Radiation Induced Oxidation Reactions of Ferrous Ions: An Agent-based Model

A.L. RIVERA1,2,*, A.S. RAMOS-BERNAL1 , A. NEGRÓN-MENDOZA

1 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México. Circuito Exterior S/N, Ciudad Universitaria, Coyoacán, 04510 Ciudad de México, México.

2 Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México.

*E-mail: ana.rivera@nucleares.unam.mx

Abstract:
Chemical Fricke dosimeter in the laboratory can be submitted to gamma radiation at low temperatures to study the evolution of oxidation reactions induced by radiation, a key process to understand the formation of complex molecules. Products generated by the interaction of the different elements under radiation can be determined through a mathematical model that considers chemical reactions as coupled nonlinear ordinary differential equations involving the mass balance of all the species in the reaction. In this paper is implemented an alternative way of solving this system of equations, species’ concentrations are calculated through an agent-based model implemented in Python. The model is a modified version of the prey-predator model where each chemical specie involved is considered as an agent that can interact with other specie with known reaction rates leading to production (source terms) and to destruction (sink terms). Here, the radiation is a factor that affects product formation while the bath temperature modifies the reaction speed. This model can reproduce experimental concentrations of products and the consumption of ferrous ions from a laboratory reaction of irradiation of iron salt solutions at 3 different temperatures (dry ice, liquid nitrogen, and room temperature).

DOI: https://doi.org/10.15415/jnp.2017.51002

LINK: http://dspace.chitkara.edu.in/jspui/bitstream/1/862/1/51002_JNP_%20RIVERA%20-%20NEGRON.pdf

Atomic Multiplet and Charge Transfer Effects in the Resonant Inelastic X-Ray Scattering (RIXS) Spectra at the Nickel L2,3 Edge of NiF2

J JIMÉNEZ-MIER,1,* P OLALDE-VELASCO,2 P DE LA MORA,3 W-L YANG,4 AND J DENLINGER4

1 Instituto de Ciencias Nucleares, UNAM, 04510 Ciudad de México, México
2 Instituto de Física, Benemérita Universidad Autónoma de Puebla, Puebla, A. Postal J-48 Puebla,         Puebla 72750, Mexico
3 Facultad de Ciencias, UNAM, 04510 Ciudad de México, México
4 The Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, CA 94720, USA

 *Email: jimenez@nucleares.unam.mx

Abstract Resonant inelastic x-ray scattering (RIXS) is used to study the electronic structure of NiF2 , which is the most ionic of the nickel compounds. RIXS can be viewed as a coherent two-steps process involving the absorption and the emission of x-rays. The soft x-ray absorption spectrum (XAS) at the metal L2,3 edge indicate the importance of atomic multiplet effects. RIXS spectra at L2,3 contain clearly defined emission peaks corresponding to d-excited states of Ni2+ at energies few eV below the elastic emission, which is strongly suppressed. These results are confirmed by atomic multiplet calculations using the Kramers-Heisenberg formula for RIXS processes. For larger energy losses, the emission spectra have a broad charge-transfer peak that results from the decay of hybridized Ni(3d)-F(2p) valence states. This is confirmed by comparison of the absorption and emission spectra recorded at the nickel L and fluorine K edges with F p and Ni d partial density of states using LDA + U calculations. Keywords: Core-level spectroscopies. RIXS, Nickel difluoride, Electronic structure

To read full paper please click here;
http://dspace.chitkara.edu.in/jspui/bitstream/1/861/1/51001_JNP_JIMENEZ.pdf

The Indoor Radon Concentration within the Tunnels of the Cholula Pyramid Through a Nuclear Tracks Methodology

