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Phase Relationships (phase + relationships)
Selected AbstractsOrientation and Phase Relationships between Titania Films and Polycrystalline BaTiO3 Substrates as Determined by Electron Backscatter Diffraction MappingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2010Nina V. Burbure Titania films have been grown on polycrystalline BaTiO3 (BTO) substrates at 700°C by pulsed laser deposition. Electron backscatter diffraction (EBSD) was used to determine grain orientations in the substrate before growth, and the phase and orientation of the supported films after growth. All BaTiO3 grains within 26° of (001) were covered by anatase films with an orientation relationship of (001)Anatase||(001)BTO and [100]Anatase||[100]BTO. Rutile with a variety of orientations grew on BaTiO3 grains with orientations closer to (110) and (111). EBSD mapping provides an efficient means for determining phase and orientation relationships of films over all orientation parameters. [source] Subsolidus Phase Relationships in the ZnO,In2O3,SnO2 SystemJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2008Steven P. Harvey The subsolidus phase relationships in the ZnO,InO1.5,SnO2 system were investigated at 1275°C using X-ray diffraction. Each of the end members of the ternary diagram is a transparent conducting oxide. There are two substantial solid solutions in the ternary phase space, the bixbyite solid solution In2,2xZnxSnxO3 (x=0,0.40), and the indium substituted zinc stannate spinel, Zn(2,x)Sn(1,x)In2xO4 (x=0,0.45). The bixbyite solid solution is an outstanding TCO, whereas the spinel is only moderately conducting. Along the ZnO,InO1.5 binary, there is a series of transparent conducting homologous compounds (ZnO)k·In2O3 (where k=3, 4, 5, 6, 7, 9, 11). Within ternary phase space, these homologous compounds were found to exhibit negligible Sn solubility, and were always found to be compatible with the spinel. Equilibrium was difficult to achieve in the phase space between the homologous series compounds and the spinel, owing to sluggish kinetics. A procedure involving mixtures of prereacted spinel and the Zn11In2O14 (k=11) compound was developed, which allowed for more rapid approach to thermodynamic equilibrium, thereby allowing for the establishment of phase relationships near the ZnO corner of the phase diagram. [source] Ternary System Al2O3,MgO,CaO: Part II, Phase Relationships in the Subsystem Al2O3,MgAl2O4,CaAl4O7JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2000Antonio H. de Aza Solid-state compatibility and melting relationships in the subsystem Al2O3,MgAl2O4,CaAl4O7 were studied by firing and quenching selected samples located in the isopletal section (CaO·MgO),Al2O3. The samples then were examined using X-ray diffractomtery, optical microscopy, and scanning and transmission electron microscopies with wavelength- and energy-dispersive spectroscopies, respectively. The temperature, composition, and character of the ternary invariant points of the subsystem were established. The existence of two new ternary phases (Ca2Mg2Al28O46 and CaMg2Al16O27) was confirmed, and the composition, temperature, and peritectic character of their melting points were determined. The isothermal sections at 1650°, 1750°, and 1840°C of this subsystem were plotted, and the solid-solution ranges of CaAl4O7, CaAl12O19, MgAl2O4, Ca2Mg2Al28O46, and CaMg2Al16O27 were determined at various temperatures. The experimental data obtained in this investigation, those reported in Part I of this work, and those found in the literature were used to establish the projection of the liquidus surface of the ternary system Al2O3,MgO,CaO. [source] ChemInform Abstract: Subsolidus Phase Relationships in the System ZnO,V2O5,WO3 Research on Suitable Flux for ZnO Crystal Growth.CHEMINFORM, Issue 31 2009Xianzhi Chen Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Phase Relationships in the Dy,Co,Sn System at 773 K.CHEMINFORM, Issue 38 2008Y. H. Zhuang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Phase Relationships of the La,Ni,Mg System at 500 °C from 66.7 to 100 at.% Ni.CHEMINFORM, Issue 34 2007S. De Negri Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Subsolidus Phase Relationships of the BaO,Ln2O3,CuOz (Ln: Gd and Er) Systems under Carbonate-Free Conditions at p(O2) = 100 Pa and T = 810 °C.CHEMINFORM, Issue 5 2005W. Wong-Ng No abstract is available for this article. [source] Crystal Structure and Phase Relationships in the Pseudobinary System Pr5Si4,Pr5Ge4.CHEMINFORM, Issue 12 2003H. F. Yang Abstract For Abstract see ChemInform Abstract in Full Text. [source] The Binary System In,Ir: A New Investigation of Phase Relationships, Crystal Structures, and Enthalpies of Mixing.CHEMINFORM, Issue 2 2003Hans Flandorfer No abstract is available for this article. [source] Abnormalities in the coordination of respiration and swallow in preterm infants with bronchopulmonary dysplasiaDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 7 2006Ira H Gewolb MD Individual rhythms of suck, swallow, and respiration are disrupted in preterm infants with bronchopulmonary dysplasia (BPD). Integration of respiration into suck-swallow efforts is critical for establishing coordinated suckle feeding. This study quantitatively assessed the coordination of respiration and swallow in infants with and without BPD. Thirty-four preterm infants of 26 to 33 weeks'gestational age were included: 14 participants with BPD (eight males, six females) and 20 comparison participants without BDP (10 males, 10 females). Participants were studied at postmenstrual age 32 to 40 weeks and postnatal age 2 to 12 weeks using digital recordings of pharyngeal pressure, nasal thermistor flow, and thoraco-abdominal plethysmography. The coefficients of variation (COV; standard deviation/mean) of the swallow-breath (SW-BR) and breath-breath (BR-BR) intervals during swallow runs, the percentage of,apneic swallows'(runs of ,3 swallows without interposed breaths), and phase relationships of respiration and swallow were used to quantify rhythmic coordination and integration of respiration into feeding episodes. Apneic swallows were significantly increased after 35 weeks in infants with BPD (mean 13.4% [SE 2.4]) compared with non-BDP infants (6.7% [SE 1.8];p < 0.05), as were SW-BR phase relationships involving apnea. The BPD cohort also had significantly higher SW-BR COV and BR-BR COV than non-BPD infants, indicating less rhythmic coordination of swallowing and respiration during feeding. Results emphasize the need for frequent rests and closer monitoring when feeding infants with respiratory compromise. Quantitative assessment of the underlying rhythms involved in feeding may be predictive of longer-term feeding and neurological problems. [source] Neural correlates of binaural masking level difference in the inferior colliculus of the barn owl (Tyto alba)EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2010Ali Asadollahi Abstract Humans and animals are able to detect signals in noisy environments. Detection improves when the noise and the signal have different interaural phase relationships. The resulting improvement in detection threshold is called the binaural masking level difference. We investigated neural mechanisms underlying the release from masking in the inferior colliculus of barn owls in low-frequency and high-frequency neurons. A tone (signal) was presented either with the same interaural time difference as the noise (masker) or at a 180° phase shift as compared with the interaural time difference of the noise. The changes in firing rates induced by the addition of a signal of increasing level while masker level was kept constant was well predicted by the relative responses to the masker and signal alone. In many cases, the response at the highest signal levels was dominated by the response to the signal alone, in spite of a significant response to the masker at low signal levels, suggesting the presence of occlusion. Detection thresholds and binaural masking level differences were widely distributed. The amount of release from masking increased with increasing masker level. Narrowly tuned neurons in the central nucleus of the inferior colliculus had detection thresholds that were lower than or similar to those of broadly tuned neurons in the external nucleus of the inferior colliculus. Broadly tuned neurons exhibited higher masking level differences than narrowband neurons. These data suggest that detection has different spectral requirements from localization. [source] Nigrostriatal lesion induces D2-modulated phase-locked activity in the basal ganglia of ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2007Camila L. Zold Abstract There is a debate as to what modifications of neuronal activity underlie the clinical manifestations of Parkinson's disease and the efficacy of antiparkinsonian pharmacotherapy. Previous studies suggest that release of GABAergic striatopallidal neurons from D2 receptor-mediated inhibition allows spreading of cortical rhythms to the globus pallidus (GP) in rats with 6-hydroxydopamine-induced nigrostriatal lesions. Here this abnormal spreading was thoroughly investigated. In control urethane-anaesthetized rats most GP neurons were excited during the active part of cortical slow waves (,direct-phase' neurons). Two neuronal populations having opposite phase relationships with cortical and striatal activity coexisted in the GP of 6-hydroxydopamine-lesioned rats. ,Inverse-phase' GP units exhibited reduced firing coupled to striatal activation during slow waves, suggesting that this GP oscillation was driven by striatopallidal hyperactivity. Half of the pallidonigral neurons identified by antidromic stimulation exhibited inverse-phase activity. Therefore, spreading of inverse-phase oscillations through pallidonigral axons might contribute to the abnormal