Epithermal Neutron Activation Analysis Research Articles

Investigation of the Specific Activity of Al-0.1%Au Wire for Epithermal Neutron Activation Analysis for Nirr-1 After Conversion from Heu to Leu

The significance that Epithermal Neutron Activation Analysis (ENAA) play in the field of science research, technology and innovations and how humans interact with elemental components in food chain and environment, has led to the development of ENAA protocol in research reactors. Epithermal neutrons, which have energy between 0.5 eV and 0.5 MeV, are increasingly needed by reactor clients. In this study, we have examined the activity of the flux monitor in the irradiation site of the inner channel (A1) of Nigeria Research Reactor-1 (NIRR-1) after its conversion to low enriched uranium fuel. The flux monitor (Al-0.1%Au thin wires) was washed with acetone, dried for 2 minutes, weighed to be 0.0122 g, and was thereafter placed in a 15.0 mm internal diameter polyethylene vials that has 1 mm wall thickness for irradiation. The activity of flux monitor Al-0.1%Au wire of 0.0122 g was calculated to be 5 x 108 count/s.g using A1 inner channels of the Cd line. This value obtained in this our studies found to be consistent with previous result and has shown that the epithermal channel A1 of the NIRR-1 remain suitable for ENAA after the reactor’s fuel conversion from HEU to LEU.

Design of an epithermal neutron velocity selection system for the Penn State Breazeale Reactor

A series of mechanical neutron choppers to operate as a velocity selection system have been developed for the Pennsylvania State Breazeal Reactor (PSBR). This chopper system will provide pulsed epithermal neutrons in the energy range of 0.5–40 eV with 2% or better energy resolution, and with a transmission of 1E-6 or better. Four different chopper geometries have been evaluated for their utility as mechanical neutron choppers. Specifically, Fermi, ring, piston, and disc choppers have been evaluated to assess their potential neutronics performance and mechanical constructability. A series of high-speed disc choppers were selected for the final design, and optimization work was performed to maximize the neutron pulse intensity. It is estimated that the optimized system will produce an epithermal neutron intensity of approximately 96 n/s. This system can also be operated in a time of flight (TOF) configuration such that the neutrons arriving at the source have a white spectrum. This operation can be accomplished by leaving the second stage of choppers in the open position, or by removing it from the beam completely. Such unique source of epithermal neutrons produced by this chopper system will have applications in both prompt and delayed epithermal neutron activation analysis (ENAA), as well as in neutron resonance transmission analysis (NRTA).

Analysis of seven micronutrients in breast milk of lactating mothers from the Central Region of Ghana using epithermal neutron activation

Background: Breast milk contains various micronutrients which nourishes a baby with nutrition, and therefore the endorsement for exclusive breastfeeding during the first six months after birth. Such micronutrients, if in excess, can have adverse effects on the baby.
 Objective: The levels of seven micronutrients in breast milk obtained from 27 lactating mothers in the Cape Coast Metropolitan area have been determined using Epithermal Neutron Activation Analysis (ENAA). This technique was used because it is suitable for performing both qualitative and quantitative multi-nutritional analyses on samples, and offers accuracies and sensitivities superior to those attainable by other methods.
 Materials and Methods: During the analysis, a- 3 mm thick flexible boron was used to cut-off thermal neutrons so as to assess epithermal neutrons, thereby creating an activation energy which measured the levels of micronutrients in the breast milk. The standard reference materials used were the International Atomic Energy Agency (IAEA)-336; IAEA-407, IAEA-350 and National Institute of Standard and Technology (NIST) USA SRM 1577b. The Relative standardization method was used in the quantification of the micronutrients, with an accuracy of about 94.7 %. The micronutrients are Sodium (Na), Magnesium (Mg), Potassium (K), Calcium (Ca), Manganese (Mn), Copper (Cu) and Iodine (I).
 Results: Except for iodine which had levels below the recommended dietary allowance (RDA), the remaining micronutrients had levels above the upper limit of the RDA, with Manganese being the highest.
 Conclusion: The levels recorded are directly linked to the food intake of the mothers, and therefore the need for pregnant and lactating mothers to be mindful about what they eat. Children could be exposed to metabolic disorders and diseases as a result of such high levels.

