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Anomalous Ferromagnetic Phase in the Gd1−xErxB4 Series: Crystal Growth, Thermal, and Magnetic Properties
(2023-07-23) MASUNAGA, S. H.; V. B. Barbeta; ABUD, F.; TORIKACHVILI, M. S.; JARDIM, R. F.
© 2023 by the authors.Rare-earth tetraborides RB4 are of great interest due to the occurrence of geometric magnetic frustration and corresponding unusual magnetic properties. While the Gd3+ spins in GdB4 align along the ab plane, Er3+ spins in the isomorphic ErB4 are confined to the c–axis. The magnetization in the latter exhibits a plateau at the midpoint of the saturation magnetization. Therefore, solid solutions of (Gd, Er)B4 provide an excellent playground for exploring the intricate magnetic behavior in these compounds. Single crystals of Gd1−xErxB4 (x = 0, 0.2, and 0.4) were grown in aluminum flux. X-ray diffraction scans revealed single-phase materials, and a drop in the unit cell volume with increasing Er content, suggesting the partial substitution of Er at the Gd sites. Heat capacity measurements indicated a systematic decrease of the Néel temperature (TN) with increasing Er content. The effective magnetic moment determined from the magnetization measurement agreed with the calculated free ion values for Gd3+ and Er3+, providing further evidence for the successful substitution of Er for Gd. The partial substitution resulted in an anomalous ferromagnetic phase below TN, exhibiting significant anisotropy, predominantly along the c-axis. This intriguing behavior merits further studies of the magnetism in the Gd1−xErxB4 borides.
The NUMEN project @ LNS: Status and perspectives
(2019-09-03) CAPPUZZELLO, F.; AGODI, C.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J. I.; BELMONT, D.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLI, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CIRALDO, I.; LOMELI, E. R. C.; COLONNA, M.; D'AGOSTINO, G.; DJAPO, H.; DE GERONIMO, G.; DELAUNAY, F.; DESHMUKN, N.; DE FARIA, P. N.; ESPEJEL, R.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FLORES, A.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; GONGORA, B.; HACISALIHOGLU, A.; HAZAR, S.; HUERTA, A.; KOTILA, J.; KUCUK, Y.; IAZZI, F.; LANZALONE, G.; LA VIA, F.; LAY, J. A.; LENSKE, H.; LINARES, R.; LONGHITANO, F.; LO PRESTI, D.; LUBIAN, J.; MA, J.; MARIN-LAMBARRI, D.; MARTINEZ, S.; MAS, J.; MEDINA, N. H.; MENDES, D. R.; MEREU, P.; MORALLES, M.; OLIVEIRA, J. R. B.; ORDONEZ, C.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; REZA, G.; RIES, P.; RIFUGGIATO, D.; RODRIGUES, M. R. D.; RUSSO, A. D.; RUSSO, G.; SANDOVAL, S.; SANTOPINTO, E.; Roberto Santos; SGOUROS, O.; Marcilei Aparecida Guazzelli; SOLAKCI, S. O.; SOULIOTIS, G.; SOUKERA, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; VSEVOLODOVNA, R. I. M.; VARGAS, H.; VEGA, G.; WANG, J. S.; WERNER, V.; YANG, Y. Y.; YILDIRIN, A.; ZAGATTO, V. A. B.
© 2019 Author(s).The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0υββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. Particular interest is given to the (18O,18Ne) and (20Ne,20O) reactions as tools for β+ β+ and β-β- decays, respectively. First evidence about the possibility to get quantitative information about NME from experiments is found for both kind of reactions. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction products are detected by the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to significantly increase the experimental yield, thus making feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models are developed aiming at extracting the nuclear structure information from the measured cross sections.
Titanium extraction from waste NORM
(2013-12-01) PEREIRA, B. R.; Marcilei Aparecida Guazzelli; FONTANA, G.; Roberto Santos; RIZZUTTO, M. A.; MEDINA, N. H.
© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.The constantly growing of global agricultural production depends on the development of a whole production to be lasting and sustainable. The phosphoric acid production is directly related to the production of fertilizers, but its process of obtaining requires numerous steps and generates a lot of waste. There are several elements in some of these wastes that are very valuable and important for economy and for technological development. An example is a residue derived from a step of physical handling of the phosphate rock, containing about 30% of titanium in its composition. Titanium can be used in various applications, such as a component in high-tech metallic alloys, or, in the form of titanium dioxide, which is the form that presents the greatest value in industry. This study focus at the concentration of titanium oxide present in a residue from the phosphoric acid production, by attacking the material chemically and doing its characterization by analytical methods. This would contribute to the national titanium concentrated production increased and enhance the economic yield of the phosphoric acid production process, by transforming an unused waste in a high value product. The methodology for the concentration of titanium oxide was based in industrial extraction of titanium ores and consists of solubilizing the impurities present in the sample by means of chemical attack. It has been determined experimentally that at temperatures around 70°C, hydrochloric acid provides a better solubilization of impurities, without extracting titanium, and it is possible to obtain a residual solid phase with about 58.5% of titanium on it. The results were determined by using the Energy Dispersive X-Ray Fluorescence (EDXRF) technique. As the original sample is a Normal Occurring Radioactive Material (NORM), an analysis of Gamma Ray Spectroscopy and EDXRF were realized to determine how the radionuclides form the U and Th series were affected by the chemical treatment.
Parasitic conduction response to X-ray radiation in unstrained and strained triple-gate SOI MuGFETs
(2014-05-05) TEIXEIRA, F. F.; BORDALLO, C. C. M.; Marcilei Aparecida Guazzelli; AGOPIAN, P. G. D.; MARTINO, J. A.; SIMOEN, E.; CLAEYS, C.
© 2014, Journal of Integrated Circuits and Systems. All rights reserved.In this work, the X-ray irradiation impact on the back gate conduction and drain current for Triple-Gate SOI FinFETs is investigated for strained and unstrained devices. Both types (P and N) of transistors were analyzed. Since X-rays promote trapped positive charges in the buried oxide, the second interface threshold voltage shifts to lower gate voltage. The performance of n-channel devices presented a strong degradation when submitted to X-rays, while for p-channel devices the opposite trend was observed. Two different dose rates were analyzed.
The influence of back gate bias on the OCTO SOI MOSFET’s response to X-ray radiation
(2015-09-10) FINO, L. M. S.; Marcilei Aparecida Guazzelli; RENAUX, C.; FLANDRE, D.; Salvador Gimenez
© 2015 Brazilian Microelectronics Society. All rights reserved.This work investigates the X-ray irradiation impact on the performance of an on-conventional transistor called OCTO SOI MOSFET that adopts an octagonal gate shape instead of a rectangular. The electrical behaviors of both devices were studied through an experimental comparative analysis of the total ionizing dose influence. In addition, the back-gate bias technique was applied in these devices to reestablish its threshold voltages and drain currents conditions that were degraded due the trapping of positive charges in the buried oxide. As the main finding of this work, after the irradiation procedure, we notice that the OCTO device is capable to reestablish its prerad electrical behavior with a smaller back gate bias than the one observed in the standard one counterpart. This is mainly because the parasitic transistors in the bird’s beak region are practically deactivated due the particular octagonal gate geometry.
Mitigating MOSFET radiation effects by using the wave layout in analog ICs applications
(2015-09-10) SOUZA, R. N.; Marcilei Aparecida Guazzelli; Salvador Gimenez
© 2015 Brazilian Microelectronics Society. All rights reserved.This paper presents an experimental comparative study of the Total Ionizing Dose (TID) effects between the Metal-Oxide-Semiconductor (MOS) Field Effect Transistors (MOSFET) manufactured with the Wave (S gate geometry) and the standard layout (CnM). Because of the special geometric characteristic of the gate, drain and source regions of the Wave MOSFET (WnM), this innovative layout proposal for transistors is able to mitigate the TID effects in order to implement in analog integrated circuits (IC) for space and medical applications without causing any additional cost to the Complementary MOS (CMOS) manufacturing process.
