scholarly journals Evaluation of supplementary comparison EURAMAT.M.P-S14 in the range 50 MPa to 1 GPa of hydraulic gauge pressure

ACTA IMEKO ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 76
Author(s):  
Jens Könemann
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Individual Measurement ◽  
Transfer Standard ◽  
Pressure Transducers ◽  
Comparison Results ◽  
Gauge Pressure ◽  
The Individual ◽  
Rich Data ◽  
Almost All

In this work, we present a mathematical procedure to evaluate a hydraulic gauge pressure comparison in the range to 1 GPa piloted by PTB and using a transfer standard consisting of two series of modern high-pressure transducers, i.e. eight pressure transducers in total. This set of parallel arranged transducers should ensure reliability of the transfer standard at high pressures and provide rich data for testing the performance of modern high-pressure transducers. The analysis of the comparison results was based on the evaluation of the individual measurement deviations of these transducers with respect to the laboratory standards, whereas the corresponding comparison reference values and their uncertainty were determined separately at each pressure point and pressure transducer. All these results were summarized to derive the degree of equivalence for each laboratory at each pressure which was found for all laboratories to be consistent at almost all pressures.

scholarly journals Determination of basal hydraulic systems based on subglacial high-pressure pump experiments

2005 ◽  
Vol 40 ◽  
pp. 37-42 ◽  
Author(s):  
Gaute Lappegard ◽  
Jack Kohler
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Water Pressure ◽  
Drainage System ◽  
Load Cell ◽  
Low Flow ◽  
Hydraulic Systems ◽  
High Pressure Pump ◽  
Pressure Transducers ◽  
Fast Flow

AbstractWe have conducted short-term pump experiments with pump pressures exceeding ice overburden to study the seasonality of the subglacial hydraulic system of Engabreen, Norway. Data were collected from load cells installed flush with the ice–bedrock interface and pressure transducers installed in boreholes leading from bedrock tunnels underneath the glacier to the ice–bedrock interface. The water-pressure recordings, seen in relation with the load-cell record, show the existence of hydraulically connected vs unconnected bed areas. Monitored boreholes have been used to inject water at high pressures. Each experiment led to the growth of a high-pressure water cavity whose spatial extent could be inferred from load-cell and pressure transducer records. Post-pump pressures were low after summer pump tests and close to ice-overburden level after winter pump experiments. We conclude that drainage takes place in a fast-flow, low-pressure, channel-based drainage system during summer, and a low-flow, high-pressure, linked-cavity drainage system during winter.

Wake, Shock, and Potential Field Interactions in a 1.5 Stage Turbine—Part I: Vane-Rotor and Rotor-Vane Interaction

2003 ◽  
Vol 125 (1) ◽  
pp. 33-39 ◽  
Author(s):  
R. J. Miller ◽  
R. W. Moss ◽  
R. W. Ainsworth ◽  
N. W. Harvey
Keyword(s):  
High Pressure ◽  
Potential Field ◽  
Pressure Field ◽  
Fast Response ◽  
Operating Conditions ◽  
Rotor Blades ◽  
Time Resolved ◽  
Pressure Transducers ◽  
Unsteady Pressure ◽  
The Individual

The composition of the time-resolved surface pressure field around a high-pressure rotor blade caused by the presence of neighboring blade rows is investigated, with the individual effects of wake, shock and potential field interaction being determined. Two test geometries are considered: first, a high-pressure turbine stage coupled with a swan-necked diffuser exit duct; secondly, the same high-pressure stage but with a vane located in the downstream duct. Both tests were conducted at engine-representative Mach and Reynolds numbers, and experimental data was acquired using fast-response pressure transducers mounted on the mid-height streamline of the HP rotor blades. The results are compared to time-resolved computational predictions of the flowfield in order to aid interpretation of experimental results and to determine the accuracy with which the computation predicts blade interaction. The paper is split into two parts: the first investigating the effect of the upstream vane on the unsteady pressure field around the rotor (vane-rotor interaction), and the second investigating the effect of the downstream vane on the unsteady pressure field around the rotor (rotor-vane interaction). The paper shows that at typical design operating conditions shock interaction from the upstream blade row is an order of magnitude greater than wake interaction and that with the design vane-rotor inter-blade gap the presence of the rotor causes a periodic increase in the strength of the vane trailing edge shock. The presence of the potential field of the downstream vane is found to affect significantly the rotor pressure field downstream of the Mach one surface within each rotor passage.