Development of a PC program for the k0-based epithermal neutron activation analysis

Development of a PC program for the k0-based epithermal neutron activation analysis

The epithermal neutron activation analysis of mineral ores driven by an electron linear accelerator-based photoneutron source

Analyzing concentrations/grades for interested valuable elements in mineral ores with low detection limit, high accuracy, high precision and high assay speed is essential in the whole processing chain for economic benefits. In this work, a method using delayed gamma rays from neutron activation, based on an e-LINAC driven photoneutron source and a high-purity germanium detector, is introduced. It fulfills the requirements in analysis of gold ores including low detection limit (0.1 g/t), high precision and high assay speed (several minutes per sample for fulfilling the standard requirements). Comparing to the traditional method of fire assay, this method shows the advantages of low labor consumption, low time consuming, no toxic pollution, multi-element analysis ability and non-destruction.

Factors conditioning the content of chemical elements in soil and mosses in Armenia

In this research, chemical element contents were determined using the Epithermal neutron activation analysis (Cr, V, Ti, Sr, Rb, As, Zn, Co, Fe, Mn and Ba) and atomic-absorption spectrometry (Cu and Pb) for mosses and X-ray fluorescence spectroscopy (Cr, V, Ti, Sr, Rb, As, Zn, Cu, Co, Fe, Mn, Pb, and Ba) for soil samples. The research team combined compositional data analysis and geospatial mapping to reveal key factors conditioning moss and soil chemical composition. The results showed that significant correlation was detected between Cr, Sr, Rb, As, and Pb for Syntrichia ruralis moss and soil contents suggesting their origin stemming from soil resuspension. Meanwhile, in the case of pleurocarpus (Homalothecium philippeanum) moss species, the mechanisms conditioning the transfer of elements to mosses from dead or living plant materials were found to be responsible for mosses Zn, Sr, Mn, Rb, As, Ba, Cu contents. Both media were identified to display multivariate outliers in the same sampling sites which were characterized by the presence of natural mineralization and mining and smelting activities. The compositional PCA and k-means clustering show that the soil element content groupings are in line with the geological base, whereas in the case of mosses, the rural and urban gradient plays a pivotal role in the spatial separation of the identified clusters. In addition, moss samples included in a cluster representing the urban areas of the country have included typical anthropogenic elements (Pb, Cu, Zn etc.) confirming the applicability of the studied mosses in pollution source identification.

Heavy Metal Atmospheric Deposition Study in Azerbaijan Based on Moss Technique and Neutron Activation Analysis

Abstract The results of this investigation show that Azerbaijan industries and agricultural sector provide considerable anthropogenic impact on the environment of Caucasus. The use of moss biomonitoring technique and neutron activation analysis (NAA) is a first attempt to study heavy metal atmospheric deposition in Azerbaijan, a country different relief and climate. The study was undertaken in the summer of 2015 of atmospheric deposition of man-made heavy metal pollutants in the area of mining and processing plant in Gadabay and Dashkasan mininig district. At the same time samples were collected from the Goygol State Reserve in the Lesser Caucasus not far from the city of Ganja. A total 85 moss samples (predominantly Pleurozium schreberi) collected in both environmentally contrast area. Elemental determination was carried out by epithermal neutron activation analysis (ENAA) at the reactor IBR-2 of Joint Institute for Nuclear Research (FLNP JINR). For the first time 44 elemental concentrations were determined (Na, Mg, Al, Si, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Mo, Ag, Cd, In, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Tm, Yb, Hf, Ta, W, Au, Th, U). Multivariate statistical analysis of the analytical results obtained will make it possible to identify the main sources of pollution and to assess the role of long-range transport of pollutants.

