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![Figure 3: Neutron energy spectrum from a nuclear fission reactor [17].](profile/Roberto-Hazenfratz-Marks/publication/330339084/figure/fig2/AS:732490448781312@1551650740190/Neutron-energy-spectrum-from-a-nuclear-fission-reactor-17_Q320.jpg)
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Regulations governing explosives have often included requirements to provide information about the manufacturer, type, and batch of a commercially produced explosive. The first method of encoding information about an explosive was simply writing desired information on the explosive's packaging. Marking explosives in this way can be considered the f...
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... The INAA nuclear analytical technique was employed, which involves neutron bombardment of the elements contained in the sample to produce artificial radioactive isotopes, which are then identified and measured. This analytic method presents a high degree of sensitivity, accuracy and precision since it can determine various chemical elements simultaneously, thus allowing a description of the elemental chemical composition of different clays (Munita et al., 2019). As mentioned, the aim of this analysis was to verify the existence of two different pastes. ...
This article sets out to broaden our knowledge of the sociopolitical dynamics of Santarém (AD 1000–1600), a regional society in the Lower Amazon, by synthesizing the existing archaeological data relating to settlement patterns, ritual ceramics, prestige goods and chronology, as well as exploring aspects linked to the technology of ceramic production at the Carapanari site, a small-scale community located in the region during the late precolonial period. Using an integrated approach, the research combines a techno-functional analysis of a sample basically composed of ceramic fragments, providing information on the original forms and possible uses, with microscopy and compositional analyses of fragments based on instrumental neutron activation analysis. This enables the identification of technological choices, processes of innovation and behavioral changes, also present at other sites in the region that are expressed over time. The set of information presented here engages with recent debates on the emergence of complex societies, providing some insight into the historical development of this polity in Amazonia during the late precolonial period.
... The energy of the neutrons developed from the fusion are controlled or deducted by using heavy water, graphite, light water and beryllium like substances which encircle the core of the reactor. Fast flux, epithermal flux and thermal flux are the main energy states of neutrons in a reactor which is presented in a spectrum as shown in Figure 5. [35] Some common neutron sources are Specifically 226 Ra (Be), 124 Sb (Be), 241 Am (Be), 252 Cf are neutron isotopic sources which emit neutrons with distinct energy distributions of 3-4 MeV with a total output of 10 5 -10 7 s À1 GBq À1 or in case of 252 Cf, 2.2 Â 10 12 s À1 g À133 . The most common reactions 2 H( 2 H, n) 3 He and 3 H( 2 H, n) 4 He result in deuterium ions that are accelerated toward the target which either contains deuterium or tritium that are the most prevalent forms of neutron generators. ...
For proper functioning of the human body, several metals are required in different concentrations but if their concentration slightly elevates, because of any metal-contaminated environment or of other food sources, which leads to high toxicity and different chronic health issues. Different analytical techniques like atomic absorption spectroscopy, X-ray fluorescence, inductively coupled plasma- mass spectroscopy (ICP-MS) and flame atomic absorption spectroscopy are used for metals analysis present in different samples in different fields but nowadays neutron activation analysis (NAA) is preferred over other analytical techniques because it is an efficient, multi-elemental, nondestructive analytical technique having an ultralow minimum detection limit, therefore it can detect heavy metals (HMs) even if at a very trace level parts per billion (ppb) with a quite simple sample preparation technique. This technique is known as "referee technique" because of its accuracy and trustworthiness. There is a widespread use of this technique in biomedical science like in Alzheimer's disease, cancer, arthritis, metabolism study, brain tumor and in many more conditions where metals are actively present. For its typical sample sizes and due to a multitude of additional benefits, it also helps in mapping of pathophysiology of the disease. Besides all, mainly in biomedical science the biological samples can easily be analyzed irrespective of any form. In recent years NAA is preferred over other analytical techniques in several research fields, so this article focuses on the analytical technique, its general principle and recent applications.
... developed by CANBERRA, was used to analyze γ-ray spectra [10]. Equation 1 describes the comparative method in which it is assumed that the neutron flux, crosssection, irradiation times, and all other variables associated with the count are identical for both the standard and sample [11]. ...
