bluuebunny/crossref_metadata_2025_split huggingface dataset:
Steinernema loci sp. n. and Steinernema thanhi sp. n. (Rhabditida: Steinernematidae) from Vietnam
Authors: Moens Maurice , Nguyen Ngoc Chau , Phan Ke Long 
Published: July 2002

AbstractTwo new species of Steinernema (Rhabditida), Steinernema loci sp. n. and S. thanhi sp. n., were isolated from beach soil in Thanhhoa and Hatinh provinces in the northern part of Vietnam. A combination of morphological, morphometric and rDNA-RFLP features indicated the distinctness of both species from other Steinernema spp. Diagnostic characters of Steinernema loci sp. n. include: total body length (896-1072 μm), distance from anterior end to excretory pore (EP = 71-86 μm), tail length (66-83 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end of the third stage infective juvenile; first generation males were characterised by body width, spicule length and the ratio spicule length : anal body width (SW). Diagnostic characters of Steinernema thanhi sp. n. third stage infective juveniles include: total body length (720-960 μm), EP (68-84 μm), tail length (52-72 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end. Spicule length, ratio SW and arrangement of genital papillae characterised the first generation males.
THE SO-CALLED COPTIC OINTMENT PRAYER OF DIDACHE 10,8 ONCE MORE
Authors: Ysebaert Joseph 
Published: July 2002

AbstractIn the so-called Coptic ointment prayer of Didache 10,8 the Coptic equivalent stinoufi does not mean 'ointment' but 'good smell'. It corresponds to Greek ευωδια which in 2Cor 2,15 is used for the good smell of Jesus that Christians are to God. This gives a good sense in the context of Did 10,8. Moreover, the expression ευχαριστεω ϑεω υπερ means 'to give thanks to God for' something. In Did 10,8 this is wrongly understood as 'to bless' or 'to consecrate'. In this meaning ευχαριστεω has an accusative object and is only used for the consecrating of the Eucharistic bread and wine.
The aggregation of methylene blue in montmorillonite dispersions
Authors: Bujdák J. , Iyi N. , Fujita T. 
Published: July 2002

AbstractTheories concerning the optical properties of cationic dyes adsorbed on clay surfaces are analysed in detail. An investigation of the aggregation of methylene blue (MB) in montmorillonite dispersions is conducted using visible (VIS) spectroscopy. The effects of the dye/ clay ratio and of the swelling properties of the montmorillonite substrate on dye aggregation are compared in terms of the effect of clay layer charge. The observed influence on dye aggregation was almost negligible for both swelling and dye loading. The layer charge of the silicate determines the extent and the type of dye aggregation in freshly prepared MB/montmorillonite dispersions. Observed spectral changes with time indicate a rearrangement and redistribution of dye H-aggregates (band close to 570 nm) to monomers (660 nm), dimers (605 nm) and J-aggregates (760 nm). Dye aggregates are probably already formed during dye cation migration in the vicinity of clay colloid particles. The extent and the type of initially formed species are probably affected by the electric double layer of clay layers. After reaching the clay surface, dye cation assemblies are rearranged and decompose as described above. Reaching chemical equilibrium, dye cations adjust the distribution of the layer charge, in order that each cation could balance the charge due to one unequivalent substitution.
A hydrogeological model for palygorskite formation in the Danian continental facies of the Provence Basin (France)
Authors: Colson J. , Cojan I. , Thiry M. 
Published: July 2002

