Navegação Periódicos - Artigos por ano de publicação "2022"

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  • IPEN-DOC 29128

    SUZART, K.F. ; PEREIRA, M.C.C. ; HAMADA, M.M. ; MESQUITA, C.H. . Zonal refining and Bridgman technique for CsI:Tl scintillation crystal growth. Brazilian Journal of Radiation Sciences, v. 10, n. 3B, p. 1-14, 2022. DOI: 10.15392/2319-0612.2022.1925

    Abstract: This work describes the development of the crystal cesium iodide doped with thallium (CsI:Tl) for use as a radiation detector. For CsI salt purification the zonal refining methodology using a horizontal oven at a constant temperature of 700 °C was used. The high temperature region corresponds to approximately 10% of the salt bed containing (260 mm). This region moves at a speed of 50 mm/h. The crystal growth was carried out by Bridgman technique, using a vertical oven at speed of 1 mm/h.

    Palavras-Chave: scintillator-photodiode detectors; zone refining; crystal growth methods; bridgman method; neutron detection; cesium iodides

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  • IPEN-DOC 28691

    KHAN, ZAHID U.; UCHIYAMA, MAYARA K.; KHAN, LATIF U.; ARAKI, KOITI; GOTO, HIRO; FELINTO, MARIA C.F.C. ; SOUZA, ANA O. de; BRITO, HERMI F. de; GIDLUND, MAGNUS. Wide visible-range activatable fluorescence ZnSe:Eu3+/Mn2+@ZnS quantum dots: local atomic structure order and application as a nanoprobe for bioimaging. Journal of Materials Chemistry B, v. 10, n. 2, p. 247-261, 2022. DOI: 10.1039/d1tb01870a

    Abstract: The development of QDs-based fluorescent bionanoprobe for cellular imaging fundamentally relies upon the precise knowledge of particle–cell interaction, optical properties of QDs inside and outside of the cell, movement of a particle in and out of the cell, and the fate of particle. We reported engineering and physicochemical characterization of water-dispersible Eu3+/Mn2+ co-doped ZnSe@ZnS core/shell QDs and studied their potential as a bionanoprobe for biomedical applications, evaluating their biocompatibility, fluorescence behaviour by CytoViva dual mode fluorescence imaging, time-dependent uptake, endocytosis and exocytosis in RAW 264.7 macrophages. The oxidation state and local atomic structure of the Eu dopant studied by X-ray absorption fine structure (XAFS) analysis manifested that the Eu3+ ions occupied sites in both ZnSe and ZnS lattices for the core/shell QDs. A novel approach was developed to relieve the excitation constraint of wide bandgap ZnSe by co-incorporation of Eu3+/Mn2+ codopants, enabling the QDs to be excited at a wide UV-visible range. The QDs displayed tunable emission colors by a gradual increase in Eu3+ concentration at a fixed amount of Mn2+, systematically enhancing the Mn2+ emission intensity via energy transfer from the Eu3+ to Mn2+ ion. The ZnSe:Eu3+/Mn2+@ZnS QDs presented high cell viability above 85% and induced no cell activation. The detailed analyses of QDs-treated cells by dual mode fluorescence CytoViva microscopy confirmed the systematic color-tunable fluorescence and its intensity enhances as a function of incubation time. The QDs were internalized by the cells predominantly via macropinocytosis and other lipid raft-mediated endocytic pathways, retaining an efficient amount for 24 h. The unique color tunability and consistent high intensity emission make these QDs useful for developing a multiplex fluorescent bionanoprobe, activatable in wide-visible region.

    Palavras-Chave: quantum dots; zinc selenides; europium; manganese; zinc sulfides; biological functions; cell membranes; particle interactions

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  • IPEN-DOC 28821

    ANDRADE, DELVONEI A. de ; ALMEIDA, MADISON C. de ; ALONSO, VANESSA M. ; PAIXAO, CLAUDIA M. ; ARQUINTO, JULIANA ; KOTANI, PALOMA O. ; MARINHO, THAYNA C. . Very high temperature reactor (VHTR): a proposal to generation IV reactors / Reactor a temperatura muito elevada (VHTR) - uma proposta para reactores da geração IV. Brazilian Journal of Development, v. 8, n. 3, p. 17576-17588, 2022. DOI: 10.34117/bjdv8n3-139

