An Al-spinel ultramafic-mafic inclusion suite and high pressure megacrysts in an analcimite and their bearing on basaltic magma fractionation at elevated pressures

1975 ◽  
Vol 53 (2) ◽  
pp. 71-104 ◽  
Author(s):  
J. F. G. Wilkinson
Keyword(s):  
High Pressure ◽  
Basaltic Magma ◽  
Elevated Pressures ◽  
Magma Fractionation ◽  
Mafic Inclusion

Desirability of Oysters Treated by High Pressure Processing at Different Temperatures and Elevated Pressures

2014 ◽  
Vol 9 (4) ◽  
pp. 209-216 ◽  
Author(s):  
David H. Kingsley ◽  
David D. Kuhn ◽  
George J. Flick ◽  
Jungmi Oh ◽  
Laura S. Lawson ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Processing ◽  
Elevated Pressures ◽  
Different Temperatures

scholarly journals Structural studies of metal–organic frameworks under high pressure

2015 ◽  
Vol 71 (6) ◽  
pp. 587-607 ◽  
Author(s):  
Scott C. McKellar ◽  
Stephen A. Moggach
Keyword(s):  
High Pressure ◽  
Coordination Polymers ◽  
Metal Organic Frameworks ◽  
Structural Studies ◽  
Structural Effects ◽  
Elevated Pressures ◽  
High Pressure Studies ◽  
Metal Organic ◽  
The Subject ◽  
Chemical Response

Over the last 10 years or so, the interest and number of high-pressure studies has increased substantially. One area of growth within this niche field is in the study of metal–organic frameworks (MOFs or coordination polymers). Here we present a review on the subject, where we look at the structural effects of both non-porous and porous MOFs, and discuss their mechanical and chemical response to elevated pressures.

Laminar Flame Speed Measurements and Modeling of Pure Alkanes and Alkane Blends at Elevated Pressures

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
William Lowry ◽  
Jaap de Vries ◽  
Michael Krejci ◽  
Eric Petersen ◽  
Zeynep Serinyel ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Gas Turbines ◽  
Laminar Flame ◽  
Flame Speed ◽  
Published Data ◽  
Laminar Flame Speed ◽  
Binary Blends ◽  
Elevated Pressures ◽  
True Value

Alkanes such as methane, ethane, and propane make up a large portion of most natural gas fuels. Natural gas is the primary fuel used in industrial gas turbines for power generation. Because of this, a fundamental understanding of the physical characteristics such as the laminar flame speed is necessary. Most importantly, this information is needed at elevated pressures to have the most relevance to the gas turbine industry for engine design. This study includes experiments performed at elevated pressures, up to 10 atm initial pressure, and investigates the fuels in a pure form as well as in binary blends. Flame speed modeling was done using an improved version of the kinetics model that the authors have been developing over the past few years. Modeling was performed for a wide range of conditions, including elevated pressures. Experimental conditions include pure methane, pure ethane, 80/20 mixtures of methane/ethane, and 60/40 mixtures of methane/ethane at initial pressures of 1 atm, 5 atm, and 10 atm. Also included in this study are pure propane and 80/20 methane/propane mixtures at 1 atm and 5 atm. The laminar flame speed and Markstein length measurements were obtained from a high-pressure flame speed facility using a constant-volume vessel. The facility includes optical access, a high-speed camera, a schlieren optical setup, a mixing manifold, and an isolated control room. The experiments were performed at room temperature, and the resulting images were analyzed using linear regression. The experimental and modeling results are presented and compared with previously published data. The data herein agree well with the published data. In addition, a hybrid correlation was created to perform a rigorous uncertainty analysis. This correlation gives the total uncertainty of the experiment with respect to the true value rather than reporting the standard deviation of a repeated experiment. Included in the data set are high-pressure results at conditions where in many cases for the single-component fuels few data existed and for the binary blends no data existed prior to this study. Overall, the agreement between the model and data is excellent.

Kinetics of pyrope megacryst reactions in ascending basaltic magma – relevance to high-pressure magmatic crystallization at Elie Ness, East Fife

1984 ◽  
Vol 121 (6) ◽  
pp. 615-620 ◽  
Author(s):  
Colin H. Donaldson
Keyword(s):  
High Pressure ◽  
Phase Equilibria ◽  
Crystallization Temperature ◽  
Basaltic Magma ◽  
Basaltic Melt ◽  
The Stability ◽  
Kinetics Of

AbstractThe rates of resorption of pyrope in basaltic melt and of pyrope decomposition to pyroxene + melt at pressures below the stability of garnet are used to examine the proposition (Chapman, 1976) that pyrope megacrysts in the Elie Ness neck began ascent from the mantle at 1300–1450°C. Both reactions are extremely rapid at these temperatures and yet the petrographic evidence is that neither occurred. Either the transporting magma cooled extremely rapidly during ascent (> 30000 °/h) or, more likely, was considerably cooler than previously proposed. Water was a significant constituent of the magma, and a crystallization temperature for the garnet of as little as 1000 °C is possible, based on existing phase–equilibria data.

scholarly journals Effect of high pressure on the topography of potential energy surfaces

2016 ◽  
Vol 94 (12) ◽  
pp. 1057-1064 ◽  
Author(s):  
Jacob Spooner ◽  
Brandon Smith ◽  
Noham Weinberg
Keyword(s):  
High Pressure ◽  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Chemical Compounds ◽  
Transfer Reactions ◽  
Reaction Systems ◽  
Elevated Pressures ◽  
Chemical Effects ◽  
Condensed Phase Reactions ◽  
Energy Surfaces

