501 research outputs found
Komatiite.
It is easy to explain roughly what a komatiite is but difficult to give a rigorous definition. The simple definition is that komatiite is an ultramafic volcanic rock (Arndt and Nisbet 1982). Alimit of 18% MgO separates komatiites from less magnesian volcanic rocks such as picrites,ankaramites or magnesian basalts. The term komatiitic basalt is applied to volcanic rocks containing less than 18% MgO that can be linked, using petrological, textural or geochemicalarguments, to komatiites
Immunologic Status of Uremic Patients
The immunologic status of 25 uremic patients was studied with a battery of tests evaluating the humoral and cytological aspects of immunity. The individual\u27s humoral immune status was evaluated as follows: quantitation of the three major serum immunoglobulins (IgG, IgA and IgM) expressed in mg/100 ml of serum and compared to established normal clinical standards (±2 SD/mean); qualitation of IgG and IgM evaluated by specific virus antibody titers and antitoxin values associated with IgG and by isoagglutinin tilers of the ABO blood groups associated with IgM. Immunoglobulin status is grouped into hyper- and hypo-immunoglobulin variations from normal and correlated with serum complement values (Beta 1C/1A and hemolytic activity). The cytological status in the evaluation consists of assaying the individual\u27s ability to produce interferon by the Sendai-Sindbis virus system in peripheral blood leukocytes. Results of the study emphasize the need for individual evaluation of uremic patients to enable more effective immuno- depressive therapy before and after renal transplantation
Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland
This is the final version of the article. Available from Springer Verlag via the DOI in this record.Two occurrences of platinum-group elements (PGEs) along the northern margin of the Skaergaard intrusion include a sulfide-bearing gabbro with slightly less than 1 ppm PGE + Au and a clinopyroxene-actinolite-plagioclase-biotite-ilmenite schist with 16 vol% sulfide and 1.8 ppm PGE + Au. Both have assemblages of pyrrhotite, pentlandite, and chalcopyrite typical for orthomagmatic sulfides. Matching platinum-group mineral assemblages with sperrylite (PtAs2), kotulskite (Pd(Bi,Te)1–2), froodite (PdBi2), michenerite (PdBiTe), and electrum (Au,Ag) suggest a common origin. Petrological and geochemical similarities suggest that the occurrences are related to the Skaergaard intrusion. The Marginal Border Series locally displays Ni depletion consistent with sulfide fractionation, and the PGE fractionation trends of the occurrences are systematically enriched by 10–50 times over the chilled margin. The PGE can be explained by sulfide-silicate immiscibility in the Skaergaard magma with R factors of 110–220. Nickel depletion in olivine suggests that the process occurred within the host cumulate, and the low R factors require little sulfide mobility. The sulfide assemblages are different to the chalcopyrite-bornite-digenite assemblage found in the Skaergaard Layered Series and Platinova Reef. These differences can be explained by the early formation of sulfide melt, while magmatic differentiation or sulfur loss caused the unusual sulfide assemblage within the Layered Series. The PGEs indicate that the sulfides formed from the Skaergaard magma. The sulfides and PGEs could not have formed from the nearby Watkins Fjord wehrlite intrusion, which is nearly barren in sulfide. We suggest that silicate-sulfide immiscibility led to PGE concentration where the Skaergaard magma became contaminated with material from the Archean basement.The authors are grateful for logistical support from Platina Resources Ltd., Geological Survey of Denmark and Greenland, and members of the 2011 Skaergaard field team. JCØA was supported by grants from Helford Geoscience LLP and the Camborne School of Mines Trust. CT was supported by the Danish Natural Research Council and the Carlsberg Foundation, and CEL was supported by the US National Science Foundation (EAR-1019887). Samples were sectioned and prepared by Steve Pendray at Camborne School of Mines. The QEMSCAN is a registered trade mark of FEI Corporation
What Journals do Psychology Graduate Students Need? A Citation Analysis of Thesis References
published or submitted for publicatio
Preparation of a ZrO₂-Al₂O₃ Nanocomposite by High-Pressure Sintering of Spray-Pyrolyzed Powders