    Abstract: The Generation IV reactors depict a revolution in terms of electricity supply for the future. The proof of concept originated in the Generation IV forum, which listed six possible technological routes for a future of nuclear generation based on fissile material, which includes safety requirements, nuclear energy efficiency and less waste generation. These are the very high temperature reactor (VHTR); supercritical water-cooled reactor (SCWR); molten salt reactor (MSR); gas-cooled fast reactor (GFR); sodium cooled fast reactor (SFR); and lead-cooled fast reactor (LFR). The present study explored the possibilities, the obstacles, as well as the challenges to be overcome, for the Very High Temperature Reactor (VHTR). VHTR technology seems to be versatile; it originates on the advancement of another type, the High Temperature Reactor (HTR). USA, Germany and UK were main countries in this avant-garde research. In addition to generating electrical energy, VHTR can provide heat for industrial sectors and other applications. Like any nuclear technology, challenges regarded to safety and the environment are key points in the implementation of the system. VHTR was here prospected, with its “pros and cons”; as a promising way to a safe nucleoelectric energy. Summarizing, VHTR is shown as a possible alternative, as long as studies of high-strength materials go ahead. In short, the reactor becomes a viable source of thermonuclear generation, also associated with hydrogen production.

    Palavras-Chave: graphite; htgr type reactors; hydrogen production; neutron flux; reactor operation; reviews; technology assessment; thermal efficiency

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  • IPEN-DOC 28880

    LARANJA, MARCIO J.; JUNIOR, FRANCISCO H.S.; NOGUEIRA, GABRIELA A.; VIEIRA, LAIS H.S.; OLIVEIRA, NAIARA C.; SOARES, JOAO M.; CORDEIRO, CARLOS H.N.; OTUBO, LARISSA ; MOREIRA, ALTAIR B.; FERREIRA, ODAIR P.; BISINOTI, MARCIA C.. Valorisation of sugar cane bagasse using hydrothermal carbonisation in the preparation of magnetic carbon nanocomposite in a single-step synthesis applied to chromium adsorption. Journal of Chemical Technology and Biotechnology, v. 97, n. 8, p. 2032-2046, 2022. DOI: 10.1002/jctb.7074

    Abstract: BACKGROUND: Sugar cane bagasse (SB) is a by-product of the sugar cane industry, and is obtained on a large scale. In this paper, SB was used as a source of carbon for preparing a magnetic carbon nanocomposite (MCN-SB) through one-step hydrothermal carbonisation (HTC), in the presence of iron (III) nitrate. By way of comparison, SB was replaced by glucose in HTC (MCN-GLU), and a thermal treatment of this material was then performed under an N2 atmosphere (MCN-GLU-HT). The physical and chemical properties of the nanocomposites were assessed, and the magnetic samples were applied as adsorbents. RESULTS: MCN-SB and MCN-GLU are composed of iron oxide nanoparticles embedded in carbonaceous matrix which also contain oxygenated groups. The MCN-SB sample was already magnetic after HTC, showing a magnetization saturation (Ms) of 5.0 emu g−1, due to the presence of magnetite, whereas MCN-GLU consisted of hematite and required additional thermal treatment (HT) to acquire magnetic properties, with MCN-GLU-HT showing an Ms of 30.5 emu g−1. In turn, the mesoporous structure and higher specific surface area (SSA) of MCN-GLU-HT (SSA 90 m2 g−1) than MCN-SB (SSA 53 m2 g−1) was a causative factor for its higher capacity of hexavalent chromium [Cr (VI)] removal (939 μg g−1), when compared to MCN-SB (768 μg g−1), which has a nonporous structure. CONCLUSION: The results suggest that SB can be reused, by means of HTC, for the preparation of a magnetically recoverable adsorbent, showing good adsorption properties. © 2022 Society of Chemical Industry (SCI).

    Palavras-Chave: sugar cane; bagasse; nanocomposites; biomass; environment; chemical properties

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  • IPEN-DOC 28433

    NUNES, R.F.; TOMINAGA, F.K. ; BORRELY, S.I. ; TEIXEIRA, A.C.S.C.. UVA/persulfate-driven nonylphenol polyethoxylate degradation: effect of process conditions. Environmental Technology, v. 43, n. 2, p. 286-300, 2022. DOI: 10.1080/09593330.2020.1786166

