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UPb isotopic measurements on individual zircon crystals combined with morphological analyses permit the identification of three distinct components within the zircon population of the Saedelhorn diorite, a Variscan dike from the western Gotthard (Central Alps, Switzerland): (i) 94% of the grains in the zircon population are elongate crystals with pronounced skeletal morphology indicative of rapid growth from a supercooled melt. (ii) 5% of the population consist of turbid, mostly subhedral zircons frequently showing D-type morphology (classification according to Pupin and Turco [1]) and elevated uranium contents compared to the skeletal variety. Single-crystal and multi-grain UPb isotopic data of group (i) and (ii) zircons define an intrusion age of 293 +5/−4 m.y. for the dike. (iii) Rare, transparent zircon crystals (

Along the northern part of the East Greenland coast the Caledonian structures are superimposed on an older fold system called the “Carolinidian”. Traces of this Carolinidian belt are preserved in a few isolated fragments within the Caledonian fold belt. According to Haller (1970) one of these fragments exhibiting the typical Carolinidian NNW to NW-trending infrastructural folds is the peninsula of Germania Land which is accessible near the Danish weather station Danmarkshavn. The rock sampled there is a banded gneiss of granodioritic composition with steeply inclined, NNW-trending layers. Isotopic age determinations yielded essentially two groups of ages: 1) 3,000±150 m.y. (zircon suite and Rb/Sr whole rock analyses of layers) and 2) 320–380 m.y. (Rb/Sr mineral isochrons, U-Th-Pb on sphene, K/Ar on hornblende and biotite). The egg-shaped zircons support a sedimentary origin of the banded gneiss and in conjunction with the Rb/Sr whole rock ages determine the age of formation of the banded gneiss (or its last high grade metamorphism) some 3,000 m.y. ago. No other Precambrian metamorphism or orogeny is recorded in the rock. The ages between 320–380 m.y. date a thermal event of lower amphibolite facies grade related to a late Caledonian spasm.

Schonemann & Steiger (1976, Theorem 5) proved that the common factor model fits a given set of observed variables if and only if a restricted regression component model fits the same variables. In the present paper a number of results, relating factor score estimates and the class of all sets of ‘factor-equivalent’ regression components, are presented. These results clarify and extend a result given by McDonald (1977).

A series of experiments, using a modification of the Shepard and Metzler mental rotation task, was performed to investigate Shepard’s “holistic rotation” hypothesis. Effective figural complexity was manipulated in the experiments in two distinct ways. In one manipulation, blocks were added to the standard 10-blockfigures. In the other manipulation, the figures used and the direction of angular rotation were restricted so that some featural information in the figures was redundant, that is, unnecessary for the discrimination task at hand. There were two major conclusions. First, when figural complexity is effectively manipulated, it has a powerful effect on the “speed of mental rotation,” as measured by the slope of the curve relating reaction time to angular disparity. Second, it is possible, by ignoring featural redundancy, to construct experimental paradigms in which “complexity” of figures is apparently manipulated but has no effect on speed of mental rotation. This fact provides a possible explanation of why some previous experiments have failed to find a complexity effect in mental rotation.

A theorem is presented which gives the range of possible correlations between a common factor and an external variable (i.e., a variable not included in the test battery factor analyzed). Analogous expressions for component (and regression component) theory are also derived. Some situations involving external correlations are then discussed which dramatize the theoretical differences between components and common factors.

In a variety of situations in psychological research, it is desirable to be able to make statistical comparisons between correlation coefficients measured on the same individuals. For example, an experimenter may wish to assess whether two predictors correlate equally with a criterion variable. In another situation, the experimenter may wish to test the hypothesis that an entire matrix of correlations has remained stable over time. The present article reviews the literature on such tests, points out some statistics that should be avoided, and presents a variety of techniques that can be used safely with medium to large samples. Several illustrative numerical examples are provided.