ZrO2-Al2O3 powders were synthesized by spray pyrolysis. These powders were sintered at 1 GPa in the temperature range of 700Ç1100 ÉC. The microstructural evolution and densification are reported in this paper. The application of 1 GPa pressure lowers the crystallization temperature from ~850 to 700 ÉC. Similarly, the transformation temperature under 1 GPa pressure for \u3c\u3eg ê a Al2O3 reduces from ~1100 to 700Ç800 ÉC range, and that for t \u3c\u3eê m ZrO2 reduces from ~1050 to 700Ç800 ÉC range. It was possible to ob-tain highly-dense nanocrystalline ZrO2-Al2O3 composite at temperatures as low as 700 ÉC. The effect of high pressure on nucleation and transformation of phases is discussed
Identification of mixed-symmetry states in an odd-mass nearly-spherical nucleus
The low-spin structure of 93Nb has been studied using the (n,n' gamma)
reaction at neutron energies ranging from 1.5 to 3.0 MeV and the 94Zr(p,2n
gamma)93Nb reaction at bombarding energies from 11.5 to 19 MeV. States at
1779.7 and 1840.6 keV, respectively, are proposed as mixed-symmetry states
associated with the coupling of a proton hole in the p_1/2 orbit to the 2+_1,ms
state in 94Mo. These assignments are derived from the observed M1 and E2
transition strengths to the symmetric one-phonon states, energy systematics,
spins and parities, and comparison with shell model calculations.Comment: 5 pages, 3 figure
A whole-rock data set for the Skaergaard intrusion, East Greenland
We report a compilation of new and published whole-rock major and trace element analyses for 646 samples of the Skaergaard intrusion, East Greenland. The samples were collected in 14 stratigraphic profiles either from accessible and well-exposed surface areas or from drill core, and they cover most regions of the intrusion. This includes the Layered Series, the Upper Border Series, the Marginal Border Series and the Sandwich Horizon. The geochemical data were obtained by a combination of X-ray fluorescence and inductively coupled plasma mass spectrometry. This data set can, for example, be used to constrain processes of igneous differentiation and ore formation.
Fast and flexible selection with a single switch
Selection methods that require only a single-switch input, such as a button
click or blink, are potentially useful for individuals with motor impairments,
mobile technology users, and individuals wishing to transmit information
securely. We present a single-switch selection method, "Nomon," that is general
and efficient. Existing single-switch selection methods require selectable
options to be arranged in ways that limit potential applications. By contrast,
traditional operating systems, web browsers, and free-form applications (such
as drawing) place options at arbitrary points on the screen. Nomon, however,
has the flexibility to select any point on a screen. Nomon adapts automatically
to an individual's clicking ability; it allows a person who clicks precisely to
make a selection quickly and allows a person who clicks imprecisely more time
to make a selection without error. Nomon reaps gains in information rate by
allowing the specification of beliefs (priors) about option selection
probabilities and by avoiding tree-based selection schemes in favor of direct
(posterior) inference. We have developed both a Nomon-based writing application
and a drawing application. To evaluate Nomon's performance, we compared the
writing application with a popular existing method for single-switch writing
(row-column scanning). Novice users wrote 35% faster with the Nomon interface
than with the scanning interface. An experienced user (author TB, with > 10
hours practice) wrote at speeds of 9.3 words per minute with Nomon, using 1.2
clicks per character and making no errors in the final text.Comment: 14 pages, 5 figures, 1 table, presented at NIPS 2009 Mini-symposi
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Forested plant associations of the Olympic National Forest
A potential vegetation classification system is presented for the Olympic National Forest. It is
based on a sample of 1046 Reconnaissance and 408 Intensive plots. The hierarchical classification
includes sixvegetation series and 64 plant associations. Diagnostickeys are presented to aid in the identification of series and associations. Descriptions are presented for each series and association which are oriented toward the application of this classification for land management objectives. Association descriptions include information about plant species occurrences, including mosses and lichens, mammals, birds, insect pests and diseases. Most descriptions include information on timber productivity and soils. Background information is also presented on the ecology, geology, soils and history of the Olympic Mountains.
Key words: vegetation classification, climax vegetation, climax plant communities, plant association,
vegetation series, plant community ecology, forest ecology, mosses, lichens, birds, mammals,
forest diseases, timber productivity, soil, Olympic Mountains
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