DOI

10.15415/jnp.2016.41008

AUTHORS

A. Lima Flores, R. Palomino-Merino, E. Espinosa, V. M. Casta ño, E. Merlo Juárez, M. Cruz Sanchez, G. Espinosa

ABSTRACT

Global organizations, including the World Health Organization (WHO), the Environmental Protection Agency of the United States (US-EPA) and the European Atomic Energy Community (EURATOM) recognize that radon gas as one of the main contributors to environmental radiation exposure for humans. Accordingly, a study and analysis of the indoors radon concentrate in the Cholula Pyramid contributes to understand the Radon dynamic inside of the Pyramid tunnels and to evaluate the radiological health risk to visitors, archaeologists, anthropologists and persons who spend extended periods inside the Pyramid. In this paper, the radon measurements along the Pyramid tunnels are presented. The Nuclear Track Methodology (NTM) was chosen for the measurements, using a close end-cup device developed at the Dosimetry Application Project (DAP) of the Physics Institute UNAM, following very well established protocols for the chemical etching and reading with the Counting Analysis Digital Imaging System (CADIS). The Cholula Pyramid consists of eight stages of constructions, each built in different periods of time. Cholula Pyramid is recognized as the pyramid with the largest base in the World, with 400 meters per side and 65 meters high. The tunnels of the pyramid were built in 1931 by architect Ignacio Marquina, with the aim of exploring and studying the structure. The results show an important indoor radon concentration in the measured tunnels, several times higher than levels recommended by United States Environmental Protection Agency (US-EPA). The recommendation will be to mitigate the radon concentration levels, in order to avoid unnecessary exposition to the people.

KEYWORDS

Indoor radon, radon concentration, Nuclear Track Methodology, Cholula pyramid

LINK: http://jnp.chitkara.edu.in/abstract.php?id=476#exactabstracts

REFERENCES

• Childs, E. Teotihuacan ceramics, chronology and cultural trends. Distrito Federal: Insti-tuto Nacional de Antropología e Historia, (2001).
• Cruz, M. Levantamiento topográfico de los túneles de la Gran Pirámide de Cholula. Proyecto de Integración Arqueológico, Histórico y Urbano de Cholula, Puebla. Puebla: Instituto Nacional de Antropología e Historia, (2002).
• Espinosa, G. Trazas Nucleares en Sólidos. Distrito Federal: Universidad Nacional Autónoma de México, (1994).
• Espinosa, G. & Gammage, R.B. Measurements methodology for indoor radon using passive track detectors. Appl. Radiat. lsot., 4, 719-723, (1993).
• Espinosa, G., Manzanilla, L., & Gammage, R.B. Radon Concentration in the Pyramid of the Sun at Teotihuacan. Radiation Measurements. 28, 667-670, (1997). http://dx.doi.org/10.1016/S1350-4487(97)00161-3
• Fieischer, R.L., Price, P.B. & Walker, R.M. Nuclear tracks in solids, principles and applications. Berkeley: University of California Press (1975).
• Gammage, R.B. & Espinosa, G. Digital Imaging System for Track Measurements. Radiation Measurements. 28, 835, (1997). http://dx.doi.org/10.1016/S1350-4487(97)00193-5
• Humboldt, A. Vistas de las cordilleras y monumentos de los pueblos indígenas de Amé-rica. Distrito Federal: Siglo XXI Editores, (1995).
• Jiménez, W. El Enigma de los Olmecas. Distrito Federal: Cuadernos Americanos, (1942).
• Matos, E. Excavaciones en la Gran Pirámide de Cholula (1931-1970). Resource Docu-ment. Arqueología Mexicana. http://www.arqueomex.com/ S2N3nProyecto115.html. Accessed 4 April 2016, (2012).
• Marquina, I. Exploraciones en la pirámide de Cholula, Pue. Distrito Federal: Secretaría de Educación Pública, (1939).
• Merlo, E. Cholula, la Roma de Mesoamérica. Resource Document. Arqueología Mex-icana. http://www.arqueomex.com/S2N3nCholula115.html. Accessed 4 April 2016, (2012).
• Noguera, E. La cerámica arqueológica de Cholula. Distrito Federal: Editorial Guaranda, (1954).
• Quinones, E. Codex Telleriano-Remensis: Ritual, Divination, and History in a Pictorial Aztec Manuscript. Texas: University of Texas Press, (1995).
• Reyes, C. El altepetl, orígen y desarrollo. Construcción de la identidad regional náhuatl. Michoacán: El Colegio de Michoacán, (2000).
• Simeon, R. Diccionario de la lengua náhuatl o mexicana. México: Siglo XXI Editores, (1977).
• Solis, F. R., Uru-uela, M. G., Plunket, P., & Cruz, M. La Gran Pirámide de Cholula. Distrito Federal: Grupo Azabache, (2007).
• Uru-uela, M. G., de Guevara, L. & Robles, M. A. Las subestructuras de la Gran Pirá-mide de Cholula. Viejos túneles, nueva tecnología, nuevos datos. Resource Document. Arqueo-logía Mexicana, (2012). http://www.arqueomex.com/S2N3nTuneles115.html. Accessed 4 April 2016.
• US-EPA. Environmental Protection Agency Report No. EPA 400-R-92-011, (1992).

