Wyniki wyszukiwania - Biblioteka Nauki

1

Target preparation of RbCl on a copper substrate by sedimentation method for the cyclotron production of no-carrier-added 85Sr for endotherapy

100%

Sadeghi M. , Alipoor Z. , Kakavand T.

Nukleonika

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2010

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tom Vol. 55, No. 3

303-306

EN

85Sr was produced via the 85Rb(p,n)85Sr reaction. Rubidium chloride deposition on copper substrate was carried out via the sedimentation method in order to produce strontium-85. Optimum conditions were achieved as a result of several repeated experiments with different amount of ethyl cellulose (EC) and acetone. 520 mg of RbCl, 208 mg of EC 4 mL of acetone were used to prepare a layer of enriched rubidium chloride of 11.69 cm2 area and 62.2 mg/cm2 thickness. Target quality control was done by a SEM photomicrograph and a thermal shock test. The deposited target was irradiated at a 20 ěA current and a 15 MeV proton beam for 30 min. No degradation was observed. The RbCl surface following bombardment was white, except the central area that was light brown and also without any crack or peeling off.

2

Nuclisome - a novel strategy for radionuclide cancer therapy

100%

Ickenstein L. M. , Gedda L. , Carlsson J. , Sjoberg S. , Edwards K.

Cellular and Molecular Biology Letters

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2005

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tom 10

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nr Suppl.

3

The National Standard Unit of Radionuclide Activity and the related standards in Poland

88%

Chyliński A. , Broda R. , Radoszewski T.

Nukleonika

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2003

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tom Vol. 48, nr 1

51-55

EN

The idea of functioning and technical realization of the National Standard Unit of Radionuclide Activity established in Poland by President of the Central Office of Measures is presented in this paper. The Radioisotope Centre POLATOM has been appointed as depositary of that National Standard. The detection circuits as well as the absolute methods of measurements used to realize the standard unit are described. Application of a liquid scintillation technique was emphasized, and the determination accuracy of measurements has been presented. All kinds of the secondary standards, prepared in the RC POLATOM for application in isotope laboratories of nuclear medicine and in industrial and scientific centres, are related to the National Standard by a chain of presented comparisons. Relationship between the National Standard Unit of Radionuclide Activity and the international system of standards has been realized in the RC POLATOM by taking part in international comparisons of the measurement results.

4

Classification of rocks radionuclide data using machine learning techniques

75%

Khan A. R. , Mir A. A. , Saeed S. , Rafique M. , Asim K. M. , Iqbal T. , Jabbar A. , Rahman S. U.

Acta Geophysica

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2018

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tom Vol. 66, no. 5

1073--1079

EN

The aim of this study is to assess the performance of linear discriminate analysis, support vector machines (SVMs) with linear and radial basis, classification and regression trees and random forest (RF) in the classification of radionuclide data obtained from three different types of rocks. Radionuclide data were obtained for metamorphic, sedimentary and igneous rocks using gamma spectroscopic method. A P-type high-purity germanium detector was used for the radiometric study. For analysis purpose, we have determined activity concentrations of 232Th, 226Ra and 40K radionuclides, published elsewhere (Rafique et al. in Russ Geol Geophys 55:1073–1082, 2014), in different rock samples and built the classification model after pre-processing the data using three times tenfold cross-validation. Using this model, we have classified the new samples into known categories of sedimentary, igneous and metamorphic. The statistics depicts that RF and SVM with radial kernel outperform as compared to other classification methods in terms of error rate, area under the curve and with respect to other performance measures.

5

Radiological assessment of atmospheric release from Tehran Research Reactor during normal operation by using Pc-Cream code

75%

Sadeghi N. , Ahangari R.

