A New Echeloned Poisson Series Processor (EPSP)

A specialized Echeloned Poisson Series Processor (EPSP) is proposed. It is a typical software for the implementation of analytical algorithms of Celestial Mechanics. EPSP is designed for manipulating long polynomial-trigonometric series with literal divisors. The coefficients of these echeloned series are the rational or floating-point numbers. The Keplerian processor and analytical generator of special celestial mechanics functions based on the EPSP are also developed.     

Hydrogen bonding in coquimbite, nominally Fe2(SO4)3·9H2O, and the relationship between coquimbite and paracoquimbite

Using single-crystal X-ray diffraction at 293, 200 and 100 K, and neutron diffraction at 50 K, we have refined the positions of all atoms, including hydrogen atoms (previously undetermined), in the structure of coquimbite ( $ P {\bar 3}1c $ , a?=?10.924(2)/10.882(2) Å, c?=?17.086(3) / 17.154(3) Å, V?=?1765.8(3)/1759.2(5) ų, at 293 / 50 K, respectively). The use of neutron diffraction allowed us to determine precise and accurate hydrogen positions. The O–H distances in coquimbite at 50 K vary between 0.98 and 1.01 Å. In addition to H₂O molecules coordinated to the Al³⁺ and Fe³⁺ ions, there are rings of six “free” H₂O molecules in the coquimbite structure. These rings can be visualized as flattened octahedra with the distance between oxygen and the geometric center of the polyhedron of 2.46 Å. The hydrogen-bonding scheme undergoes no changes with decreasing temperature and the unit cell shrinks linearly from 293 to 100 K. A review of the available data on coquimbite and its “dimorph” paracoquimbite indicates that paracoquimbite may form in phases closer to the nominal composition of Fe₂(SO₄)₃·9H₂O. Coquimbite, on the other hand, has a composition approximating Fe_1.5Al_0.5(SO₄)₃·9H₂O. Hence, even a “simple” sulfate Fe_2-x Al _x (SO₄)₃·9H₂O may be structurally rather complex.     

Mechanism of water solubility in silicate melts of the albite-nepheline system

Water solubility and speciation have been studied in melts from the system albite-nepheline. Water solubility was determined at P_H2O = 200 MPa and T = 1200ºC using Karl Fischer titration (KFT) and weight loss methods. It increases from 5.8?±?0.1 wt. % in the albite melt to 7.25?±?0.25 % in the nepheline melt. The solubility dependence has a sigmoidal shape with a steep increase in the Ab40–Ab60 compositional range. The densities of the hydrous glasses have been measured using the thermal-gradient method. Infrared (IR) combination bands of molecular H₂O and hydroxyl groups in these glasses demonstrate a systematic shift to lower frequencies with increasing alkalinity. The data are consistent with the appearance of aluminate species (Al-O-Al fragments) appearing at 40–60 wt.% nepheline (Ab60–Ab40).     

Shock magnetism in fine particle iron

Abstract— All solid solar system bodies have been affected by impact to varying degrees, and, thus, magnetic records in these bodies may have been modified by shock events. Shock events may have overprinted all primordial magnetic records in meteorites. Shock metamorphism stages ranging from very little to extreme, when melting takes place, have been identified in meteorites. We are examining the creation and destruction of magnetic remanence associated with shock. In this paper, we develop a preliminary framework for understanding the magnetic properties of fine‐grained Fe particles (20–110 nm), which carry most of the remanent magnetization in lunar samples and, by extension, the kamacite phase in meteorite samples. Initial experiments on shock effects due to a first‐order shock‐induced crystallographic transformation are described. The first characterization of pre‐ and postshock magnetic properties for sized Fe particles and the first characterization of the transformation remanent magnetization (TMRM) associated with the face‐centered‐cubic (fcc) to body‐centered‐cubic (bcc) transformation in fine particle Fe spheres are described. This is equivalent to the 13 GPa transitions in bcc Fe. We show that the TMRM is in the same direction as the ambient magnetic field present during the shock, but is deflected from the field direction by 30–45° and that the remanence intensity is 1–2 orders of magnitude less than expected for thermoremanent magnetization (TRM) acquired during cooling through the Curie temperature. Isothermal remanence acquisition curves (RA) reveal the increasing magnetic hardness due to shock. Magnetic hysteresis loops are used to characterize the particle size and the shock‐induced magnetic anisotropy. Thermal demagnetization experiments describe the probable presence of particle size effects and the effects associated with recovery‐recrystallization due to the annealing that takes place during the thermomagnetic experiment. These observations have implications for paleofield determinations and the recognition of thermal unblocking. A TMRM mechanism could produce a shock overprint in a meteorite and might impart a significant directional feature in an asteroid magnetic signature.     

