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Wyszukujesz frazę "gamma-ray" wg kryterium: Temat


Tytuł:
A modified method for the determination of radioactive isotopes in building raw and construction materials with multichannel gamma spectrometry
Autorzy:
Charewicz, W.
Żebrowski, A.
Walkowiak, W.
Borek, B.
Powiązania:
https://bibliotekanauki.pl/articles/147083.pdf
Data publikacji:
2000
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
building materials
multichannel gamma-ray spectrometry
radioactive isotopes
Opis:
A modified method is presented for the determination of natural and artificial isotopes in building raws and materials using multichannel gamma-ray spectrometry. A procedure is given for the preparation of standards as well as for the determination of radioisotopes content in typical building raws and/or materials. Results of these determinations were compared with those from standard, tri-channel gamma spectrometry described in Instruction No. 234/95 [2] issued by the Institute of Building Technology in Warsaw, Poland.
Źródło:
Nukleonika; 2000, 45, 4; 243-247
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of magnetic field with chemomutagen and gamma rays on the variability of yielding parameters in barley [Hordeum vulgare L.]
Autorzy:
Rybinski, W.
Pietruszewski, S.
Kornarzynski, K.
Powiązania:
https://bibliotekanauki.pl/articles/24954.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
variability
magnetic field
chemomutagen
barley
mutagen
spring barley
biostimulation
gamma-ray
Hordeum vulgare
biological injury
yielding parameter
Źródło:
International Agrophysics; 2003, 17, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-ray and magnetic susceptibility correlation across a Frasnian carbonate platform and the search for "punctata" equivalents in stromatoporoid-coral limestone facies of Moravia
Autorzy:
Geršl, M.
Hladil, J.
Powiązania:
https://bibliotekanauki.pl/articles/2058866.pdf
Data publikacji:
2004
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Moravian Karst
Devonian
limestones
stratigraphy
natural gamma-ray activity
magnetic susceptibility
Opis:
A comparison of the HV-105 Křtiny gamma-ray log (carbonate platform margin and proximal slope, thickness of Frasnian beds ~270 m) with the three times thinner gamma-ray spectrometric section from Mokrá (inner platform, Frasnian ~93.5m) has significantly increased the reliability of stratigraphic correlation between the outer and inner platform areas, i.e. it has allowed strengthening of the detailed links between conodont-bearing and barren sequences. The detailed gamma-ray and magnetic susceptibility patterns also provide promising clues which might help trace the "punctata Zone" stratigraphic equivalents, located far in the interior of the platform stromatoporoid-coral facies.
Źródło:
Geological Quarterly; 2004, 48, 3; 283-292
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large Sample Neutron Activation Analysis: correction for neutron and gamma attenuation
Autorzy:
Tzika, F.
Stamatelatos, I.
Kalef-Ezra, J.
Bode, P.
Powiązania:
https://bibliotekanauki.pl/articles/147265.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutron activation analysis
neutron self-shielding
gamma-ray attenuation
MCNP code
Opis:
A Large Sample Neutron Activation Analysis (LSNAA) facility is under development at the GRR-1 research reactor, NCSR "Demokritos". The LSNAA facility design incorporates sample irradiation in the reactor graphite thermal neutron column and subsequent measurement of the activity induced in a gamma spectroscopy system with gamma ray transmission measurement options included. The Monte Carlo neutron and photon transport code MCNP-4C was used to model the facility. Appropriate correction factors accounting for neutron field perturbation during sample irradiation and high-purity germanium detector efficiency for the volume source were derived. The results of the computations were experimentally verified by measurements for a set of known materials. The LSNAA facility will be used to perform multi-element, non-destructive, contamination-free analysis of large volume samples with high sensitivity and excellent sampling. End-users of the facility will be archaeological, environmental, bio-medical research laboratories and industry.
Źródło:
Nukleonika; 2004, 49, 3; 115-121
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time of soil water thermodynamic equilibrium during retention curve establishment using gamma-ray beam attenuation
Autorzy:
Pires, L.
Bacchi, O.