Twenty-five new K-Ar ages for amphiboles from the Tertiary Barrovian-type metamorphic terrain of the Central Alps were determined. These results lead to the conclusion that the meso-Alpine metamorphism reached its peak condition and maximum expanse about 26 ± 3 m.y. ago. Along a profile of increasing grade of Alpine metamorphism in both basement and cover rocks, the following observations can be made: (1)Pre-Alpine hornblendes in the zone of greenschist-facies show ages ranging from 639 to 152 m.y. The implied open-system behavior may be related to the observed mineralogical instability of these hornblendes during the Alpine overprint. In contrast, two greenschist facies hornblendes which grew in Pennine Mesozoic rocks during the Alpine metamorphism yield ages of 23 ± 2 and 29 ± 3 m.y. (2)On both sides of the boundary marking the first occurrence of Alpine staurolite Pre- or Early-Alpine hornblende K-Ar ages are not fully reset unless the rocks were completely recrystallized. For one rock specimen which clearly exhibits two generations of hornblende, an age two times greater was obtained for the smaller crystals oriented parallel to the foliation than for the structurally younger hornblende porphyroblasts which overgrew the preexisting texture. (3)In the high-grade area of Alpine metamorphism only young Alpine ages between 23 and 28 m.y. were found for hornblendes which grew syn- to postkinematically with respect to the last penetrative deformation. One amphibolitic inclusion not affected by this deformation yielded a significantly older hornblende age of 32 ± 1 m.y. These results suggest that temperature-controlled Ar diffusion is not the main factor governing the K-Ar system of metamorphic hornblendes. We conclude that these hornblende ages should not be interpreted as cooling ages from a structurally ill-defined earlier event; instead they indicate that the high-grade metamorphism responsible for the well-known isograd pattern in the Lepontine area persisted until some 23 m.y. ago.

A partition of the vector space of all deviation score vectors for fixed sample size N is used to show that the (indeterminate) factors of the factor model can always be constructed so as to predict any criterion perfectly, including all those that are entirely uncorrected with the observed variables.

Plaque formation of phage kappa on Serratia marcescens strain HY normally depends on the presence of either a psi or y prophage in the indicator bacteria. Bacterial ink mutants allowing kappa growth in the absence of either prophage were isolated from the doubly cured strain HY (psi, y)--. By means of a kappa mutant, named gdy, an active participation of kappa in antagonizing inhibition of its own growth on HY (psi, y)-- was demonstrated. The gdy mutation is closely linked to gene cIII coding for the kappa repressor. The prophages psi and y enable kappa to grow undisturbed probably by modifying the kappa DNA during replication in such a way that it is not susceptible to the ink+ effect. Whereas kappa grown on HY (psi, y)--ink-- gave only rare productive infections of HY (kappa, y)--, psi and y grown on the same strain were fully infective. The interference exerted by a kappa prophage on vegetative propagation of y is based upon a multi-component mechanism, the interference being removed, or diminished by mutations residing either inside or outside of the kappa prophage. The responsive phage gene iny+ is dominant over its mutant allele iny--; hence it codes for a diffusible product. Both on the vegetative and the prophage genome iny is located near gene lI responsible for lysogenic conversion of bacteria to non-adsorption of kappa. The restriction-modification system of HY is not involved in the growth inhibition of kappa by HY (psi, y)--. Contrary to the other phages used in this work y is refractory to restriction.

Over 5000 harbor seals haul out on icebergs calved from tidewater glaciers in Muir and Johns Hopkins inlets in Glacier Bay, Alaska. During June, these sites are used primarily by parous females and pups, and in August, by molting seals. The number of mothers and pups was higher than expected for the total number of seals in Glacier Bay, indicating an immigration of some parturient females from outside Glacier Bay. The number of seals counted varied throughout the day with greatest numbers around midday. In Muir Inlet the number of seals hauled out was positively correlated with percent ice cover. Ice that is suitable for hauling out may presently limit the abundance of seals in this area. The retreat of Muir Glacier has dramatically reduced the ice available to seals and, if it continues, will likely result in the elimination of drift-ice habitat in the near future. Seals from both inside and outside Glacier Bay apparently use ice habitat in Muir and Johns Hopkins inlets when giving birth, when nursing pups, and when moulting for protection from terrestrial and marine predators, and because it is relatively abundant and easily accessible at all tides and times.