direct-phase cortical entrainment of basal ganglia output described previously. Systemic administration of the D2 agonist quinpirole to 6-hydroxydopamine-lesioned rats reduced GP inverse-phase coupling with slow waves, and this effect was reversed by the D2 antagonist eticlopride. Because striatopallidal hyperactivity was only slightly reduced by quinpirole, other mechanisms might have contributed to the effect of quinpirole on GP oscillations. These results suggest that antiparkinsonian efficacy may rely on other actions of D2 agonists on basal ganglia activity. However, abnormal slow rhythms may promote enduring changes in functional connectivity along the striatopallidal axis, contributing to D2 agonist-resistant clinical signs of parkinsonism. [source] Amphibolite and blueschist,greenschist facies metamorphism, Blue Mountain inlier, eastern JamaicaGEOLOGICAL JOURNAL, Issue 5 2008Richard N. Abbott Jr Abstract Cretaceous (possibly older) metamorphic rock occurs mainly in the Blue Mountain inlier in eastern Jamaica. Fault-bounded blocks reveal two styles of metamorphism, Westphalia Schist (upper amphibolite facies) and Mt. Hibernia Schist (blueschist (BS),greenschist (GS) facies). Both Westphalia Schist and Mt. Hibernia Schist preserve detailed records of retrograde P,T paths. The paths are independent, but consistent with different parts of the type-Sanbagawa metamorphic facies series in Japan. For each path, phase relationships and estimated P,T conditions support a two-stage P,T history involving residence at depth, followed by rapid uplift and cooling. Conditions of residence vary depending on the level in a tectonic block. For the critical mineral reaction (isograd) in Westphalia Schist, conditions were P ,7.5,kbars, T ,600°C (upper amphibolite facies). Retrograde conditions in Hibernia Schist were P,=,2.6,3.0,kbars, T,=,219,237°C for a(H2O),=,0.8,1.0 (GS facies). Mt. Hibernia Schist may represent a volume of rock that was separated and uplifted at an early time from an otherwise protracted P,T path of the sort that produced the Westphalia Schist. Reset K,Ar ages for hornblende and biotite indicate only that retrograde metamorphism of Westphalia Schist took place prior to 76.5,Ma (pre-Campanian). Uplift may have commenced with an Albian,Aptian (,112,Ma) orogenic event. Copyright © 2008 John Wiley & Sons, Ltd. [source] Characterizing instantaneous phase relationships in whole-brain fMRI activation dataHUMAN BRAIN MAPPING, Issue 2 2002Angela R. Laird Abstract Typically, fMRI data is processed in the time domain with linear methods such as regression and correlation analysis. We propose that the theory of phase synchronization may be used to more completely understand the dynamics of interacting systems, and can be applied to fMRI data as a novel method of detecting activation. Generalized synchronization is a phenomenon that occurs when there is a nonlinear functional relationship present between two or more coupled, oscillatory systems, whereas phase synchronization is defined as the locking of the phases while the amplitudes may vary. In this study, we developed an application of phase synchronization analysis that is appropriate for fMRI data, in which the phase locking condition is investigated between a voxel time series and the reference function of the task performed. A synchronization index is calculated to quantify the level of phase locking, and a nonparametric permutation test is used to determine the statistical significance of the results. We performed the phase synchronization analysis on the data from five volunteers for an event-related finger-tapping task. Functional maps were created that provide information on the interrelations between the instantaneous phases of the reference function and the voxel time series in a whole-brain fMRI activation data set. We conclude that this method of analysis is useful for revealing additional information on the complex nature of the fMRI time series. Hum. Brain Mapping 16:71,80, 2002. © 2002 Wiley-Liss, Inc. [source] Amphibolites with staurolite and other aluminous minerals: calculated mineral equilibria in NCFMASHJOURNAL OF METAMORPHIC GEOLOGY, Issue 1 2000Arnold Amphibolite facies mafic rocks that consist mainly of hornblende, plagioclase and quartz may also contain combinations of chlorite, garnet, epidote, and, more unusually, staurolite, kyanite, sillimanite, cordierite and orthoamphiboles. Such assemblages can provide tighter constraints on the pressure and temperature evolution of metamorphic terranes than is usually possible from metabasites. Because of the high variance of most of the assemblages, the phase relationships in amphibolites depend on rock composition, in addition to pressure, temperature and fluid composition. The mineral equilibria in the Na2O,CaO,FeO,MgO,Al2O3,SiO2,H2O (NCFMASH) model system demonstrate that aluminium content is critical in controlling the occurrence of assemblages involving hornblende with