International Letters of Natural Sciences

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2016

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tom 54

EN

In this work, radiological assessment of atmospheric release from Tehran’s Research Reactor (TRR) stack and assessment of public exposures under normal operation has been studied. To perform tasks mentioned above, Pc-Cream computer code which simulates Gaussian Dispersion air transport plume model as well as laboratory analysis of the soil and leaves samples and TLD (Thermo Luminescent Dosimeter) monitoring around the TRR site was used. Results of the Pc- Cream code showed that the annual committed and external dose received by the individual in the vicinity of the reactor is below the regulatory limit. Also, the results of laboratory analysis of available radionuclides in the soil and leaves samples showed that the concentrations are close to the background (K40=635, Th232=28, Cs137=0.29 up to 28.82, Ra226=25 (Bq1/Kg) in soil and K40=457, Be7≈70 (Bq/Kg) in leaves) and confirm the code results. The monitored dose values of the TLD detectors were positioned around the reactor within 500 m radius shows that the background dose in vicinity of TRR (113 μSv up to 150 μSv) is consistent with the background dose in Tehran province (125 μSv).

6

Water Quality and Radionuclides Content Assessment of the Al-Najaf Sea: Case Study

75%

Zwain H. M. , Almurshedi K. R. , Vakili M. , Dahlan I. , Naje A. S.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 2

262--271

EN

The Al-Najaf state is witnessing an increased economic development and attracting more investments that require the development of new areas and exploring new water resources. This study evaluates the quality of 12 surface water samples and groundwater from 12 wells for irrigation according to the salinity and sodicity hazards based on electrical conductivity (EC) and sodium adsorption ratio (SAR). In addition, the concentrations of radionuclides, which include Thorium (232Th), Uranium (238U), Potassium (40K) and Cesium (137Cs) were tested in four soil samples in the study area. It was found that the average values of pH, total hardness, Na, Ca, Mg, K, Cl, SO4, NO3 for groundwater and surface water were 8 and 6, 2287 and 4006 mg/L, 1140 and 1232 mg/L, 378 and 637 mg/L, 327 and 587 mg/L, 2 and 2 mg/L, 989 and 2007 mg/L, 1149 and 1325 mg/L, as well as 2 and 2 mg/L, respectively. From salinity and sodicity hazards analysis, the groundwater had EC of 5242 µS/cm and SAR of 61, whereas surface water had EC of 6253 µS/cm and SAR of 50. Furthermore, the concentrations of radionuclides, i.e. 232Th, 238U, 40K and 137Cs in the soil samples were found to be 11.02, 34.12, 544.45, and 1.6 Bq/kg, respectively. The concentrations of radionuclides were within the worldwide baseline, expect for 40K. The study concluded that both water sources are classified as very high salinity and sodium water (class C4-S4), and it cannot be used for irrigation, only suitable for the salt tolerant crops.

7

Radionuclides in ground-level air and deposits near the Ignalina NPP

75%

Jasiulionis R. , Savickaite I.

Nukleonika

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2001

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tom Vol. 46, nr 4

183-187

EN

Abstract Results of systematic measurements of radionuclide activity concentrations in the air and deposits from January 1997 to July 2000 near the Ignalina Nuclear Power Plant (hereafter detoted as NPP) are presented. The data on NPP produced radionuclides 60Co and 54Mn in deposits and results of calculation are used for establishment of their distribution near NPP. Water-soluble and water-insoluble radionuclide fractions in the airborne effluents of NPP were investigated. The possibility to evaluate the deposition factor of water-soluble and water-insoluble radionuclides from the NPP jet by comparing the experimental data in the NPP stack and the environment is shown.

8

Mobile forms of radionuclide 137 Cs in sandy soils in Northeastern Poland

75%

Niesiobedzka K.

Polish Journal of Environmental Studies

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2000

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tom 09

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nr 2

EN

Mobile forms of radionuclide 137Cs in different soils (natural pastures) of northeastern Poland were evaluated. An attempt was made to show if and what mobile forms of 137Cs are related to different soil properties. For this reason 108 soil samples from 0 to 10 cm in depth were measured for mobile forms of 137Cs activity and analyzed for clay fraction, pH-value, exchangeable potassium (Kex.), exchangeable calcium (Caex.), magnesium (Mgex.), sodium (Naex.) content, organic matter and organic carbon content (C org.), and cation exchange capacity (CEC). Samples of soils were collected in the period from June 1995 to July 1996. The radiocaesium and mobile forms of 137Cs activity were determined by gamma spectrometry. The mobility of 137Cs was studied by means of sequential extraction. Mobile forms of radionuclide l37Cs were related to physicochemical parameters of soils.