Wake, Shock, and Potential Field Interactions in a 1.5 Stage Turbine—Part II: Vane-Vane Interaction and Discussion of Results

2003 ◽  
Vol 125 (1) ◽  
pp. 40-47 ◽  
Author(s):  
R. J. Miller ◽  
R. W. Moss ◽  
R. W. Ainsworth ◽  
N. W. Harvey
Keyword(s):  
High Pressure ◽  
Potential Field ◽  
Pressure Fluctuations ◽  
Interaction Mechanism ◽  
Fast Response ◽  
Rotor Blades ◽  
Suction Surface ◽  
Time Resolved ◽  
Pressure Transducers ◽  
The Individual

The composition of the time-resolved surface pressure field around a high-pressure rotor blade caused by the presence of neighboring blade rows is investigated with the individual effects of wake, shock and potential field interaction being determined. Two test geometries are considered: first, a high-pressure turbine stage coupled with a swan-necked diffuser exit duct; secondly, the same high pressure stage but with a vane located in the downstream duct. Both tests were conducted at engine-representative Mach and Reynolds numbers and experimental data was acquired using fast-response pressure transducers mounted on the mid-height streamline of the HP rotor blades. The results are compared to time-resolved computational predictions of the flow field in order to aid interpretation of experimental results and to determine the accuracy with which the computation predicts blade interaction. In the first half of this paper it is shown that, in addition to the two main interaction mechanisms (upstream vane-rotor and rotor-downstream vane interactions, presented in Part I of this paper) a third interaction occurs. This new interaction mechanism is shown to be caused by the interaction between the downstream vane’s potential field and the upstream vane’s trailing edge potential field and shock. The unsteady rotor surface static pressure fluctuations caused by this interaction are shown to occur on the late rotor suction surface at a frequency corresponding to the difference in the numbers of upstream and downstream vanes. The second part to the paper discusses the mechanisms that cause vane-rotor-vane interaction. The rotor’s operating point is periodically altered as it passes the downstream vane. It is shown that for a large downstream vane, the flow conditions in the rotor passage, at any instant in time, are close to being steady state.

Wake, Shock and Potential Field Interactions in a 1.5 Stage Turbine: Part II — Vane-Vane Interaction and Discussion of Results

2002 ◽  
Author(s):  
R. J. Miller ◽  
R. W. Moss ◽  
R. W. Ainsworth ◽  
N. W. Harvey
Keyword(s):  
High Pressure ◽  
Potential Field ◽  
Pressure Fluctuations ◽  
Interaction Mechanism ◽  
Fast Response ◽  
Rotor Blades ◽  
Suction Surface ◽  
Time Resolved ◽  
Pressure Transducers ◽  
The Individual

The composition of the time-resolved surface pressure field around a high-pressure rotor blade caused by the presence of neighbouring blade rows is investigated with the individual effects of wake, shock and potential field interaction being determined. Two test geometries are considered: first, a high-pressure turbine stage coupled with a swan-necked diffuser exit duct; secondly, the same high-pressure stage but with a vane located in the downstream duct. Both tests were conducted at engine-representative Mach and Reynolds numbers and experimental data was acquired using fast-response pressure transducers mounted on the mid-height streamline of the HP rotor blades. The results are compared to time-resolved computational predictions of the flowfield in order to aid interpretation of experimental results and to determine the accuracy with which the computation predicts blade interaction. In the first half of this paper it is shown that, in addition to the two main interaction mechanisms (upstream vane-rotor and rotor-downstream vane interactions, presented in Miller et al. [1]) a third interaction occurs. This new interaction mechanism is shown to be caused by the interaction between the downstream vane’s potential field and the upstream vane’s trailing edge potential field and shock. The unsteady rotor surface static pressure fluctuations caused by this interaction are shown to occur on the late rotor suction surface at a frequency corresponding to the difference in the numbers of upstream and downstream vanes. The second part to the paper discusses the mechanisms that cause vane-rotor-vane interaction. The rotor’s operating point is periodically altered as it passes the downstream vane. It is shown that for a large downstream vane, the flow conditions in the rotor passage, at any instant in time, are close to being steady state.

scholarly journals Influence of high pressure on amino acids and their multicomponent crystals

2014 ◽  
Vol 70 (a1) ◽  
pp. C1192-C1192
Author(s):  
Boris Zakharov ◽  
Elena Boldyreva ◽  
Boris Kolesov ◽  
Evgeniy Losev ◽  
Sergey Arkhipov
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
High Pressure ◽  
Phase Transitions ◽  
Crystal Structures ◽  
High Pressures ◽  
Ministry Of Education ◽  
Amino Acid Salts ◽  
The Individual ◽  
Academy Of Sciences

The studies of molecular crystals at high pressures help to understand intermolecular interactions, their role in the formation of crystal structures and in crystal structure response to external actions. Multicomponent crystals are promising for high-pressure research since a large number of phenomena has been observed for them [1]. Crystals of amino acids, their salts and co-crystals are of special interest in this respect. They are promising as new materials and can serve as biomimetics since the structure forming units of these crystals are similar to those in biomolecules. The aim of this study was to follow the effect of increasing pressure on crystal structures of amino acid salts and co-crystals to compare the results with those obtained for individual amino acids. Glycine, alanine, serine and their corresponding salts with carboxylic acids were chosen as objects of the study. Single-crystal X-ray diffraction and Raman spectroscopy were used as main experimental techniques. Three different types of behavior of salts on increasing pressure as compared with individual crystals were observed. For some salts, adding the second component stabilized the crystal structure with respect to phase transitions [2]. In the second group, on the contrary, the salts underwent phase transitions at relatively low pressures, though individual components did not undergo phase transitions at least up to 8-10 GPa. The last, third group of salts showed phase transitions in a similar pressure range as the individual components, but the mechanism of the transition changed. The phase transitions were accompanied either by crystal structure disordering, or by switching-over hydrogen bonds [3]. This work was supported by a grant from RFBR (12-03-31541 mol_a), by the Ministry of Education and Science of Russia, Russian Academy of Sciences, and by a grant of President of Russia for State support of Russian leading Scientific Schools (project NSh-279.2014.3).

