A re-examination of pseudoleucite from Spotted Fawn Creek, west-central Yukon

1969 ◽  
Vol 6 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Dirk J. Tempelman-Kluit
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Water Pressure ◽  
Fluid Phase ◽  
Yukon Territory ◽  
Chemical Data ◽  
Partial Removal ◽  
West Central

New petrographic and chemical data for pseudoleucite from Spotted Fawn Creek and two new nearby localities in central Yukon Territory are presented and discussed in the light of recent experimental evidence on the origin of pseudoleucite. The petrologic, chemical, and experimental data suggest that natural pseudoleucite results from subsolidus breakdown of leucite under water pressure and that the space provided by this breakdown results in influx of the fluid phase that accomplishes partial removal of potash, enrichment in soda, and addition of water.

Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Analytical Model ◽  
Excellent Agreement ◽  
Experimental Results ◽  
Simple Analytical Model ◽  
Refined Model ◽  
Wall Area

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

Solid-Fluid Phase Equilibria Measurement for Mixtures of Methane, Carbon-Dioxide and N-Hexadecane

2021 ◽  
Author(s):  
Oluwakemi Victoria Eniolorunda ◽  
Antonin Chapoy ◽  
Rod Burgass
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Equation Of State ◽  
Phase Equilibria ◽  
Activity Coefficients ◽  
Fluid Phase ◽  
Ternary Mixtures ◽  
Binary Interaction ◽  
Thermodynamic Models ◽  
Methane Carbon

Abstract In this study, new experimental data using a reliable approach are reported for solid-fluid phase equilibrium of ternary mixtures of Methane-Carbon-dioxide- n-Hexadecane for 30-73 mol% CO2 and pressures up to 24 MPa. The effect of varying CO2 composition on the overall phase transition of the systems were investigated. Three thermodynamic models were used to predict the liquid phase fugacity, this includes the Peng Robison equation of state (PR-EoS), Soave Redlich-Kwong equation of state (SRK-EoS) and the Cubic plus Association (CPA) equation of state with the classical mixing rule and a group contribution approach for calculating binary interaction parameters in all cases. To describe the wax (solid) phase, three activity coefficient models based on the solid solution theory were investigated: the predictive universal quasichemical activity coefficients (UNIQUAC), Universal quasi-chemical Functional Group activity coefficients (UNIFAC) and the predictive Wilson approach. The solid-fluid equilibria experimental data gathered in this experimental work including those from saturated and under-saturated conditions were used to check the reliability of the various phase equilibria thermodynamic models.

Lherzolite - carbonatite melt interaction in the presence of additive CO2 and H2O: Experimental data at 5.5 GPa and 1200-1450°C

2021 ◽  
Author(s):  
Aleksei Kruk ◽  
Alexander Sokol
Keyword(s):  
Experimental Data ◽  
Lithospheric Mantle ◽  
Fluid Phase ◽  
Experimental Results ◽  
Silicate Melt ◽  
Silicate Melts ◽  
Garnet Lherzolite ◽  
Russian Science ◽  
Continental Lithospheric Mantle