The program presented computes a chi-square statistic for testing pattern hypotheses on correlation matrices. The statistic is based on a multivariate generalization of the Fisher r-to- z transformation. Monte Carlo studies have demonstrated that this statistic has small sample performance which is superior to an analogous likelihood ratio statistic obtained via the analysis of covariance structures.

Rb-Sr, U-Pb and K-Ar analyses on rocks and minerals from a tectonic window below a Caledonian thrust sheet in the westernmost part of the Scoresby Sund region (70°-72°N) give evidence for a Precambrian age of formation. The Charco't Land supracrustal sequence rests on a basement that is probably of Archaean development and older than at least 2100 m.y. The major regional metamorphism of the supracrustal rocks is probably not much older than the intrusion of two post-kinematic bodies, i.e. about 1840 m.y. Low-grade metamorphism in a tillite and low-grade retrogressive overprinting of the supra­crustal rocks are related to Caledonian orogenesis.

An experimental study of the nuclear stopping mechanism has been carried out by performing high precision range and range straggling measurements of 96.5 keV 224Ra α-disintegration recoil particles in the following isotopic gases: H2/D2/T2,3He/4He, 14N2/15N2,16O2/18O2, and 20Ne/22Ne. Distinct range differences for light to heavy isotope mass ratios up to about 0.9 were determined. The results obtained establish clearly that the prediction of the isotope effect of the stopping medium, as derived from the Lindhard theory by using the power law potential as an approximation to the Thomas–Fermi potential, is to a good degree of accuracy, confirmed by experiment.

Most of the energy generated during the fission process is released as kinetic energy of the fission products. This energy moves the fission products a distance of a few microns in solid materials. When the fissionable material is prepared as a powder of particles with diameters smaller than the range of the fission products in the material used, it is expected that the fission products will leave the particles of the fissionable material. To avoid the penetration of the fission product into an adjacent particle of fissionable matter, the latter may be diluted with a liquid or solid diluent. The use of solid diluents having strong adsorption properties is believed to improve the separation between fission products and fuel when sedimentation in water is chosen as the separation method. In a series of experiments, mixtures of U/sub 3/O/sub 8/ with infusorial earth and sllica gel as diluents having strong adsorbing properties were irradiated. About 95% of the fission products were found in the diluent. Most of the activity of the U/sub 3/O/sub 8/ was due to Np. The readsorption of fission products to U/sub 3/O/sub 8/ was smaller than in previous experiments in which no adsorbent was mixed with themore » fissionable material. Surface activation of the U/sub 3/O/sub 8/ was found after irradiation. About half of the fission products taken up by the diluent were found to be absorbed at its surface. Mean fissionproduct ranges in U/sub 3/O/sub 8/ were estimated on an experimental and theoretical basis and agreement between theory and experiment is found to be good for most of the fission products. (auth)« less

Sets of similar solutions applicable within a linearized approximation are derived for twodimensional compressible and axisymmetric incompressible viscous free mixing with streamwise pressure gradients Viewed as eigenfunctions these solutions can be superposed to represent arbitrary initial conditions However, it is observed that only one solution of the family possesses a net momentum defect (or excess) different from zero This mode decays exponentially in the normal direction and has a stronger streamwise persistence than any of the other solutions that have exponential normal decays; it is usually referred to as "the" similar solution

One-dimensional inviscid nonequilibrium flows of a twocomponent model gas are studied for prescribed pressure variations and an average reaction rate based on recent data for oxygen recombination. These flows are interpreted in relation to the flow along streamlines around blunt hypersonic bodies. Assuming equilibrium conditions in the subsonic region, it is estimated that the flow in the initial supersonic expansion region, which is approximately of Prandtl-Meyer character, will be chemically frozen with respect to the molecular dissociation of the primary components under the hypersonic, high-altitude flight conditions considered. The flight conditions consist of flight velocities between 15,000 and 25,000 ft/sec at altitudes between 154,000 and 246,000 ft. Furthermore, on bodies of small surface inclination beyond the nose, the flow will continue to be effectively frozen for at least 20 ft downstream of the nose. These conclusions may lead to the simplification of procedures for theoretical calculation and testing. The problem of distinguishing a dimensionless length-reaction rate parameter, which characterizes the extent of departures from equilibrium or from frozen behavior in the flow fields of interest here, is discussed.

