Journal of Nuclear Physics, Material Sciences, Radiation and Applications
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Effects of Low-Energy Laser Irradiation on Sperm Cells Dynamics of Rabbit (Oryctolagus Cuniculus)
Get PDFInfertility is a world disease in which a couple is unable to achieve pregnancy. There are numerous parameters to determinate fertility; nevertheless, sperm motility is by consensus one of the most important attributes to evaluate male fertility. Contributions to a better understanding of this crucial parameter are imperative; hence, the aim of this investigation was to assess the effect of low-energy laser irradiation on sperm cell dynamics in thawed samples that were cryopreserved. We used a 405 nm blue laser beam to irradiate spermatic cells from rabbit inside a temperature-controlled dispersion chamber at 37 °C; then, we applied an image recognizing system to calculate individual sperm trajectories and velocities. We found that sperms raise its motility after irradiation suggesting that λ=405 nm is an optimal wavelength for spermatic photo-stimulation
Heavy-ion Fusion Cross Sections of 32S on 90,96Zr Targets Using Coulomb and Proximity Potential
Get PDFThe fusion excitation functions for the fusion of 32S on 90,96Zr have been calculated larger value, while using one-dimensional barrier penetration model, taking scattering potential as the sum of Coulomb and proximity potential and the calculated values are compared with experimental data with considerations to shape degrees of freedom. At and above the barrier the computed cross sections match well with the experimental data, whereas below the barrier, calculations with nuclear surface tension coefficient improved by Reisdorf in the proximity potential with considerations to shape degrees of freedom give an approximate fit. Reduced reaction cross sections for the systems 32S on 90,96Zr have also been described
Study of L-Glutamic Acid in Solid State for its Possible Use as a Gamma Dosimeter at Different Temperatures (77, 195 and 295 K)
Get PDFThe experimental response of the dosimeter as a function of the irradiation temperature plays an important role, and this effect has consequences in the practical applications of dosimetry. In this work, L-glutamic acid (2-aminopentanedioic acid) is proposed to be a good response, easy to handle, and a cheap gamma dosimeter. For this purpose, polycrystalline samples were irradiated with gamma rays at 77, 195, and 295 K and doses in the kiloGray range (43–230 kGy). The potential use of the glutamic acid system as a chemical dosimeter is based on the formation of stable free radicals when the amino acid is exposed to ionizing radiation. The observed species in these experiments were attributed to deamination and decarboxylation reactions that were studied using electron spin resonance (ESR). The results indicate that the analysis generates a linear response as the irradiation dose increases in a reliable range for industrial and research purposes at three different temperatures
Rubber Additions into Concrete and Gamma Radiation Effects on Mechanical Properties and Microwave Absorption Capacity
Get PDFRubber is the indispensable raw material for the manufacture of tires; it is obtained from plants, trees and currently can be produced synthetically. The tire rubber is mixed with compounds such as carbon black, sulfur, cement, paints, antioxidants, oils and fats, steel wire, almost etc., making impossible to recycle the tires itself. In this work, we investigate, the effects of the incorporation of ground rubber in concrete, mixture designed to establish the possibility of being used in the construction industry. The samples of concrete were addition with, 5 vol. %., 15 vol. % and 25 vol. % of rubber. Samples with different rubber addition were irradiated by a cobalt 60 gamma source to study the effect on their mechanical compression properties and microwave absorption capacity. Likewise, the microwave absorption capacity was studied for both irradiated and the non-irradiated. It was found that between 5 vol. % and 15 vol. % of rubber addition change the mechanical properties approximately 25 %, higher rubber additions result in a decrease in a 75 % of its mechanical properties. The fracture behavior is not the expected one due to as the curves of stress vs. strain show a double slope, which is associated with the concrete porosity and rubber content. The aging with the gamma rays generates loss of mechanical properties, especially at lower rubber addition, since at content greater than 15 Vol % the radiation effect is less. These rubber additions allow moderate deformations in compression, thus contributing to the care and preservation of the environment
