0000000000020012

AUTHOR

Gunta ĶIzāne

showing 9 related works from this author

Thermokinetic Investigation of the Drying Conditions on Amorphous Calcium Phosphate

2017

The present work investigated dried calcium phosphate powders which still retain an amorphous or poorly crystalline structure under a variety of conditions. In previous studies, freeze-drying was found to be the optimum drying condition. However, several publications, as well as our previous studies, have shown that calcium phosphate amorphous, or a poorly crystalline structure, can retain their structure even if the samples are dried immediately after synthesis up to 200°C. In our study, we used the thermokinetic studies FTIR and XRD and showed that the samples are amorphous, or poorly crystalline, but were unable to answer the questions: Is there a difference between the differently dried…

0303 health sciencesChemistryMechanical EngineeringInorganic chemistry02 engineering and technologyActivation energy021001 nanoscience & nanotechnologyArrhenius plot03 medical and health sciencesMechanics of MaterialsGeneral Materials ScienceAmorphous calcium phosphate0210 nano-technologyFtir pas030304 developmental biologyKey Engineering Materials
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Characterisation and radiolysis of modified lithium orthosilicate pebbles with noble metal impurities

2017

Modified lithium orthosilicate (Li4SiO4) pebbles with additions of titanium dioxide (TiO2) are suggested as an alternative tritium breeding ceramic for the European solid breeder test blanket module. The noble metals – platinum (Pt), gold (Au) and rhodium (Rh), can be introduced into the modified Li4SiO4 pebbles during the melt-based process, due to the corrosion of Pt-Rh and Pt-Au alloy crucible components. In this study, the surface microstructure, chemical and phase composition of the modified Li4SiO4 pebbles with different contents of the noble metals was analysed. The influence of the noble metals on the radiolysis was evaluated after irradiation with accelerated electrons (E = 5 MeV),…

Materials scienceInorganic chemistryAlloychemistry.chemical_element02 engineering and technologyengineering.material01 natural sciences010305 fluids & plasmasRhodiumchemistry.chemical_compoundImpurity0103 physical sciencesRadiolysisTritium breeding ceramicGeneral Materials ScienceCivil and Structural EngineeringMechanical EngineeringNoble metalsLithium orthosilicate021001 nanoscience & nanotechnologyNuclear Energy and EngineeringchemistryRadiolysisengineeringNoble metalLithiumOrthosilicate0210 nano-technologyPlatinum
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Tritium release behavior of beryllium pebbles after neutron irradiation between 523 and 823K

2013

Abstract Post-irradiation tritium release from the Pebble Bed Assembly (PBA) neutron-irradiated beryllium (Be) pebbles (∅ ≈ 1 mm; the total tritium inventory 2–4 GBq/g) was investigated on annealing in He + 0.1% H 2 . Temperature ramps of 2.3 K/min followed by annealing for 1 h at 1310–1320 K resulted in complete detritiation of the PBA Be pebbles. The tritium burst release occurred after a time lag of 1–6.5 h during constant temperature anneals at 1089–1180 K, with the release time measured after reaching the annealing temperature. Tritium burst release was also observed to occur during cool down. Anneals at 1089 K for 8 h and at 1045 K for 23 h caused detritiation of the PBA Be pebbles by…

Nuclear and High Energy PhysicsAnnealing (metallurgy)Radiochemistrychemistry.chemical_elementThermal diffusivityRelease timeTritium releaseNuclear Energy and EngineeringchemistryGeneral Materials ScienceTritiumBerylliumPebbleNeutron irradiationJournal of Nuclear Materials
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Effects of external energetic factors on tritium release from the EXOTIC 8-3/13 neutron-irradiated beryllium pebbles

2009

Abstract Tritium release from samples of 9–13 mg of the EXOTIC 8-3/13 neutron-irradiated beryllium pebbles under the separate and simultaneous action of temperature 490–770 K, 5 MeV fast-electron radiation 14 MGy h−1 for 3 h and magnetic field (MF) of 1.7 T was investigated. The pebbles were found to be very dissimilar with respect to their total tritium content—2.5–9 MBq g−1. The batch contained also some coarse agglomerates of the pebbles containing 10–19 MBq g−1 of tritium having also a high tritium release. For the pebbles having the total tritium 2.5–5.3 MBq g−1, the electron radiation for 3 h caused the fractional tritium release 17–26% (B = 0) and 21–29% (B = 1.7 T), the temperature …

Materials scienceMechanical EngineeringRadiochemistrychemistry.chemical_elementBlanketFusion powerNuclear physicsNuclear Energy and EngineeringchemistryAgglomerateGeneral Materials ScienceNeutronTritiumIrradiationBerylliumHeliumCivil and Structural EngineeringFusion Engineering and Design
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FTIR Analysis of Electron Irradiated Single and Multilayer Si<sub>3</sub>N<sub>4</sub> Coatings

