scholarly journals New Developments in the Field of Reaction Technology: The Multiparallel Reactor HPMR 50-96

2005 ◽  
Vol 2005 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Arne Allwardt ◽  
Norbert Stoll ◽  
Christian Wendler ◽  
Kerstin Thurow
Keyword(s):  
High Pressure ◽  
Drug Development ◽  
Systems Integration ◽  
Laboratory Automation ◽  
Parallel Reaction ◽  
New Developments ◽  
Reaction Systems ◽  
Reaction Chambers ◽  
Bulk Chemistry

Catalytic high-pressure reactions play an important role in classic bulk chemistry. The optimization of common reactions, the search for new and more effective catalysts, and the increasing use of catalytic pressure reactions in the field of drug development call for high-parallel reaction systems. A crucial task of current developments, apart from the parameters of pressure, temperature, and number of reaction chambers, is, in this respect, the systems' integration into complex laboratory automation environments.

Some high-pressure pyroxenes

1974 ◽  
Vol 39 (307) ◽  
pp. 768-787 ◽  
Author(s):  
R. N. Thompson
Keyword(s):  
High Pressure ◽  
Alkali Basalt ◽  
High Pressures ◽  
Major Element ◽  
Distribution Coefficients ◽  
The Other ◽  
Strong Negative Correlation ◽  
Complex Behaviour ◽  
Complex Variation ◽  
Bulk Chemistry

SummaryMicroprobe analyses of Ca-rich pyroxenes crystallized in the melting ranges of a magnesian alkali basalt, a transitional basalt, an olivine tholeiite, a tholeiitic andesite, and an augite leucitite at pressures between 8 and 45 kb show complex variation. Ca-poor pyroxene precipitated only from the alkali basalt at pressures between 14 and 18 kb. Pyroxene falling near the Di-Hed join in the pyroxene quadilateral formed at all pressures and temperatures from the leucitite, whereas ‘Ca-rich’ pyroxene crystallizing from the other four compositions was Ca-poor augite to sub-calcic augite. The liquidus Ca-rich pyroxenes all show rising Al and Na and falling Ti with increasing pressure and temperature. Other elements show complex behaviour; all but the leucitite pyroxenes tend to make temporary excursions of solid solution towards Ca-poor pyroxene at intermediate pressures, returning to more Ca-rich compositions at high pressures. At sub-liquidus temperatures Na and Ti consistently rise with falling T at constant P and also with rising P at constant T in these pyroxenes. The behaviour of the other elements in these circumstances depends on the nature of the coexisting phases.Fe/Mg distribution between Ca-rich pyroxene and liquid, in the form has a constant value of 0.29 for three separate bulk compositions at widely differing temperatures and pressures. Distribution coefficients for Mg and Fe between pyroxenes and coexisting garnets at high pressures are very similar to those found in garnet pyroxenite xenoliths from Oahu, Hawaii. Systematic shifts in the apparent stoichiometry (all Fe taken as Fe2+) of the augite leucitite pyroxenes are thought to indicate that they have considerable Fe3+ contents at low pressure, decreasing as P rises. If so, they show a strong negative correlation between Na and Fe3+, which negates the customary practice of forming acmite before jadeite component when recalculating the analyses of high-pressure pyroxenes.The sets of pyroxenes crystallized from each composition show consistent trends when plotted on such diagrams as jadeite vs Ca-Tschermak's ‘molecule’, which have often been used in attempts to discriminate natural pyroxenes formed in differing P-T environments. However, these new data show clearly that the bulk chemistry of the magma has a predominating influence on the composition of the pyroxenes crystallizing from it. Unless it is certain that a suite of natural pyroxenes have all precipitated from the same magma, it is probably pointless to attempt to deduce the relative P-T conditions of their formation from their major element chemistry.

Nanoscale Reactor Engineering: Hydrothermal Synthesis of Uniform Zeolite Particles in Massively Parallel Reaction Chambers

2008 ◽  
Vol 120 (47) ◽  
pp. 9236-9239 ◽  
Author(s):  
Won Cheol Yoo ◽  
Sandeep Kumar ◽  
Zhiyong Wang ◽  
Nicholas S. Ergang ◽  
Wei Fan ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Massively Parallel ◽  
Parallel Reaction ◽  
Reaction Chambers

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.

An Opposed Piston Rapid Compression Machine for Preflame Reaction Studies

1968 ◽  
Vol 183 (1) ◽  
pp. 365-387 ◽  
Author(s):  
W. S. Affleck ◽  
A. Thomas
Keyword(s):  
High Pressure ◽  
Rapid Quenching ◽  
Chemical Processes ◽  
Spontaneous Ignition ◽  
Rapid Compression Machine ◽  
Compression Process ◽  
New Developments ◽  
Temperature And Pressure ◽  
Rapid Compression ◽  
Novel Design

Mixtures of fuel and air ignite spontaneously if exposed to sufficiently high temperatures. Such ignition is not an instantaneous event, and there is always a delay of chemical origin between the establishment of the particular conditions of temperature and pressure and the rapid, exothermic chemical reactions that constitute ignition. This delay is of outstanding importance in any fuel application in which spontaneous ignition plays a part. It is determined by the progress of the near-isothermal chemical processes that precede ignition, and these processes therefore merit continued study. This paper describes the development of an experimental technique which allows these studies to be extended to much higher pressures than those accessible in glass vessels, while retaining many of the advantages of laboratory vessel experiments. This technique is centred on a rapid compression machine of novel design which is used to heat and compress fuel/air mixtures to conditions near those in a knocking engine. After this compression process, which occupies a few milliseconds only, the hot, high pressure charge is held at constant volume while thermochemical, spectroscopic or analytical observations are made. The principal new developments in the machine are the use of twin opposed pistons for compression with an associated hydraulic synchronizing system and a precisely triggered valve that enables rapid quenching and sampling of the reacting mixture to be made at an appropriate stage of reaction.

Laboratory automation of high-quality and efficient ligand-binding assays for biotherapeutic drug development

Bioanalysis ◽  
2013 ◽  
Vol 5 (13) ◽  
pp. 1635-1648 ◽  
Author(s):  
Jin Wang ◽  
Vimal Patel ◽  
Daniel Burns ◽  
John Laycock ◽  
Kinnari Pandya ◽  
...  
Keyword(s):  
Drug Development ◽  
Ligand Binding ◽  
Laboratory Automation ◽  
Binding Assays ◽  
High Quality
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