AbstractThe Danian of the Provence basin (SE France) is characterized by a strong subatmospheric alteration processes throughout the basin. A wide range of facies, depositional and weathering, were recognized in an interval of 5 Myr and include floodplain fine-grained alluvium, palustrine limestones, playa dolostones, mottled palaeosols, vadose and phreatic calcretes, and phreatic dolocretes. Palygorskite was invariably found in laminar, massive and honeycomb vadose calcretes and phreatic dolocretes, as well as in playa dolostones, and only exceptionally in floodplain siltstones, nodular calcretes and palustrine limestones. Regardless of the facies, palygorskite is associated with smectites. An authigenic origin, based on the morphology of the fibres and the vertical distribution of clay minerals, is proposed for palygorskites in all of the facies. The simultaneous occurrence of palygorskite in these environments is interpreted as a sign of a stable seasonal semi-arid climate and low detrital input during a period of low lake level (-0.5 Myr). The occurrence of authigenic palygorskite in siltstones around the lake was attributed to the rising of the water table, retention of the already saturated water in the pore spaces of the sediment, and its subsequent evaporation in a confined environment. A hydrogeological model is proposed for the distribution of palygorskite. The elongated shape of the Provence basin enhanced the influence of lateral inflow of freshwater during the low lake period which explains the distribution of palygorskite in different environments of the Provence basin as well as spatial distribution of phreatic calcretes and dolocretes. During the high lake level, palygorskite formed in the few remaining ephemeral ponds and on the floodplain along the lake margin.
Removal of organic matter by disodium peroxodisulphate: effects on mineral structure, chemical composition and physicochemical properties of some clay minerals
Authors: Menegatti A. P. , Früh-Green G. L. , Stille P. 
Published: July 2002

AbstractThe use of disodium peroxodisulphate combined with a neutral buffer is a new method for the efficient removal of organic matter from clay-bearing sediments. The effects of this oxidation procedure on mineral structure were investigated by treatment of different standard clay minerals (kaolinite ‘china clay’, illite ‘Le Puy’, montmorillonite SWy-1). The materials were characterized by means of XRD, FTIR, SEM and TEM before and after leaching with disodium peroxodisulphate. Systematic experiments were conducted to determine the effects of leaching on the chemical and isotopic composition of oxygen, hydrogen and K-Ar in these samples. Effects on the physicochemical properties of the clays such as BET external surface area, cation exchange capacity (CEC) and expandability with ethylene glycol were also investigated. The results show that structure, chemical composition, oxygen and hydrogen isotope ratios, as well as the K-Ar system remain unaffected by leaching with disodium peroxodisulphate. The CEC and expandability remain unchanged, whereas changes in BET area can be attributed to mechanical dispersion by ultrasonic treatment.
Hydrothermal reactivity of K-smectite at 300°C and 100 bar: dissolution-crystallization process and non-expandable dehydrated smectite formation
Authors: Mosser-Ruck R. , Cathelineau M. , Baronnet A. , Trouiller A. 
Published: July 2002

AbstractThe hydrothermal reactivity of a smectite saturated with K was studied experimentally at 300°C and 100 bar in (Na,K) chloride solutions (Na/K = 0, 50 and 100, liquid/solid ratio = 10/1). X-ray diffraction, TEM and microprobe results show: (1) a partial to total dissolution of the initial smectite layers; and (2) the crystallization of newly-formed euhedral I-S. Random I-S is formed after 7 days, but an ordered mixed-layer I-S containing <30% expandable layers formed in the longest runs (112 days). The I-S is characterized by non-expandable layers of two distinct types: dehydrated smectite and illite. The Si content is lower in the I-S than in the initial smectite, thus creating a charge deficit, mostly compensated by the introduction of Na to the interlayer space, and yielding a silica release to the solution and subsequent crystallization of quartz and cristobalite.
The steam condensate alteration mineralogy of Ruatapu cave, Orakei Korako geothermal field, Taupo Volcanic Zone, New Zealand
Authors: Rodgers K. A. , Hamlin K. A. , Browne P. R. L. , Campbell K. A. , Martin R. 
Published: July 2002

