PRINCIPAL OBSERVATIONS

In attempting to characterize mantle reservoir compositions, any model of the geochemical structure of the Earth s mantle should include or allow for the following basic observations. 

The mantle is characterized by elevated ratios of °Ne/ Ne and Ne/ Ne compared to the atmosphere. Mid-ocean ridge basalts and ocean island basalts show distinct °Ne/ Ne- Ne/ Ne trends that result from differences in the dilution, by primordial Ne, of the nucleogenic Ne that is produced in their respective mantle sources. The 

MORE trend passes through the composition of air and extends to values of °Ne/ Ne 12.5 and Ne/ Ne 0.07. OIB trends are much steeper in the case of Iceland they pass through the composition of air and extend to values of e/ Ne 12.5 and Ne/ Ne 0.035. It seems likely that the whole mantle is characterized by a uniform value of °Ne/ Ne, but this has not been proven. 

MORE and OIE samples show a range of measured °Ar/ °Ar that is mostly due to variable proportions of atmospheric and magmatic components. The highest Ar/ Ar ratio measured in a MORE is -40,000. The correlation between °Ar/ Ar and Ne/ Ne for the MAR popping rock, when extrapolated to a solar %le/ Ne = 13.8, indicates a possible upper limit of 44,000 for Ar/ Ar in the upper mantle. High He/ He ocean islands range to moderately high °Ar/ Ar ratios, up to -8000. This may be the minimum value appropriate for the mantle source of OIEs. 

Coupled He-Ne isotope systematics reveal that the highest values of He/ e at 

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A limited number of minus-x orientation samples were impact loaded in the vicinity of the Hugoniot elastic limit at stresses from 5.9 to 6.7 GPa. The principal observation of these experiments was that positive currents were observed from negative polarity disks when a stress of 5.9 GPa was exceeded. Such an observation confirms that quartz responds as predicted by the model, and that the elastic limit is in the vicinity of 6 GPa. 

The principal observation, which the laboratory scientist should not forget, was that most lifetime assessment of polymers is based on experience from service. Many of the respondents to the survey report examining parts taken from service at the end of life, or those that failed during warranty. Service experience is the principal source of information for the definition of insured lifetimes for polymer components in the construction industry. 

Steroid administration was once thought to lead to the formation of peptic ulcers, with hemorrhage or perforation or reactivation of a healed ulcer. It is now realized that this effect is principally observed in patients who have received concomitant nonsteroidal antiinflammatory treatment. Since there is a minimal increase in the incidence of ulcers in patients receiving glucocorticoid treatment alone, prophylactic antiulcer regimens are usually not necessary. 

From Figure 2, it appears that higher selectivity for MA at 420°C is observed for catalysts 1 and 2 for which (VO)2P207 is principally observed with a small extent of... 

The preceding statements are very general they summarize the principal observations for a process which until recently was regarded as... 

Before discussing the examples, the notation used in Sections 2 and 3 is briefly summarized. Principal observables are the rate constant k, trapping coefficient a,... 

The principal observation made is that dioctahedral montmorillonite... 

We end by restating the principal observations afforded by biochemical and structural studies of G protein effector activation and signal termination. 

The modified baseline process for Pueblo that the committee examined was developed from successful operations of the baseline system at JACADS and lessons learned during the processing there of mustard-filled munitions. Solutions developed and tested at JACADS for problems encountered during the disposal of mustard-filled munitions were the basis for process modifications and arc considered to be applicable to the PCD stockpile. The committee s principal observations from the JACADS experience arc as follows ... 

With regard to urine, the principal observations that have been made are concerned with pH and calcium and phosphorus content. 

Irreversible swelling is a phenomenon principally observed with acrylic strong base anion exchange resins whereby upon undergoing their first few aqueous ion exchange cycles an irreversible expansion occurs of around 7—10% over and above the reversible volume changes which thereafter apply. 

In summary, we have demonstrated in this section how quadrature-based moment methods can be used to evaluate the terms in the moment-transport equations arising from collisions. The principal observation is that it suffices to know the functional forms for the terms which are derived and tabulated in Section 6.1. We also observed that, unlike traditional moment closures, the closures developed in this section are applicable to highly non-equilibrium flows. 

The principal observation behind the Helffrich and Wood (2001) model of the mantle is that the scattering of seismic waves in the lower mantle indicates that small heterogeneities are present, mostly about 4 km in size. As with all seismic methods the physical cause of the seismic scattering anomalies could theoretically be either thermal or compositional in origin. Helffrich and Wood (2001)... 

There are two principal observations which we can use to constrain models for the origin of the Earth s continental crust. The first is a knowledge of the age structure of the crust and the second is its average composition. Both of... 

The effect of tensile draw on the "cluster" reflection is shown in Figure 12 and should be compared with Figure 7 for unhydrolyzed polymer. Under moderate strains, 1.75 times, it is seen that the "cluster" reflection is observed mostly in a direction normal to the strain. This is also true in the SAXS scan from fiber where the reflection is principally observed in the equatorial scan. This implies a periodicity which is normal to the fiber axis. Thus, the periodicity associated with this reflection tends to be orthogonal to the periodicity associated with the reflection observed in the meridional SAXS scan of unhydrolyzed fiber. Similar effects of sample orientation have recently been reported for ethylene-methacrylic acid ionomer (23). 

A systematic study of the product distributions resulting on photolysis of diphenyl- and substituted diphenyliodonium cations as functions of both solvent and counterion was carried out by Timpe and Schikowsky [71]. Unlike the earlier results of Pappas, these authors found that, taking into consideration all organic products, quantum yields of the disappearance of iodonium cations and of formation of protic acid are within experimental error. Significantly, light intensity, /, dependence of the quantum yields was observed in this study. Timpe and Schikowsky s principal observations are summarized in Table 3. 

In this paper, I will address two different perspectives on government-university-industry relationships. The first is collaboration on matters of policy through the operations of the Government-University-Industry Research Roundtable. I will describe the purposes, essential features, and accomplishments of the Roundtable. The second is programmatic collaboration in research and education. Here I will present the principal observations on university-industry cooperative programs that have emerged from several Roundtable activities on this topic. ... 

The principal observation to be drawn from the fission-energy relation (1.10) is that, in the case of the heavier nuclei, the fission fragments represent a lower energy state than the original nucleus. This would imply that the heavier nuclei are inherently unstable toward fission and could conceivably undergo spontaneous disintegration. Experience shows, however, that spontaneous fission does not occur at anything... 

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