La1-xSrxMnO3 as a candidate for a room temperature pressure sensor /

Perovskite manganite compounds, Lai-xDxMnOs (D-divalent alkaline earth Ca, Sr or Ba), whose electrical and magnetic properties were first investigated nearly a half century ago, have attracted a great deal of attention due to their rich phase diagram. From the point of view of designing a future application, the strong pressure dependence of the resistivity and the accompanying effects in thin films have potential for application in pressure sensing and electronic devices. In this study we report our experimental investigations of pressure dependence of the resistivity of Lao.siSvo^iQMnOs and Lai-xSvxMnOs (LSMO) epitaxial films with x= 0.15, 0.20, 0.25, 0.30, 0.35, on SrTiOs substrates.

Evaluation of Lubricating Oil Preparation Procedures for the Determination of Al, Ba, Mo, Si and V by High-Resolution Continuum Source FAAS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reação de redução de oxigênio sobre perovskitas La1-xSrxFeyCo1-yO3-δ, para células a combustível de óxido sólido (SOFC)

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Working Alliance Inventory-Short Revised (WAI-SR): psychometric properties in outpatients and inpatients

The Working Alliance Inventory-Short Revised (WAI-SR) is a recently refined measure of the therapeutic alliance that assesses three key aspects of the therapeutic alliance: (a) agreement on the tasks of therapy, (b) agreement on the goals of therapy and (c) development of an affective bond. The WAI-SR demonstrated good psychometric properties in an initial validation in psychotherapy outpatients in the USA. The generalizability of these findings is limited because in some countries a substantial portion of individual psychotherapy is delivered in inpatient settings. This study investigated and compared the psychometric properties of the WAI-SR in German outpatients (N = 88) and inpatients (N = 243). In both samples reliability (alpha > 0.80) and convergent validity with the Helping Alliance Questionnaire were good (r > 0.64). Confirmatory factor analysis showed acceptable to good model fit for the proposed Bond-Task-Goal model in both samples. Multi-group analysis demonstrated that the same constructs were measured across settings. Alliance ratings of outpatients and inpatients differed regarding the overlap of alliance components and the magnitude of the alliance ratings: The differentiation of the alliance components was poorer in inpatients and they reported lower alliances. Unique aspects of the alliance in inpatient treatment are discussed and a need for further research on the alliance in inpatient settings is pointed out. Overall, the WAI-SR can be recommended for alliance assessment in both settings.

(Table 1) Isotopic and trace-element composition of ODP Leg 127/128 basalts

The western Pacific includes many volcanic island arc and backarc complexes, yet multi-isotopic studies of them are rare. Basement rocks of the Sea of Japan backarc basin were encountered at Sites 794,795, and 797, and consisted of basaltic sills and lava flows. These rocks exhibit a broad range in isotopic composition, broader than that seen in any other western Pacific arc or backarc system: 87Sr/86Sr = 0.70369 to 0.70499, 143Nd/144Nd = 0.51267 to 0.51317, 206Pb/204Pb = 17.64 to 18.36. The samples form highly correlated arrays between very depleted mid-ocean ridge basalt (MORB) and the Pacific pelagic sediment fields on Pb-Pb plots. Similarly, on plots of Sr-Pb and Nd-Pb, the Sea of Japan samples lie on mixing curves between depleted mantle and enriched mantle ("EM II"), which is interpreted to be of average crustal or pelagic sediment composition. The source of these backarc rocks appears to be a MORB-like mantle source, contaminated by pelagic sediments. Unlike the Mariana and Izu arc/backarc systems, Japanese arc and backarc rocks are indistinguishable from each other in a Sr-Nd isotope plot, and have similar trends in Pb-Pb plots. Thus, sediment contamination of the mantle wedge appears to control the isotopic compositions of both the arc and backarc magmas. Two-component mixing calculations suggest that the percentage of sediments in the magma source varies from 0.5% to 2.5%.

(Table 1) K and Ar content, and age determination of ODP Holes 126-792E and 126-793B

Results of conventional K-Ar dating on five samples from two sites from the Izu-Bonin forearc are presented. Two samples recovered from a volcanic edifice and overlying sediments drilled on the western side of the forearc basin (Site 792) indicate a basement age of 34 Ma. This is consistent with early Oligocene biostratigraphic ages from the overlying sediments. Three samples from the basement of Hole 793B at the center of the basin are not analytically distinguishable, with a best age of 27.1 +/- 0.6 Ma. This is slightly younger than the 30-33 Ma biostratigraphic and magnetostratigraphic estimates from the overlying sediments, suggesting that alteration processes have lowered the apparent K-Ar ages. These ages suggest that syn-rift volcanism occurred in a forearc location during the middle Oligocene.

