Ring data

Registry File. This CAS file contains more than 11.8 million chemical substance records. About 8,000—14,000 records are added each week as new substances are identified by the CAS Registry System. The substance records contain CAS Registry Numbers, chemical names, stmctures, molecular formulas, ring data biosequence information, and classes for polymers. AH of this information may be displayed. 

Figure 8.22. Comparison of numerical cumulative fragment size data and aluminum expanding ring data.

At the conclusion of the calculation, a fragment size distribution as well as fragment number is provided. A cumulative number distribution is shown in Fig. 8.22 and compared with aluminum ring data acquired at = lO s (Grady and Benson, 1983). With the assumed fracture site nucleation law, the calculated distribution appears to agree reasonably well with the data. The calculation better predicts the tails of the distribution which have trends which deviate from strict exponential behavior as was noted in the previous section. 

Figure 9-34B. Efficiency versus C-factor for metal rings. Data from Billet (Symposium Series 32, Institution of Chemical Engineers), London (1969). Used by permission of Glitsch, Inc., Bull. 345.

Figure 5. Schematic diagram of the topology of interprocessor communication on a four-processor ring. Data on each processor is sent to every other processor.

After publication of the ion-storage-ring data, new recombination mechanisms were proposed1 that do not require crossings between ionic and neutral potential curves. However, no detailed calculations have been made for Hj and it is not yet clear if such mechanisms are capable of explaining the experimental findings. 

Scheme 8 Computed free reaction energies (in kcal mol-1 at the B3LYP/6-311 + G(d,p) level) for [1 + 4]-cycloreversion reactions of 1,3,2-NHPs with isolated and annulated rings. (Data from [69])...

For more than 80 years, tree-ring data have been used to make inferences about past climatic variation. In general, the characteristic most often used has been the variations in widths of the annual growth rings. However, during the past decade other properties, such as cell density (measured by x-ray densiometric techniques), relative widths of early and late wood, and isotopic composition of the cellulose have been used to infer past environmental conditions. It is the isotopic composition that is of interest here. 

Fig. 14. Experimental (symbols) and fitted (lines) spectral densities of 5CB-di5. J and J2 data are smoothed experimental values, (a), (b), (c), and (d) contain C1 C2, C3, and C4 data, respectively. In addition, the C0 (ring) data are also shown in (b). For the aliphatic deuterons, circles, uptriangles, and diamonds denote /o(0), and /2(2< ), while for the ring deuterons, downtriangles and squares denote J co) and J2(2a>), respectively. Closed symbols are for 46 MHz and open symbols are for 15.1 MHz. Solid and dashed curves are fitted spectral densities. (Adapted from Ref. 180.)...

CAS Registry Numbers are included in the printed Chemical Abstracts chemical substance and formula indexes and in the CAS databases. The full set of CAS Chemical Registry System database information—structures, names, formulas, and ring data—is available for search and display through STN International, SciFinder, and other CAS search services. CAS Registry information is also available in CAS databases offered by other online system vendors. 

Fig. 20 CD spectra of a carbacepham derivative at different temperatures. The chromophore related to the CD band at 220 nm is the amide group of the azetidin-2-one ring. Data to prepare the plot were taken from [253]...

Significant interpretative problems in the use of radiocarbon values are apparent immediately when the C-dated tree ring data are examined (Figures 3 and 4). If we ignore for the moment the short-term perturbations, the radiocarbon and dendrochronological values approximately agree ( 1-3%) for the last 2000 years. However, as one moves back in time from about the beginning of the Christian era, there is an increas-... 

Various publications from the Chemical Abstracts Service can be nsed to find the name of a known ring system. The most comprehensive sonrce of ring system names is the Ring Systems Handbook (RSH). Entries are in ring analysis order, i.e., according to the following hierarchy of ring data ... 

We will present flow-rate, particulate dry weight, and particulate-calcium data from selected MULVFS and LVFS stations to (1) further document the sampling performance of the MULVFS and (2) demonstrate one application of large-volume in situ filtration to understanding the processes governing the distributions of particulate matter in a productive environment. Detailed presentation and interpretation of warm core ring data are outside the scope of this chapter. 

A striking illustration of the relative stability of the benzenoid and of a hydroaromatic ring is afforded by the oxidation of tetra-hydro-naphthalene with air. The preponderating product is phthalic anhydride, with little or no tetrahydronaphthalic acid present, showing the selectively complete destruction of the non-benzenoid ring. Data on the oxidation of tetrahydronaphthalene are available from the work of Maxted,J7 and are shown in Table XLI. 

Figure 13-5. Influence of load on the type of wear behavior unlubricated rubbing at 186 cm/s load in newtons as indicated on diagrams. (a) Stellite pin on tool steel ring (b) 60/40 brass pin on tool steel ring. Data by J. F. Archard [8].

This explanation is complementary with the fraction of a fraction explanation advanced by Kresge, which says that development of resonance stabilization will, at most, be proportional to the loss of Cl -Nl bond order. However, the rehybridization of Cl from tetrahedral to planar is not complete, resulting in only partial resonance stabilization due to poorer electronic overlap. Thus, resonance stabilization is only a fraction of the fraction of Cl -Nl bond breakage. These explanations are also consistent with the idea that TS imbalance is correlated with changes in atom hybridization, which is in turn consistent with the results of calculations on the dissociation of methyl nicotinamide (equation 7). The sum of total bond orders to Nl (X ni) was a linear function of the main process, i.e. loss of the Nl-Cl bond, as was the sum of Nl-C bond orders within the ring (data not shown). The essential difference between this and the oxocarbenium ion example is... 

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