AbstractRuatapu cave has developed beneath a block of hydrothermally altered Quaternary vitric tuff in the active Orakei Korako geothermal field. The cave extends ∼45 m, with a vertical drop of 23 m, to a shallow pool of clear, sulfate-rich (∼.450 µg/g), warm (T = 43–48°C), acid (pH = 3.0) water. Steam, accompanied by H2S, rises from the pool surface, from a second pool nearby, and from fumaroles and joints in the ignimbrite, to condense on surfaces within the cave. Oxidation of the H2S to H2SO4 produces acid sulfate fluids which react with the surficial rocks to generate three principal and distinct assemblages of secondary minerals. Kaolinite ± opal-A ± cristobalite ± alunite ± alunogen dominate the assemblage at the cave mouth; the essential Al, K and Si are derived from the tuffs and Na, Ca, Fe and Mg removed. In the main body of the cave the highly limited throughflow of water results in the more soluble of the leached constituents, notably Na and K, being retained in surface moisture and becoming available to form tamarugite and potash alum as efflorescences, in part at the expense of kaolin, along with lesser amounts of alunogen, meta-alunogen, mirabilite, halotrichite, kalinite, gypsum and, possibly, tschermigite; the particular species being determined by the prevailing physico-chemical conditions. Heat and moisture assist in moving Fe out of the rock to the air-water interface but, unlike typical surficial acid alteration systems elsewhere in the TVZ, there is an insufficient flow of water, of appropriate Eh-pH, to continue to move Fe out of the cave system. Much becomes locally immobilized as Fe oxides and oxyhydroxides that mottle the sides and roof of the cave. Jarosite crusts have developed where acid sulfate pool waters have had protracted contact with ignimbrite wallrock coated with once-living microbial mats. Subsequent lowering of the waters has caused the porous jarositic crusts to alter to potash alum ± akaganéite or schwertmannite. Meteoric water, with chloride concentrations of up to 10,000 µg/g, seeping through the roof produces a white, semi-thixotropic slurry which when dried yields 5.7 wt.% chloride and consisted of tamarugite plus halite. Some of this chloride (and sulfate) eventually enters the pool waters which have Cl− concentrations of 200 µg/g. This implies that the pools are not necessarily fed by a neutral pH alkali chloride fluid ascending from the geothermal reservoir, but are perched waters heated by ascending steam and fed largely by steam condensate.
A revised phase diagram for the bornite-digenite join from in situ neutron diffraction and DSC experiments
Authors: Grguric B. A. , Harrison R. J. , Putnis A. 
Published: July 2002

AbstractPhase relations along the join bornite (Cu5FeS4)-digenite (Cu8.52Fe0.12S4.88) have been redefined using a combination of in situ high-resolution neutron diffraction and differential scanning calorimetry (DSC). Time-of-flight neutron diffraction patterns were collected on a synthetic sample of bn90 at 16 temperatures between 35 and 350°C. This data is compared with data from a natural end-member bornite sample obtained in an earlier study under identical conditions. Phase relations along the bornite-digenite join are inferred from the temperature evolution of the lattice parameters and the intensity of subcell and supercell reflections of coexisting phases.The DSC scans over the temperature range 50–300°C were performed on a natural digenite sample and samples synthesized at 5 mol.% intervals along the join Cu5FeS4-Cu9S5. The thermal anomalies are correlated with structural phase transitions in componen phases and the solvus temperature for each bulk composition. A phase diagram topology is defined, which was consistent with both diffraction and calorimetric data, but in marked contrast to previous diagrams, shows a consolute point at X = Cu5FeS4 and T = 265°C. This temperature corresponds to that of the tricritical intermediate-high transition in bornite. Isothermal annealing experiments carried out on synthetic starting materials for up to 7 months showed coarsening behaviour consistent with the revised phase diagram topology.
Petrogenetic implications from biotite compositional variations in the Cornubian granite batholith
Authors: Stone M. 
Published: July 2002

AbstractLithium oxide contents of biotites in some Cornubian granites which have been studied by electron microprobe are estimated from their SiO2 and F contents using samples formerly analysed by XRF and wet chemistry. Better formulae which include Li show that most of these biotites are lithian siderophyllites/ lithian Al-annites although some Dartmoor samples, especially those in the basic microgranite (ME) enclaves, are closer to Al-annites. Dartmoor samples are slightly more basic and poorer in Alvi than those from the Isles of Scilly and Carnmenellis granites agreeing with the broad differences in the host rocks. Biotites in volcanic clasts from the New Red Sandstone are significantly different in having much higher Si, Ti, Mg, F and ΣY and lower Alvi contents than those of the granite biotites: these are lithian Fe-Mg biotites. These clasts are believed to be the volcanic equivalents of an evolving Dartmoor magma (Awad et al., 1996). If so, their biotites reflect the composition of the granite biotites at the time of magma emplacement. They subsequently evolved as they equilibrated with the cooling granite to give the present biotite compositions of the Dartmoor granites.
Analcime reactions at 25–90°C in hyperalkaline fluids
Authors: Savage D. , Rochelle C. , Moore Y. , Milodowski A. , Bateman K. , Bailey D. , Mihara M. 
Published: July 2002

