Papers by Ailson Oliveira
Physical Review C, 2021
In this article, we develop a technique to determine the analytical result of some Kaup-Kupershmi... more In this article, we develop a technique to determine the analytical result of some Kaup-Kupershmidt equations with the aid of a modified technique called the new iteration transform method. is technique is a mixture of the novel integral transformation Elzaki transformation and the new iteration technique. e nonlinear term can be handled easily by a new iteration technique. e results show that the combination of the Elzaki transformation and the new iteration technique is quite capable and basically well suited for applying in such problems and that it can be implemented to other nonlinear models. is technique is viewed as an effective alternative approach to certain existing approaches for such accurate models.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2021
Bulletin of the American Physical Society, 2016
Bulletin of the American Physical Society, 2017
products (FPYs) with half lives of a few minutes to an hour contain a wealth of information about... more products (FPYs) with half lives of a few minutes to an hour contain a wealth of information about the fission process. Knowledge of short lived FPYs would contribute to existing data on longer lived FPY mass and charge distributions. Of particular interest are the relative yields between the ground states and isomeric states of FPYs since these isomeric ratios can be used to determine the angular momentum of the fragments. Over the past five years, a LLNL-TUNL-LANL collaboration has made precision measurements of FPYs from quasi-monoenergetic neutron induced fission of 235 U, 238 U and 239 Pu [1]. These efforts focused on longer lived FPYs, using a well characterized dual fission chamber and several days of neutron beam exposure. For the first time, this established technique will be applied to measuring short lived FPYs, with half lives of minutes to less than an hour. A feasibility study will be performed using irradiation times of < 1 hour, improving the sensitivity to short lived FPYs by limiting the buildup of long lived isotopes. Results from this exploratory study will be presented, and the implications for isomeric ratio measurements will be discussed. [1] M. Gooden et al. Nucl. Data Sheets. 131, 319 (2016) 1 This work was performed under the auspices of US DOE by LLNL under contract DE-AC52-07NA27344.
Bulletin of the American Physical Society, 2018
This paper deals with the some oscillation criteria for the two dimensional
Submitted for the DNP16 Meeting of The American Physical Society Measurements of the 169Tm(n,2n)1... more Submitted for the DNP16 Meeting of The American Physical Society Measurements of the 169Tm(n,2n)168Tm cross section between 9.0 and 17.5 MeV J. SOTER, Drew University, MEGHA BHIKE, FNU KR-ISHICHAYAN, S.W. FINCH, W. TORNOW, Duke University-Measurements of the 169 Tm(n,2n) 168 Tm cross section have been performed in 0.5 MeV intervals for neutron energies ranging from 9.0 MeV to 17.5 MeV in order to resolve discrepancies in the current literature data. The neutron activation technique was used with 90 Zr and 197 Au as monitor foils. After irradiation, de-excitation gamma rays were recorded off-line with High-Purity Germanium (HPGE) detectors in TUNL's Low-Background Counting Facility. In addition, data for the 169 Tm(n,3n) 167 Tm reaction have also been obtained from 15.5 MeV to 17.5 MeV. The results of these measurements provide the basis for investigating properties of the interial confinement fusion plasma in deuterium-tritium (DT) capsules at the National Ignition Facility located at Lawrence Livermore National Laboratory.
BACKGROUND Dengue fever has been a common and fatal vector borne disease in tropical countries an... more BACKGROUND Dengue fever has been a common and fatal vector borne disease in tropical countries and is found to be present throughout the year and also to occur in epidemics. There has been very little information on dengue illness in infants; also, there are few efforts to compare the illness of infants and that of older children. We wanted to compare the clinical features of dengue fever including complications and outcome along with the laboratory parameters in infants with those of older children.
EPJ Web of Conferences, 2018
Nuclear Resonance Fluorescence (NRF) experiments on the nuclei 82 Kr and 82 Se were performed, th... more Nuclear Resonance Fluorescence (NRF) experiments on the nuclei 82 Kr and 82 Se were performed, that are a candidates for a mother-daughter pair for the hypothetical neutrinoless double-beta (0νββ) decay. The experiment aimed at providing high-precision data to benchmark theoretical calculations of the nuclear matrix elements involved in this exotic decay mode. We have investigated the excitation energy range from 2.3 MeV to 4.2 MeV, where the nuclear scissors mode is expected to be located in nuclei of this mass region. Our experiment was able to constrain decay branches of the scissors mode down to a level of a few percents, comparable to previous experiments on heavy deformed 0νββ decay candidates. Reduced transition strengths of the magnetic dipole-excited states have been determined by a method that exploits the non-resonant background in the NRF spectra. They are compared to a calculation within the nuclear shell model for 82 Se, which reveals their mixed orbital and spin character, hinting at a more complex microscopic structure of low-lying 1 + states.
Journal of Physics G: Nuclear and Particle Physics, 2018
Physical Review C, 2015
Background: Multiple large collaborations are currently searching for neutrinoless double-β decay... more Background: Multiple large collaborations are currently searching for neutrinoless double-β decay, with the ultimate goal of differentiating the Majorana-Dirac nature of the neutrino. Purpose: Investigate the feasibility of resonant neutrinoless double-electron capture, an experimental alternative to neutrinoless double-β decay. Method: Two clover germanium detectors were operated underground in coincidence to search for the deexcitation γ rays of 156 Gd following the neutrinoless double-electron capture of 156 Dy. 231.95 days of data were collected at the Kimballton underground research facility with a 231.57 mg enriched 156 Dy sample. Results: No counts were seen above background and half-life limits are set at O(10 16 − 10 18) yr for the various decay modes of 156 Dy. Conclusion: Low background spectra were efficiently collected in the search for neutrinoless double-electron capture of 156 Dy, although the low natural abundance and associated lack of large quantities of enriched samples hinders the experimental reach.
Physical Review C, 2012
ABSTRACT The activation technique was used to measure the cross section for the reaction 40Ar(n, ... more ABSTRACT The activation technique was used to measure the cross section for the reaction 40Ar(n, p) 40Cl in 0.5 MeV energy steps in the neutron energy range between 9 and 15 MeV. These data are important for estimating background contributions in neutrinoless double-beta decay and dark matter searches, as well as in argon-based large neutrino detectors. The data are compared to evaluations and theoretical predictions.
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Papers by Ailson Oliveira