A Scaling Law for L-Shell X-Ray Production Cross Sections Induced by Impact of 4He+, 9Be2+, and N2+ Ions

DOI

10.15415/jnp.2016.41007

AUTHORS

Javier Miranda

ABSTRACT

Experimental results of L-subshell X-ray production cross sections induced by the impact of several ions heavier than protons were compiled in order to propose possible scaling laws. The ions of interest in this work are ⁴He+, ⁹Be²+, and ¹⁴N²+. A feasible universal scaling for the x-ray production cross sections of the Lα (L₃M₄ + L₃M₅) line is based on a reduced velocity parameter ξ R L. In this scheme, the experimental data follow well resolved curves for each ion. A similar scaling for the Lγ line (L₂N₄ + L₁N₂ + L₁N₃ + L₁O₃ + L₁O₂ + L₂N₁ + L₂O₄) is also recommended, based on a different reduced velocity parameter ξ R L1,2. These results appear to be useful for all the studied projectile-target combinations covered in this work, supporting the idea that more theoretical studies in this direction should be done. However, the behavior of the fitting does not seem to follow the previously observed one.

KEYWORDS

X-rays, cross sections, heavy ion impact, PIXE.

LINK: http://jnp.chitkara.edu.in/abstract.php?id=475#exactabstracts

REFERENCES

• Batyrbekov, E., Gluchshenko, N., Gorlachev, I., Ivanov, I., and Platov, A. X-ray production cross section for K-, L- and M-shell by 14 MeV and 19.6 MeV nitrogen.Nucl.Instrum. Meth. B330, 86-90, (2014). http://dx.doi.org/10.1016/j.nimb.2014.04.003
• Brandt W. and Lapicki, G. Energy-loss effect in inner-shell Coulomb ionization by heavy charged particles.Phys. Rev. A 23, 1717-1729, (1981). http://dx.doi.org/10.1103/PhysRevA.23.1717
• Kamiya, M., Kinefuchi, Y., Endo, H., Kuwako, A., Ishii, K., and Morita, S. Projectile-energy dependence of intensity ratio of Lα to Ll x rays produced by proton and 3He impacts on Ho and Sm. Phys. Rev. A 20, 1820-1827, (1979). http://dx.doi.org/10.1103/PhysRevA.20.1820
• Lapicki, G., Mehta, R., Duggan, J.L., Kocur, P.M., Price J.L., and McDaniel, F.D. Multiple outer-shell ionization effect in inner-shell X-ray production by light ions.Phys. Rev. A 34, 3813-3821, (1986). http://dx.doi.org/10.1103/PhysRevA.34.3813
• Malhi, N.B. and Gray, T.J. Measurements of the L-shell X-ray production cross sections of Yb and Au by Li, Be, C, N, F, and Si bombardments.Phys. Rev. A44, 7199-7206, (1991). http://dx.doi.org/10.1103/PhysRevA.44.7199
• Miranda, J., de Lucio O.G., and Lugo-Licona, M. X-ray production induced by heavy ion impact: challenges and possible uses. Rev. Mex. Fís. S53, 29-32, (2007).
• Miranda, J. Evaluation of L-shell X-ray production cross sections by impact of He ions. AIP Conf. Proc. 1544, 101-106, (2013). http://dx.doi.org/10.1063/1.4813466