(Table 1) Position and astronomical ages of sedimentary cycles in the eastern Mediterranean Sea

An astronomically calibrated timescale has recently been established [Hilgen, 1991, doi:10.1016/0012-821X(91)90082-S; doi:10.1016/0012-821X(91)90206-W] for the Pliocene and earliest Pleistocene based on the correlation of dominantly precession controlled sedimentary cycles (sapropels and carbonate cycles) in Mediterranean marine sequences to the precession time series of the astronomical solution of Berger and Loutre [1991, doi:10.1016/0277-3791(91)90033-Q ] (hereinafter referred to as Ber90). Here we evaluate the accuracy of this timescale by (1) comparing the sedimentary cycle patterns with 65°N summer insolation time series of different astronomical solutions and (2) a cross-spectral comparison between the obliquity-related components in the 65°N summer insolation curves and high-resolution paleoclimatic records derived from the same sections used to construct the timescale. Our results show that the carbonate cycles older than 3.5 m.y. should be calibrated to one precession cycle older than previously proposed. Application of the astronomical solution of Laskar [1990, doi:10.1016/0019-1035(90)90084-M], (hereinafter referred to as La90) with present-day values for the dynamical ellipticity of the Earth and tidal dissipation by the Sun and Moon results in the best fit with the geological record, indicating that this solution is the most accurate from a geological point of view. Application of Ber90, or La90 solutions with dynamical ellipticity values smaller or larger than the present-day value, results in a less obvious fit with the geological record. This implies that the change in the planetary shape of the Earth associated with ice loading and unloading near the poles during the last 5.3 million years was too small to drive the precession into resonance with the perturbation term, s6-g6+g5, of Jupiter and Saturn. Our new timescale results in a slight but significant modification of all ages of the sedimentary cycles, bioevents, reversal boundaries, chronostratigraphic boundaries, and glacial cycles. Moreover, a comparison of this timescale with the astronomical timescales of ODP site 846 [Shackleton et al., 1995, doi:10.2973/odp.proc.sr.138.106.1995; doi:10.2973/odp.proc.sr.138.117.1995] and ODP site 659 [Tiedemann et al., 1994, doi:10.1029/94PA00208] indicates that all obliquity-related glacial cycles prior to ~4.7 Ma in ODP sites 659 and 846 should be correlated with one obliquity cycle older than previously proposed.

(Table 1) Isotopic and trace-element ratios of Emperor Seamount basalts

When a mantle plume interacts with a mid-ocean ridge, both are noticeably affected. The mid-ocean ridge can display anomalously shallow bathymetry, excess volcanism, thickened crust, asymmetric sea-floor spreading and a plume component in the composition of the ridge basalts (Schilling, 1973, doi:10.1038/242565a0; Verma et al., 1983, doi:10.1038/306654a0; Ito and Lin, 1995, doi:10.1130/0091-7613(1995)023<0657:OSCHIC>2.3.CO;2; Müller et al., 1998, doi:10.1038/24850). The hotspot-related volcanism can be drawn closer to the ridge, and its geochemical composition can also be affected (Ito and Lin, 1995, doi:10.1130/0091-7613(1995)023<0657:OSCHIC>2.3.CO;2; White et al., 1993, doi:10.1029/93JB02018; Kincaid et al., 1995, doi:10.1038/376758a0; Kingsley and Schilling, 1998, doi:10.1029/98JB01496 ). Here we present Sr-Nd-Pb isotopic analyses of samples from the next-to-oldest seamount in the Hawaiian hotspot track, the Detroit seamount at 51° N, which show that, 81 Myr ago, the Hawaiian hotspot produced volcanism with an isotopic signature indistinguishable from mid-ocean ridge basalt. This composition is unprecedented in the known volcanism from the Hawaiian hotspot, but is consistent with the interpretation from plate reconstructions (Mammerickx and Sharman, 1988, doi:10.1029/JB093iB04p03009) that the hotspot was located close to a mid-ocean ridge about 80 Myr ago. As the rising mantle plume encountered the hot, low-viscosity asthenosphere and hot, thin lithosphere near the spreading centre, it appears to have entrained enough of the isotopically depleted upper mantle to overwhelm the chemical characteristics of the plume itself. The Hawaiian hotspot thus joins the growing list of hotspots that have interacted with a rift early in their history.

(Table 1) Bulk and grain density, porosity, and p- and s-wave velocity characteristics of ODP Hole 163-990A sediments

Seismic velocities in rocks are influenced by the properties of the solid, the pore fluid, and the pore space. Cracks dramatically affect seismic velocities in rocks; their influence on the effective elastic moduli of rocks depends on their shape and concentration. Thin cracks (or fractures) substantially lower the moduli of a rock relative to the effect of spherical voids (or vesicles), and lower moduli are reflected by lower P- and S-wave velocities. The objective of this research is to determine the types and concentrations of cracks and their influence on the seismic properties of subaerially erupted basalts drilled from Hole 990A on the Southeast Greenland margin during Ocean Drilling Program Leg 163. Ellipsoidal cracks are used to model the voids in the rocks. The elastic moduli of the solid (grains) are also free parameters in the inverse modeling procedure. The apparent grain moduli reflect a weighted average of the moduli of the constituent minerals (e.g., plagioclase, augite, and clay minerals). The results indicate that (1) there is a strong relationship between P-wave velocity and porosity, suggesting a similarity of pore shape distributions, (2) the distribution of crack types within the massive, central region of aa flows from Hole 990A is independent of total porosity, (3) thin cracks are the first to be effectively sealed by alteration products, and (4) grain densities (an alteration index) and apparent grain moduli of the basalt samples are directly related.