Palaeotemperature curve for the Late Cretaceous of the northwestern circum-Pacific

In the northwestern circum-Pacific, two main trends in Late Cretaceous temperatures can be recognized. (1) In general, a recurrent warming trend is thought to have begun in the Turonian–Campanian, reaching temperature maxima in the early Late Santonian and early Late Campanian, and temperature minima in the earliest Santonian and perhaps early Campanian. (2) During the Maastrichtian, temperatures dropped sharply, with only a slight warming in the early Late Maastrichtian. The existence of a thermal maximum at the Coniacian–Santonian transition has previously been expected, but is not confirmed by new isotopic results.     

Soil redistribution and pedologic transformations in coastal plain croplands

In agricultural basins of the southeastern coastal plain there are typically large disparities between upland soil erosion and sediment delivered to streams. This suggests that colluvial storage and redistribution of eroded soil within croplands is occurring, and/or that processes other than fluvial erosion are at work. This study used soil morphology and stratigraphy as an indicator of erosion and deposition processes in a watershed at Littlefield, North Carolina. Soil stratigraphy and morphology reflect the ways in which mass fluxes associated with cultivation transform the local soils. Fluvial, aeolian and tillage processes were all found to be active in the redistribution of soil. The soil transformations are of five general types. First, erosion and compaction in the cultivated area as a whole result in the thinning of Arenic and Grossarenic Paleudults and Paleaquults to form Arenic, Typic and Aquic Paleudults and Paleaquults. Second, redistribution of surficial material within the fields results in transitions between Arenic and Typic or Aquic subgroups as loamy sand A and E horizons are truncated or accreted. Third, aeolian deposition at forested field boundaries leads to the formation of compound soils with podzolized features. Fourth, sandy rill fan deposits at slope bases create cumulic soils distinct from the loamy sands of the source area or the darker, finer terrace soils buried by the fan deposits. Finally, tillage and fluvial deposition in upland depressions results in the gradual burial of Rains (poorly drained Typic Paleaquults) soils. Results confirm the importance of upland sediment storage and redistribution, and the role of tillage and aeolian processes as well as fluvial processes in the region. Copyright © 1999 John Wiley & Sons, Ltd.     

Physiological responses of juvenile and adult shore crabs Carcinus maenas (Crustacea: Decapoda) to pyrene exposure

This study measured aspects of the physiology of juvenile [(<35mm carapace width (CW)] and adult (>60mm CW) Carcinus maenas to test the hypothesis that these different life-history stages exhibit different sensitivities to environmental contamination. Newly-collected juveniles had significantly (P<0.05) lower immunocompetence (phagocytosis and cellular integrity), lower metabolic energy (haemolymph glucose) and increased scope for growth compared with adults. Seven day exposure to a sub-lethal concentration (200microgL(-1)) of pyrene significantly (P<0.01) reduced immunocompetence, elevated basal heart rate and decreased respiration (at rest) for juveniles but had no overall impact on adult crab physiology. Results confirm that physiological differences exist between juvenile and adult shore crabs, and cause juveniles to be more susceptible to the effects of pyrene exposure than adults. Such differences in sensitivity to contamination between life-cycle stages of the same species have to be taken into account during the risk assessment process.