9 research outputs found
Rediscovery of Cicindela scabrosa floridana Cartwright (Coleoptera: Cicindelidae) and its elevation to species level
First discovered in 1934 and described as a variety of Cicindela abdominalis Fabricius (Coleoptera: Cicindelidae), the form floridana, to our knowledge, has not been recollected until we discovered it in 2007, south of the presumed type locality. From our examination of the type specimen, eight paratypes and 40 specimens from the new locality and additional study, we reinterpreted its status to be a full species. This interpretation is based on distinctive and consistent differences from the closely related Cicindelidia scabrosa (Schaupp). These differences include morphology (maculation, color and elytral microsculpture), distribution, habitat, and seasonality. We present here a more detailed description of this species within the genus Cicindelidia Rivalier, following Rivalier and Wiesner becoming Cicindelidia floridana (Cartwright) new combination
Chemiluminescence from the decomposition of alkyl hyponitrites in poly(methyl methacrylate) and polystyrene
The kinetics of decay of chemiluminescence (CL) from the decomposition of 1-phenylethyl hyponitrite (PEH) and isopropyl hyponitrite (IPH) in poly(methyl methacrylate) (PMMA) and polystyrene (PS) films was investigated in nonisothermal and isothermal experiments. The measured rate constants for decay varied by about 20% with changes in initial concentration, and were about 50% slower than rate constants calculated from solution-based activation parameters. The luminescence yields from the hyponitrites in polymer matrices were lowered with increasing hyponitrite concentration, and also by the presence of low-molecular-weight residues or, most spectacularly, by dissolved oxygen. The photosensitized destruction of IPH by 9,10-dibromoanthracene (DBA) in PMMA was demonstrated. © 1997 Published by Elsevier Science S.A
Multi-stage metamorphic and metasomatic imprints on apatite-monazite-xenotime assemblages in a set of small iron oxide-apatite (IOA) ore bodies, Prins Karls Forland, Svalbard
On Prins Karls Forland, Svalbard Archipelago, a set of small iron oxide-apatite (IOA) ore bodies have been discovered within a crustal shear zone, which deformed the polymetamorphosed Neoproterozoic metasedimentary rocks. The ores have various styles and grades of deformation and distinct mineral assemblages whose compositions record a multi-stage tectonothermal and metasomatic history. These IOA ore bodies can be subdivided into fluorapatite-bearing and predominant low-Th monazite in the upper section of the shear zone and FCl apatite-bearing and predominant high Th-monazite in the structurally lower higher-grade deformed part. The first stage of alteration for these ore bodies resulted in metasomatic alteration of the apatite and liberation of REE and P redeposited as monazite and xenotime. The transport of dissolved REE and P was likely enhanced by deformation. The second stage of alteration had a distinct impact on the individual ore bodies, which resulted in the Th-enrichment of a small subset of the monazite grains in the upper section of the shear zone. In the lower section of the shear zone most of the monazite was replaced by high Th monazite. Here the original fluorapatite is enriched in Cl, Mn, and Sr, most probably due to interaction with CaCl2-rich fluids enriched in Sr and Mn that was scavenged from the hosting metasediments and altered metagabbros. Contrasting textures, mineral assemblages, and the geochemistry of the ores from distinct localities reflect involvement of compositionally different fluids from the gabbroic rocks and surrounding metasedimentary rocks during the protracted tectonothermal evolution of Prins Karls Forland. Therefore, it is concluded that the IOA ore bodies most likely resulted due to the fractionation of Fe, P, Ca, and REE from hypersaline fluids associated with the gabbros. Once deposited, these IOA ore bodies were subsequently altered during at least one and perhaps two later metamorphic events