• Miranda, J., Lugo, M., Murillo, G., Méndez, B., Díaz, R.V., López-Monroy, J., Aspiazu, J., Villase-or, P. L-shell x-ray production cross sections of selected lanthanoids by impact of 4He+, 7Li2+, 10B2+, 12C4+, 16O4+, and 19F3+ ions with energies between 0.50 Mev/u and 0.75 Mev/u, 13th International Conference on Particle Induced X-ray Emission (UFRGS, Porto Alegre, Brazil), (2013a).
• Miranda, J., Murillo, G., Méndez, B., Díaz, R.V., López-Monroy, J., Aspiazu, J., Villase-or, P. L-shell X-ray production cross sections of selected lanthanoids by impact of 7Li2+ ions with energies between 3.50 MeV and 5.25 MeV. Rad. Phys. Chem. 83, 48-53, (2013b). http://dx.doi.org/10.1016/j.radphyschem.2012.09.023
• Murillo, G., Méndez, B., López-Monroy, J., Miranda, J., and Villase-or, P. X-ray Production Cross Sections of Lanthanoids by impact of nitrogen ions. LVII NationalPhysicsCongress (Sociedad Mexicana de Física, Mexico), (2014).
• Murillo, G., Méndez, B., Miranda, J., López-Monroy, J., and Villase-or, P. X-ray Production Cross Sections of Lanthanoids by impact of beryllium ions. LVIII NationalPhysicsCongress (Sociedad Mexicana de Física, Mexico) p. 14, (2015).
• Pajek, M., Banaś, D., Braziewicz, J., Majewska, U., Semaniak, J.,Fijał-Kirejczyk, I., Jaskóła, M., Czarnacki, W., Korman, A.,Kretschmer, W.,Mukoyama, T., and Trautmann, D. Nucl. Instrum. Meth. B 363, 19-23, (2015). http://dx.doi.org/10.1016/j.nimb.2015.08.058
• Pálinkás, J., Sarkadi, L., Schlenk, B., Török, I., Kálmán, G., Bauer, C., Brankoff, K., Grambole, D., Heiser, C., Rudolph, W., Thomas, H.J. Study of the L-shell ionisation of gold by 3.0-18.2 MeV nitrogen-ion bombardment. J. Phys. B 17, 131-145, (1984). http://dx.doi.org/10.1088/0022-3700/17/1/018
• Sarkadi, L. and Mukoyama, T. Study of the L-shell ionisation of gold by 3.0- 18.2 MeV nitrogen-ion bombardment.J. Phys. B 13, 2255-2268, (1980). http://dx.doi.org/10.1088/0022-3700/13/11/017
• Sarkadi,L. and Mukoyama, T. Systematic study of helium-induced L shell ionization cross sections.Nucl. Instr. and Meth. B 61, 167-174, (1991). http://dx.doi.org/10.1016/0168-583X(91)95456-N
• Semaniak, J., Braziewicz, J., Pajek, M., Czyżewski, T., Jaskól, M., Haller, M., and Trautmann, D. L-subshell ionization of heavy elements by carbon and nitrogen ions of energy 0.4–1.8 MeV/amu.Phys. Rev. A 52, 1125-1136, (1995). http://dx.doi.org/10.1103/PhysRevA.52.1125
• Šmit, Ž. and Lapicki, G. Energy loss in the ECPSSR theory and its calculation with exact integration limits.J. Phys. B 47, 055203, (2014). http://dx.doi.org/10.1088/0953-4075/47/5/055203

Theoretical Model to Estimate the Distribution of Radon in Alveolar Membrane Neighborhood