9

Accumulation of radionuclides by mushrooms in the Western Region of Ukraine

75%

Hrabovskyy V. , Dzendzelyuk O.

Acta Agrophysica

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2002

|

tom 67

10

The influence of soil parameters on the 137Cs soil-to-plant transfer factors

75%

Niesiobedzka K.

Polish Journal of Environmental Studies

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1996

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tom 05

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nr 5

EN

The transfer of radionuclide l37Cs from uncultivated different soils (natural pastures) to grass in northeastern Poland was evaluated. Samples of soil and grass were collected from the same area of about 1 m2 in the period from June 1994 to July 1995 twice a year. Grass was sampled from 1 m x 1 m squares by cutting to the plant base. The 137 Cs and 40K activity concentrations were determined by gamma spectrometry. The average concentration of 137Cs (to 10 cm depth) in the studied soils ranged from 17.94 Bq/kg to 37.78 Bq/kg dry weight. The average concentration of radiocesium in grass varied from 1.03 Bq/kg to 12.33 Bq/kg dry weight and depended upon the type of soil.

11

Pesticides and radionuclides in human's environment and disorders in endocrine system

75%

Molozhanova O. , Chaika Y.

Folia Histochemica et Cytobiologica. Supplement

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2001

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tom 39

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nr 1

12

Migration of strontium, cesium, europium and uranium from poly(methyl styrene)- and polystyrene - phosphate composites prepared using gamma radiation

63%

Alhassanieh O. , Ajji Z.

Nukleonika

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2012

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tom Vol. 57, No. 3

369-374

EN

Composites consisting of natural phosphate powder and two monomers (styrene or methyl styrene) have been prepared by means of gamma irradiation. The polymerization reaction was followed up using a thermogravimetric analyzer (TGA) to determine the conversion of the polymerization. Differential scanning calorimeter (DSC) was used to locate and determine the glass transition temperature (Tg) of the prepared samples. The distribution of 137Cs, 152Eu, 85Sr and 238U in a solid-aqueous system, composites of phosphate-poly(methyl styrene) and of phosphate-polystyrene in contact with groundwater, was investigated using alfa-spectrometry and fluorometry. The effects of contact time, pH, and the concentration of concurrent element (Ca) were studied. The results were compared with earlier results with phosphate alone in the solid phase. The ability of the produced composites to keep the studied radioisotopes in the solid phase is much higher than in the mineral phosphate. This improvement is more remarkable for strontium and cesium than for europium and uranium, due to their high element ratio in the solid phase in phosphate experiments.

13

Radionuclides content in tissues and organs of pumpkinseed Lepomis gibbosus (Linnaeus, 1758) from the Zaporizhzhia (Dnipro) reservoir

63%

Marenkov O. M. , Nasterenko O. S.

International Letters of Natural Sciences

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2020

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tom 79

EN

The article presents the results of studies on the content of artificial (¹³⁷Cs, ⁹⁰Sr) and natural radionuclides (²²⁶Ra, ²³²Th, ⁴⁰K) in tissues and organs of various individuals of pumpkinseed Lepomis gibbosus (Linnaeus, 1758) from the Zaporizhzhia (Dnipro) reservoir. It has been revealed that in the bones of sexually mature pumpkinseed females, the content of radionuclides ¹³⁷Cs and⁹⁰Sr is 24.7% and 28.6% less, respectively, than in the bones of males. Summing up the materials of radioecological studies of 2017–2018, the following sequence of tissues and organs of the pumpkinseed by the ability to accumulate radionuclides was obtained: bone> muscle> scales> gills. Research results can be useful for further study on the fish radiation load in the basins of the Dnipro River and during monitoring radioecological research. It was determined that the content of radionuclides in the pumpkinseed muscles did not exceed the permissible levels of radionuclide content for fish as a food product (permissible levels of radionuclide content for ¹³⁷Cs – 150 Bq/kg, ⁹⁰Sr – 35 Bq/kg).

14

Natural radioactivity in underground waters

63%

Walencik A. , Kozlowska B. , Dorda J. , Szlapa P. , Zipper W.