Reichardt, K.
Powiązania:
https://bibliotekanauki.pl/articles/148674.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma-ray attenuation
time of equilibrium
pressure chamber
soil water retention curve
Opis:
The soil water retention curve (SWRC) represents a fundamental part of the characterization of the soil hydraulic properties. The establishment of SWRC is usually time-consuming and presents several problems such as the difficulty of a correct judgment of the time of equilibrium. This work presents a new methodology that involves gammaray beam attenuation technique associated with the traditional pressure chambers, having as objective the more precise judgment of the time to attain equilibrium. The gamma-ray source used has an activity of 3.7 GBq consisting of 241Am, with peak energy of 59.54 keV. For the determination of retention curves using the gamma-ray attenuation technique, an acrylic pressure chamber was projected and constructed to be positioned between the source and detector with the gamma-ray beam crossing the center of the chamber and the soil sample during water extraction. The proposed technique allowed, through a specifically elaborated software for data acquisition, to evaluate with precision the exact instant of the equilibrium and, consequently, to obtain the right moment to change the chamber pressure to a new desired level, leading to a reduction of the time required for the whole retention curve determination. The results obtained show that the gamma-ray attenuation technique can be very useful as an auxiliary tool to evaluate SWRC, utilizing the Richards chamber.
Źródło:
Nukleonika; 2005, 50, 4; 173-177
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design, construction and performance of a pressure chamber for water retention curve determination through traditional and nuclear methods
Autorzy:
Pires, L.
Bacchi, O.
Powiązania:
https://bibliotekanauki.pl/articles/146181.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
soil water potential
gamma-ray attenuation
soil water content
soil physics
radioisotope application
Opis:
We present in this work a detailed design of a small low-pressure chamber outfitted with a ceramic porous plate for evaluating the soil water retention curve (SWRC) in the water potential range from 0 to -100 kPa. The chamber is made of acrylic and permits the use of one unique soil sample each time. The use of this chamber allows quick measurements of soil moisture using nuclear (based on gamma-ray attenuation) and conventional methods and SWRC determinations made with the designed chamber are in agreement with those obtained using a commercial low-pressure chamber. The chamber was designed especially for testing the use of the nuclear method as an auxiliary tool for SWRC determinations but it can be easily adapted for routine investigations and a practical alternative for the conventional SWRC method.
Źródło:
Nukleonika; 2006, 51, 4; 225-230
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-ray beam attenuation to assess the influence of soil texture on structure deformation
Autorzy:
Pires, L.
Bacchi, O.
Dias, N.
Powiązania:
https://bibliotekanauki.pl/articles/147480.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma-ray attenuation
soil physical properties
soil structure deformation
soil sampling
soil porosity
Opis:
Gamma-ray beam attenuation is a non-invasive technique that permits analysis of soil porosity without disturbing the region of interest of the core sample. The technique has as additional advantage to allow measurements point by point on a millimetric scale in contrast to other methodologies that are invasive and analyze the soil properties in the bulk sample volume. Soil porosity can be used as an important parameter to quantify soil structural damages, which affect soil aeration, water movement and retention. In this study, porosities of three soils different in texture were measured at various positions in order to analyze the impact of the sampling procedure on the structure of each particular soil texture. The gamma-ray attenuation system consisted of an 241Am radioactive source having an activity of 3.7 GBq, collimated with cylindrical lead collimators of 2 mm diameter. The results obtained show the presence of dense regions near the edges of samples and that different soil textures can suffer distinct deformations at sampling.
Źródło:
Nukleonika; 2006, 51, 2; 125-129
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Promieniotwórczość naturalna skał paleozoicznych z rejonu Krzeszowic
Natural radioactivity of the Paleozoic rocks from the area of Krzeszowice (southern Poland)
Autorzy:
Malczewski, D.
Badera, J.
Lizurek, G.
Mirkowski, Z.
Dorda, J.
