule limit), and the OSHA PEL STEL is 30 000 ppm the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit is 10 000 ppm (TWA). [Pg.420]

There is a special kind of site-selectivity which has been called periselectivity. When a conjugated system enters into a reaction, a cycloaddition for example, the whole of the conjugated array of electrons may be mobilized, or a large part of them, or only a small part of them. The Woodward-Hoffmann rules limit the total number of electrons (to 6, 10, 14 etc. in all-suprafacial reactions, for example), but they do not tell us which of 6 or 10 electrons would be preferred if both were feasible. Thus in the reaction of cyclopentadiene (355) and tropone (356), mentioned at the beginning of this book, there is a possibility of a Diels-Alder reaction, leading to 354, but, in fact, an equally allowed, ten-electron reaction is actually observed,121 namely the one leading to the adduct (357). The product is probably not thermodynamically much preferred to the... [Pg.173]

Figure 1. Sublett basin (solid line, dashed where uncertain) in relation to major Permian structural and paleogeographic elements. Areal extent of Meade Peak indicated by left diagonal rules Retort, by right diagonal rules limit of middle Permian epicontinental shelf deposits indicated by dotted line. Cross-section A-A shown in Figure 3, B-B in Figure 2. Figure 1. Sublett basin (solid line, dashed where uncertain) in relation to major Permian structural and paleogeographic elements. Areal extent of Meade Peak indicated by left diagonal rules Retort, by right diagonal rules limit of middle Permian epicontinental shelf deposits indicated by dotted line. Cross-section A-A shown in Figure 3, B-B in Figure 2.
Some visual stress grading rules limit the growth rate and exclude all pith. There are two separate issues. The exclusion of with-pith material is understandable as corewood in its vicinity has a number of undesirable characteristics, including low density, low stiffness, and dimensional instability. However, a restriction on growth rate is less satisfactory unless it is coupled with a criterion that addresses ring curvature to ensure that such sorting only excludes material in proximity to the pith. [Pg.362]

Bredfs Rule Limitations. The decarboxylation of lycoctonamic acid (38) and other reactions in which C-18 was lost ° seemed to require transient formation of a 4,19 double bond. Ferris and Biichi have questioned this explanation in view of the likely angle strain involved (Bredt s rule) and have offered alternative explanations. Recent preparations of bicyclo[3,3,l]non-l-ene (39) and studies... [Pg.353]

Standards of performance for new stationary sources requirements to prevent equipment leaks of volatile organic compounds (VOCs) in the synthetic organic chemical manufacturing industry (SOCMI) in compliance with the Clean Air Act carbon disulfide Final rule limits ... [Pg.171]

Table 9.6 compares the residues from thermal waste treatment with respect to their long-term behavior. This assessment is usually made using leach tests in Table 9.6, the Swiss Technical Rule limits for residuals requiring a leach strength of pH 4 were used (Anonymous 1990 see Section 9.5.3). Tests have shown that the untreated and even the scrubbed electrostatic precipitator (ESP) filter residues do not meet these limits, and even the zinc content of ESP filter residue solidified with cement is only slightly below the limit at which landfilling would be permitted at a... [Pg.172]

Figs. 3 and 4. The tunneling rate decreases exponentially with distance, as it should. In the weak-coupling (golden rule) limit, the rate goes as the square of the effective coupling of the donor and acceptor,, propor-... [Pg.108]

The results of the fractionation model (Fig. 18.9) differ from the equilibrium model in two principal ways. First, the mineral masses can only increase in the fractionation model, since they are protected from resorption into the fluid. Therefore, the lines in Fig. 18.9 do not assume negative slopes. Second, in the equilibrium calculation the phase rule limits the number of minerals present at any point along the reaction path. In the fractionation calculation, on the other hand, no limit to the number of minerals present exists, since the minerals do not necessarily maintain equilibrium with the fluid. Therefore, the fractionation calculation ends with twelve minerals in the system, whereas the equilibrium calculation reaches an invariant point at which only six minerals are present. [Pg.276]


See other pages where Rules limitations is mentioned: [Pg.23]    [Pg.165]    [Pg.372]    [Pg.276]    [Pg.365]    [Pg.390]    [Pg.396]    [Pg.529]    [Pg.417]    [Pg.27]    [Pg.60]    [Pg.371]    [Pg.263]    [Pg.99]    [Pg.529]    [Pg.2431]    [Pg.596]    [Pg.305]    [Pg.573]    [Pg.92]    [Pg.525]    [Pg.334]    [Pg.355]    [Pg.505]    [Pg.893]    [Pg.217]    [Pg.511]   


SEARCH



18-Electron rule limitations

Design Rules and Limits of Macropore Array Fabrication

Limitations of Rule

Limitations of Rules 1 and

Limitations of the 18-Electron Rule

Limitations of the Hughes-Ingold Rules

Nitrogen rule limitations

Phase rule limitations

Same limit rule

Test rules limitations

The Limitations of Rule

Writing Lewis Formulas Limitations of the Octet Rule

© 2024 chempedia.info