The features of heavy metals and metalloids accumulation in the phytomass of the amphipodous moss <i>Pleurozium schreberi</i> (Brid.) Mitt. in the conditions of the Krasnosamarsky Forest area (Samara Region) and the National Park «Buzuluksky Bor» (Orenburg Region)

The paper analyzes ecological and geochemical features of the moss Pleurozium schreberi (Brid.) Mitt., growing in artificial pine plantings of the National Park Buzuluksky Bor (Orenburg Region) and the Krasnosamarsky Forest (Samara Region). The research has been carried out within the framework of the International Program ICP Vegetation (https://icpvegetation.ceh.ac.uk), on the practical use of some bryophyte species in the environmental monitoring of multi-element air pollution in the countries of Western and Eastern Europe and a number of other countries. In the National Park Buzuluksky Bor and the Krasnosamarsky Forest, where species diversity and ecological characteristics of bryophytes have been studied for several years, the phytomass of the moss Pleurozium schreberi has been selected. This species is included in the species list proposed by the organizers of the research work under the UNECE ICP Vegetation Program. A multi-element analysis of Pleurozium schreberi phytomass has been carried out on the basis of the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research in Dubna using instrumental epithermal neutron activation analysis (ENAA). The biogeochemical similarity of the moss Pleurozium schreberi from the Krasnosamarsky Forest and Buzuluksky Bor, estimated by the concentration coefficients, has manifested itself in relation to a large group of heavy metals and metalloids, characterized by a relatively low ability to accumulate in its phytomass (Ti, V, Cr, Fe, Co, As, Se, Rb, Sr, Mo, Cd). Some differences have been revealed in relation to the elements with the maximum accumulation: Cu and Zn in the Krasnosamarsky Forest area, Mn and Ni - in the Buzuluksky Bor. A relatively low content of most of the analyzed heavy metals and metalloids in the soil of the studied territories as well as in the phytomass of the biomonitor moss Pleurozium schreberi allows us to consider them to be background for the steppe zone of the European part of the Russian Federation.

Iodine determination in edible algae species using epithermal neutron activation analysis methodology

Iodine is one of the essential trace elements of much interest in nutritional research being responsible for the production of the thyroid hormones, which has great importance for human metabolism. Edible algae species accumulate iodine from seawater and are considered a good dietary source of this nutrient. The Epithermal Neutron Activation Analysis (ENAA) was applied to determine the iodine concentration in edible algae species and derivatives. Twenty-one samples for 4 edible algae species Porphyra umbilicalis (common name: Nori), Hijikia fusiforme (Hijiki), Undaria pinnatifida (Wakame) and Laminaria spp. (Kombu) and 3 samples of the derivative sample, ágar, were analyzed. The results pointed out a great variability of I concentration in these species. The highest I concentration obtained was 9324±113 mg/kg in Laminaria spp. (Kombu). Hijikia fulsiforme (Hijiki) also presented high values (1803±86 mg/kg). The lowest I content was obtained in agar samples (3.18±0.29 mg/kg). All analyzed algae samples exceed the recommended value (150 µg/day) and an ingestion of 1 g/day of Laminaria spp. (Kombu) exceed the maximum tolerable limit (1100 μg/day) and its consumption must be controlled to avoid possible health problems.

First Results on Moss Biomonitoring of Trace Elements in the Central Part of Georgia, Caucasus

The moss biomonitoring technique was used for assessment of air pollution in the central part of Georgia, Caucasus, in the framework of the UNECE ICP Vegetation. A total of 35 major and trace elements were determined by two complementary analytical techniques, epithermal neutron activation analysis (Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Se, B, Rb, Sr, Zr, Mo, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Yb, Hf, Ta, W, Th, and U) and atomic absorption spectrometry (Cu, Cd, and Pb) in the moss samples collected in 2019. Principal Component Analyses was applied to show the association between the elements in the study area. Four factors were determined, of which two are of geogenic origin (Factor 1 including Na, Al, Sc, Ti, V, Cr, Fe, Co, Ni, Th, and U and Factor 3 with As, Sb, and W), mixed geogenic–anthropogenic (Factor 2 with Cl, K, Zn, Se, Br, I, and Cu) and anthropogenic (Factor 4 comprising Ca, Cd, Pb, and Br). Geographic information system (GIS) technologies were used to construct distributions maps of factor scores over the investigated territory. Comparison of the median values with the analogous data of moss biomonitoring in countries with similar climatic conditions was carried out.