AbstractExtensive use of cement and concrete is envisaged in the construction of geological disposal facilities for radioactive wastes. The hyperalkaline porefluids typical of groundwaters that have reacted with these materials have the potential to react chemically with other engineered barrier components such as bentonite, potentially degrading their performance. Analcime, NaAlSi2O6.H2O, has been identified from previous modelling and experimental studies as a potential alteration product of bentonite.Laboratory experiments to investigate the stability of analcime under hyperalkaline porefluid conditions have been performed. Experiments used both batch and fluidized bed equipment at 25, 50, 70 and 90°C in K-based pH buffer solutions, both under- and over-saturated with respect to analcime. Results from dissolution experiments demonstrate that release of Na was greatly enhanced (by up to a factor of thirty) over that for Si and Al, particularly at pH 10 and 11. However, enhanced release of both Na and Al occurred in the batch experiments at pH 12–13. Near stoichiometric dissolution was observed in fluidized bed experiments under steady-state conditions at 70°C. Sodium was removed from the analcime structure by ion exchange for K, without involving dissolution and re-precipitation of the analcime framework. Scanning electron microscopy of reacted analcime grains showed that some grains had pronounced cracks parallel to original cleavage traces. These cracks were a result of volume decrease due to the substitution of K for Na ions and water molecules in the analcime structure to form leucite, KAlSi2O6.Synthesis of the dissolution data shows that the rate of dissolution increased with increasing temperature in the range 25–70°C and with pH at each temperature. Absolute rates of dissolution ranged from 10−10 mol m−2 s−1 at pH 9.5 at 25°C to 10−7 mol m−2 s−1 a pH 12 at 70 and 90°C. The rate of dissolution at any temperature was pH-dependent, such that the rate could be described by k (aH+)n, where k is the rate constant and n is −0.3 at 25°C, −0.4 at 50°C, −0.6 at 70°C and −0.7 at 90°C. Attempts to measure the growth rate of analcime in supersaturated solutions at 70 and 90°C were unsuccessful, although a limiting rate at 70°C, pH 10 was calculated to be 4 × 10−11 mol m−2 s−1, roughly 100× less than the rate of dissolution under the same conditions.These results imply that any trace amounts of analcime in bentonite will be converted to leucite by reaction with cement fluids with a high K/Na ratio. In some instances, leucite may thus incorporate K+ in preference to other phases (e.g. illite, K-feldspar) during alteration of bentonite by cement porefluids.
A reexamination of the turquoise group: the mineral aheylite, planerite (redefined), turquoise and coeruleolactite
Authors: Foord Eugene E. , Taggart Joseph E. 
Published: July 2002

AbstractThe turquoise group has the general formula:A0–1B6(PO4)4−x(PO3OH)x(OH)8.4H2O, wherex= 0–2, and consists of six members: planerite, turquoise, faustite, aheylite, chalcosiderite and an unnamed Fe2+-Fe3+analogue. The existence of ‘coeruleolactite’ is doubtful. Planerite is revalidated as a species and is characterized by a dominantA-site vacancy. Aheylite is established as a new member of the group, and is characterized by having Fe2+dominant in theA-site.Chemical analyses of 15 pure samples of microcrystalline planerite, turquoise, and aheylite show that a maximum of two of the (PO4) groups are protonated (PO3OH) in planerite. Complete solid solution exists between planerite and turquoise. Other members of the group show variableA-site vacancy as well. Most samples of ‘turquoise’ are cation-deficient or are planerite. Direct determination of water indicates that there are 4 molecules of water.Planerite, ideally ☐Al6(PO4)2(PO3OH)2(OH)8.4H2O, is white, pale blue or pale green, and occurs as mamillary, botryoidal crusts as much as several mm thick; may also be massive; microcrystalline, crystals typically 2–4 micrometres, luster chalky to earthy, H. 5, somewhat brittle, no cleavage observed, splintery fracture, Dm2.68(2), Dc2.71, not magnetic, not fluorescent, mean RI about 1.60.a7.505(2),b9.723(3),c7.814(2) Å, α 111.43°, β 115.56°, γ 68.69°, V 464.2(1) Å3, Z = 1.Aheylite, ideally Fe2+Al6(PO4)4(OH)8.4H2O, is pale blue or green, and occurs as isolated and aggregate clumps of hemispherical or spherical, radiating to interlocked masses of crystals that average 3 micrometres in maximum dimension; porcelaneous-subvitreous luster, moderate to brittle tenacity, no cleavage observed, hackly to splintery fracture, not magnetic, not fluorescent, biax. (+), mean RI is about 1.63, Dm2.84(2), Dc2.90.a7.400(1),b9.896(1),c7.627(1) Å, α 110.87°, β 115.00°, γ 69.96°, V 460.62(9) Å3, Z = 1.
Manganese valency and the colour of the Mn2AsO4(OH) polymorphs eveite and sarkinite
Authors: Hålenius Ulf , Westlund Erika 
Published: July 2002