    Abstract: UV/persulfate (UV/PS) technologies have gained increased attention as efficient alternatives for removing pollutants from different classes, although processes based on the UVA-driven S2O2−8 (PS) activation have not yet been discussed in the literature for the removal of the nonionic surfactant nonylphenol polyethoxylate (NPEO). The present study investigated the simultaneous effect of the initial persulfate concentration ([PS]0) and specific photon emission rate (EP,0) on NPEO degradation by UVA/PS following a Doehlert experimental design. The results for [NPEO]0 = (4.65 ± 0.15) mg L−1 indicated more than 97.8% NPEO removal after 2 h, with pseudo first-order specific degradation rate (kobs) of 0.0320 min−1, for [PS]0 = 7.75 mmol L−1 and EP,0 = 0.437 μmol photons L−1 s−1. Under these conditions, NPEO half-life time was about 22 min, and the EC50-48 h (% v/v) values for Daphnia similis before and after treatment did not differ significantly. Higher values of EP,0 would influence NPEO removal for [PS]0 not higher than 8–10 mmol L−1, although lower degradation efficiencies were obtained with higher [NPEO]0 or real wastewater, except for longer reaction times. Additionally, UVA/PS showed to be efficient for tensoactivity removal, despite the negligible total organic carbon (TOC) removal achieved. Finally, UVC and UVA resulted in NPEO degradation higher than 96% and similar tensoactivity removals when UVA/PS was conducted under optimal conditions ([PS]0 = 10 mmol L−1; EP,0 = 0.324 μmol photons L−1 s−1), suggesting that UVA radiation available in solar light could be advantageously employed for NPEO removal at concentrations usually found in wastewater.

    Palavras-Chave: surfactants; pollution control; biodegradation; persulfates; ultraviolet radiation; surface tension

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  • IPEN-DOC 29092

    GASPARIAN, PATRICIA B.R. ; MALTHEZ, ANNA L.M.C.; CAMPOS, LETICIA L. . Using the optically stimulated luminescence technique for one- and two-dimensional dose mapping: a brief review. Physics in Medicine and Biology, v. 67, n. 19, p. 1-15, 2022. DOI: 10.1088/1361-6560/ac9030

    Abstract: In respect of radiation dosimetry, several applications require dose distribution verification rather than absolute dosimetry. Most protocols use radiological and radiochromic films and ionization chambers or diode arrays for dose mapping. The films are disposable which causes the precision of the results dependent on film production variability. The measurements with arrays of ionization chambers or diodes mainly lack spatial resolution. This review aims to provide an overview of the use of optically stimulated luminescence detectors (OSLDs) for one-dimensional (1D) and two-dimensional (2D) dose mapping in different applications. It reviews the ideas, OSL materials, and applications related to the assessment of dose distribution using OSLDs in the form of film or ceramic plate (BeO). Additionally, it reviews research published in the international scientific literature from 1998 to 2021. As an outcome, a table containing the main characteristics of each relevant paper is shown. The results section was divided by the type of OSL material, and we briefly described the principal findings and the significant developments of each mentioned study such as film production and OSL reader assembly. The purpose of this study was to present an overview of the main findings of several research groups on the use of OSLD in the form of film or plate for 1D and 2D dose mapping. Finally, the potential future development of dose mapping using OSLD films was outlined.

    Palavras-Chave: luminescent dosemeters; one-dimensional calculations; two-dimensional calculations; dosimetry; ionization chambers; dose rates; films; radiation detection

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  • IPEN-DOC 28809

    LEBRE, DANIEL T. ; THIPE, VELAPHI C. ; COTRIM, MARYCEL E.B. ; BUSTILLOS, JOSE O.V. . Use of sugar cane bagasse as solid extraction phase sorbent to analyze hormones from industrial effluent. ACS Omega, v. 7, n. 12, p. 10069-10076, 2022. DOI: 10.1021/acsomega.1c06064

    Abstract: Sugar cane bagasse (SCB) is an abundant byproduct of sugar and bioethanol mills. It has been effectively used as a low-cost biosorbent to remove hazardous chemical compounds from a variety of effluent sources. Herein, we report on the preparation of SCB and its use as a solid phase extraction (SPE) sorbent to retain synthetic hormones (ethinylestradiol, drospirenone, and levonorgestrel) from industrial pharmaceutical plant effluent samples prior to LC–MS/MS quantitative analysis. We evaluated the reproducibility and recoveries and accuracy data analyses were compared with that of commercial SPE (cSPE) cartridges. The results from the evaluated parameters indicated that the SCB bed had an efficiency of >99%, comparable to that of cSPE cartridges, demonstrating the applicability and feasibility of this material as an effective and green chemistry alternative, as well as its biosorbent potential to remove hormones from industrial pharmaceutical effluent.