Brazilian coastal terraces contain abundant evidence that can be used to explain how the coastal plain evolved during the last 120k years. These studies include geochronology of marine sediments based on physical methods of dating by dosimetry, especially thermoluminescence. To determine terrace age by luminescence dosimetry methods is necessary to determine the exact mass fractions of 238U, 232Th and 40K. The values for these mass fractions are used to calculate the annual dose rate of ionizing radiation. In this context, in the present work, we studied eight marine sediment samples collected in the city of São Vicente on the coast of São Paulo state, Brazil, and determined the mass fractions of elements 238U, 232Th and 40K through instrumental neutron activation analysis (INAA) and γ-ray spectroscopy. The mathematical method of linear regression was used to evaluate the precision of the analytical methods. The results indicate excellent correlations with R2 values above 0.71. The resulting mass fractions can calculate dose rates in these sediments, thus contributing to their dating.
... Among other available methods, neutron activation analysis (NAA) is one of the most promising analytical techniques for determination of poorly studied trace elements. The NAA enables to get information about concentrations of up to 40 elements in one sample without pre-treatment of the sample before analysis (Munita et al. 2019). The latter option is very important, since any additional step used before determining very low concentrations of elements can lead to unwanted analytical errors and, as a consequence, to incorrect results of the analysis. ...
Up to now, information about biogeochemistry of many trace elements is scarce. Meanwhile, all the elements are always present in soil and plants. It may be suggested that the trace elements also play certain role in the biogeochemical processes. The aim of the research was to study bioaccumulation of poorly investigated trace elements (scandium, cerium, europium, hafnium, and tantalum) and well-known elements (chromium, iron, cobalt, zinc, and arsenic) in two crops, oats and barley, and examine how these elements interact with each other as they absorbed by plants. The plants were grown in the soils that differed in their parameters and in level of contamination. Although oats and barley are botanically similar and were grown under the same conditions, the plants differed in the ability to accumulate many elements. The uptake of the elements by the plants also depended on type of soil. For example, concentrations of Cr, Fe, Co, As, Sc, Ce, Eu, Hf, and Ta in roots of the oats grown in slightly contaminated soil were much higher as compared to the concentrations of the elements in roots of the barley grown in the same soil. In leaves of the oats grown in moderately contaminated soil, the concentrations of Cr, As, Ce, Eu, and Ta were statistically significantly higher than those in leaves of the barley grown in the soil. In soils and in plants, relationships between elements were both similar and different. A statistically significant correlation was found between the poorly investigated trace elements and well-studied elements.
... Due to its recognized high accuracy for trace element analysis INAA has been widely used for calibration of other methods and plays a relevant role as reference technique against traditional methods [92]. Our intercomparison study of INAA vs ICP-OES (see Section 3.1.4), ...
A new instrumental neutron activation analysis (INAA) for the simultaneous determination of titanium (TiO2) and silica (SiO2) dioxide as UV-filters in sunscreens is described. Samples are encapsulated, neutron irradiated (30 s) and after a suitable decay (3 min), the induced ⁵¹Ti (T1/2 = 5.76 min) and ²⁹Al (T1/2 = 6.56 min) radionuclides are measured for the emitted γ-ray fingerprint. Three applications were carried out: (i) screening study (analysis of commercial sunscreens in combination with single particle inductively coupled plasma mass spectrometry (sp-ICP-MS); (ii) research study (development of innovative UV-filters such as titanium dioxide or bismuth titanate loaded inorganic mesoporous silica nanoparticles, MSN); (iii) validation study (intercalibration of a spectrochemical method (inductively coupled plasma optical emission spectrometry, ICP-OES). Collectively, the nuclear method appears a powerful tool adequate for quantifying TiO2 and SiO2 in the above studies. The limited accessibility at the nuclear reactor for neutron activation is probably one of the reasons why the excellent characteristics of the nuclear technique are not always fully known and exploited in the industrial and research chemical world.
... A análise por ativação com nêutrons se baseia no bombardeamento com nêutrons dos elementos presentes numa amostra para produzir isótopos radioativos artificiais os que são identificados e quantificados [9,10]. A versão instrumental da análise, INAA, não requer a dissolução da amostra com reagentes químicos. ...
... A interação do nêutron incidente com o núcleo alvo do átomo, mediante uma colisão inelástica ou captura (entre outros), produz um núcleo composto em estado altamente energético, que volta para condições estáveis de forma imediata. O radioisótopo resultante emite partículas ou raios gama atrasados (delayed gamma rays) característicos de cada elemento num processo espontâneo e estatístico de transformação de átomos, conhecido como decaimento radioativo e governado pela meia-vida do radioisótopo [10]. A meia-vida é o período necessário para o decaimento da metade do número de átomos radioativos iniciais, que pode ir desde minutos até muitos anos, no caso dos elementos determinados em amostras de sedimento e de cerâmica. ...