Major and Trace Element Content of Tribulus terrestris L. Wildlife Plants.

The genus Tribulus L. (Zygophyllaceae) includes 12 species, the most important of which is Tribulus terrestris L. This annual herb grows in temperate and tropical climates, and has a rich chemical composition of biologically active substances and chemical elements. Medicinal plants, and the phytopreparations obtained from them, are becoming more and more popular in world practice as they are used to successfully treat human diseases. Their therapeutic effect is due to the presence in them, of a variety of natural compounds and biologically important trace elements, especially in higher concentrations present in higher doses. T. terrestris is becoming more and more popular for the treatment of diseases of the human genital area and sexual dysfunctions. The elemental content in the tissues of leaf, flower, and fruit of T. terrestris was determined by using multi-element instrumental epithermal neutron activation analysis. For the first time, 26 essential and trace elements were observed in the plant species collected in Russia (from cultivated) and China (wild growing). It was confirmed that the elemental composition of T. terrestris grass varies depending on the habitat (geographic zones). The place of growth affects the accumulation of elements by the plant.

MACRO- AND MICROELEMENTS DISTRIBUTION IN URBANIZED ECOSYSTEMS OF KARELIA

The aim was to study the distribution of macro-and microelements in the main urban ecosystems of Karelia. Methods. Samples of soil, vegetation, surface water, sediments and biota (fish) were taken. In total, 300 samples were collected. The analysis of the material was carried out using epithermal instrumental neutron activation analysis (INAA), x-ray spectral analysis (XRF), and atomic absorption spectrometry (AAS) with "cold steam" and inductively coupled plasma spectrometry (ICP-MS). Concentration of 32 chemical elements in soil, birch leaves, sediments, water and biota (fish) was determined. Results. The distribution of macro- and microelements in soil and vegetation of these main cities of Karelia was determined. Geochemical profiles of distribution of elements in soils and vegetation were constructed. Concentration of heavy and toxic metals in the samples of water and sediments was close to the background values. High concentration of mercury in the muscles of predatory fish was found (CHg = 0.2÷0.3 mcg/kg). Conclusions. The levels of total accumulation of heavy and toxic metals in the soil of Petrozavodsk are classified as hazardous (Zc = 56), and soil pollution in Pitkyaranta, Sortavala and Suoyarvi is considered moderately dangerous (Zc = 15-31). A high degree of correlation between the concentration of elements in the soil and birch leaves was found. The water in lake Ladoga, lake Onega, and lake Suoyarvi in terms of the concentration of the elements presented in the article meets the Russian standards for drinking water.

Chronological and chemical approaches to obsidians from Bakla Tepe and Liman Tepe, Western Anatolia

In this study, the provenance of 42 obsidians from the Chalcolithic and Early Bronze Age levels of two settlements – Bakla Tepe and Liman Tepe – located on the Aegean coast of Anatolia were investigated with an interdisciplinary approach using fission-track (FT) dating, Instrumental Neutron Activation Analysis (INAA) and Epithermal Neutron Activation Analysis (ENAA). Some artefacts showed FT ages of a few thousand years. Apparent FT ages of the remaining samples are distributed over a wide range, from 0.53 ± 0.03 to 1.43 ± 0.20 Ma. After application of the size-correction method, most artefacts were distributed in a homogeneous group characterized by FT ages varying from 1.48 ± 0.47 to 1.80 ± 0.20 Ma, with a mean value of 1.65 ± 0.05 Ma and low induced track density corresponding to low U content. The remaining 3 samples showed relatively high induced track densities. One of them has an apparent age of 0.53 ± 0.03 Ma and a size-corrected age of 1.02 ± 0.07 Ma. The probable potential sources for the studied samples were identified as the island of Melos in the Aegean, and the central Anatolian sources – particularly the Göllüdağ complex – through comparison of the FT data. INAA and ENAA studies have been carried out on 34 artefacts at the TRIGA Mark II research reactor of the University of Pavia. The identification of the sources was attained through cluster analysis of the chemical data. These results agree fully with those obtained by FT dating: most artefacts originated from the Melos–Dhemenegaki flow, and only 3 samples from central Anatolia. The current study provides a contribution to a better understanding of the circulation of obsidians in Anatolia.