Evaluating the Reliability of Different Voting Schemes for Fault Tolerant Approximate Systems
(2023-06-20) BALEN, T. R.; GONZALEZ, C. J.; OLIVEIRA, I. F. V.; DA ROSA JR. L. S.; SOARES, R. I.; SCHVITTZ, R. B.; ADDED, N.; MACCHIONE, E. L. A.; AGUIAR, V. A. P.; Marcilei Aparecida Guazzelli; MEDINA, N. H.; BUTZEN, P. F.
© 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.This work presents a study on the reliability of voters for approximate fault tolerant systems in the context of single event effects and electromagnetic interference. A first case study analyses different topologies of single-bit majority voters for logic circuits employing fault injection by simulation. In these simulations, an analysis is first performed to identify the critical diffusion areas of the physical implementation according to the voter input vector. Additionally, as a second case study, practical heavy ion experiments on different architectures of software-based approximate voters for mixed-signal applications are also presented, and the cross section of each voter is evaluated. The system comprising the voters was irradiated in two distinct experiments with an 16O ion beam, producing an effective LET at the active region of 5.5 MeV/mg/cm 2 . As a complementary study, a conducted electromagnetic interference injection was also performed, considering two distinct voting schemes. Results of the case-studies allow identifying the most tolerant voter architectures (among the studied ones) for approximate computing applications under single event effects and electromagnetic interference.
Modeling of MOSFETs Altered by Ionizing Radiation Using Artificial Neural Networks
(2023-08-05) SANTOS, L. S. A. DOS; ALLEGRO, P. R. P.; Marcilei Aparecida Guazzelli; GUIDI, A. L.; G. JUNIOR, P. R.; A. JUNIOR, V. S.; TOUFEN, D. L.; VILAS BOAS, A. C.
© 2023, The Author(s) under exclusive licence to Sociedade Brasileira de Física.The ionizing radiation absorbed by semiconductor devices can change their properties by modifying their electrical parameters and, in the case of memories, it can modify the information contained in these components. Thus, the ability to predict how ionizing radiation affects electronic circuits becomes especially important in environments where there is the possibility of prolonged exposure to intense radiation, such as satellites, nuclear reactors, particle accelerators, and medical equipment, among others. In this sense, this paper proposes a methodology to reproduce the behavior of TID (total ionizing dose) damaged MOSFET transistors using the fully connected artificial neural networks, taking advantage of its universal estimator characteristics to oversample the dataset’s pattern and give it a better resolution. The dataset complexity requires a specific architecture choice, being necessary the use of two neural network models to separately reproduce the MOSFET electric current magnitude order and its curve shape. Results show a very good capability to reproduce and interpolate the MOSFET behavior, which makes the proposed method a promising way to simulate circuits based on MOSFETs that are exposed to ionizing radiation.
New experimental campaign of NUMEN project
(2019-09-05) AGODI, C.; CAPPUZZELLO, F.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J. I.; BELMONT, D.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOSTOZUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CIRALDO, I.; LOMELI, E. R. C.; COLONNA, M.; D' AGOSTINO, G.; DJAPO, H.; DE GERONIMO, G.; DELAUNAY, F.; DESHMUKH, N.; DE FARIA, P. N.; ESPEJEL, R.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA M.; FLORES A.; FOTI A.; GALLO G.; GARCIA-TECOCOATZI H.; GONGORA B.; HACISALIHOGLU A.; HAZAR S.; HUERTA A.; KOTIJA J.; KUCUK Y.; IAZZI F.; LANZALONE G.; LA VIA F.; LAY J. A.; LENSKE H.; LINARES R.; LONGHITANO F.; LO PRESTI D.; LUBIAN J.; MA J.; MARIN-LAMBARRI D.; MATINEZ S.; MEDINA N. H.; MENDES D. R.; MEREU P.; MORALLES M.; OLIVEIRA J. R. B.; ORDONEZ C.; PAKOU A.; PANDOLA L.; PETRASCU H.; PIETRALLA N.; PINNA F.; REITO S.; REZA G.; RIES P.; RIFUGGIATO D.; RODRIGUES M. R. D.; RUSSO A. D.; RUSSO G.; SANDOVAL S.; SANTOPINTO E.; Roberto Santos; SGOUROS O.; Marcilei Aparecida Guazzelli; SOLAKCI S. O.; SOULIOTIS G.; SOUKERAS V.; SPATAFORA A.; TORRESI D.; TUDISCO S.; VSEVOLODOVNA R. I. M.; VARGA H.; VEGA G.; WANG J. S.; WERNER V.; YANG Y. Y.; YILDIRIN A.; ZAGATTO V. A. B.
