Glasses Tech - Prescription Glasses, Prescription Eyeglasses » Glasses 2001

Seeing One’s Partner Through Intimacy-Colored Glasses: An Examination of the Processes Underlying the Intimacy Goals-Relationship Satisfaction Link

admin — Mon, 08 Mar 2010 03:50:53 +0000

This research extends previous work demonstrating that individuals with intimacy goals experience greater relationship satisfaction by examining three distinct processes that may underlie this association (e.g., engaging in intimacy-conducive interactions with their partners, having intimacy-focused partners, perceiving partners as intimacy focused). The study included 100 female college students who completed measures of intimacy goals, patterns of relationship interaction, perceptions of their partner’s intimacy goals, and relationship satisfaction. Their dating partners also completed the intimacy goals measure. Results indicate that individuals with intimacy goals engage in particular patterns of interaction and perceive their partners as having intimacy goals, although there was no association between own and partner’s goals. Moreover, women’s perceptions of their partners’ intimacy goals partially mediated the intimacy goals-relationship satisfaction link.

Catherine A. Sanderson
Amherst College, casanderson@amherst.edu

Sarah M. Evans

Amherst College

Personality and Social Psychology Bulletin, Vol. 27, No. 4, 463-473 (2001)
DOI: 10.1177/0146167201274007

U-series Isotope Data on Lau Basin Glasses: the Role of Subduction-related Fluids during Melt Generation in Back-arc Basins

admin — Mon, 08 Mar 2010 03:49:18 +0000

New thermal ionization mass spectrometry U-series disequilibrium data are presented for 24 basaltic to dacitic glasses from active spreading centres in the back-arc Lau Basin (SW Pacific), together with additional inductively coupled plasma mass spectrometry trace element analyses and Sr–Nd–Pb isotope data. Valu Fa Ridge samples, adjacent to the arc front, have high U/Th and (230Th/238U) <1, implying a recent (<<350 ka) addition of a U-rich slab-derived fluid. The Valu Fa data can be combined with existing 230Th–238U data for the Central Tonga arc to infer a fluid addition event at 50 ka. The similar sources and time scales for fluid transfer beneath the Valu Fa Ridge and beneath the arc itself suggest that the Valu Fa Ridge is propagating into the arc-front region. Central Lau Basin samples, further behind the arc, have lower U/Th and (230Th/238U) 1, similar to typical mid-ocean ridge basalts (MORB). Within the Central Lau Basin, a water-rich subduction component is seen only in samples closest to the arc, and this fluid does not have the high-U/Th composition of the fluid at Valu Fa. Melt generation in the Central Lau Basin appears to be dominated by normal ridge-type processes, but the relatively low (230Th/238U) for these shallow ridges compared with global MORB could be a consequence of increased melt productivity as a result of the elevated water contents. The transition from 238U to 230Th excesses within the back-arc basin is not a smooth function of decreasing addition of a U-rich fluid moving away from the arc front, but also reflects the complex dynamics between two major mantle domains within the mantle wedge (‘Pacific’ beneath Valu Fa Ridge, ‘Indian’ beneath the Central Lau Basin).

KEY WORDS: back-arc basins; U-series disequilibrium; fluids; subduction zones; melting

DAVID W. PEATE1,*, THOMAS F. KOKFELT1,, CHRIS J. HAWKESWORTH1,, PETER W. VAN CALSTEREN1, JANET M. HERGT2 and JULIAN A. PEARCE3
1DEPARTMENT OF EARTH SCIENCES, THE OPEN UNIVERSITY, WALTON HALL, MILTON KEYNES MK7 6AA, UK
2SCHOOL OF EARTH SCIENCES, THE UNIVERSITY OF MELBOURNE, MELBOURNE, VIC. 3010, AUSTRALIA
3DEPARTMENT OF EARTH SCIENCES, CARDIFF UNIVERSITY, MAIN COLLEGE, PARK PLACE, P.O. BOX 914, CARDIFF CF1 3YE, UK

Volatiles in Basaltic Glasses from Loihi Seamount, Hawaii: Evidence for a Relatively Dry Plume Component

admin — Mon, 08 Mar 2010 03:47:00 +0000

New H2O, CO2 and S concentration data for basaltic glasses from Loihi seamount, Hawaii, allow us to model degassing, assimilation, and the distribution of major volatiles within and around the Hawaiian plume. Degassing and assimilation have affected CO2 and Cl but not H2O concentrations in most Loihi glasses. Water concentrations relative to similarly incompatible elements in Hawaiian submarine magmas are depleted (Loihi), equivalent (Kilauea, North Arch, Kauai–Oahu), or enriched (South Arch). H2O/Ce ratios are uncorrelated with major element composition or extent or depth of melting, but are related to position relative to the Hawaiian plume and mantle source region composition, consistent with a zoned plume model. In front of the plume core, overlying mantle is metasomatized by hydrous partial melts derived from the Hawaiian plume. Downstream from the plume core, lavas tap a depleted source region with H2O/Ce similar to enriched Pacific mid-ocean ridge basalt. Within the plume core, mantle components, thought to represent subducted oceanic lithosphere, have water enrichments equivalent to (KEA) or less than (KOO) that of Ce. Lower H2O/Ce in the KOO component may reflect efficient dehydration of the subducting oceanic crust and sediments during recycling into the deep mantle.