<p>We study the reaction of garnet lherzolite with carbonatitic melt rich in molecular CO<sub>2</sub> and/or H<sub>2</sub>O in experiments at 5.5 GPa and 1200-1450°C. The experimental results show that carbonation of olivine with formation of orthopyroxene and magnesite can buffer the CO<sub>2</sub> contents in the melt, which impedes immediate separation of CO<sub>2</sub> fluid from melt equilibrated with the peridotite source. The solubility of molecular CO<sub>2</sub> in melt decreases from 20-25 wt.% at 4.5-6.8 wt.% SiO<sub>2</sub> typical of carbonatite to 7-12 wt.% in more silicic kimberlite-like melts with 26-32 wt.% SiO<sub>2</sub>. Interaction of garnet lherzolite with carbonatitic melt (2:1) in the presence of 2-3 wt.% H<sub>2</sub>O and 9-13 wt.% molecular CO<sub>2</sub> at 1200-1450°С yields low SiO<sub>2</sub> (<10 wt.%) alkali‐carbonatite melts, which shows multiphase saturation with magnesite-bearing garnet harzburgite. Thus, carbonatitic melts rich in volatiles can originate in a harzburgite source at moderate temperatures common to continental lithospheric mantle (CLM).</p><p>Having separated from the source, carbonatitic magma enriched in molecular CO<sub>2</sub> and H<sub>2</sub>O can rapidly acquire a kimberlitic composition with >25 wt.% SiO<sub>2 </sub>by dissolution and carbonation of entrapped peridotite. Furthermore, interaction of garnet lherzolite with carbonatitic melt rich in K, CO<sub>2</sub>, and H<sub>2</sub>O at 1350°С produces immiscible kimberlite-like carbonate-silicate and K-rich silicate melts. Quenched silicate melt develops lamelli of foam-like vesicular glass. Differentiation of immiscible melts early during ascent may equalize the compositions of kimberlite magmas generated in different CLM sources. The fluid phase can release explosively from ascending magma at lower pressures as a result of SiO<sub>2</sub> increase which reduces the solubility of CO<sub>2</sub> due to decarbonation reaction of magnesite and orthopyroxene.</p><p>The research was performed by a grant of the Russian Science Foundation (19-77-10023).</p>

scholarly journals Oscillatory subglacial drainage in the absence of surface melt

2014 ◽  
Vol 8 (3) ◽  
pp. 959-976 ◽  
Author(s):  
C. Schoof ◽  
C. A Rada ◽  
N. J. Wilson ◽  
G. E. Flowers ◽  
M. Haseloff
Keyword(s):  
Water Pressure ◽  
Drainage System ◽  
Yukon Territory ◽  
Strongly Correlated ◽  
Pressure Oscillations ◽  
Power Failure ◽  
Multiple Data ◽  
Data Loggers ◽  
Diurnal Cycling ◽  
Subglacial Drainage

Abstract. The presence of strong diurnal cycling in basal water pressure records obtained during the melt season is well established for many glaciers. The behaviour of the drainage system outside the melt season is less well understood. Here we present borehole observations from a surge-type valley glacier in the St Elias Mountains, Yukon Territory, Canada. Our data indicate the onset of strongly correlated multi-day oscillations in water pressure in multiple boreholes straddling a main drainage axis, starting several weeks after the disappearance of a dominant diurnal mode in August 2011 and persisting until at least January 2012, when multiple data loggers suffered power failure. Jökulhlaups provide a template for understanding spontaneous water pressure oscillations not driven by external supply variability. Using a subglacial drainage model, we show that water pressure oscillations can also be driven on a much smaller scale by the interaction between conduit growth and distributed water storage in smaller water pockets, basal crevasses and moulins, and that oscillations can be triggered when water supply drops below a critical value. We suggest this in combination with a steady background supply of water from ground water or englacial drainage as a possible explanation for the observed wintertime pressure oscillations.

scholarly journals Simultaneous Determination of Water Retention Curve and Unsaturated Hydraulic Conductivity of Substrates Using a Steady-state Laboratory Method

HortScience ◽  
2010 ◽  
Vol 45 (7) ◽  
pp. 1106-1112 ◽  
Author(s):  
Paraskevi A. Londra
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Hydraulic Conductivity ◽  
Water Retention ◽  
Water Pressure ◽  
Pressure Head ◽  
Laboratory Method ◽  
Water Retention Curve ◽  
Retention Curve ◽  
Unsaturated Hydraulic Conductivity