Powiązania:
https://bibliotekanauki.pl/articles/2074494.pdf
Data publikacji:
2006
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
skała paleozoiczna
tuf wulkaniczny
promieniotwórczość naturalna
badanie in situ
Paleozoic rocks
tuff
melaphyre
porphyry
diabase
limestone
natural radioactivity
in situ gamma-ray spectrometry
Krzeszowice
Polska
Opis:
In this paper results of natural radioactivity of 40K, 208Tl, 212Pb, 212Bi, 214Pb, 214Bi and 228Ac in common rocks raw materials mined in the Krakow vicinity measured in situ using a portable gamma-ray spectrometry are presented. The study area occupies the SE edge of regional geologic unit called Krakow–Lubliniec Zone. Most Upper Paleozoic rocks exposed in this area like tuff, porphyry, limestone, dolomite, diabase and melaphyre have great economic importance and are used in building and road construction industry. The activity concentrations of 40K for the measured Paleozoic rocks ranged from 53 Bq/kg (Carboniferous limestone) to 3150 Bq/kg (Permian tuff). The activity concentrations associated with 228Ac (232Th) varied from about 7 Bq/kg (Carboniferous limestone) to 56 Bq/kg (Permian tuff), whereas activity concentrations of 226Ra (238U) ranged from 19 Bq/kg (Devonian dolomite) to 43 Bq/kg (Devonian limestone). Besides, the natural radioactivity of the Jurassic limestones (widespread in this region) was measured for comparision with Devonian and Carboniferous limestones.
Źródło:
Przegląd Geologiczny; 2006, 54, 9; 815-822
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Self-absorption correction in gamma-ray spectrometry of environmental samples - an overview of methods and correction values obtained for the selected geometries
Autorzy:
Jodłowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/148531.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma-ray spectrometry
self-attenuation
self-absorption
correction factor
Opis:
Of major concern are the self-absorption correction factors Cs in precise gamma-ray spectrometry of environmental samples. The overview of Cs determination methods (experimental, Monte Carlo calculations, analytical function application) is presented. Among several available methods, the author chose the one proposed by Debertin where the uncertainty level of Cs correction factor is 1÷2%. The point-like detector model is assumed whilst its efficiency is taken to be proportional to the weighted sum (integral) of the number of photons coming from sample volume elements. Computer program was developed to support the computation of Cs by the Debertin's method for samples in cylindrical geometries and Marinelli beakers. The input data are sample dimensions, density and the mass attenuation coefficient. The Cs uncertainty due to an arbitrarily chosen position of a point-like detector would not exceed 1% for the considered photon energies and the sample density range. Utilising this computer program, the relationships Cs(E,ń) were obtained for the applied geometries and a SiO2 matrix to support routine measurements. The SiO2 matrix is widely encountered in environmental spectrometry. This relationship was derived by fitting the computed data with the function Cs(E,ń) in the form proposed by Bolivar. It was shown that while handling this function to samples with the H2O matrix, the error involved in estimations would not exceed 3%.
Źródło:
Nukleonika; 2006, 51,suppl.2; 21-25
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-ray computed tomography as a tool to evaluate porosity changes along depth for surface crusted soils
Autorzy:
Pires, L. F.
Bacchi, O. O. S.
Reichardt, K.
Dias, N. M. P.
Powiązania:
https://bibliotekanauki.pl/articles/146838.pdf
Data publikacji:
2007
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma-ray attenuation
soil density
soil structure
soil surface sealing
241 Am
applied nuclear physics
gamma tomography
Opis:
Assessment of changes in porosity (ö) along depth for soils with surface crusting is difficult because conventional soil physical investigation tools are destructive and usually require a long period of time for preparation and analysis of the samples. Computed tomography (CT) has frequently been used as a method to evaluate soil structure in a nondestructive, sensitive, and rapid manner. CT data can be used for measuring at a millimetric scale changes in ö along depth for soils with surface crusting. The main objective of this work was to investigate the sensibility of the gamma-ray CT to assess soil structural changes along depth in samples presenting structural crust. CT images were taken with a first generation scanner of 1.14 mm resolution along eight different soil layers within the 0 28 mm depth. Porosity increased along depth up to the 14 17.5 mm layer. Through the analysis of the ö distribution of each layer it was possible to show that the sealed surface layer presented ö values of approximately 30%, while the other layers were greater than 30% up to 60% (macropore regions). The sealing crust thickness was estimated to be in the range of 2.3 3.5 mm.
