Measurement and Simulation of Transient Phenomena in Metal Hydride Bed

2015 ◽  
Vol 816 ◽  
pp. 204-212
Author(s):  
Tomáš Brestovič ◽  
Natália Jasminská ◽  
Mária Čarnogurská ◽  
Marián Lázár
Keyword(s):  
Metal Hydride ◽  
Time Interval ◽  
Transient Phenomena ◽  
Key Points ◽  
Extreme Load ◽  
Safe Limits ◽  
Kinetics Of ◽  
Temperature Time ◽  
Stationary Heat Transfer ◽  
Absorption Of Hydrogen

The article analyses the measurement with increased absorption kinetics of hydrogen into the La0.85Ce0.15Ni5 alloy. Within a time interval of 180 s an amount of 0.142 kg (1.58 m3) of hydrogen was absorbed into 56 kg of alloy. The process of absorption was accompanied by an increased temperature of the bed. Therefore it was simultaneously cooled by a cooler using Peltier elements. The numerical calculation of non-stationary heat transfer within the bed was performed with a known amount of heat generated in the bed, known temperatures and flow rates. Simulation results allow us to determine temperature time paths at key points of the bed and give insight on the transient phenomena which occurs in the extreme load of the metal hydride (MH) bed. This allows establishing safe limits for the absorption of hydrogen into a particular alloy.

scholarly journals Comparing hydrogen absorption kinetics of the samples of intermetallic compound and metal hydride compact on its basis

2021 ◽  
Vol 2057 (1) ◽  
pp. 012043
Author(s):  
I A Romanov ◽  
V I Borzenko ◽  
A N Kazakov
Keyword(s):  
Intermetallic Compound ◽  
Metal Hydride ◽  
Hydrogen Absorption ◽  
Reaction Rate ◽  
Nickel Foam ◽  
High Confidence ◽  
Compact Sample ◽  
Kinetics Of ◽  
Rate Controlling Step ◽  
Absorption Of Hydrogen

Abstract This work is devoted to an experimental study and comparison of the kinetics of hydrogen absorption by an intermetallic compound LaNi4.4Al0.3Fe0.3 in form of pure intermetallic compound free backfill and a compact based on it obtained by cold pressing with a spiral matrix of nickel-foam. To calculate the kinetic parameters of the hydrogen absorption reaction, the initial rates method is used. The PCT absorption isotherms are measured at temperatures of 313, 333, and 353 K. The experimental data are described with quite high confidence by the chosen model, which assumes that the reaction rate controlling step is the dissociative absorption of hydrogen on the surface of the a-phase. The rate of hydrogen absorption increases with increasing pressure drop and temperature. It is shown that the rate of hydrogen absorption by the sample of pure IMC is significantly less dependent on temperature compared to the compact sample. In addition, the reaction rate at temperatures of 313 and 333 K is higher for the free backfill sample, and at 353 K it is higher for the metal hydride compact. The values of the absorption constant and the activation energy of the hydrogen absorption reaction are determined for both samples.

Intrapartum Basal Ganglia–Thalamic Pattern Injury and Radiologically Termed “Acute Profound Hypoxic–Ischemic Brain Injury” Are Not Synonymous

2020 ◽  
Author(s):  
Johan Smith ◽  
Regan Solomons ◽  
Lindi Vollmer ◽  
Eduard J. Langenegger ◽  
Jan W. Lotz ◽  
...  
Keyword(s):  
Brain Injury ◽  
Basal Ganglia ◽  
Caesarean Section ◽  
Median Time ◽  
Mode Of Delivery ◽  
Time Interval ◽  
Key Points ◽  
Admission Status ◽  
Sentinel Event ◽  
Magnetic Resonance Imaging Mri

Objective Human cases of acute profound hypoxic-ischemic (HI) injury (HII), in which the insult duration timed with precision had been identified, remains rare, and there is often uncertainty of the prior state of fetal health. Study Design A retrospective analysis of 10 medicolegal cases of neonatal encephalopathy-cerebral palsy survivors who sustained intrapartum HI basal ganglia-thalamic (BGT) pattern injury in the absence of an obstetric sentinel event. Results Cardiotocography (CTG) admission status was reassuring in six and suspicious in four of the cases. The median time from assessment by admission CTG or auscultation to birth was 687.5 minutes (interquartile range [IQR]: 373.5–817.5 minutes), while the median time interval between first pathological CTG and delivery of the infant was 179 minutes (IQR: 137–199.25 minutes). The mode of delivery in the majority of infants (60%) was by unassisted vaginal birth; four were delivered by delayed caesarean section. The median (IQR) interval between the decision to perform a caesarean section and delivery was 169 minutes (range: 124–192.5 minutes). Conclusion The study shows that if a nonreassuring fetal status develops during labor and is prolonged, a BGT pattern HI injury may result, in the absence of a perinatal sentinel event. Intrapartum BGT pattern injury and radiologically termed “acute profound HI brain injury” are not necessarily synonymous. A visualized magnetic resonance imaging (MRI) pattern should preferably solely reflect the patterns description and severity, rather than a causative mechanism of injury. Key Points

Kinetics of Hydrogen Absorption, Desorption And Permeation of Metals

CORROSION ◽  
1958 ◽  
Vol 14 (12) ◽  
pp. 34-38 ◽  
Author(s):  
T. G. OWE BERG
Keyword(s):  
Experimental Data ◽  
Reaction Mechanisms ◽  
Hydrogen Absorption ◽  
Hydrogen Gas ◽  
Acid Solutions ◽  
Dilute Acid ◽  
Energy Diffusion ◽  
Dissolved Hydrogen ◽  
Kinetics Of ◽  
Absorption Of Hydrogen