For effective irrigation and fertilization management, the knowledge of substrate hydraulic properties is essential. In this study, a steady-state laboratory method was used to determine simultaneously the water retention curve, θ(h), and unsaturated hydraulic conductivity as a function of volumetric water content, K(θ), and water pressure head, K(h), of five substrates used widely in horticulture. The substrates examined were pure peat, 75/25 peat/perlite, 50/50 peat/perlite, 50/50 coir/perlite, and pure perlite. The experimental retention curve results showed that in the case of peat and its mixtures with perlite, there is a hysteresis between drying and wetting branches of the retention curve. Whereas in the case of coir/perlite and perlite, the phenomenon of hysteresis was less pronounced. The increase of perlite proportion in the peat/perlite mixtures led to a decrease of total porosity and water-holding capacity and an increase of air space. Study of the K(θ) and K(h) experimental data showed that the hysteresis phenomenon of K(θ) was negligible compared with the K(h) data for all substrates examined. Within a narrow range of water pressure head (0 to –70 cm H2O) that occurs between two successive irrigations, a sharp decrease of the unsaturated hydraulic conductivity was observed. The comparison of the K(θ) experimental data between the peat-based substrate mixtures and the coir-based substrate mixture showed that for water contents lower than 0.40 m3·m−3, the hydraulic conductivity of the 50/50 coir/perlite mixture was greater. The comparison between experimental water retention curves and predictions using Brooks-Corey and van Genuchten models showed a high correlation (0.992 ≤ R2 ≤ 1) for both models for all substrates examined. On the other hand, in the case of unsaturated hydraulic conductivity, the comparison showed a relatively good correlation (0.951 ≤ R2 ≤ 0.981) for the van Genuchten-Mualem model for all substrates used except perlite and a significant deviation (0.436 ≤ R2 ≤ 0.872) for the Brooks-Corey model for all substrates used.

scholarly journals Estimation of subglacial hydraulic properties from induced changes in basal water pressure: a theoretical framework for borehole-response tests

1993 ◽  
Vol 39 (132) ◽  
pp. 327-340 ◽  
Author(s):  
Dan B. Stone ◽  
Garry K.C. Clarke
Keyword(s):  
Skin Friction ◽  
Hydraulic Properties ◽  
Field Experiments ◽  
Water Pressure ◽  
Turbulent Transport ◽  
Basal Layer ◽  
Coupled System ◽  
Yukon Territory ◽  
Water Levels ◽  
Borehole Water

AbstractIn this paper we develop a theoretical model describing water motion in a coupled borehole-subglacial flow system. The theory applies to basal drainage systems having multiple and extensive interconnected flow paths. Within this domain it encompasses a broad range of flow regimes, from laminar Darcian flow in a thick permeable unit to turbulent sheet flow in a very thin layer. Important terms in the model are highlighted by recasting the problem in dimensionless form. The non-dimensional formulation indicates that there are four free parameters in the coupled system. These parameters characterize skin friction in the borehole, and diffusion, transmissivity and turbulent transport in the subglacial flow layer. Dimensionless results show that, under most circumstances, the effects of skin friction in the borehole are negligible. Diffusion, transmissivity and especially turbulent transport in the basal layer are found to influence subglacial water flow strongly. We use our model to predict fluctuations of borehole-water levels that result from different types of disturbances. We show how this framework can be used to estimate subglacial hydraulic properties by comparing model results with data collected during field experiments on Trapridge Glacier, Yukon Territory, Canada in 1989 and 1990.

Hydrogen Distributions and Model Lineshapes of ESR Signals of Dangling Bonds in a-Si:H

2001 ◽  
Vol 664 ◽  
Author(s):  
P. A. Fedders
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Esr Spectra ◽  
Dangling Bonds ◽  
Model Calculations ◽  
Induced Defects

ABSTRACTFor many years it has been assumed widely that hydrogen is involved in some way in the formation of light induced defects. However recently some doubt has been cast on this because of experimental evidence that there is little H near light induced dangling bonds. In this paper we present a number of model calculations comparing ESR spectra of dangling bonds with and without correlations with H positions. The above models include different distributions of H and correlations or anti correlations of nearby H. In all cases the spectra are compared to those with no correlations or clustering. Our results coupled with published experimental data strongly suggest that dangling bonds are not correlated positively with the presence of nearby H and, in fact, it appears that light induced dangling bonds are negatively correlated with nearby H.