© 2019 Author(s).The NUMEN main goal is the extraction from measured cross-sections of "data-driven" information on Nuclear Matrix Elements for all the systems candidate for 0νββ. The idea is to use as experimental tool Heavy Ions -Double Charge Exchange (HI-DCE) reactions. Crucial for the experimental challanges is the INFN Laboratori Nazionali del Sud (LNS) facility, made by the Superconducting Cyclotron (CS) and the MAGNEX magnetic spectrometer. The experimental measurements of HI-DCE reactions present a number of challenging aspects, since they are characterized by very low cross sections. Here it is reported the new experimental campaign of NUMEN Project.
A focus on selected perspectives of the NUMEN project
(2022-11-09) CAVALLARO, M.; AGODI, C.; BELLONE, J. I.; BRASOLIN, S.; BRISCHETTO, G. A.; BUSSA, M. P.; CALABRESE, S.; CALVO, D.; CAMPAJOLA, L.; CAPIROSSI, V.; CAPPUZZELLO, F.; CARBONE, D.; CIRALDO, I.; COLONNA, M.; DE BENEDICTIS, C.; DE GREGORIO, G.; DELAUNAY, F.; DUMITRACHE, F.; FERRARESI, C.; FINOCCHIARO, P.; FISICHELLA, M.; GALLIAN, S.; GAMBACURTA, D.; GANDOLFO, E. M.; GARGANO, A.; GIOVANNINI, M.; IAZZI, F.; LANZALONE, G.; LAVAGNO, A.; MEREU, P.; NERI, L.; PANDOLA, L.; PANERO, R.; PERSIANI, R.; PINNA, F.; RUSSO, A. D.; RUSSO, G.; SANTOPINTO, E.; SARTIRANA, D.; SGOUROS, O.; SHAR,A, V. R.; SOUKERAS, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; AVANZI, L. H.; CARDOZO, E. N.; CHINAGLIA, E. F.; COSTA, K. M.; FERREIRA, J. L.; LINARES, R.; LUBIAN, J.; MASUNAGA, S. H.; MEDINA, N. H.; MORALLES, M.; OLIVEIRA, J. R. B.; SANTARELLI, T. M.; Roberto Santos; Marcilei Aparecida Guazzelli; ZAGATTO, V. A. B.; KOULOURIS, S.; PAKOU, A.; SOULIOTIS, G.; ACOSTA, L.; AMADOR-VALENZUELA, P.; BIJKER, R.; CHAVEZ LOMELI, E. R.; GARCIA-TECOCOATZI, H.; HUERTA HERNANDEZ, A.; MARIN-LAMBARRI, D. J.; VARGA HERNANDEZ, H.; VILLAGRAN, R. G.; BOZTOSUN, I.; DAPO, H.; EKE, C.; FIRAT, S.; HACISALIHOGU, A.; KUCUK, Y.; SOLAKCI, S. O.; YILDIRIM, A.; AUERBACH, N.; BURRELLO, S.; LENSKE, H.; ISSAK, J.; PIETRALLA, N.; WERNER, V.; LAY, J. A.; PETRASCU, H.; FERRETTI, J.; KOTILA, J.; DONALDSON, L. M.; KHUMALO, T.; NEVELING. R.; PELLEGRI, L.
