The microstructure of the crinoid endoskeleton

52 p., 30 pl.http://paleo.ku.edu/contributions.htm

48Ca Production in Matter Expanding from High Temperature and Density

We calculate with a large nuclear reaction network the nuclear dynamics associated with the expansions and cooling of initially hot and dense matter. We study matter with neutron excess near that of 48Ca, because one objective is to clarify the nucleosynthesis of that abundant neutron-rich nucleus, whose origin has been enigmatic. Expecting that supernovae provide the site of its origin, we take initial temperatures near T9 = 10 but survey a wide range of initial densities, corresponding to a wide range in initial entropies. The highest entropies are probably associated with winds from newborn neutron stars in Type II collapse events, whereas the smallest entropies are probably associated with very high density Type Ia cores. Our survey objective is the analysis of the dynamics of the nuclear assembly as it cools, and how the correct description of it depends on the specific entropy

Calculating Chemical Evolution on the Web

We have constructed a web site that may be of interest to cosmochemists seeking to under-stand the evolution of isotopes in the Galaxy. The URL is http://photon.phys.clemson.edu/gce.html. It is fully interactive and uses IDL on the Net (ION) to construct tables and graphs dynamically. The resulting tables may be downloaded as text files while the graphs may be downloaded as gif or postscript files. The present ab-stract presents a brief tutorial on using the “GCE tool” on this site and illustrates some of its capabilities. Ques-tions or comments should be addressed to either of the first two authors

Molybdenum Isotopes from a Neutron Burst

The molybdenum isotopes in two silicon carbide X grains have been studied with resonant-ionization mass spectrometry (1). The resulting isotopic patterns are anomalous and quite puzzling. In particular, the grains show large excesses in 95Mo and 97Mo. Such an isotopic signature is distinctly different from the s-process pattern seen in the mainstream SiC grains in which 96Mo and 98Mo excesses pre-vail. It is also different from the expected r-process pattern for which the largest expected excess would be at 100Mo. The X grain Mo isotopic patterns suggest a different origin for these isotopes than the classical s- and r-processes

Zoogeography of Tropical Western Atlantic Crinoidea (Echinodermata)

Recent collections of crinoids from the intertidal zone to 1,650 m in the tropical western Atlantic have provided significant range extensions for more than half of the 44 comatulid and stalked species known from the region. Of the 34 comatulid species, over 60% are endemic to the region; of the 10 stalked species, 90% are endemic. At the familial level, this fauna has its strongest affinities with the tropical Indo-Pacific region. Comatulids are most abundant above 300 m, while stalked species occur primarily between 100 and 700 m. Species that occur primarily above 600 m (the deepest penetration of the 10°C isotherm in the region) have depth ranges generally narrower than 200 m. Species that are found below 1,000 m generally have much broader depth ranges

Abundances of Linear Carbon-Chain Molecules in Supernovae

This paper continues our effort to under-stand the condensation of carbon solids in a gas of pure C and O atoms when these exist within the interior of an expanding young supernova. This setting has a sufficiently large number of energetic electrons that the CO molecule is disrupted with a lifetime of a few months, causing the abundance of CO to be no greater than 1% or so of the C abundance. As a consequence, the CO molecule cannot consume the available C atoms, even when the O abundance exceeds that of

Creating and Certifying the Professional Mediator -- Education and Credentialing

Existing and pending law school mediation programs, post-graduate mediator training programs, mentorship programs, credentialing movements, and continuing mediation education were examined by a panel and speakers directly involved in those fields. Are we effectively training new mediators in law schools and post-graduate programs? Should we, and how can we, credential mediators? Do good mediators need to be re-trained? How would continuing mediation educational requirements be implemented

Creating and Certifying the Professional Mediator -- Education and Credentialing

Existing and pending law school mediation programs, post-graduate mediator training programs, mentorship programs, credentialing movements, and continuing mediation education were examined by a panel and speakers directly involved in those fields. Are we effectively training new mediators in law schools and post-graduate programs? Should we, and how can we, credential mediators? Do good mediators need to be re-trained? How would continuing mediation educational requirements be implemented

Carbon and Nitrogen Isotopes in Type II Supernova Diamonds

We construct a model for the origin of the abundant nanometer diamonds found in meteorites. We interpret them as interstellar particles that were grown during the expansions of supernova interiors. The physical setting and the chemical-vapor-deposition process that we describe present clear reasons both for the small sizes (nm) of the diamonds and for their mean isotopic composition being not greatly different from solar. To delineate the isotopic requirements for collections of diamonds (which are too small for analysis individually) we present measurements of carbon and nitrogen isotopes obtained by stepped combustion of diamond collections. Our model for the growth of supernova diamonds is motivated by a series of postulates, unremarkable as single postulates, that together produce a successful calculation. The computed growth occurs in the continuously mixing envelopes of expanding Type II supernova remnants. It provides a good characterization of these facts: (1) the C isotopic composition is not far from solar; (2) both carbon and nitrogen become isotopically lighter as the diamonds are combusted; (3) the C/N ratio changes during combustion; (4) the diamonds are individually tiny; (5) collections of diamonds are carriers of Xe-HL. We show that the isotopic gradient during combustion may be interpreted in this model as either an isotopic gradient within each diamond or as a correlation between isotopic composition and size of individual diamonds contained in the bulk collections