Źródło:
Nukleonika; 2007, 52, 3; 125-131
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bone powder as EPR dosimetry system for electron and gamma radiation
Autorzy:
Ziaie, F.
Hajiloo, N.
Fathollahi, H.
Mehtieva, S. I.
Powiązania:
https://bibliotekanauki.pl/articles/148156.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
bone powder dosimeter
EPR response
dose rate
electron beam
gamma ray
Opis:
In this work bovine bone powder samples were irradiated at three different dose rates of 100, 260 and 630 kGy/min for the absorbed dose range of 3 to 110 kGy, using 10 MeV electron beam radiation. The samples were subjected to EPR measurement at room temperature in air. The variation of EPR signal intensities were constructed and evaluated base on quantitative data related to the absorbed doses. Moreover, they were compared with the obtained results from the samples irradiated by a 60Co gamma-ray source with a dose rate of 2.65 kGy/h. The time and temperature effects on the EPR response of this dosimeter were also studied. The results indicated that the bone sample was a suitable dosimeter especially for electron beam at high doses.
Źródło:
Nukleonika; 2009, 54, 4; 267-270
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distributed radiation monitoring system for linear accelerators based on CAN bus
Autorzy:
Kozak, T.
Makowski, D.
Napieralski, A.
Powiązania:
https://bibliotekanauki.pl/articles/397933.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
obszar pod kontrolą sieci
dozymetria promieniowania gamma
dozymetria promieniowania neutronowego
akcelerator liniowy
controller area network
gamma radiation dosimetry
neutron radiation dosimetry
radiation sensing Field Effect Transistor
linear accelerator
X-ray free electron laser
Opis:
Gamma and neutron radiation is produced during the normal operation of linear accelerators like Free-Electron Laser in Hamburg (FLASH) or X-ray Free Electron Laser (X-FEL). Gamma radiation cause general degeneration of electronics devices and neutron fluence can be a reason of soft error in memories and microcontrollers. X-FEL accelerator will be built only in one tunnel, therefore most of electronic control systems will be placed in radiation environment. Exposing control systems to radiation may lead to many errors and unexpected failure of the whole accelerator system. Thus, the radiation monitoring system able to monitor radiation doses produced near controlling systems is crucial. Knowledge of produced radiation doses allows to detect errors caused by radiation, schedule essential replacement of control systems and prevent accelerator from serious damages. The paper presents the project of radiation monitoring system able to monitor radiation environment in real time.
Źródło:
International Journal of Microelectronics and Computer Science; 2010, 1, 1; 52-55
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-Ray Spectrometry Laboratory for high-precision measurements of radionuclide concentrations in environmental samples
Autorzy:
Jodłowski, P.
Kalita, S. J.
Powiązania:
https://bibliotekanauki.pl/articles/148485.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma-ray spectrometry
environmental samples
efficiency
self-absorption
coincidence summing
Opis:
The paper outlines the methodology used in the Gamma-Ray Spectrometry Laboratory for high-precision measurements of radionuclide activity concentrations in environmental samples. The Laboratory equipment includes a semiconductor detector HPGe with a 42% relative efficiency. The detector is placed in a Pb housing made of bricks 10 cm in thickness. Three measurement geometries are considered: Marinelli beakers 710 cm3 in volume and two cylindrical geometries 121 and 48 cm3 in volume. In the efficiency calibration (E = 32 division sign 1836 keV) mixed gamma standard solutions were used. Obtained experimental efficiency values epsilon were fitted with two quadratic functions. The junction point is that equivalent to 200 keV. Uncertainty of the calibration curve is 2% for E > 200 keV. The relationship between the total efficiency and the energy epsilon t(E) was also found for energies E = 33 division sign 1250 keV. Self-absorption correction factors Cs are calculated by the method proposed by K. Debertin, the uncertainty level being 1 division sign 2% for E > 100 keV. These correction factors are calculated by an original computer program. Coincidence summing correction factors Cc for the selected nuclides are derived using the ETNA computer program, basing on the relationships epsilon(E) and epsilon t(E). Minimum detectable activity (MDA) for selected nuclides encountered in environmental samples was determined for the water matrix. The methodology used was successfully verified in the course of international intercomparison measurements.
