scholarly journals GAMMA-RADIATION SPECTRA OF 1200 MeV ELECTRONS IN THICK BERYLLIUM, SILICON AND TUNGSTEN SINGLE CRYSTALS

2019 ◽  
pp. 86-93
Author(s):  
G. L. Bochek ◽  
O. S. Deiev ◽  
V. I. Kulibaba ◽  
N. I. Maslov ◽  
V. D. Ovchinnik ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Single Crystals ◽  
Angular Distributions ◽  
Γ Radiation ◽  
Radiation Spectra ◽  
Solid Angles ◽  
Crystallographic Axes ◽  
And Tungsten

Gamma radiation spectra of 1200 MeV electrons from the single crystals of the beryllium 1.2 mm thick, silicon 1.5 mm and 15 mm thick and tungsten 1.18 mm thick along of the crystallographic axes were measured. Also spectral-angular distributions of gamma radiation from the silicon single crystals 1.5 mm thick along of the crystallographic axes < 100 >, < 110 > and < 111 > were measured. On the basis of these measurements the γ-radiation spectra for the different solid angles up to 6.97 × 10−6 sr were obtained.

scholarly journals BREMSSTRAHLUNG OF ELECTRONS AND YIELD OF NEUTRONS FROM THICK CONVERTERS, PASSING OF GAMMA RADIATION AND NEUTRONS THROUGH BIOLOGICAL SHIELDING

2019 ◽  
pp. 65-73
Author(s):  
O.S. Deiev ◽  
G. L. Bochek ◽  
V. N. Dubina ◽  
S. K. Kiprich ◽  
G. P. Vasilyev ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Total Yield ◽  
Atomic Charge ◽  
Angular Distributions ◽  
Photonuclear Reactions ◽  
Medium Energy ◽  
Radiation Spectra ◽  
The Difference ◽  
Different Thickness ◽  
Forward Hemisphere

In GEANT4 spectral-angular distributions of the bremsstrahlung of medium-energy electrons from amorphous targets of different thickness and atomic charge were calculated. The total yield of gamma quanta in the forward hemisphere and at large scattering angles were determined depending on the converter thickness. The difference in the characteristics of gamma radiation for thin and thick targets was shown. The neutron yield is calculated due to photonuclear reactions for various converters. Numerical estimates of the radiation spectra after passing through the biological shielding for neutron and bremsstrahlung were carried out.

scholarly journals Conversion of Methanol on Rutile TiO2 (110) and Tungsten Oxide Clusters: 1. Population of Defect-Dependent Thermal Reaction Pathways

2021 ◽  
Author(s):  
Lars Mohrhusen ◽  
Katharina Al-Shamery
Keyword(s):  
Tungsten Oxide ◽  
Single Crystals ◽  
Model System ◽  
Thermal Reaction ◽  
Reaction Pathways ◽  
Bifunctional Catalysts ◽  
Rutile Tio2 ◽  
Reaction Routes ◽  
And Tungsten

Tungsten oxide clusters deposited on rutile TiO2 (110) single crystals were used as a model system for heterogenous oxide-oxide bifunctional catalysts. The population of different thermal reaction routes in methanol...

scholarly journals Facile preparation of new polystyrene leucomalachite green thick films and study of their radiochromic behavior for low doses of gamma radiation

2017 ◽  
Vol 5 (2) ◽  
pp. 80
Author(s):  
Anuradha Bera ◽  
Shatrughan Malav ◽  
Bajrang Lal Tiwari ◽  
Shyam Govind Vaijapurkar
Keyword(s):  
Film Thickness ◽  
Gamma Radiation ◽  
Thick Films ◽  
Radiation Processing ◽  
Γ Radiation ◽  
Dye Loading ◽  
Leucomalachite Green ◽  
Colour Development ◽  
Green Coloration ◽  
Potential Use

Colourless polystyrene-leucomalachite green (PS-LMG) thick films containing a suitable chloroalkane were prepared by a fast and facile casting method, and were investigated for their radio chromic response behavior under the influence of 1.25 MeV γ-radiation. Their gamma response was studied in the 0.05 kGy to 10 kGy range to evaluate their suitability for potential use as the dosimeter in the radiation processing industries. The films were found to undergo a visibly distinct green coloration in the studied range, with the colour intensity increasing with an increase in the total dose. The radiochromic response of these films when investigated as a function of film thickness showed that the colour development as well as the linearity of the response was markedly affected by the thickness of the films. The effect of dye loading and the chloroalkane concentration on the radiochromic response of these films were also investigated. Depending upon the film thickness and reactant concentrations, the films were found to be capable of visually detecting gamma radiation doses as low as few tens of grays.

scholarly journals Differential expression of NPM, GSTA3, and GNMT in mouse liver following long-term in vivo irradiation by means of uranium tailings

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Lan Yi ◽  
Hongxiang Mu ◽  
Nan Hu ◽  
Jing Sun ◽  
Jie Yin ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Radiation Exposure ◽  
Central Vein ◽  
Glutathione S Transferase ◽  
Γ Radiation ◽  
Dose Rates ◽  
Living Organisms ◽  
Uranium Tailings