Assessment of the ecological and geochemical conditions in surface sediments of the Varzob river, Tajikistan

The aims of present study consist of collecting more information on the geochemistry of the Varzob river unconsolidated sediments as reflecting the diversity of the South-Hissar range together with a comprehensive evaluation of the anthropogenic contamination of the same sediments. Accordingly, the content of nine major, rock forming elements - Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe as well as of other 27 trace ones - Sc, V, Cr, Co, Ni, Zn, As, Br, Rb, Sr, Zr, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Yb, Hf, Ta, W, Th, and U was determined by Epithermal Neutron Activation Analysis. A special attention was given to potential heavy contaminants - V, Cr, Mn, Co, Ni, Zn, As, Sb and Ba whose content was used to calculate more environmental contamination proxies i.e. contamination factor, geoaccumulation, and pollution load indices. At the same time, the content of Cr, Ni, Sc, Zr, REE, Th and U were used to establish the nature and origin of recent sediments. The increased values of some pollution indices characteristic of industrial activity in the upper part of the Varzob River indicate an anthropogenic origin of As, Sb and Mn while the increased contents of Th and U in the lower reaches of the Varzob River could be attributed to the pegmatite field of the Odjuk tributary.

Vertical Distribution of Major and Trace Elements in a Soil Profile from the Nile Delta, Egypt

Abstract The present study was conducted to highlight the elemental composition of ten soil samples collected at different depths along of a soil profile (0.25-17 m). The collected samples were subjected to epithermal neutron activation analysis at the pulsed reactor IBR-2 of Frank Laboratory of Neutron Physics - Joint Institute for Nuclear Research - Dubna - Russian Federation. The concentrations in mg/kg of 36 major and trace elements were determined. Symbatic behaviour of geochemically related elements was observed: Th and U; Cl and Br and Fe, Ti, Ca, Al, and Mg, etc. A sharp increase of certain concentrations at the depth of 8 m was observed. Significant mafic sources of elements were observed and mostly are attributed to Ethiopian High Plateau with small amount of felsic volcanic rocks.

The Geochemistry of 1 ky Old Euxinic Sediments of the Western Black Sea

To get more data on the geochemistry of Black Sea euxinic sediments, a 50-cm core was collected at a depth of 600 m on a Western Black Sea Continental Platform slope. The core contained unconsolidated sediments rich in cocoolithic ooze and mud. Epithermal Neutron and Prompt Gamma Activation Analysis were used to determine the content of nine major (Na, Mg, Al, Si, K, Ca, Ti, Mn, and Fe as oxides) and 32 trace elements (Cl, Sc, V, Cr, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Sn, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Yb, Hf, Ta, W, Th, and U) with a precision varying between 3 and 9%. The core contained unconsolidated sediment rich in coccolithic ooze and mud. Previous 210 Pb geochronology suggests an age of ∼1 ky of considered sediments. Major components distribution showed that, except for Cl and Ca, the contents of all other elements are similar to Upper Continental Crust (UCC) and North American Shale Composite (NASC). The distribution of the 32 trace elements showed similarities to the UCC, except for redox-sensitive metals Fe, Se, Mo, and U, of which the significantly higher content reflects the presence of euxinic conditions during deposition. A chondrite normalized plot of nine rare earth elements indicated a similarity to UCC and NASC, suggesting a continental origin of sedimentary material.