... O grupo tem utilizado desde o começo a técnica multielementar de INAA, que está baseada no bombardeamento com nêutrons dos elementos presentes numa amostra para produzir isótopos radioativos artificiais, que são identificados e medidos (Glascock, 1992;Munita et al., 2019). A fonte de nêutrons usada pelo grupo é o reator nuclear de pesquisas do IPEN (no Centro do Reator de Pesquisas -CRPq), no qual os nêutrons são produzidos como resultado da fissão termal induzida por nêutrons de urânio ( 235 U). ...
... Tem-se utilizado a técnica de ressonância paramagnética eletrônica (daqui em diante, EPR, pela sua sigla em inglês), também conhecida como ressonância de spin eletrônico, 3 Ver Glascock e Neff (2003) e Munita et al. (2019). 4 Ver a seção "A matemática envolvida: breve descrição", neste artigo. ...
Resumo: O presente artigo traz uma revisão da principal literatura produzida pelo Grupo de Estudos Arqueométricos do Instituto de Pesquisas Energéticas e Nucleares, Comissão Nacional de Energia Nuclear, de São Paulo (IPEN-CNEN/SP), criado em 1997, como consequência de uma iniciativa internacional para motivar o uso de técnicas nucleares para caracterização de materiais arqueológicos. Desde aquele momento, e até hoje, o grupo tem desenvolvido parcerias com pesquisadores/as de diferentes regiões do Brasil e de outros países para oferecer subsídios à compreensão interdisciplinar das cadeias operatórias de produção da cerâmica. Além disso, também vem aportando dados para o estudo multielementar e mineralógico de depósitos arqueológicos. Ao descrever brevemente os princípios das técnicas empregadas e a síntese dos resultados obtidos para cada estudo de caso, o objetivo foi demonstrar a contribuição das análises físico-químicas para questões relacionadas a aspectos culturais, como escolhas tecnológicas compartilhadas, redes de trocas e interações sociais em diferentes períodos do passado.
... This aspect is very important when archaeological and cultural objects are analyzed. In addition, it is also possible to determine several elements simultaneously with high sensitivity, precision and accuracy [4][5][6][7] This paper aims to study ceramic provenance in southwest Amazonia by means of chemical characterization of pottery sherds from the Monte Castelo shellmound. In order to establish the chronology of the samples, the thermoluminescence technique, TL, was used. ...
... During the procedure, a standard containing a known quantity of elements of interest is irradiated together with an unknown sample. The principle of the method are given elsewhere [3][4][5][6][7]. ...
... The TL measurements were performed using a Risø TL/OSL Luminescence Reader Model TL/OSL DA-20 equipped with a 90 Sr/ 90 Y β radioactive source with a dose rate of 0.081 Gy/s. The annual dose value was estimated from uranium, thorium and potassium concentrations obtained by INAA [3][4][5][6][7]. ...
This research aims to contribute to the discussion of ceramic objects found at the Monte Castelo shellmound, an archaeological site located at south-west Amazonia, Brazil. This paper provides the results of a preliminary characterization of eighty-four pottery samples using instrumental neutron activation analysis (INAA) and dating by thermoluminescence (TL). The results showed the existence of three different chemical groups whose dates range from 3000 to 1500 BP. confirming changes in clay sources during that period. These results agree with previous studies about the technological changes and continuities in the Bacabal phase, one of the oldest ceramic cultures of South America.
Chemical sensors are detecting probes that translate information of analyte into a quantifiable signal for chemical exploration studies. Fabrication of (E)-2-(5-chloro-2-hydroxy-3-iodobenzylidene) hydrazine-1-carboxamide stabilized silver nanoparticles (1c-AgNPs) is one-dimensional synthesis avenue in present study exhibiting the ability of metal cations detection and selectivity of sensing mercury (Hg²⁺) ions in various samples of water and cosmetic creams. The newly synthesized silver nanoparticles (AgNPs) were comprehensively elucidated by ultraviolet-visible spectroscopy, Fourier-transform infrared (FTIR), zeta-sizer, atomic force microscopy (AFM), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and thermal degradation analysis. 33.2 ± 1.3 nm sized polydispersed nanoparticles showed selective, sensitive and efficient detection of Hg²⁺ ions with detection limit of 0.274 µM by significant quenching in UV-Vis spectral band at 410 nm in real water and cosmetic cream samples. The theoretical findings displayed changes in reactive descriptors, electronic parameters, bond angles, and bond lengths of 1c and conjugated AgNPs using DFT method. The biological application of 1c-AgNPs showed significant synergistic potential as antibacterial agent against Escherichia coli and Staphylococcus aureus compared to ligand. Thus, the newly engineered 1c-AgNPs could be a favorable appliance in nature and health restoration.