© 2022 Institute of Physics Publishing. All rights reserved.The use of double charge exchange reactions is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The strategy adopted in the experimental campaigns performed at INFN - Laboratori Nazionali del Sud and in the analysis methods within the NUMEN project is briefly described, emphasizing the advantages of the multi-channel approach to nuclear reaction data analysis. An overview on the research and development activities on the MAGNEX magnetic spectrometer is also given, with a focus on the chosen technological solutions for the focal plane detector which will guarantee the performances at high-rate conditions.
Banana and its nutrients: the power of the heart
(2022-11-09) PALMA, M. S.; CURADO, J. F.; RIZZUTTO, M.; MEDINA, N. H.; Marcilei Aparecida Guazzelli
© 2022 Institute of Physics Publishing. All rights reserved.Macro and micronutrients are essential minerals for the development of living beings, and this separation is given in quantitative reason, that is, while macronutrients, such as potassium and calcium, are required in larger amounts, micronutrients such as iron and zinc, are required in small quantities. For humans, potassium (K) is an essential macronutrient. In the human body, potassium has the function of regulating osmotic pressure, transmitting nerve impulses and carrying out muscle contraction. Its existence is found in high concentration in bananas. The heart banana plant is a little-known part among the by-products generated by banana cultivation, and is commonly discarded in the soil in order to increase its organic content, due to its high content of minerals such as potassium, calcium and zinc. Thus, this research work aimed to explore the nutritional potential of unconventional parts of banana for human consumption, through Energy Dispersion X-Ray Fluorescence technique, with which it is possible to identify and quantify the main constituent elements. The species were studied Musa Acuminata 'Dwarf/Cavendish', Musa Acuminata x M. Balbisiana 'Apple/Manzano', Musa Ornata 'Ornamental' and Musa Acuminata 'Fig'. The quantity of potassium and of other elements such as Ca, Fe, Mn, Zn, and Rb in the banana heart samples were studied superior to the findings in the literature.
Vibration measurement by projection of phase-modulated and amplitude-modulated structured light
(2023-01-05) DIB, L. F. G.; HENRIQUE, M. C.; SAITA, M. T.; BARBOSA, E. A.
© 2023 Universidad Nacional Autonoma de Mexico. All rights reserved.Most of the whole-field optical methods for vibration measurement have low sensitivity when the points of the studied surface vibrate with the same amplitude. Those techniques also usually require complex and/or expensive solutions which are difficult to implement in engineering processes when the vibration amplitudes are relatively high. In order to overcome those limitations we propose a method for out-of-plane vibration measurement which uses structured light projection. The vibrating surface is obliquely illuminated by straight and parallel interference fringes produced by a Twyman-Green interferometer with a 532-nm laser as light source. In order to enable fringe visualization two techniques were employed, namely, the phase modulation of the fringe pattern by using a vibrating mirror in the interferometer, and a stroboscopic illumination by using a Fabry-Perot etalon amplitude modulator. We demonstrated the technique by measuring the vibration amplitudes of small objects in the millimeter and submillimeter range.
Multichannel experimental and theoretical approach to the C 12 (O 18, F 18) B 12 single-charge-exchange reaction at 275 MeV: Initial-state interaction and single-particle properties of nuclear wave functions
(2023) SPATAFORA, A.; CARBONE, D.; CAPPUZZELLO, F.; CAVALLARO, M.; ACOSTA, L.; AGODI, C.; AMADOR-VALENZUELA, P; BORELLO-LEWIN, T.; BRISCHETTO, G. A.; CALABRESE, S.; CALVO, D.; CAPIROSSI, V.; CHAVEZ LOMELI, E. R.; CIRALDO, I.; DE GREGORIO, G.; DELAUNAY, F.; DJAPO, H.; EKE, C.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FOTI, A.; GARGANO, A.; HACISALIHOGLU, A.; IAZZI, F.; LA FAUCI, L.; LINARES, R.; LUBIAN, J.; MEDINA, N.; MORALLES, M.; OLIVEIRA, J. R. B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PINNA, F.; RUSSO, G.; SGOUROS, O.; Marcilei Aparecida Guazzelli; SOLAKCI, S. O.; SOUKERAS, V.; SOULIOTIS, G.; TORRESI, D.; TUDISCO, S.; YILDIRIM, A.; ZAGATTO, V. A. B.