2018

Silicon nitride (Si3N4) due to its good mechanical and electrical properties is a promising material for wide range of applications, including exploitation under action of ionizing radiation. For estimating the changes of chemical bonds in silicon nitride nanolayers under action of ionizing radiation single and multi-layer silicon nitride nanolayered coatings on prepared Si subtrate were investigated by means of Fourier transform infrared spectrometry. Three main groups of signals were identified in both types of nanolayers, at 510 and 820 cm-1 and group of broad signals at 1000-1200 cm-1. Irradiation with accelerated electrons up to absorbed doses 36 MGy causes minor changes of signal inte…

010302 applied physicsMaterials scienceMechanical Engineering02 engineering and technologyElectron021001 nanoscience & nanotechnology01 natural sciencesMechanics of Materials0103 physical sciencesGeneral Materials ScienceIrradiationFourier transform infrared spectroscopy0210 nano-technologyNuclear chemistryKey Engineering Materials
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TRITIUM RELEASE CHARACTERISTICS OF NEUTRON-IRRADIATED REFERENCE BERYLLIUM PEBBLES FOR THE HELIUM COOLED PEBBLE BED (HCPB) BLANKET

2011

In this paper, we present results on tritium release from the beryllium pebbles irradiated for 294 full power days from 17 April 2003 to November 2004 to the neutron fluence of 1.5-2 × 1025 m-2 (E>...

Nuclear and High Energy PhysicsMaterials science020209 energyMechanical EngineeringNuclear engineeringchemistry.chemical_element02 engineering and technologyBlanket01 natural sciences010305 fluids & plasmasTritium releaseNuclear Energy and EngineeringchemistryNeutron flux0103 physical sciences0202 electrical engineering electronic engineering information engineeringGeneral Materials ScienceNeutronIrradiationBerylliumPebbleHeliumCivil and Structural Engineering
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New Fluorescent Heterocyclic Compounds Derived From 3-Cyanobenzanthrone

2021

The four-cyclic condensed aromatic ketone 7H-benz[de]anthracene-7-one and its derivatives belong to the class of important anthraquinoid dyes, including laser and luminescent dyes. Current work is ...

Aromatic ketonechemistry.chemical_compoundPolymers and PlasticschemistryOrganic ChemistryMaterials ChemistryFluorescenceCombinatorial chemistryBenzanthronePolycyclic Aromatic Compounds
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Magnetic field effects on tritium release from neutron-irradiated beryllium pebbles

2007

The effects of temperature, magnetic field (MF), and ionizing radiation on the release of tritium from the Be pebbles irradiated in the BERYLLIUM experiment in 1994 in Petten, The Netherlands (irradiation neutron fluence 1.24×10 25 m -2 , irradiation temperature 780 K, and 3 H content 7 appm) were investigated in this study. Simultaneous action of these factors corresponds to the real operating conditions of the blanket of a fusion reactor. The total amount of tritium in a separate pebble, the chemical forms of localized tritium (T 0 , T 2 , and T + ), and the tritium distribution in the pebble volume were determined by a lyomethod (dissolution). Thermoannealing experiments were performed a…

Nuclear and High Energy Physics020209 energyRadiochemistrychemistry.chemical_element02 engineering and technologyFusion powerCondensed Matter PhysicsIonizing radiation020303 mechanical engineering & transports0203 mechanical engineeringNuclear Energy and EngineeringchemistryNeutron flux0202 electrical engineering electronic engineering information engineeringTritiumNeutronIrradiationBerylliumPebble
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Tritium sorption and desorption from JET beryllium tiles under temperature, electron radiation and magnetic field

2008

Abstract Tritium release at annealing of samples cut from beryllium tiles exposed to D + D, D + T plasma in the Joint European Torus (JET) was investigated under 5 MeV fast-electron radiation at the dose rate 14 MGy h −1 and in a magnetic field of 1.7 T separately and simultaneously in order to evaluate possible effects of these factors. Abundances of chemical forms of tritium—molecular T 2 (44%), atomic T 0 (42%), and ionic T + (14%) and their distribution were determined in the plasma-exposed beryllium samples with lyomethods. Fast-electron radiation considerably increased the fractional tritium release at annealing by a factor of approximately 5. The magnetic field increased the fraction…

Materials scienceAnnealing (metallurgy)Mechanical EngineeringJoint European TorusAnalytical chemistrychemistry.chemical_elementSorptionPlasmaRadiationNuclear physicsNuclear Energy and EngineeringchemistryDesorptionGeneral Materials ScienceTritiumBerylliumCivil and Structural EngineeringFusion Engineering and Design
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