aluminous minerals such as sillimanite, kyanite, staurolite and cordierite. Except in aluminous compositions, these assemblages are restricted to higher pressures. The iron to magnesium ratio (XFe), and to a lesser extent, sodium to calcium ratio, have important roles in determining which (if any) of the aluminous minerals occur under particular pressure,temperature conditions. Where aluminous minerals occur in amphibolites, the P,T,X dependence of their phase relationships is remarkably similar to that in metapelitic rocks. The mineral assemblages of Fe-rich amphibolites are typically dominated by garnet- and staurolite-bearing assemblages, whereas their more Mg-rich counterparts contain chlorite and cordierite. Assemblages involving staurolite,hornblende can occur over a wide range of pressures (4,10 kbar) at temperatures of 560,650 °C; however, except in the more aluminous, iron-rich compositions, they occupy a narrow pressure,temperature window. Thus, although their occurrence in ,typical' amphibolites may be indicative of relatively high pressure metamorphism, in more aluminous compositions their interpretation is less straightforward. [source] Subsolidus Phase Relationships in the ZnO,In2O3,SnO2 SystemJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2008Steven P. Harvey The subsolidus phase relationships in the ZnO,InO1.5,SnO2 system were investigated at 1275°C using X-ray diffraction. Each of the end members of the ternary diagram is a transparent conducting oxide. There are two substantial solid solutions in the ternary phase space, the bixbyite solid solution In2,2xZnxSnxO3 (x=0,0.40), and the indium substituted zinc stannate spinel, Zn(2,x)Sn(1,x)In2xO4 (x=0,0.45). The bixbyite solid solution is an outstanding TCO, whereas the spinel is only moderately conducting. Along the ZnO,InO1.5 binary, there is a series of transparent conducting homologous compounds (ZnO)k·In2O3 (where k=3, 4, 5, 6, 7, 9, 11). Within ternary phase space, these homologous compounds were found to exhibit negligible Sn solubility, and were always found to be compatible with the spinel. Equilibrium was difficult to achieve in the phase space between the homologous series compounds and the spinel, owing to sluggish kinetics. A procedure involving mixtures of prereacted spinel and the Zn11In2O14 (k=11) compound was developed, which allowed for more rapid approach to thermodynamic equilibrium, thereby allowing for the establishment of phase relationships near the ZnO corner of the phase diagram. [source] A petrogenetic model for the origin and compositional variation of the martian basaltic meteoritesMETEORITICS & PLANETARY SCIENCE, Issue 12 2003Lars E. BORG The models are based on low to high pressure phase relationships estimated from experimental runs and estimates of the composition of silicate Mars from the literature. These models attempt to constrain the mechanisms by which the martian meteorites obtained their superchondritic CaO/Al2O3 ratios and their source regions obtained their parent/daughter (87Rb/86Sr, 147Sm/144Nd, and 176Lu/177Hf) ratios calculated from the initial Sr, Nd, and Hf isotopic compositions of the meteorites. High pressure experiments suggest that majoritic garnet is the liquidus phase for Mars relevant compositions at or above 12 GPa. Early crystallization of this phase from a martian magma ocean yields a liquid characterized by an elevated CaO/Al2O3 ratio and a high Mg#. Olivine-pyroxene-garnet-dominated cumulates that crystallize subsequently will also be characterized by superchondritic CaO/Al2O3 ratios. Melting of these cumulates yields liquids with major element compositions that are similar to calculated parental melts of the martian meteorites. Furthermore, crystallization models demonstrate that some of these cumulates have parent/daughter ratios that are similar to those calculated for the most incompatible-element-depleted source region (i.e., that of the meteorite Queen Alexandra [QUE] 94201). The incompatible-element abundances of the most depleted (QUE 94201-like) source region have also been calculated and provide an estimate of the composition of depleted martian mantle. The incompatible-element pattern of depleted martian mantle calculated here is very similar to the pattern estimated for depleted Earth's mantle. Melting the depleted martian mantle composition reproduces the abundances of many incompatible elements in the parental melt of QUE 94201 (e.g., Ba, Th, K, P, Hf, Zr, and heavy rare earth elements) fairly well but does not reproduce the abundances of Rb, U, Ta and light rare earth elements. The source regions for meteorites such as Shergotty are successfully modeled as mixtures of depleted martian mantle and a late stage liquid trapped in the magma ocean cumulate pile. Melting of this hybrid source yields liquids with major element abundances and incompatible-element patterns that are very similar to the Shergotty bulk rock. [source] | |||||||||||||