© 2023 American Physical Society. Background: Single-charge-exchange reactions are appropriate tools to study the nuclear response to one-particle/one-hole isospin probes, gaining additional interest from the connection to beta decay. This analogy has been recently extended to second order, connecting double-charge-exchange reactions and double beta decays. Nowadays, the availability of powerful experimental setups and advanced nuclear theories and models allows one to access precious information on key nuclear structure aspects embedded in the widely sought neutrinoless double beta decay. Purpose: We intend to bring to light the main nuclear structure and reaction features involved in the O18+C12 collision at 275 MeV incident energy. In this paper, the main focus is on the role of the initial- and final-state interactions in the overall reaction dynamics and on the single-particle nuclear structure properties accessed via the study of single-nucleon transfer reactions. Forthcoming articles will be devoted to go into the details of the response to one- and two-particle/hole isospin probes. Methods: Cross-section energy spectra and angular distributions were measured in a unique experimental setup for the C12(O18,O18)C12 elastic and inelastic scattering, the C12(O18,O17)C13 one-neutron stripping, the C12(O18,F19)B11 one-proton pickup, and the C12(O18,F18)B12 single-charge-exchange nuclear reactions. A unique comprehensive and coherent theoretical calculation, able to describe the whole network of direct reactions using state-of-the-art nuclear structure and reaction theories, was performed, and it is presented for the first time in this article. This holistic approach, applied both to the experimental and theoretical analysis, is the main feature and worth of the work here presented. Results: The energy and angular resolutions achieved in each reaction channel allowed us to isolate specific transitions and to map the diffraction patterns in the angular distributions. The cross-section calculations describe well the experimental data, both in terms of the absolute values and diffraction patterns. Although the distorted wave Born approximation (DWBA) calculations prove to be accurate in describing all the studied channels, better results are achieved when the couplings to inelastic transitions in both the incoming and outgoing partitions are introduced, as done in the coupled channels Born approximation (CCBA) calculations. Otherwise, no real improvement is found when the coupling effects among different partitions are explicitly taken into account in the coupled reaction channels (CRC) calculations. Conclusions: The multichannel approach proposed in this paper is a promising method for accurate investigations of direct reactions originating in heavy-ion collisions. This is quite appealing for the precise spectroscopy of heavy nuclei proposed in many areas of nuclear physics. An example is the NUMEN project with its challenging commitment to provide valuable information on neutrinoless double beta decay nuclear matrix elements from single- and double-charge-exchange cross-section measurements.
Unsupervised machine learning application to identify single-event transients (SETs) from noise events in MOSFET transistor ionizing radiation effects
(2023) ALLEGRO, P. R. P.; TOUFEN, D. L.; AGUIAR, V. A. P.; SANTOS, L. S. A.; OLIVEIRA W. N.; ADDED, N.; MEDINA, N. H.; MACCHIONE, E. L. A.; ALBERTON , S. G.; Marcilei Aparecida Guazzelli; MELO, M. A. A.; OLIVEIRA, J. A.
© 2023This article presents a novel application of the k-means unsupervised machine learning algorithm to the problem of identifying single event transient (SET) events from noise during heavy-ion irradiation experiments of an electronic device. We explore the performance of the k-means algorithm by analyzing experimental datasets of SET events produced by several heavy-ions irradiations of a MOSFET transistor. Data anomalies and effectiveness of the chosen features (mean, standard deviation, skewness, and kurtosis) were investigated using the Isolation Forest and Random Forest algorithms, respectively. The results show a high capability of the K-means algorithm to identify SET events from noise using the first four statistical moments as features, allowing in the future the use of this method for in situ event detection and diagnosis without previous algorithm training or pre-analysis of the experimental data.