DOI

110.15415/jnp.2016.41006

AUTHORS

J. C. Corona, F. Zaldívar, L. A. Mandujan o-Rosas, F. Méndez, J. Mulia, D. Osorio-González

ABSTRACT

Radon is a naturally occurring radioactive gas which tends to concentrate indoors, easily emanates from the ground into the air, where it disintegrates and emits radioactive particles. It can enter the human body through breathing or ingesting mostly water. When radon inhaled, travels through the respiratory tract to alveoli where the majority is expelled into the environment. Moreover, when ingested in water, it passes into the intestine where it is absorbed and driven from the bloodstream to the lungs; in these organs, due to differences in partial pressures, it is transported to alveoli by simple diffusion process. When radon is not removed, it decays in short-lived solid disintegration products (218Po and 214Po) with high probability of being deposited in biological tissues, causing DNA damage because of the densely ionizing alpha radiation emitted. We propose a semi-empirical, smooth, and continuous pair potential function in order to model the molecular interactions between radon and lung alveolar walls; we use Molecular Dynamics (MD) to determine the gas distribution in an alveolar neighborhood wall, and estimate the quantity thereof it diffuses through the alveolar membrane as a concentration function.

KEYWORDS

Radon distribution; alveolar membrane; molecular dynamics; radon in alveoli

LINK:http://jnp.chitkara.edu.in/abstract.php?id=474#exactabstracts 

REFERENCES

• Chen, J., Chen, Z., Narasaraju, T.,Jin, N. & Liu, L. Isolation of highly pure alveolar epithelial type I and type II cells from rat lungs. Laboratory Investigation. 84,727–735 (2004). http://dx.doi.org/10.1038/labinvest.3700095
• Dobbs L.G., Gonzalez, R., Matthay, M.A., Carter, E.P., Allen, L. &Verkman, A.S. Highly water-permeable type I alveolar epithelial cells confer high water permeability between the airspace and vasculature in rat lung. Cell Biology. 95, 2991–2996 (1998). http://dx.doi.org/10.1073/pnas.95.6.2991
• ] Hill, R. W., Wyse, G. A.& Anderson, M. (2012).Animal Physiology.3rd ed. Sinauer Associates, Inc. Publishers. Sunderland, Massachusetts.
• Jason R. M. (2016).Prediction of Radon-222, Phase Behavior by Monte Carlo Simulation.J. Chem. Eng. Data. Article ASAP. doi: 10.1021/acs.jced.5b01002. http://dx.doi.org/10.1021/acs.jced.5b01002
• Johnson, M. D.,Widdicombe, J. H., Allen, L.,Barbrys, P. & Dobbs, L. G. Alveolar epithelial type I cells contain transport proteins and transport sodium, supporting an active role for type I cells in regulation of lung liquid homeostasis. PNAS. 99(4), 1966-1971(2002). http://dx.doi.org/10.1073/pnas.042689399
• Koulich V. V., Lage, J. L., Hsia, C. C. W. & Johnson, Jr, R. L. A porous medium model of alveolar gas diffusion. J. Porous Media, 2, 263–75 (1999). http://dx.doi.org/10.1615/JPorMedia.v2.i3.4
• Koulich, V., Lage, JL., Hsia, C.C. W.& Johnson, R.L. Jr. Three-dimensional unsteady simulation of alveolar respiration. J Biomed Eng 124, 609–616 (2002).
• National Academy of Sciences.(1999). Risk Assessment of Radon in Drinking Water. Committee on Risk Assessment of Exposure to Radon in Drinking Water, National Research Council. National Academy Press. Washington D.C.
• Nussbaum, E. (1957). Radon Solubility in Body Tissues and in Fatty Acids. Report UR-503. Rochester, NY. University of Rochester.
• Tchorz-Trzeciakiewicz, D. E. &Solecki, A. T. Seasonal variation of radon concentrations in atmospheric air in the NowaRuda area (Sudety Mountains) of southwest Poland. Geochemical Journal, 45, 455-461 (2011). http://dx.doi.org/10.2343/geochemj.1.0149