In a study of cogenetic zircons it was found that the measured Pb^(208)/Th^(232) and Pb^(207)/U^(235) ratios formed a linear array in the corresponding coupled Pb-U-Th evolution diagram, which has an upper intersection on the concordia curve at the same time point as that determined by the Pb^(206)/U^(238), Pb^(207)/U^(235) array. Although the U-Pb data lie in the accessible region for nonfractionating daughter loss, the Th-Pb results lie outside the corresponding region. The zircon concentrates analyzed were shown to be multiphase assemblages with variable U and Th contents and variable Th/U ratios, even within single crystals. The zircons contain local domains of high radioactivity which appear to be highly discordant. A relationship between discordance and the average concentration of U and Th in a sample is given. The degree of discordance increases with the concentration of U and Th and with the increasing Th/U ratio, causing preferential loss of Pb^(208) and the departure from the region accessible to a single phase without fractionation. The theoretical aspects of the (equation image) diagram from the viewpoint of single-phase and multiphase assemblages are discussed, and it is shown that the variability of the Th/U ratio is of fundamental importance in understanding the evolution of the Th-U-Pb system. The existence of these systematics in nature may provide an additional independent dating system and a further means of studying transport from natural systems.

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The velocity fields of three-dimensional viscous wakes are examined with the use of the boundary-layer approximations, Oseen's linearization of the convective terms, and the assumption of constant fluid properties. Transform methods yield solutions for general types of initial conditions. As an illustration, the axial velocity distribution of a wake whose initial isovels (lines of constant velocity) are of elliptic shape and their decay to axial symmetry are demonstrated. Both laminar and turbulent flows are considered.

Eine fruher von den Verff. beschriebene Methode, mit der man staubbeladene Membranfilter fur die elektronenoptische Untersuchung praparieren kann, wurde fur weitere Messungen des Schwebestaubes in Bergwerken verwandt. Der durch das Schiesen entwickelte Staub lies hohe Staubkonzentrationen erkennen und zeigte ein enges Teilchenspektrum. Auserdem wurden mit der Membranfiltermethode Untersuchungen der atmospharischen Luftverunreinigungen durchgefuhrt. Die in Dusseldorf entnommenen Staubproben wiesen vor allem Teilchen mit einer Korngrose unter 0,1Μ auf, wahrend in Bochum vor allem Ruspartikeln in den Vordergrund traten.

Adsorption of ions at the surface of solutions of ionic surface-active substances can be studied directly using recoil atoms. Extremely small amounts of suitable radioactive ions, when added to such solutions, replace some of the normal counter-ions coadsorbed at the primary adsorbed organic ions. Recoiling atoms with energies from about 100 kev down to a few eletron volts give ranges in water from about 1000 A. down to monomolecular layers. This makes them suitable for sensitive surface layer studies. The recoiling atoms ejected from the surface are collected and counted. Among a-disintegration recoils the system Bi-212/Tl-208 proved to be suitable. Adsorption isotherms of Bi-ions as a function of the bulk concentration of the surface-active substance under varying conditions of ionic strength, pH, and Bi-212 activity were measured. By comparing these isotherms with those obtained by measuring the surface tension of the solutions and calculating the surface excess, the adsorption of Bi +++ and Pb ++ relative to that of Na + and H 3 O + , and thus the extent of ion exchange in the adsorbed layer, was determined. As the method measures the adsorption of charged species, surface reactions transforming primary adsorbed organic anions to a nonionic state could be followed.

Human performance on hierarchical inferences may be suboptimum. As a means of improving this performance, it is suggested that a hierarchical inference task be decomposed into a series of simpler intuitive inferences linking each stage in the hierarchy and that assessments of these inferences be formally combined using the optimum hierarchical model. The results of laboratory experiments with this procedure show that it can improve performance over a completely intuitive approach. A case study in which the procedure was applied to a real world inference problem is also described and some practical difficulties are identified.