AbstractPolarized optical absorption spectra of single crystals of the two dimorphic Mn2AsO4(OH)-minerals eveite and sarkinite show that minor concentrations of Mn3+ at the octahedral site determine the colour and cause the distinct pleochroism in green and yellow of eveite. In the sarkinite spectra only absorption bands due to spin-forbidden d-d transitions in Mn2+ at six- and five-coordinated sites are observed, which produce a weak flesh-red mineral colour and a very faint pleochroism.
Molecular processes on oxide surfaces studied by first-principles calculations
Authors: Gillan M. J. , Lindan P. J. D. , Kantorovich L. N. , Bates S. P. 
Published: July 2002

AbstractFirst-principles quantum techniques based on density functional theory (DFT) have made important contributions to the understanding of oxide surfaces over the last four years. Important features of these calculations include: the use of periodic boundary conditions, which avoid the edge effects associated with the cluster approach; plane-wave basis sets, which make the calculation of ionic forces straightforward, so that both static relaxation and dynamical simulation can be done; and the approximate inclusion of electron correlation. A short introduction to DFT techniques is given, and recent work on the structure and energetics of a variety of oxide surfaces is presented. It is shown how the techniques can be used to study molecular and dissociative adsorption of molecules on oxide surfaces, with the emphasis on water and simple organic molecules. The growing importance of dynamical first-principles simulation in the study of surface chemical reactions is illustrated.
Circulating autoantibodies to oxidized cardiolipin correlate with isoprostane F2α-VI levels and the extent of atherosclerosis in ApoE-deficient mice: modulation by vitamin E
Authors: Praticò Domenico , Tangirala Rajendra K. , Hörkkö Sohvi , Witztum Joseph L. , Palinski Wulf , FitzGerald Garret A. 
Published: July 2002

AbstractLipid peroxidation plays an important role in atherogenesis. Previous studies suggested that autoantibodies against epitopes of oxidized low-density lipoprotein may indicate the extent or rate of progression of atherosclerosis. The aim of this study was to investigate whether autoantibodies to oxidized phospholipids, such as oxidized cardiolipin (OxCL), correlate with levels of isoprostane F2α-VI, a sensitive marker of in vivo lipid peroxidation, as well as with the extent of atherosclerosis. Two groups of apolipoprotein E-deficient mice were fed chow with or without vitamin E (2000 IU/kg diet) for 16 weeks. In untreated animals, autoantibodies against OxCL and urinary, plasma, and aortic isoprostane F2α-VI levels increased significantly. Vitamin E treatment significantly reduced antibody titers, isoprostane levels, and atherosclerosis at the end of the study, compared with untreated mice. Autoantibodies to OxCL correlated with aortic isoprostane F2α-VI levels (r2 = 0.42,P = .001 for IgG andr2 = 0.63, P &lt; .001 for IgM). Both aortic isoprostane F2α-VI levels (r2 = 0.59, P &lt; .001) and titers of OxCL antibodies (r2 = 0.70, P &lt; .001 for IgG and r2 = 0.68,P &lt; .001 for IgM) correlated with the extent of aortic atherosclerosis. The fact that the levels of autoantibodies to OxCL correlated with a sensitive direct measure of lipid peroxidation in vivo and that both autoantibodies and aortic isoprostane F2α-VI levels correlated with the extent of atherosclerosis suggests that antibodies to OxCL are a sensitive indicator of in vivo lipid peroxidation and atherosclerosis.