Alpha Emitter Intrinsic Concentration in Copper required for Nuclear Spectrometry Application
Get PDFLow-level radioactivity content in copper are employed for bolometric thermal radiation sensors and astro-nuclear spectrometers. The required lowest achievable alpha emitters concentration, for treated and untreated surfaces, are measured by Double Sided Silicon Strip Detectors in a high vacuum chamber and provide information on its intrinsic NORM content. Results shows that copper alpha emitters content can be achieved in the range below 0.01 (counts. keV-¹·kg-¹·y-¹) adequate for specific nuclear spectrometry applications
Radiolysis of Serine in High Radiation Field
Get PDFThe formation of amino acids under simulated condition suggests that this type of compounds were readily formed on the primitive Earth. Nevertheless, there is no conclusive explanation to the origin of their specific chirality in biological systems. Differences in their stability in the primitive conditions may give some clues about this unsolved problem. Protection mechanisms have been considered, such as the adsorption of the organic compounds onto mineral surfaces. By using HPLC/ELSD to analyze aqueous suspensions of serine adsorbed on clay (sodium montmorillonite) and a meteorite (Allende) irradiated in different doses with a cobalt-60 gamma source, the aim of this work was to study the possible protector role of these mineral surfaces when an amino acid, serine, is adsorbed onto them and the system is exposed to a high radiation source. The results showed that adsorption is better at acidic pH and desorption from the mineral at basic pH. The irradiation of the free amino acid destroyed it almost completely at a dose of 91 kGy, but the presence of the mineral abruptly decreases the decomposition, acting as a protective agent. At the same time, the results in aqueous solution show no statistically significant differences in adsorption or radiolysis of D and L serine
Effects of Aging Time and Sintering Temperatures on Thermal, Structural and Morphological Properties of Coralline Hydroxyapatite
Get PDFBiphasic Calcium Phosphate bioceramics belong to a group of bone substitute biomaterials comprised of an intimate mixture of Hydroxyapatite (HAP) and β-Tricalcium Phosphates. In the present work, Coralline Hydroxyapatite was synthesized using wet precipitation method. Powder particles were aged for 24 and 48 hours at 5. X-Ray Diffraction, Fourier Transform Infrared and Thermogravimetric spectroscopic techniques were used. Biphasic Calcium Phosphate was identified as the chief structural constitution of the synthetic powders. Weight fraction of Hydroxyapatite increased with the rise of sintering temperature. Aging time of 24 hours yielded maximum amount of hydroxyapatite, thus confirming optimum aging time for the synthesis of Coralline Hydroxyapatite
A Scaling Law for L-Shell X-Ray Production Cross Sections Induced by Impact of 4He+, 9Be2+, and 14N2+ Ions
Get PDFExperimental 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 ξRL1,2. 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 ξRL1,2. 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
The Indoor Radon Concentration within the Tunnels of the Cholula Pyramid Through a Nuclear Tracks Methodology
Get PDFGlobal 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
The Status of Natural Radioactivity and Heavy Metals Pollution on Marine Sediments Red Sea Coast, At Safaga, Egypt
Get PDFNatural 226Ra, 232Th and 40K radio nuclides concentration in beach Sediments along Safaga coast of Red sea, Egypt has been carried out using a NaI (Tl) gamma ray spectrometric technique. The total average concentrations of radionuclides ± uncertainty of 226Ra, 232Th and 40K were 22.2 ± 1.7, 19.2 ± 2.5, and 477.6 ± 27.6 Bqkg-1, respectively. The total average absorbed dose rate is found to be 41.4 nGyh-1, whereas the annual effective dose rate has an average value of 54 μSvy-1. The total organic matter (TOC), carbonates (CaCo3) and Heavy metals distribution have been measured at some locations, the concentration for the investigated heavy metals overtake the allowable limits recommended by the Canadian Environmental Quality Guidelines, this assigned to the ratio of metals pollution is caused by anthropogenic activities (phosphate shipment as in Abu Tartour harbor and navigation as in Touristic harbor) and or by natural impacts such in mangrove interment. Statistical analyses were carried out between the parameters obtained from the radioactivity to know the existing relations and to study the spatial distribution of radionuclide