KEY WORDS: basalt; Hawaii; mantle; plumes; volatiles

JACQUELINE EABY DIXON1,* and DAVID A. CLAGUE2
1ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE, UNIVERSITY OF MIAMI, 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149, USA
2MONTEREY BAY AQUARIUM RESEARCH INSTITUTE, PO BOX 628, MOSS LANDING, CA 95039-0628, USA

Ab initio studies of possible fluorine-bearing four- and fivefold coordinated Al species in aluminosilicate glasses

admin — Mon, 08 Mar 2010 03:45:16 +0000

Ab initio NMR gauge-including atomic orbital (GIAO) calculations were used to constrain assignments of resonances in 27Al NMR spectra of F-bearing alkali aluminosilicate glasses. The effect of bond angles within the range 126–150° on the chemical shift was investigated using cluster models of next-nearest atoms that are charge balanced by hydrogen atoms. GIAO calculations used geometries obtained through optimization at fixed Al-O-Si bond angles. The calculated peak positions for all of the 4-fold coordinated Al species yielded calculated 27Al NMR peak positions in good agreement with the experimental data, suggesting that any or all of the species AlF4–, AlF3O(SiH3)–, AlF2O2(SiH3)2–, and AlFO3(SiH3)3– may be present. Three of the investigated 5-fold coordinated species AlF52–, AlF3O2(SiH3)22–, and AlF2O3(SiH3)32– fit the experimental requirements well, whereas the remaining 5-fold coordinated species that were tested [AlF4O(SiH3)2–, and AlFO4(SiH3)42–] did not.

Yun Liu and Hanna Nekvasil*
Center for High Pressure Research and Department of Geosciences, State University of New York, Stony Brook, New York 11794-2100, U.S.A.

Correspondence: * E-mail: hanna.nekvasil@sunysb.edu

THE VALENCE AND SPECIATION OF SULFUR IN GLASSES BY X-RAY ABSORPTION SPECTROSCOPY

admin — Mon, 08 Mar 2010 03:43:44 +0000

The geochemical behavior of sulfur in magmas depends strongly on the oxidation state of sulfur, but this is not easily determined by standard analytical methods. We have measured XANES absorption spectra at the sulfur K-edge and have found that such measurements are useful to characterize the oxidation state and speciation of sulfur in silicate glasses of geological relevance. Measured spectra of a set of reference minerals show the effects of different oxidation states and coordination numbers of sulfur; there is a large shift in energy (~10–12 eV) of the sulfur K-edge between S2– and S6+. This large and easily detectable difference makes possible the measurement of the valence of sulfur in unknown samples by measuring the shift in energy of the absorption edge. This approach is applicable to both crystalline and glassy materials, and useful results have been obtained on samples with as little as 450 ppm S. We have used XANES measurements to characterize oxidation state and speciation of sulfur in a set of natural and synthetic sulfur-bearing glasses. The samples cover a range of composition from basaltic to almost rhyolitic, and some were synthesized over a range of pressure, temperature and oxygen fugacity; glass S content varies between 450 and 3000 ppm. XANES analyses, carried out in fluorescence mode at LURE, allowed determination of the sulfur oxidation state in all of the samples and clearly show that some samples contain a mixture of S2– and S6+; no other sulfur species were observed. Quantitative determination of the abundance of sulfide and sulfate shows good agreement with independent measurements based on electron-microprobe determination of the wavelength shift of sulfur K X-rays.

Eleonora Paris1,, Gabriele Giuli1, Michael R. Carroll1 and Ivan Davoli2

1 Dipartimento di Scienze della Terra, Università di Camerino and INFM (Istituto Nazionale Fisica della Materia) – Unità di Camerino, I-62032 Camerino, Italy
2 Dipartimento di Fisica, Università di Roma “Tor Vergata”, and INFM (Istituto Nazionale Fisica della Materia) – Unità di Roma 2, I-00133 Roma, Italy

E-mail address: paris@camars.unicam.it

Keywords: sulfur, silicate glasses, X-ray absorption spectroscopy, XANES.