Properties and reactivity of chemical compounds change dramatically at elevated pressures. Since kinetics and mechanisms of condensed-phase reactions are described in terms of their potential energy (PESs) or Gibbs energy (GESs) surfaces, chemical effects of high pressure can be assessed through analysis of pressure-induced deformations of GESs of solvated reaction systems. We discuss general trends expected for such changes and use quantum mechanical calculations to construct PESs of compressed species for hydrogen and methyl transfer reactions.

scholarly journals Instrumentation development for crystallography at high-pressure

2014 ◽  
Vol 70 (a1) ◽  
pp. C392-C392
Author(s):  
Konstantin Kamenev ◽  
Matthew Jacobsen ◽  
Christopher Ridley ◽  
Xiao Wang ◽  
Craig Bull ◽  
...  
Keyword(s):  
High Pressure ◽  
Computer Aided Design ◽  
Cryogenic Temperatures ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
X Ray ◽  
Elevated Pressures ◽  
Developed Pressure ◽  
Aided Design ◽  
Larger Sample

Historically high-pressure (HP) research has been an area that is heavily dependent on the availability of the experimental equipment. Many of the discoveries in HP science followed promptly from breakthroughs in instrumentation development, which provided researchers with higher pressure limits or larger sample volumes. A limited availability of commercial pressure cells and the need to remain at the cutting edge of the research make it likely that anyone working in this field will at some point engage in designing new or in modifying existing HP equipment. This presentation aims to introduce an engineering approach to developing pressure cells and to present such generic tools as computer aided design (CAD) and finite element analysis (FEA). The use of engineering methods in the design of HP equipment will be illustrated using recently developed pressure cells. This includes some new devices for neutron scattering such as gas-driven sapphire anvil pressure cell for changing pressure at cryogenic temperatures in neutron diffraction experiments [1]. Another example is a gas loader for the P-E press which can be used to load gases into the sample space at elevated pressures for subsequent studies of gases and gas mixtures as well as for use of gases as pressure-transmitting media to pressures of over 18 GPa [2]. The examples of use of FEA for miniaturization of the pressure cells and their components will include miniature pressure cells for X-ray diffraction with cryo-flow refrigerators shown in the Figure below [3].

Microdiffraction With Synchrotron Beams (Or Ultra-High Pressure Research)

1987 ◽  
Vol 31 ◽  
pp. 1-7 ◽  
Author(s):  
E. F. Skelton
Keyword(s):  
High Pressure ◽  
Theoretical Models ◽  
Normal Phase ◽  
Light Sources ◽  
Extreme Pressure ◽  
Interatomic Distances ◽  
Reasonable Time ◽  
Ultra High Pressure ◽  
Elevated Pressures ◽  
Time Period

Pressure is an important thermodynamical variable. It provides the most efficient means of altering interatomic distances while leaving the thermal energy of a system invariant. It therefore provides an important mechanism for testing theoretical models that are based upon atomic separations and crystallographic configurations. Like its counterpart, temperature, pressure can be used to assist chemical reactions or to bring about crystallographic phase transformations. New allotropes, formed under conditions of extreme pressure and/or temperature, may have physical properties that are significantly different from those of the material formed under normal conditions. A classic example is that of carbon: the hardness, electrical and thermal conductivities, transparency, and cost of graphite, the normal phase of carbon, are significantly different from those of diamond, the phase formed at elevated pressures and temperatures. In the quest for higher static pressures, researchers have been reducing the size of the pressure chamber, and hence the sample, to microscopic dimensions; this, in turn, necessitates the use of brighter light sources to "see" the sample in a reasonable time period.

Photon Monte Carlo Model for High-Pressure Reacting Laminar Flows

2012 ◽  
Author(s):  
Shenghui Lei ◽  
Jian Cai ◽  
Adhiraj Dasgupta ◽  
Michael F. Modest ◽  
Daniel Haworth
Keyword(s):  
High Pressure ◽  
Monte Carlo ◽  
Spectral Line ◽  
Monte Carlo Model ◽  
Laminar Flows ◽  
Present Problem ◽  
Elevated Pressures

In this paper, laminar H2-air flames at elevated pressures up to 10 bar are numerically studied. To capture the influence of radiation on high-pressure flames, a photon Monte Carlo (PMC) scheme combined with a spectral line-by-line (LBL) method previously developed by the authors is employed. In the present problem, the only radiating species is H2O. The importance of radiation in high-pressure flames is demonstrated by comparing differences of temperature and concentration fields for the cases with and without radiation.

Anin situpowder diffraction cell for high-pressure hydrogenation experiments using laboratory X-ray diffractometers

2015 ◽  
Vol 48 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Romain Moury ◽  
Klaus Hauschild ◽  
Wolfgang Kersten ◽  
Jan Ternieden ◽  
Michael Felderhoff ◽  
...  
Keyword(s):  
High Pressure ◽  
Powder Diffraction ◽  
Experimental Setup ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elevated Pressures ◽  
Temperature Suitability ◽  
Proof Of Principle ◽  
Gas Pressures

Anin situdiffraction cell is presented which has been designed and constructed for in-house powder diffraction experiments under high gas pressures up to 30 MPa. For a proof of principle, thein situcell has been tested for several hydrogenation experiments under elevated pressures and temperatures. LaNi5was chosen as an example for hydrogenation, applying simultaneously 5.5 MPa H2pressure at a temperature of 423 K. For testing the high-pressure–temperature suitability of thein situcell, pressure–temperature experiments up to 14 MPa at 373 K were performed, studying the rehydrogenation of NaH and Al to NaAlH4. The experimental setup enables recording ofin situX-ray diffraction data on laboratory instruments with short data acquisition times at elevated hydrogen pressures and temperatures.

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