High precision range and straggling measurements of 96.5 keV224Ra α-disintegration recoil particles in various gaseous media are described. Special emphasis is placed on the development of a uniform and non-degrading recoil source in order to insure accurate range determination and to prevent broadening of the straggling results by the source. Excellent symmetry for the range distribution curves for all, even the heavy gases, was obtained. The performance of the measurements in gases, where successive collisions can be considered as uncorrelated, enabled a detailed comparison with theoretical treatments of the nuclear stopping mechanism, dominating in this energy region. The results obtained were compared with the Lindhard theory and show good agreement, especially for the medium mass gases.

Fission cross sections for the systems $^{169}\mathrm{Tm}$ + $^{11}\mathrm{B}$, $^{175}\mathrm{Lu}$ + $^{11}\mathrm{B}$, and $^{12}\mathrm{C}$, $^{174}\mathrm{Y}$ + $^{12}\mathrm{C}$, $^{182}\mathrm{W}$ + $^{12}\mathrm{C}$, $^{165}\mathrm{Ho}$ + $^{14}\mathrm{N}$, and $^{159}\mathrm{Tb}$ + $^{19}\mathrm{F}$ have been measured for heavy-ion bombarding energies up to 10.4 MeV per nucleon. The experimental technique consisted of counting coincident fission-fragment pairs with two gold-surface-barrier silicon-diode detectors. For the above systems, fission takes place only in reactions in which a compound nucleus is formed between the incident projectile and the target nucleus. Values of the compound-nucleus cross sections for these reactions are estimated from other data in order to account for surface reactions which occur in heavy-ion bombardment. The difference between the cross section for compoundnucleus formation and that for fission is assumed to be equal to the cross section for neutron-evaporation products. The ratio of the fission cross section to that for neutron evaporation is then taken to be equal to $〈\frac{{\ensuremath{\Gamma}}_{f}}{{\ensuremath{\Gamma}}_{n}}〉$, the ratio of the level widths for the two competing processes averaged over the various reaction channels. A theoretical fit to the $〈\frac{{\ensuremath{\Gamma}}_{f}}{{\ensuremath{\Gamma}}_{n}}〉$ values is obtained for the low-energy region of the excitation function, where first-chance fission is highly probable. We find the ratio of the level-density parameter for fission to that for neutron emission to be 1.2 \ifmmode\pm\else\textpm\fi{} 0.1, and values for the fission barrier to be in agreement with those predicted by Myers and Swiatecki.

For maximum liquid-holding capacity, an uncompressed fibrous assembly requires wettable fibers of high wet modulus. Tests with rayons of various denier, state of finishing, and modulus indicate that, for compressed absorbents, it also is desirable to minimize the required compaction forces by reducing the dry modulus and resilience of the fibers. The use of wet crosslinked rayon, which has the requisite combination of wet and dry properties, leads to significant improve ments in absorbency. The effect of increasing bulk density on the liquid capacity per unit weight and capacity per unit volume of absorbents is discussed, and a mechanistic description of the latter is presented.

This paper discusses the application of decomposition rules to Bayesian man—machine diagnostic inference systems. An experiment is reported which investigates the use of such decomposition rules in dealing with conditionally dependent data. The experiment, unlike its predecessors, employs an intuitive inference task where the veridical odds can be closely estimated. One major conclusion of this research is that logically equivalent decomposition rules are not necessarily of equal difficulty. Consequently, recommendations as to the superority of a particular decomposition rule should not be made; the systems designer's choice of a particular decision rule should be based on the types of data and conditional dependencies encountered in his particular situation. Such considerations may lead to the adoption of hybrid decomposition rules of a type not previously used.

Following a brief summary of the published methods for the measurement of static electricity on textiles, the effect of test variables is explored. The relations between charge, resistivity, and the concentration of the antistatic finish are investigated, and it is demonstrated that on a given fabric the logarithm of the charge is a linear function of the logarithm of the surface resistivity, independent of the finish which produces the electrical conductivity.

