scholarly journals Alpha Radiation-Induced Luminescence by Am-241 in Aqueous Nitric Acid Solution

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1602 ◽  
Author(s):  
Thomas Kerst ◽  
Rikard Malmbeck ◽  
Nidhu Banik ◽  
Juha Toivonen
Keyword(s):  
Nitric Acid ◽  
Sample Volume ◽  
Alpha Particles ◽  
Alpha Radiation ◽  
Broadband Emission ◽  
Light Production ◽  
Steep Decrease ◽  
Radiation Induced ◽  
Luminescence Process ◽  
Aqueous Nitric Acid

When exposed to air, alpha particles cause the production of light by exciting the molecules surrounding them. This light, the radioluminescence, is indicative of the presence of alpha radiation, thus allowing for the optical sensing of alpha radiation from distances larger than the few centimeters an alpha particle can travel in air. While the mechanics of radioluminescence in air and other gas compositions is relatively well understood, the same cannot be said about the radioluminescence properties of liquids. Better understanding of the radioluminescence properties of liquids is essential to design methods for the detection of radioactively contaminated liquids by optical means. In this article, we provide radioluminescence images of Am-241 dissolved in aqueous nitric acid ( HNO 3 ) solution and present the recorded radioluminescence spectrum with a maximum between 350 nm and 400 nm , and a steep decrease at the short wavelength side of the maximum. The shape of the spectrum resembles a luminescence process rather than Cerenkov light, bremsstrahlung, or other mechanisms with broadband emission. We show that the amount of light produced is about 150 times smaller compared to that of the same amount of Am-241 in air. The light production in the liquid is evenly distributed throughout the sample volume with a slight increase on the surface of the liquid. The radioluminescence intensity is shown to scale linearly with the Am-241 concentration and not be affected by the HNO 3 concentration.

Electrochemical behaviour of galena (PbS) in aqueous nitric acid and perchloric acid solutions

2004 ◽  
Vol 34 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Yu. Mikhlin ◽  
A. Kuklinskiy ◽  
E. Mikhlina ◽  
V. Kargin ◽  
I. Asanov
Keyword(s):  
Nitric Acid ◽  
Perchloric Acid ◽  
Electrochemical Behaviour ◽  
Acid Solutions ◽  
Aqueous Nitric Acid

scholarly journals Direct Observation of Ion Pairing in Aqueous Nitric Acid Using 2D Infrared Spectroscopy

2018 ◽  
Vol 123 (1) ◽  
pp. 225-238 ◽  
Author(s):  
Nicholas H. C. Lewis ◽  
Joseph A. Fournier ◽  
William B. Carpenter ◽  
Andrei Tokmakoff
Keyword(s):  
Infrared Spectroscopy ◽  
Nitric Acid ◽  
Direct Observation ◽  
Ion Pairing ◽  
Aqueous Nitric Acid

scholarly journals Modeling of Respiratory System Dysfunction among Nuclear Workers: A Preliminary Study

Dose-Response ◽  
2008 ◽  
Vol 6 (4) ◽  
pp. dose-response.0 ◽  
Author(s):  
Z.D. Belyaeva ◽  
S.V. Osovets ◽  
B.R. Scott ◽  
G.V. Zhuntova ◽  
E.S. Grigoryeva
Keyword(s):  
Cigarette Smoking ◽  
Respiratory System ◽  
Respiratory Function ◽  
Radiation Doses ◽  
Alpha Radiation ◽  
Nuclear Workers ◽  
Chronic Radiation ◽  
Mayak Production Association ◽  
Radiation Induced ◽  
Total Body

Numerous studies have reported on cancers among Mayak Production Association (PA) nuclear workers. Other studies have reported on serious deterministic effects of large radiation doses for the same population. This study relates to deterministic effects (respiratory system dysfunction) in Mayak workers after relatively small chronic radiation doses (alpha plus gamma). Because cigarette smoke is a confounding factor, we also account for smoking effects. Here we present a new empirical mathematical model that was introduced for simultaneous assessment of radiation and cigarette-smoking-related damage to the respiratory system. The model incorporates absolute thresholds for smoking- and radiation-induced respiratory system dysfunction. As the alpha radiation dose to the lung increased from 0 to 4.36 Gy, respiratory function indices studied decreased, although remaining in the normal range. The data were consistent with the view that alpha radiation doses to the lung above a relatively small threshold (0.15 to 0.39 Gy) cause some respiratory system dysfunction. Respiratory function indices were not found to be influenced by total-body gamma radiation doses in the range 0–3.8 Gy when delivered at low rates over years. However, significant decreases in airway conductance were found to be associated with cigarette smoking. Whether the indicated cigarette smoking and alpha radiation associated dysfunction is debilitating is unclear.