Vibration amplitude mapping by stroboscopic structured light projection
(2023-03-15) RIBEIRO, I. L. F.; CARVALHO, G. L.; DIB, L. F. G.; BARBOSA, E. A.; WETTER, N. U.
© 2022 Elsevier B.V.In this work a method to evaluate the distribution of vibration amplitudes of objects was demonstrated, combining for the first time oblique structured light projection, stroboscopic illumination and fringe evaluation. The light pattern was formed by straight and parallel fringes produced by a slightly misaligned Twyman–Green interferometer illuminated by a 40-mW, 650-nm diode laser. Stroboscopic illumination was achieved by driving the laser with a PWM signal with the same frequency than that of the vibrating object. By evaluating the fringes with phase stepping and phase unwrapping procedures, the amplitude mapping of a formica bar and circular rubber membranes was performed. By averaging the fringe position over the light pulse duration a correction ratio between the actual phase and the measured phase was obtained as a function of the pulse duty cycle, and the dependence of the fringe visibility on the duty cycle was studied. The experiments showed that relatively large amplitudes in a range from tens of millimeters up to few millimeters can be measured.
Heavy-Ion-Induced Avalanche Multiplication in Low-Voltage Power VDMosfet
(2021-09-13) ALBERTON. S. G.; MEDINA, N. H.; ADDED, N.; AGUIAR, V. A. P.; Marcilei Aparecida Guazzelli; Roberto Santos
© 2021 IEEE.Lackner's theory for avalanche multiplication in semiconductor devices provides physical interpretation for the model parameters and obtaining them through experimental methods is necessary. In this work, the charge collection mechanisms of heavy-ion-induced avalanche multiplication in power MOSFETs are studied based on Lackner's impact ionization model. The heavy-ion-induced impact ionization coefficients were estimated by comparing collected charge values obtained from computational simulations and experimental measurements.
Data Release 2 of S-PLUS: Accurate template-fitting based photometry covering ∼1000 deg2in 12 optical filters
(2022-04-01) ALMEIDA-FERNANDES, F.; SAMPEDRO, L.; HERPICH, F. R.; MOLINO, A.; BARBOSA, C. E.; BUZZO, M. L.; OVERZIER, R. A.; DE LIMA, E. V. R.; NAKAZONO, L. M. I.; OLIVEIRA SCHWARZ, G. B.; PEROTTONI, H. D.; BOLUTAVICIUS, G. F.; GUTIERREZ-SOTO, L. A.; SANTOS-SILVA, T.; VITORELLI, A. Z.; WERLE, A.; WHITTEN, D. D.; COSTA DUARTE, M. V.; BOM, C. R.; COELHO, P.; SODRE, L.; PLACCO, V. M.; TEIXEIRA, G. S. M.; ALONSO-GARCIA, J.; Cassio Barbosa; BEERS, T. C.; BONATTO, C. J.; CHIES-SANTOS, A. L.; HARTMANN, E. A.; LOPES DE OLIVEIRA, R.; NAVARETE, F.; KANAAN, A.; RIBEIRO, T.; SCHOENELL, W.; MENDES DE OLIVEIRA, C.
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.The Southern Photometric Local Universe Survey (S-PLUS) is an ongoing survey of ∼9300 deg2 in the southern sky in a 12-band photometric system. This paper presents the second data release (DR2) of S-PLUS, consisting of 514 tiles covering an area of 950 deg2. The data has been fully calibrated using a new photometric calibration technique suitable for the new generation of wide-field multifilter surveys. This technique consists of a χ2 minimization to fit synthetic stellar templates to already calibrated data from other surveys, eliminating the need for standard stars and reducing the survey duration by ∼15 per cent. We compare the template-predicted and S-PLUS instrumental magnitudes to derive the photometric zero-points (ZPs). We show that these ZPs can be further refined by fitting the stellar templates to the 12 S-PLUS magnitudes, which better constrain the models by adding the narrow-band information. We use the STRIPE82 region to estimate ZP errors, which are 10 mmags for filters J0410, J0430, g, J0515, r, J0660, i, J0861 and z; 15 mmags for filter J0378; and 25 mmags for filters u and J0395. We describe the complete data flow of the S-PLUS/DR2 from observations to the final catalogues and present a brief characterization of the data. We show that, for a minimum signal-to-noise threshold of 5, the photometric depths of the DR2 range from 19.1 to 20.5 mag (measured in Petrosian apertures), depending on the filter. The S-PLUS DR2 can be accessed from the website: https://splus.cloud.