The pour crease recovery-strength relationship exhibited by cotton which has been reacted with formaldehyde by a dry curing process has been shown to be primarily a function of the formal linkage and not of the degradative effects of acid Inconsistencies in results obtained with formaldehyde are associated with the slow rate of hemiformal formation in the padding bath. Cotton in the wet state can be cross-linked by means of hemiacetal linkages with glyoxal, and it has been shown that the strength loss produced by cured dimethylol ethyleneurea at a given level of crease recovery is comparable to that obtained from uncured glyoxal in the absence of those degradative effects associated with the hot. acidic curing of thermosetting finishes The ratio of wet to dry crease recovery suggests that the areas of cellulose and/or the hydroxyl groups which are involved when cotton is cross-linked in glyoxal solutions are the same as those involved in the dry curing of cross-linkers A high wet to dry crease recovery ratio evidently requires that cross-linking at some stage take place in a state of swelling beyond that found during the application of typical aqueous cotton creaseproofing reagents. The thests that different areas and or hydroxyl groups are involved in the attamment of wet and dry crease recovery is further supported by experiments in which dry crease recovery was obtamed on cotton independently of the high wet crease recovery which had been established first

Calculations based on comparison of the isotopic composition of lead from iron meteorites with that of various modern terrestrial leads have placed the age of the earth at around 4550 million years. However, recent data from young volcanic rocks reveal that modern terrestrial lead can have a wide range in isotopic composition. The variations in its coinposition mean that one or more of the assumptions used in the age calculation have been violated. We modified the usual approach by comparing meteorite lead with lead from rocks 2700 million years old, from the Canadian Shield. Using this method and the same constants and assumptions utilized in the earlier calculations we calculated an age of 4750 +/- 50 million years for the earth. The earth may be approximately 200 million years older than previously thought; alternatively, primordial terrestrial lead may not have had the same isotopic composition as lead in iron meteorites does.

The wall jet with suction or injection is investigated; an analysis under conditions corresponding to similar flows is shown to reduce to an eigenvalue problem. Asymptotic solutions valid far from the surface are used to initiate the integration and circumvent the usual iteration associated with the two-point boundary value problem. Typical solutions for various rates of suction and injection are obtained. It is found th t the skin friction decreases with increasing rate of suction. Representative thermal solutions are obtained for Prandtl and Lewis numbers equal to one, under the pecial condition that the surface temperature is equal to the ambient temperature or that the enthalpy varies monotonically from the surface value to the ambient value. (Author)

TLYTECHNIC Inst. of Brooklyn, N. Y. THREE-DIMENSIONAL EFFECTS IN VISCOUS WAKES, by Martin H. Steiger and Martin H. Bloom. June 62, 32p. incl. illus. table, 9 refs. (PIBAL rept. no. 711) (Contract AF $((638)445, Proj. 9781) Unclassified report DESCRIPTORS: *Wake, *Fluid flow, Compressible flow, Jet mixing flow, Viscosity, Turbulent flow, Laminar boundary layer, Turbulent bound ary layer, Integral equations, Mathematical analysis. Three-dimensionality in wake-like or jet-like free-mixing is investigated. The first section of the report deals with the general mathematical model, in which the boundary layer approximations are used and with methods of solution. Laminar and turbulent flow, compressibility, unsteadiness and streamwise pressure gradients are admitted initially. The flux forms of the equations are given. Algebraic integrals of the energy equations and the diffusion (frozen-flow) equations are obtained. A simplification of the convective terms, roughly corresponding to the Oseen approximation, is used in the asymptotic downstream region. This results in linearization in the case of constant-fluid-properties, and permits the derivation of convenient solutions. Corresponding first-approximation solutions are obtained for the compressible case. Finally, second-approximation improvements are derived. The second section contains explicit solutions for specific configurations, in particular for flows whose initial isovels are of elliptic shape. These flows may be wake-like or jet-like. Compressibility is admitted; however, the flows must have uniform pressure and be steady. The final section deals with interpretation and evaluation of the results. (Author)

