Listar Ciencias Exactas y Naturales por autor "Dias, Johnny Ferraz"
Mostrando ítems 1-20 de 30
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Basal levels of inorganic elements, genetic damages, and hematological values in captive Falco peregrinus
(2022) [Artículo de periódico]It is essential to determine the basal pattern of different biomarkers for future evaluation of animal health and biomonitoring studies. Due to their great displacement capacity and to being at the top of their food chains, ... -
Coulomb heating of channeled C+ and C2+ molecules in Si
(2008) [Artículo de periódico]Si x-ray and backscattering yields have been measured as a function of the C⁺ and C₂⁺ entrance angle along the Si ‹100› channel in an energy interval between 900 and 2200 keV/atom. A significant enhancement of the x-ray ... -
Coulomb heating of channeled H/sup + sub 2/ and H/sup + sub 3/ molecules in Si
(2004) [Artículo de periódico]Si-K x-ray and backscattering yields have been measured as a function of the projectile entrance angle for atomic and molecular (H2 + and H3 +) hydrogen ions channeling at kinetic energies of 150 keV per proton along the ... -
Direct etching of SiO2 and Al2O3 by 900-keV gold ions
(2009) [Artículo de periódico]We report the direct etching of Al2O3 and SiO2 using 900-keV Au+ ions. 2000-mesh Cu grids were employed as masks using two different configurations: 1 the Cu mesh was placed on top of each insulator separately and independent ... -
Electrofission of (sup 239) pu in the energy range 7-12 mev
(1997) [Artículo de periódico]The electrofission cross section of ²³⁹Pu(e,f) is measured between 7 and 12 MeV. The data are analyzed by means of the virtual photon formalism, assuming that E1, E2 (T=0), and M1 transitions are involved. Using known ... -
Electronic energy loss of channeled ions : the giant Barkas effect
(2004) [Artículo de periódico]In this work we have measured the electronic energy loss of ⁹Be and ¹¹B ions for the ‹100› and ‹110› directions in Si as a function of the incident ion energy. The channeling measurements cover a wide energy range between ... -
Elemental composition of vegetables cultivated over coal-mining waste
(2017) [Artículo de periódico]We assessed elemental composition of the liver in mice subjected to one-time or chronic consumption of the juice of vegetables cultivated in a vegetable garden built over deposits of coal waste. Lactuca sativa L. (lettuce), ... -
Energy loss of helium ions in zinc
(2004) [Artículo de periódico]The energy loss of helium ions in zinc has been measured in the energy range from 37.5 to 1750 keV/amu using the transmission technique and the Rutherford backscattering method. In addition, calculations using the extended ... -
Energy loss of swift H+2 and H+3 molecules in gold : vicinage effects
(2011) [Artículo de periódico]We present experimental and theoretical results of vicinage effects due to the interaction of H+ 2 and H+ 3 molecules with thin gold foils. High-energy-resolution backscattering experiments were carried out at energies ... -
Evaluation of toxicological effects of an aqueous extract of shells from the pecan nut Carya illinoinensis (Wangenh.) K. Koch and the possible association with its inorganic constituents and major phenolic compounds
(2016) [Artículo de periódico]Background. Industrial processing of the pecan nut Carya illinoinensis K. Koch generated a large amount of shells, which have been used to prepare nutritional supplements and medicinal products; however, the safe use of ... -
Experimental energy straggling of protons in SiO/sub 2/
(2003) [Artículo de periódico]The energy straggling of proton beams in SiO₂ has been measured in the energy range from 30 to 1500 keV using the transmission, nuclear reaction analysis and Rutherford backscattering techniques. The experimental results ... -
Gambling as a teaching aid in the introductory physics laboratory
(1998) [Artículo de periódico]Dice throwing is used to illustrate relevant concepts of the statistical theory of uncertainties, in particular the meaning of a limiting distribution, the standard deviation, and the standard deviation of the mean. It is ... -
Genotoxicity of Nicotiana tabacum leaves on Helix aspersa
(2013) [Artículo de periódico]Tobacco farmers are routinely exposed to complex mixtures of inorganic and organic chemicals present in tobacco leaves. In this study, we examined the genotoxicity of tobacco leaves in the snail Helix aspersa as a measure ... -
Giant Barkas effect observed for light ions channeling in Si
(2001) [Artículo de periódico]Measurements of the electronic energy loss are presented for ⁴He and ⁷Li ions channeling along the Si main axial directions at intermediate to high projectile energies. The Barkas effect, an energy-loss enhancement ... -
Interplay between the Coulomb explosion and vicinage effects studied using H/sub 2//sup +/ molecules under channeling conditions
(2006) [Artículo de periódico]The aim of this work is to investigate how the mean energy loss and straggling due to H2 + molecules interacting with silicon are affected by the Coulomb explosion and vicinage effects. To that end, a SIMOX-type sample ... -
Investigation of potential biomarkers for the early diagnosis of cellular stability after the exposure of agricultural workers to pesticides
(2016) [Artículo de periódico]Agricultural workers involved in the harvest of tobacco crops are regularly exposed to large quantities of pesticides. In order to determine how this exposure to pesticides induces genetic alterations in these workers, ... -
Ion beam analysis (IBA) and instrumental neutron activation analysis (INAA) for forensic characterisation of authentic Viagra® and of sildenafil-based illegal products
(2021) [Artículo de periódico]Illegal trafficking of pharmaceutical products by criminal organisations is a global threat for public health. Drugs for erectile dysfunction such as phosphodiesterase type 5 inhibitors are the most commonly counterfeited ... -
Macro and microminerals are frozen fruits a good source?
(2010) [Artículo de periódico]As frutas são ricas em minerais, sendo estes essenciais para uma grande variedade de processos metabólicos e fisiológicos no corpo humano. A utilização de frutas congeladas tem se ampliado nos últimos anos, não só na ... -
Magnetic and structural properties of Fe-implanted cubic GaN
(2016) [Artículo de periódico]In this article, we report on structural and magnetic properties of cubic GaN epitaxial layers implanted with Fe ions and subsequently subjected to thermal annealing. The epitaxial quality of the layers was studied by X-ray ... -
Neutralization and wake effects on the Coulomb explosion of swift H2+ ions traversing thin films
(2015) [Artículo de periódico]The Coulomb explosion of small cluster beams can be used to measure the dwell time of fragments traversing amorphous films. Therefore, the thickness of thin films can be obtainedwith the so-called Coulomb depth profiling ...