Polish Journal of Environmental Studies

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2010

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tom 19

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nr 2

461-465

EN

Nine underground water springs from the Szczawno-Jedlina health resort and one from Zagorze Śląskie were investigated for natural radioactivity content (²²²Rn, ²²⁶,²²⁸Ra, ²³⁸,²³⁴U). In order to obtain the necessary data, two different nuclear spectrometry techniques were applied: a liquid scintillation counter that enabled us to determine ²²²Rn and ²²⁶,²²⁸Ra isotope content, and α spectrometer for measurements of uranium isotopes (²³⁴,²³⁸U) in investigated samples. The activity concentrations of ²²²Rn in investigated samples varied from 6 Bq/l to 227 Bq/l. For radium isotopes the concentrations ranged from 13 mBq/l to 808 mBq/l for ²²⁶Ra and from below 30 mBq/l to 184 mBq/l for ²²⁸Ra. The activity concentrations for uranium isotopes varied from 2.4 mBq/l to 964 mBq/l for ²³⁴U, and from 1.0 mBq/l to 725 mBq/l for ²³⁸U. The isotopic ratios between uranium and radium isotopes (²²⁶Ra/²²⁸Ra, ²²⁶Ra/²³⁸U, ²³⁴U/²³⁸U) and annual effective doses due to these isotopes’ consumption were evaluated. Risk levels due to carcinogenic effects of ²²⁶,²²⁸Ra and ²³⁴,²³⁸U radionuclides consumed with water were estimated.

15

Studium literaturowe nad zdolnością sorpcyjną technetu-99 oraz strontu-90 w warunkach zróżnicowania fizykochemicznego osadów geologicznych

63%

Miecznik M.

Technika Poszukiwań Geologicznych

|

2012

|

tom R. 51, nr 1

73-85

PL

Migracja pierwiastków promieniotwórczych z warstw powierzchniowych gleby poprzez kolejne warstwy osadów geologicznych ma ogromne znaczenie ze względu na przedostawanie się potencjalnego zagrożenia radiologicznego do warstw wodonośnych, a przez to do ujęć wody pitnej i użytkowej. Obecność antropogenicznych radionuklidów w środowisku jest związana zarówno z występującymi w przeszłości awariami obiektów jądrowych, takich jak katastrofa w Czarnobylu, próbnych testów jądrowych jak i coraz częstszego wykorzystywania tych pierwiastków w przemyśle i medycynie nuklearnej. Poniższa praca ma na celu nakreślenie poprzez studium literaturowe własciwości fizykochemicznych pierwiastków strontu i technetu, w celu określenia ich potencjału sorpcyjnego do osadów geologicznych z okolic Krajowego Składowiska Odpadów Promieniotwórczych w Różanie (ok. 90 km na NE od Warszawy). Omówione zostały tutaj czynniki zewnętrzne mające wpływ na sorpcyjność danego pierwiastka, takie jak pH, rodzaj osadu geologicznego, obecność mikroflory bakteryjnej jak i innych pierwiastków w warstwie wodonośnej. Sam mechanizm sorpcji także może być różny dla różnych pierwiastków. Wyniki tej analizy posłużą w przyszłości do przygotowania eksperymentu polegającego na doświadczalnej ocenie potencjału sorpcyjnego osadów geologicznych pobranych w rejonie KSOP w Różanie, jak i czułość strontu i technetu pod względem sorpcyjności na pozostałe czynniki mogące wystąpić w badanym środowisku.

EN

Migration of radionuclides from the surface through the underground geological layers has a great meaning because of their radiological hazard during a contact with underground water and possible infiltration into useable and drinking water. Anthropogenic radionuclides presence in the environment is the effect of both past breakdowns of nuclear objects like the Czarnobyl reactor damage, nuclear weapon tests and more common usage of radionuclides in the industry and nuclear medicine. The goal of this paper is to highlight physicochemical characteristic of strontium and technetium based on the literature study to find out their sorption potential to the geological sediments present in National RadioactiveWaste Repository area at Różan (about 90 km to the NE from Warsaw). This paper discusses different parameters having influence on the strontium or technetium sorption potential like pH, type of geological sediment, bacterium occurrence or other elements presence in the groundwater. The sorption mechanism may also differ among different elements. Conclusions from this analysis will be the base to the planning of experiment which assumes the measurement of the discussed sorption potential of geological sediments sampled in the National Radioactive Waste Repository area at Różan for strontium and technetium.