Granitic rocks at Manitouwadge, Ontario, have an age of 2720±50 m.y. based on isotopic lead data from zircon and sphene, and on Rb-Sr measurements from whole rocks. The rocks are stratigraphically and lithologically similar to ones called Algoman elsewhere in the Canadian Shield. Lead from the conformable ore body at Manitouwadge yields a model age of 3000 m.y., using an age of 4550 m.y. for the earth, and using a closed-system evolution model for the lead. Field relations show that the ore is younger than the granites. Lead in potassium feldspars from the granitic rocks appears to be closely related to lead in the ore; in particular, the Pb208/Pb204 ratios are identical in ore and feldspars. Lead from ores along a 1100 km traverse across the Superior Province from Noranda, Quebec, to Kenora, Ontario, have isotopic compositions generally similar to the composition of the ore at Manitouwadge. Radiometric age data do not indicate ages older than 2700 m.y. in the area. Less complete data from the continents of Africa, Australia, Asia, and Europe suggest that ore leads with model ages of 3000 m.y. are associated with rocks having radiometric ages of 2700 m.y. For these reasons the Manitouwadge data do not appear to represent a local anomaly. If this is true, several possibilities can explain the data: (1) the age of the earth is not 4550 m.y., in which case closed-system evolution and terrestrial primordial lead identical in isotopic composition to that in iron meteorites can be retained; (2) terrestrial primordial lead did not have the same isotopic composition as iron meteorite lead, in which case a 4550 m.y. age of the earth and closed system isotopic evolution for lead can be retained; (3) isotopic evolution of lead did not take place in a chemically closed system. None of these possibilities can be eliminated with certainty. It is difficult to reconcile lead data with a closed-system evolution model, a 4550 m.y. age of the earth, and terrestrial primordial lead identical in composition to iron meteorite lead.

Treatment with thermosetting formaldehyde resins increases the tendency of nylon to yellow when heated The terminal amine groups of nylon are involved in the discolora tion. These amine groups can be blocked by reaction with urea under normal textile curing conditions in order to produce a fabric with less tendency to yellow.

U-Pb analyses of zircons from the southern paragneiss zone of the Gotthard massif in the central Alps indicate these rocks were derived from one or more source areas ≧ 1400 m.y. old and were strongly affected by both the Caledonian and Hercynian orogenies. Rb-Sr whole-rock analyses also appear to reflect the Hercynian event while Rb-Sr analyses of a metamorphic inclusion and a boudin indicate that these small-scale samples were affected by the Alpine orogeny.

The quantitative, semiquantitative, and morphological examinations of the bronchi and the analysis of dust of the lungs in 139 cases of sudden deaths showed the following results.(a) In the healthy mu

Viscous laminar axially symmetric free mixing with large swirl is investigated by a boundary-layer type of analysis with integral methods. Large swirl generates axial pressure gradients as well as large radial pressure gradients, and therefore alters the streamwise flow. Examples calculated for both incompressible and compressible flow show that the wake may be significantly lengthened by large swirl. However, this effect is shown to be diminished in the compressible case where higher free-stream Mach numbers lead to decreased densities, and to decreased centrifugal effects, decreased radial pressure gradients, and decreased axial pressure gradients. In the limiting special case of small or moderate swirl the results agree with those previously obtained by Steiger and Bloom [1] in analysis wherein the induced pressure gradients were neglected a priori.

References 1 McCarthy, J. R. and Wolf, H., "The heat transfer characteristics of gaseous hydrogen and helium," Rocket dyne Research Rept. 60-12, p. 50 (December 1960). 2 McAdams, W. H., Heat Transmission (McGraw-Hill Book Co., Inc., New York, 1954), 3rd ed., Chap. 8, pp. 184-188. 3 Bartz, D. R., "An approximate solution of compressible turbulent boundary-layer development and convective heat transfer in convergent-divergent nozzles," Trans. Am. Soc. Mech. Engrs. 77, 1235-1245 (1955).

When a pair of monaural pure tones, A and B, are repeatedly alternated in one ear, with noise bursts presented in synchrony with B in the other ear, the noise sometimes delateralizes B. This is presumably a case of Warren and Bashford's (1976) contralateral induction effect. However, the present experiment shows that the degree of contralateral induction is proportional to the separation in frequency between A and B. It was also found that the degree to which the noise bursts influenced B's timbre was proportional to the separation in frequency between A and B. The combined results suggest that cues that govern the sequential organization of sounds influence the use of binaural cues not only during the assignment of position to auditory events but during the assignment of timbre.