Wake, Shock and Potential Field Interactions in a 1.5 Stage Turbine: Part I — Vane-Rotor and Rotor-Vane Interaction

2002 ◽  
Author(s):  
R. J. Miller ◽  
R. W. Moss ◽  
R. W. Ainsworth ◽  
N. W. Harvey
Keyword(s):  
High Pressure ◽  
Potential Field ◽  
Pressure Field ◽  
Fast Response ◽  
Operating Conditions ◽  
Rotor Blades ◽  
Time Resolved ◽  
Pressure Transducers ◽  
Unsteady Pressure ◽  
The Individual

The composition of the time-resolved surface pressure field around a high-pressure rotor blade caused by the presence of neighboring blade rows is investigated, with the individual effects of wake, shock and potential field interaction being determined. Two test geometries are considered: first, a high-pressure turbine stage coupled with a swan-necked diffuser exit duct; secondly, the same high-pressure stage but with a vane located in the downstream duct. Both tests were conducted at engine-representative Mach and Reynolds numbers, and experimental data was acquired using fast-response pressure transducers mounted on the mid-height streamline of the HP rotor blades. The results are compared to time-resolved computational predictions of the flowfield in order to aid interpretation of experimental results and to determine the accuracy with which the computation predicts blade interaction. The paper is split into two parts, the first investigating the effect of the upstream vane on the unsteady pressure field around the rotor (vane-rotor interaction) and the second investigating the effect of the downstream vane on the unsteady pressure field around the rotor (rotor-vane interaction). The paper shows that at typical design operating conditions shock interaction from the upstream blade row is an order of magnitude greater than wake interaction and that with the design vane-rotor inter-blade gap the presence of the rotor causes a periodic increase in the strength of the vane trailing edge shock. The presence of the potential field of the downstream vane is found to affect significantly the rotor pressure field downstream of the Mach one surface within each rotor passage.

Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

Peculiarities of high-pressure hydrogen adsorption on Pt catalyzed Cu-BTC metal–organic framework

2021 ◽  
Vol 23 (7) ◽  
pp. 4277-4286
Author(s):  
S. V. Chuvikov ◽  
E. A. Berdonosova ◽  
A. Krautsou ◽  
J. V. Kostina ◽  
V. V. Minin ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Hydrogen Adsorption ◽  
Metal Organic Framework ◽  
Pt Catalyst ◽  
Metal Organic ◽  
Pt Catalyzed ◽  
Pressure Hydrogen ◽  
Organic Framework

Pt-Catalyst plays a key role in hydrogen adsorption by Cu-BTC at high pressures.

scholarly journals Crystal and electronic structure engineering of tin monoxide by external pressure

2021 ◽  
Author(s):  
Kun Li ◽  
Junjie Wang ◽  
Vladislav A. Blatov ◽  
Yutong Gong ◽  
Naoto Umezawa ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Band Gap ◽  
High Pressures ◽  
Low Pressure ◽  
Widespread Application ◽  
Space Group ◽  
Tin Monoxide ◽  
High Possibility ◽  
Pressure Phase

AbstractAlthough tin monoxide (SnO) is an interesting compound due to its p-type conductivity, a widespread application of SnO has been limited by its narrow band gap of 0.7 eV. In this work, we theoretically investigate the structural and electronic properties of several SnO phases under high pressures through employing van der Waals (vdW) functionals. Our calculations reveal that a metastable SnO (β-SnO), which possesses space group P21/c and a wide band gap of 1.9 eV, is more stable than α-SnO at pressures higher than 80 GPa. Moreover, a stable (space group P2/c) and a metastable (space group Pnma) phases of SnO appear at pressures higher than 120 GPa. Energy and topological analyses show that P2/c-SnO has a high possibility to directly transform to β-SnO at around 120 GPa. Our work also reveals that β-SnO is a necessary intermediate state between high-pressure phase Pnma-SnO and low-pressure phase α-SnO for the phase transition path Pnma-SnO →β-SnO → α-SnO. Two phase transition analyses indicate that there is a high possibility to synthesize β-SnO under high-pressure conditions and have it remain stable under normal pressure. Finally, our study reveals that the conductive property of β-SnO can be engineered in a low-pressure range (0–9 GPa) through a semiconductor-to-metal transition, while maintaining transparency in the visible light range.

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