16

Chitozan jako alternatywny sorbent w procesie usuwania Am-241 z rozcieńczonych roztworów wodnych

63%

Oszczak-Nowińska A.

Przemysł Chemiczny

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2020

|

tom T. 99, nr 12

1777--1779

PL

Przeprowadzono syntezę sferycznego sorbentu na bazie chitozanu. Określono jego zdolność sorpcyjną, a także możliwości użycia do usuwania radionuklidu Am-241 z rozcieńczonych roztworów wodnych. W celu określenia zdolności sorpcyjnej chitozanu wyznaczono współczynniki dekontaminacji oczyszczanych roztworów oraz wartości współczynników podziału. Symulację rozkładu kompleksów Am(III) w zależności od pH roztworów wykonano za pomocą programu Medusa. Określono trwałość termiczną sorbentu, wykorzystując analizę termograwimetryczną sprzężoną z różnicową kalorymetrią skaningową i spektrometrią mas. Wykazano, że chitozan może stać się alternatywnym sorbentem do oczyszczania roztworów zawierających ciekłe odpady promieniotwórcze.

EN

Spheric chitosan sorbent was prepd. and used for removal of Am-241 from its aq. solns. The sorbability was detd. as decontamination factor and distribution coeff. The parameters depended on pH of soln. and were highest in alkaline solns. The thermogravimetric anal. coupled with differential scanning calorimetry and mass spectrometry were used to det. the thermal stability of the sorbent. Water and CO2 were found in the decompn. products.

17

Radiation background of the dumps of some Donbass coal mines

63%

Vorobjov S. , Kredencer S. , Kudlenko V.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

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2010

|

tom 10D

18

Concentrations of 137Cs, 40K radionuclides and some heavy metals in soil samples of Chocholowska Valley from Tatra National Park

63%

Kubica B. , Kwiatek W. M. , Stobinski M. , Skiba S. , Skiba M. , Golas J. , Kubica M. , Tuteja-Krysa M. , Wrona A. , Misiak R. , Krzan Z.

Polish Journal of Environmental Studies

|

2007

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tom 16

|

nr 5

723-729

EN

This paper presents the results of determination of artificial 137cs and natural 40K activity concentrations and some heavy metals in soil samples from the region of one of the main valleys of Tatra National Park (Chochołowska). Our investigation concentrated on 137Cs and heavy metal levels in mountain soil taken from Chochołowska Valley, which revealed great variability in their concentration. The results show considerably small amounts of radionuclides 137cs and 40K in the soils. Larger amounts of those elements can be found in the organic surface horizons of the soils. The evaluation of the content of those elements must be based on the bulk density analysis of the soil.

19

Budget of 90Sr in the Gulf of Gdansk (Southern Baltic Sea)

63%

Saniewski M. , Zalewska T.

Oceanologia

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2018

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tom 60

|

nr 3

20

Radionuclides in deposition in the Ignalina NPP region in 2005

63%

Jasiulionis R. , Rožkov A.

Open Physics

|

2006

|

tom 4

|

nr 4

417-428

EN

Results of radionuclide activity concentration measurements in deposition and ground-level air conducted at the station of the Institute of Physics situated 3.5 km from the Ignalina Nuclear Power Plant (Ignalina NPP) in 2005 are analyzed. Atmospheric depositional fluxes of 7Be, 60Co and 137Cs are estimated. Radionuclide particle deposition rates are calculated. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model of the global dispersion and deposition is used to explain variations in the 137Cs activity concentration in the ground-level air in the Ignalina NPP region in 2005. An increase in the 137Cs activity concentration of up to 17.4 µBq m−3 on 30 October-5 November is studied. Modelling results show that the Chernobyl NPP Unit 4 Sarcophagus and the radiocaesium resuspension from the Chernobyl NPP accident polluted regions are sources of 137Cs to the environment of the Ignalina NPP. Results on solubility in water of aerosols - carriers of 137Cs - are discussed.