Abstract The reaction mechanisms for the absorption of hydrogen by metals from moist hydrogen gas and dilute acid solutions, for the desorption from metals of dissolved hydrogen in the presence of water and for hydrogen solubility and permeation under those conditions are discussed. Their kinetics are also given. Formulae are derived for rates and equilibria. These are compared with experimental data. The migration of H atoms in the metal is concluded to be associated with zero or nearly zero activation energy. Diffusion is rapid enough to maintain almost uniform distribution of H atoms in the metal during absorption and desorption under ordinary conditions. 3.8.4

The kinetics of a moving metal hydride layer

2000 ◽  
Vol 312 (1-2) ◽  
pp. 135-153 ◽  
Author(s):  
Joseph Bloch
Keyword(s):  
Metal Hydride ◽  
Kinetics Of

scholarly journals Latest results of the ANTARES neutrino telescope

2019 ◽  
Vol 209 ◽  
pp. 01022
Author(s):  
Juan-de-Dios Zornoza
Keyword(s):  
Angular Resolution ◽  
High Energy ◽  
Transient Phenomena ◽  
New Era ◽  
Neutrino Telescopes ◽  
Key Points ◽  
The Galaxy ◽  
Neutrino Astronomy ◽  
The Mediterranean ◽  
The Universe

Neutrino astronomy is in an exciting moment. The discovery of a cosmic flux of high energy neutrinos by IceCube heralds a new era in which neutrinos have finally joined the multi-messenger study of the Universe. This new important window complements more “traditional” probes (as cosmic rays or photons), given the particular combination of characteristics of neutrinos (neutral, stable and weakly interacting). The ANTARES detector, built in the Mediterranean Sea, has succeeded in two key points. First, it has shown the feasibility of the technique of underwater neutrino telescopes, which offers important advantages in terms of performance (better angular resolution, better visibility of the Galaxy if built in the Northern Hemisphere). This has paved the way for the next step, KM3NeT, already in construction. Second, the physics harvest of ANTARES is very rich, including many results that show the particular advantages of being in the Mediterranean, as mentioned above. The analyses performed include the search for point-like sources, diffuse fluxes, transient phenomena, dark matter, etc. In this talk we will review this long list of achievements.

scholarly journals Studies on the Nature of the Circulating Anticoagulant Directed against Antihemophilic Factor: With Notes on an Assay for Antihemophilic Factor

Blood ◽  
1962 ◽  
Vol 20 (2) ◽  
pp. 137-149 ◽  
Author(s):  
ROBERT T. BRECKENRIDGE ◽  
OSCAR D. RATNOFF
Keyword(s):  
Substrate Concentration ◽  
Clotting Time ◽  
Heat Stable ◽  
Concentration Dependency ◽  
Proportional Relationship ◽  
Kaolin Clotting Time ◽  
Antigen Antibody ◽  
Kinetics Of ◽  
Temperature Time ◽  
Antihemophilic Factor

Abstract Modification of the kaolin clotting time has produced a reliable, simple assay system for antihemophilic factor. This system has been utilized for an investigation of the nature and mode of action of the circulating anticoagulant directed against antihemophilic factor. The anticoagulant has been shown to be present in equal amounts in plasma and serum, to be associated with fractions II and III of plasma prepared by the method of Cohn, to be relatively heat stable and to be stable for prolonged periods at -20 C. Investigation of the kinetics of the anticoagulant-antihemophilic reaction has demonstrated its temperature, time, pH, and substrate concentration dependency. The anticoagulant is not inactivated during the reaction with antihemophilic factor, and there is a proportional relationship between the anticoagulant and the antihemophilic factor during their interaction. No antigen-antibody manifestations could be detected during the anticoagulant-antihemophilic factor reaction. These characteristics support the hypothesis that the inactivation of antihemophilic factor by specific circulating anticoagulants is enzymatic.

Kinetics of the reactive absorption of hydrogen sulfide into aqueous ferric sulfate solutions

2003 ◽  
Vol 58 (2) ◽  
pp. 417-427 ◽  
Author(s):  
S Ebrahimi ◽  
R Kleerebezem ◽  
M.C.M van Loosdrecht ◽  
J.J Heijnen
Keyword(s):  
Hydrogen Sulfide ◽  
Ferric Sulfate ◽  
Sulfate Solutions ◽  
Reactive Absorption ◽  
Kinetics Of ◽  
Absorption Of Hydrogen

Explosive crystallization phenomena in SOI structures

1989 ◽  
Vol 4 (6) ◽  
pp. 1473-1479 ◽  
Author(s):  
H. D. Geiler ◽  
M. Wagner ◽  
E. Glaser ◽  
G. Andrä ◽  
D. Wolff ◽  
...  
Keyword(s):  
Solid Phase ◽  
Amorphous Layer ◽  
Nucleation And Growth ◽  
Time Interval ◽  
Two Phase ◽  
Pulse Technique ◽  
Explosive Crystallization ◽  
Crystalline Nucleus ◽  
Phase Nucleation ◽  
Temperature Time

Using the double pulse technique with two synchronized lasers, we studied the conditions of ignition and evolution of explosive crystallization. The structure of the resulting crystallized layers is analyzed by TEM. Results of calculations are reported describing the development of the two phase fronts: amorphous/molten and molten/crystalline. It is shown that the system takes more than 500 ns to reach the steady state. The experimental results support the model of creating first a melt nucleus in the amorphous layer followed by the formation of the crystalline nucleus in the molten sphere. Competitive solid phase nucleation and growth in the amorphous layer limit the temperature-time interval of melt nucleation. Defined explosively crystallized areas in laterally structured SOI layers are presented.

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