A Ten-Year Biomonitoring Study of Atmospheric Deposition of Trace Elements at the Territory of the Republic of Belarus

Abstract For the third time since 2005 atmospheric deposition of trace elements in Belarus was monitored by the moss technique widely used in Europe for air pollution studies. Samples of moss species of Hylocomium splendens and Pleurozium schreberi were collected at 86 sites over the Gomel, Vitebsk and Minsk Regions in the summer of 2015. A total of 30 elements were determined by epithermal neutron activation analysis. Studying of the temporal trends in Belarus was undertaken with the results obtained in previous moss surveys in 2005/2006 and 2010/2011. Comparison with the analogous data from the neighbouring countries showed relatively low contamination levels in Belarus for the most heavy and toxic elements. The results of survey 2010/2011 showed that, except Cr, other element concentrations reduce or are at the same levels.

Complex investigation of the five 19th century Russian-Lipovan icons

For a better description and chronology of the liturgical art of the Russian-Lipovan community of Romania and, in view of correct attestation, a set of five icons presumed painted in the first half of the 19th century belonging to the patrimony of Antim Monastery (Bucharest) and One-wood Monastery (Valcea county), have been investigated by means of non-invasive Digital Radiography (DR), X-Ray Fluorescence (XRF), Fourier Transform Infrared (FT-IR) and Raman (FT-Raman) Spectroscopy. Only a few fragments being left after some restorations have been analysed by invasive Epithermal Neutron Activation Analysis (ENAA).DR proved a relative good state of conservation of wooden panel evidencing the presence of different metallic artefacts, XRF confirmed the presence of Ca, Cr, Fe, Ba, Ag, Hg, Au and Pb as components of pigments or metallic ornaments, ENAA, although being reduced to only a few fragments, allowed to evidence the presence of Sr, as well as of small amounts of Zn and As, most probably as impurities. Judging on FT-IR data, a protein-rich binder, most probably hen egg yolk was used, suggesting tempera as the main painting technique. Complementarily, FT-Rama spectroscopy showed that in all cases painters had used vermilion, red lead and at a less extent - litharge as red pigments, while white lead, anhydrite, chalk had been used as white pigments or as components of the primer. Only in the case of the most elaborated Saint Nicholas icon, FT-Raman spectroscopy allowed to identify the use of chrome yellow and ultramarine. All data suggest the first half of the 19th century as a possible age of the icon painted in local ateliers belonging to the Russian-Lipovan community of Romania.

Determination of uranium in tree bark samples by epithermal neutron activation analysis

In this study uranium (U) concentrations were determined in certified reference materials (CRMs) and in tree bark samples collected in “Cidade Universitária Armando de Salles Oliveira” (CUASO) USP, São Paulo. The barks were collected from different species namely Poincianella pluviosa and Tipuana tipu. These bark samples were cleaned, dried, grated and milled for the analyses by epithermal neutron activation analysis method (ENAA). This method consists on irradiating samples and U standard in IEA-R1 nuclear reactor with thermal neutron flux of 1.9 x 1012 n cm-2 s-1 during 40 to 60 seconds depending on the samples’ matrices. The samples and standard were measured by gamma ray spectroscopy. U was identified by the peak of 74.66 keV of 239U with half life of 23.47 minutes. Concentration of U was calculated by comparative method. For analytical quality control of U results, certified reference materials were analyzed. Results obtained for CRMs presented good precision and accuracy, with |Z score| ≤ 0.39. Uranium concentrations in tree barks varied from 83.1 to 627.6 ng g-1 and the relative standard deviations of these results ranged from 1.8 to 10 %.

Moss and Lichen Biomonitoring of Atmospheric Pollution in the Western Cape Province (South Africa)

For the first time, the atmospheric deposition of trace elements was investigated in two regions (Cape Winelands and Cape Peninsula) of the Western Cape Province of the Republic of South Africa (RSA) using naturally growing mosses and lichens. A total of 33 elements were determined by epithermal instrumental neutron activation analysis (INAA). Multivariate statistical analysis was used to identify and characterize different pollution sources.