Near-infrared Spectroscopy of Ultracompact H ii Regions in W51A with NIFS/ALTAIR
(2022-12-01) Cassio Barbosa; NAVARETE, F.; BLUM, R. D.; DAMINELI, A.; CONTI, P. S.
© 2022. The Author(s). Published by the American Astronomical Society.W51A is the most active star formation region of the giant H ii region W51. It harbors the two massive protoclusters W51e and W51 IRS2, which are very rare in the Galaxy. We aim to identify the newborn massive stars and ultracompact H ii regions to derive its distance and age. We performed Integral Field Unit observations with NIFS+ALTAIR of nine targets in the W51A subregion. The distance modulus was obtained using the spectral classification in the K band and a reddening law appropriate to the inner Galactic plane. We derived the distance and the spectral types for five of the targets, ranging from O8 to O9.5, similar to those derived from radio continuum data, except for two sources to which we assigned a somewhat later spectral type. We included another seven objects with precise spectral classification from other works, which allowed us to better constrain the distance estimate. Our spectrophotometric distance d = 4.80 ± 1.27 kpc is in good agreement with those derived from the Galactic rotation model and trigonometric parallaxes, placing the region near the tangent point of the Sagittarius arm. We conclude that the stars studied in this work have an age spread of 1.5-4 Myr, substantially older than thought to date.
Ingestion doses and elemental composition of herbal plants and fish
(2022-11-09) PIEDADE, F. G.; NASCIMENTO, N. B.; SCIANI, W.; CURADO, J. F.; Marcilei Aparecida Guazzelli
© 2022 Institute of Physics Publishing. All rights reserved.It is known that the determination of ingestion doses of radioactive elements is a complex problem due to the different metabolic behaviours of the human beings. To contribute to this topic, this work presents the analysis of the ingestion doses of 40K, 232Th and 238U in some species of herbal plants and fish. These analyses were done using technique of gamma ray spectrometry and applying the estimation models for ingestion dose of ICRP and IAEA. Furthermore, in this article was applied the analytic technique of Energy Dispersive X-ray fluorescence (EDXRF) in the analysis of elementary composition and concentrations of components in those same species of herbal plants and fish.
Ingestion dose and elemental composition in coffee by x-ray fluorescence and gamma-ray spectrometry
(2022-11-09) Marcilei Aparecida Guazzelli; CURADO. J. F.; LOUREIRO, K. P.; MEDINA, N. H.; RIZZUTTO, M. A.
© 2022 Institute of Physics Publishing. All rights reserved.The study proposed in this paper aims to analyze macro and micronutrients in coffee powder samples from Brazil, Venezuela and Colombia, in two different stages of coffee preparation: before and after coffee filtering. In the analyzed samples, presence of K, Rb, Ca, Cl, S, Sr and Fe elements in coffee powder and coffee grounds using Energy Dispersive X-ray fluorescence (ED-XRF) was quantified. The presence of 40K and the radionuclides from the uranium and thorium series decays were verified using gamma-ray spectrometry analyses. With the results obtained using these two techniques, it was possible to estimate the ingestion index for natural radioisotopes. The results show that the annual dose due to coffee ingestion reaches 1.96(4) mSv, depending on the origin of the coffee and considering the annual coffee consumption in Brazil. Elemental Composition analysis of coffee grounds indicates that it can be reused as a product with a high concentration of nutrients.

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