Źródło:
Nukleonika; 2010, 55, 2; 143-148
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena typu zailenia w skałach piaskowcowo-ilastych na podstawie danych geofizyki otworowej - metoda wykresów krzyżowych
Evaluation of shale distribution in shaly-sand rocks on the basis of well logging data - the crossplots method
Autorzy:
Bała, M.
Powiązania:
https://bibliotekanauki.pl/articles/183775.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
zailenie
porowatość
profilowania geofizyki otworowej
profilowanie gamma
wykresy krzyżowe
shaliness
porosity
well logging data
gamma ray
crossplots
Opis:
W pracy przeanalizowano wpływ obecności frakcji ilastej na rejestrowane w otworach wartości profilowań geofizyki otworowej. Wykorzystując koncepcję przedstawioną po raz pierwszy przez Thomasa & Stiebera (1975), przeprowadzono obliczenia "odpowiedzi" sond w założonym modelu piaskowcowo-ilastym o zróżnicowanych miąższościach. Porównano wyniki modelowań z rzeczywistymi krzywymi, zarejestrowanymi w otworze J4 w interwale występowania utworów miocenu autochtonicznego. Wykonane wykresy krzyżowe na podstawie pomiarów sondą neutronową i gamma, gęstościową i akustyczną potwierdzają możliwość określenia zarówno typu zailenia, jak i poprawnej porowatości oraz udziału frakcji piaskowcowej (tzw. net to gross) w warstwach złożowych. Wykres krzyżowy oparty na pomiarach gamma i oporności pozwala na rozdzielenie warstw nasyconych wodą i gazem.
The analysis of effects of shale distribution and clay volume in reservoir formations on well logging curves is presented in this paper. A conception given originally by Thomas & Stieber (1975) was applied into modelling the response of well logging tools for an assumed shaly-sand model. Results of calculations were compared with logs registered in the J4 well which drilled the autochthonous Miocene deposits. Different crossplots obtained based on Gamma Ray and Neutron and Density or Acoustic logs prove that there is a possibility to determine porosity, shale distribution and sand volume (net to gross) in the reservoir horizons.
Źródło:
Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie; 2010, 36, 2; 223-239
0138-0974
Pojawia się w:
Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radioactivity of some building and raw materials used in Croatia
Autorzy:
Sofilić, T.
Barišić, D.
Sofilić, U.
Đuroković, M.
Powiązania:
https://bibliotekanauki.pl/articles/778819.pdf
Data publikacji:
2011
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
radioaktywność
materiały budowlane
popiół lotny
spektometr promieniowania gamma
skuteczna dawka roczna
radioactivity
building materials
fly ash
Gamma-ray spectrometer
annual effective dose
Opis:
In the present study, the activity concentrations of 226Ra, 232Th, 40K in some building and raw materials used in Croatia were measured by using a gamma-ray spectrometer with the HPGe detector. The average activity concentrations of the studied different building and raw materials ranged from 11.6 š 1.7 (concrete) to 251.2 š 25.7 Bqkg-1 (GBFS), 14.0 š 2.7 (concrete) to 54.4 š 8.3 (coal fly ash) and 147.2 š 19.0 (concrete) to 773.7 š 82.0 Bqkg-1 (tuff) for 226Ra, 232Th and 40K, respectively. Radium equivalent activity, activity concentration index, absorbed gamma dose rate indoor due to the external exposure and corresponding annual effective dose were determined to estimate the exposure risk arising due to the use of these building and raw materials.
Źródło:
Polish Journal of Chemical Technology; 2011, 13, 3; 23-27
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł

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