scholarly journals Application of the Electret in Alpha Radiation Sensor to Measure the Concentration of Radon in Selected Ambient Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Adam Gubanski ◽  
Jan Kupracz ◽  
Paweł Kostyla ◽  
Dominika Kaczorowska ◽  
Jerzy Wrobel
Keyword(s):  
Charge Density ◽  
Radon Concentration ◽  
Radioactive Decay ◽  
Reference Electrode ◽  
Alpha Particles ◽  
Measuring System ◽  
Ambient Conditions ◽  
Alpha Radiation ◽  
Effective Surface ◽  
Radiation Sensor

A novel electret sensor, made from a polytetrafluoroethylene (PTFE) foil, is proposed for monitoring of radon concentration in closed spaces. A triode air system was implemented to form the electret foil. In order to calibrate the electret sensor, the ionization chamber with the electret embedded at its bottom, was placed in an emanation chamber containing radon of known concentration. The change in the effective charge density of the electret resulting from the interaction of the electret sensor with ionizing radiation, make it possible to determine the degree of its response to the radon concentration in the examined environment. The electric charge of the electret sensor was evaluated at the beginning and at the end of the concentration measurement using a field chopper. The measurement of the value of the electric field between the electret and the reference electrode directly corresponds to the effective surface charge density of the electret. The measuring system was calibrated in values of the electret equivalent voltage of Uz. In order to assess the electret properties, both the thermostimulated charge relaxation (TSQ) method and the thermostimulated discharge current (TSDC) method were used to evaluate corresponding parameters. These investigations led to the optimization of the electret formation process for the maximum sensitivity to the effects of alpha particles resulting from radon radioactive decay.

scholarly journals Radiation-Stimulated Epigenetic Reprogramming of Adaptive-Response Genes in the Lung: An Evolutionary Gift for Mounting Adaptive Protection against Lung Cancer

Dose-Response ◽  
2008 ◽  
Vol 7 (2) ◽  
pp. dose-response.0 ◽  
Author(s):  
Bobby R. Scott ◽  
Steven A. Belinsky ◽  
Shuguang Leng ◽  
Yong Lin ◽  
Julie A. Wilder ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Adaptive Response ◽  
Risk Model ◽  
Epigenetic Reprogramming ◽  
Histone Deacetylation ◽  
Early Years ◽  
High Dose ◽  
Alpha Radiation ◽  
Adaptive Protection ◽  
Radiation Induced

Humans are continuously exposed to low-level ionizing radiation from natural sources. However, harsher radiation environments persisted during our planet's early years and mammals survived via an evolutionary gift - a system of radiation-induced natural protective measures (adaptive protection). This system includes antioxidants, DNA repair, apoptosis of severely damaged cells, epigenetically regulated apoptosis ( epiapoptosis) pathways that selectively remove precancerous and other aberrant cells, and immunity against cancer. We propose a novel model in which the protective system is regulated at least in part via radiation-stress-stimulated epigenetic reprogramming (epireprogramming) of adaptive-response genes. High-dose radiation can promote epigenetically silencing of adaptive-response genes ( episilencing), for example via promoter-associated DNA and/or histone methylation and/or histone deacetylation. Evidence is provided for low linear-energy-transfer (LET) radiation-activated natural protection (ANP) against high-LET alpha-radiation-induced lung cancer in plutonium-239 exposed rats and radon-progeny-exposed humans. Using a revised hormetic relative risk model for cancer induction that accounts for both epigenetic activation ( epiactivation) and episilencing of genes, we demonstrate that, on average, >80% of alpha-radiation-induced rat lung cancers were prevented by chronic, low-rate gamma-ray ANP. Interestingly, lifetime exposure to residential radon at the Environmental Protection Agency's action level of 4 pCi L−1 appears to be associated with on average a > 60% reduction in lung cancer cases, rather than an increase. We have used underlined italics to indicate newly introduced terminology.

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