Measuring glacier-motion fluctuations using a computer-controlled survey system

1986 ◽  
Vol 23 (5) ◽  
pp. 727-733 ◽  
Author(s):  
Garry K. C. Clarke ◽  
Robert D. Meldrum ◽  
Sam G. Collins
Keyword(s):  
Field Experiments ◽  
Water Pressure ◽  
Yukon Territory ◽  
Measuring System ◽  
Time Intervals ◽  
Stationary Target ◽  
Survey System ◽  
Computer Controlled ◽  
Glacier Flow ◽  
Glacier Motion

We describe a computer-controlled, distance-measuring system designed for glacier-motion surveys. A Sharp PC-1500 pocket computer is used to control an AGA Geodimeter 122 infrared laser ranger. Slope distance and vertical angle are automatically measured and plotted at preselected time intervals and recorded on magnetic tape. As a demonstration, three field experiments were performed on Trapridge Glacier, Yukon Territory. In the first experiment the position of a glacier flow marker was measured at 1 min intervals for 39 h. The average velocity (toward the instrument) was found to be 2.99 mm h−1. Subglacial water pressure was simultaneously measured at the flow marker site. For the duration of the survey, water pressure was low, and there is no clear relationship between pressure variations and glacier motion. In the second experiment the distance to a stationary target was measured at 1 min intervals for 9 h. The calculated motion of this target was −0.149 mm h−1, giving an indication of the magnitude of uncorrected distance errors. The third experiment lasted 35 h and again involved measurements of glacier flow. The calculated target motion was 1.80 mm h−1 toward the instrument.

A Light-Induced Annealing of Silicon Implanted Layers

2008 ◽  
Vol 573-574 ◽  
pp. 229-235
Author(s):  
Bo Lojek
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Band Gap ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Semiconductor Material ◽  
Damaged Material ◽  
Optical Irradiation ◽  
Energy States ◽  
The Impact

Since introducing Rapid Thermal Annealing, there has been disagreement among experimental data of ion-implanted and annealed layers. One explanation of these differences is the impact of optical irradiation and its interaction with semiconductor material. Although no plausible explanation has been offered, experimental evidence of “photonic effects” was reported in many works. In this work we estimate energy per atom available during recombination of the excited carriers. It is argued that the localization of energy states inside the band gap in ion-implant damaged material is responsible for “photonic effects.”

scholarly journals Linking learner corpus and experimental data in studying second language learners’ knowledge of verb-argument constructions

ICAME Journal ◽  
2014 ◽  
Vol 38 (1) ◽  
pp. 115-135 ◽  
Author(s):  
Ute Römer ◽  
Audrey Roberson ◽  
Matthew B. O’Donnell ◽  
Nick C. Ellis
Keyword(s):  
Experimental Data ◽  
Second Language ◽  
Experimental Evidence ◽  
Language Learners ◽  
Second Language Learners ◽  
First Language ◽  
Data Sets ◽  
Advanced Learners ◽  
Learner Corpus ◽  
Learner Corpora

Abstract This paper combines data from learner corpora and psycholinguistic experiments in an attempt to find out what advanced learners of English (first language backgrounds German and Spanish) know about a range of common verbargument constructions (VACs), such as the ‘V about n’ construction (e.g. she thinks about chocolate a lot). Learners’ dominant verb-VAC associations are examined based on evidence retrieved from the German and Spanish subcomponents of ICLE and LINDSEI and collected in lexical production tasks in which participants complete VAC frames (e.g. ‘he ___ about the...’) with verbs that may fill the blank (e.g. talked, thought, wondered). The paper compares findings from the different data sets and highlights the value of linking corpus and experimental evidence in studying linguistic phenomena

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