Uranium tailings (UT) are formed as a byproduct of uranium mining and are of potential risk to living organisms. In the present study, we sought to identify potential biomarkers associated with chronic exposure to low dose rate γ radiation originating from UT. We exposed C57BL/6J mice to 30, 100, or 250 μGy/h of gamma radiation originating from UT samples. Nine animals were included in each treatment group. We observed that the liver central vein was significantly enlarged in mice exposed to dose rates of 100 and 250 μGy/h, when compared with nonirradiated controls. Using proteomic techniques, we identified 18 proteins that were differentially expressed (by a factor of at least 2.5-fold) in exposed animals, when compared with controls. We chose glycine N-methyltransferase (GNMT), glutathione S-transferase A3 (GSTA3), and nucleophosmin (NPM) for further investigations. Our data showed that GNMT (at 100 and 250 μGy/h) and NPM (at 250 μGy/h) were up-regulated, and GSTA3 was down-regulated in all of the irradiated groups, indicating that their expression is modulated by chronic gamma radiation exposure. GNMT, GSTA3, and NPM may therefore prove useful as biomarkers of gamma radiation exposure associated with UT. The mechanisms underlying those changes need to be further studied.

scholarly journals Preferred orientation of ferromagnetic phases in rock-forming minerals: insights from magnetic anisotropy of single crystals

2019 ◽  
Vol 56 (9) ◽  
pp. 994-1001 ◽  
Author(s):  
Ann M. Hirt ◽  
Andrea R. Biedermann
Keyword(s):  
Magnetic Field ◽  
Magnetic Anisotropy ◽  
Single Crystals ◽  
Remanent Magnetization ◽  
Igneous Rocks ◽  
Flow Structures ◽  
Silicate Minerals ◽  
Fine Grained ◽  
Crystallographic Axes ◽  
Paleomagnetic Direction

In the early days of paleomagnetism, David Strangway was interested in understanding why igneous rocks are faithful recorders of the Earth’s magnetic field. He recognized that ferromagnetic (s.l.) grains that could be discerned by optical microscopy were too large to carry a stable remanent magnetization, and speculated whether fine-grained, ferromagnetic (s.l.) inclusions or exsolutions in silicate minerals are responsible. When these inclusions or exsolutions are randomly oriented, or the silicate hosts are randomly oriented in a rock, they can be a good recorder of the field. If these minerals, however, show an alignment within the silicate host, and the host is preferentially aligned due to flow structures or deformation, then the paleomagnetic direction and paleointensity could be biased. We examine the magnetic anisotropy arising from the ferromagnetic (s.l.) phases in silicate-host minerals. Single crystals of phyllosilicate, clinopyroxene, and calcite show most consistent ferrimagnetic fabric with relation to the minerals’ crystallographic axes, whereas olivine and feldspar display only a weak relationship. No discernable relationship is found between the ferrimagnetic anisotropy and crystallographic axes for amphibole minerals. Our results have implications when single crystals are being used for either studies of field direction or paleointensity or in cases where silicate minerals have a preferential orientation. Phyllosilicate minerals and pyroxene should be screened for significant magnetic anisotropy.

Influence of gamma-radiation on optical and lasing properties of YAG-Er single crystals

1997 ◽  
Author(s):  
Dmitry Y. Sugak ◽  
Andrej O. Matkovskii ◽  
Andrzej Suchocki ◽  
A. N. Durygin ◽  
Slawomir M. Kaczmarek ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Single Crystals

scholarly journals Gamma Flux in 14C Laboratories

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 428-430 ◽  
Author(s):  
Páll Theodórsson ◽  
Lauri Kaihola ◽  
H. H. Loosli ◽  
José M. Rodríguez
Keyword(s):  
Gamma Radiation ◽  
Radiocarbon Dating ◽  
Radiation Flux ◽  
Cosmic Ray ◽  
Cosmogenic Nuclides ◽  
Collaborative Group ◽  
Counting System ◽  
Γ Radiation ◽  
Gamma Flux ◽  
Anticoincidence Counting

An informal collaborative group of radiocarbon dating laboratories, the Low-Level Club, has been established to measure the gamma radiation flux and to test the efficiency of the anticoincidence counting system in laboratories with a NaI detector unit. The detector will record gamma radiation from cosmogenic nuclides, muons and secondary γ radiation formed in the passive shield by charged cosmic-ray particles. We present here the first phase of this work.

Synthesis and Characterisation of B-Site Doped Cu2Ta4O12

2002 ◽  
Vol 755 ◽  
Author(s):  
Bernd Renner ◽  
Stefan Ebbinghaus ◽  
Armin Reller ◽  
David Schrupp ◽  
Hans-Albrecht Krug von Nidda ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Dielectric Properties ◽  
Single Crystals ◽  
Rietveld Refinement ◽  
Copper Content ◽  
Tantalum Oxide ◽  
Powder Samples ◽  
Magnetic And Dielectric Properties ◽  
And Tungsten

ABSTRACTWe investigated synthesis, structure, composition as well as electric and magnetic properties of copper tantalum oxide single crystals and powder samples. It was possible to flux-grow single crystals of undoped Cu2Ta4O12. To modify the copper content in this structure, tetravalent and hexavalent ions like titanium and tungsten have been incorporated. Rietveld refinement data as well as magnetic and dielectric properties are presented.

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