    Palavras-Chave: sugar cane; bagasse; bioethanol; hormones; bioremediation; liquid wastes

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  • IPEN-DOC 28848

    LEON, MORGANE; BEEK, PIETER van; SCHOLTEN, JAN; MOORE, WILLARD S.; SOUHAUT, MARC; OLIVEIRA, JOSELENE de ; JEANDEL, CATHERINE; SEYLER, PATRICK; JOUANNO, JULIEN. Use of 223Ra and 224Ra as chronometers to estimate the residence time of Amazon waters on the Brazilian continental shelf. Limnology and Oceanography, v. 67, n. 4, p. 753-767, 2022. DOI: 10.1002/lno.12010

    Abstract: When rivers mix into the ocean, radium isotopes are released into the dissolved phase allowing us to apply these isotopes as powerful tracers of river plumes spreading into the ocean. We report 223Ra and 224Ra radium activities that were determined in the Amazon River mouth and along the Amazon plume that extends off the coasts of Brazil and French Guyana into the Atlantic Ocean. We summarize 223Ra and 224Ra data from AmasSeds (1991), AMANDES (GEOTRACES process study GApr01; 2007–2008) and M147 (2018) projects, which were conducted in different seasons corresponding to different Amazon discharge rates. We determined the 224Raex/223Ra activity ratios (AR) along the Amazon plume to derive apparent ages and to estimate the residence time of the Amazon waters on the Brazilian continental shelf. Our data suggest that it takes 9–14 d for the Amazon waters to reach the northern continental shelf off French Guyana and 12–21 d to reach the eastern part of the Brazilian continental shelf. These time scales are in good agreement with those derived from a high-resolution numerical simulation of the regional ocean dynamics. We do not find any relationship between the discharge rate of the Amazon River and the residence time of the waters on the Brazilian continental shelf, suggesting that the residence time of the Amazon waters is primarily driven by the ambient northwestward current. Using the apparent ages along the plume, we estimate an average velocity of 26 cm s−1 for the northward transport of the Amazon waters on the continental shelf.

    Palavras-Chave: radium 223; radium 224; rivers; plumes; water pollution; isotopes; amazon river

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  • IPEN-DOC 29048

    WATANABE, TAMIRES ; GUILHEN, SABINE N. ; MARUMO, JULIO T. ; SOUZA, RODRIGO P. de; ARAUJO, LEANDRO G. de . Uranium biosorption by hydroxyapatite and bone meal: evaluation of process variables through experimental design. Environmental Science and Pollution Research, v. 29, n. 53, p. 79816-79829, 2022. DOI: 10.1007/s11356-021-17551-x

    Abstract: Biosorption has been examined for the treatment of aqueous solutions containing uranium, a radiotoxic pollutant. Nevertheless, the evaluation of the role of process variables by experimental design on the use of hydroxyapatite and bone meal as biosorbents for uranium has not yet been previously addressed. In this study, the effects of adsorbent dosage (M), initial uranium concentrations ([U]0), and solution pH were investigated, using a two-level factorial design and response surface analysis. The experiments were performed in batch, with [U]0 of 100 and 500 mg L−1, pH 3 and 5, and adsorbent/uranium solution ratios of 5 and 15 g L−1. Contact time was fixed at 24 h. Removal rates were higher than 88%, with a maximum of 99% in optimized conditions. [U]0 and M were found to be the most influential variables in U removal in terms of adsorption capacity (q). The experiments revealed that bone meal holds higher adsorption capacity (49.87 mg g−1) and achieved the highest uranium removal (~ 100%) when compared to hydroxyapatite (q = 49.20 mg g−1, removal = 98.5%). The highest value of q for both biomaterials was obtained for [U]0 = 500 mg L−1, pH 3, and M = 5 g L−1. Concerning the removal percentage, bone meal achieved the best performance for [U]0 = 500 mg L−1, pH 3, and M = 15 g L−1. Further experiments were made with real radioactive waste, resulting in a high uranium adsorption capacity for both materials, with 22.11 mg g−1 for hydroxyapatite and 22.08 mg g−1 for bone meal, achieving uranium removal efficiencies higher than 99%.

    Palavras-Chave: adsorption; radioisotopes; radioactive wastes; surface; skeleton

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  • IPEN-DOC 29069

    BARIONI, A.; KAUR, G.; ALCANTARA-NUNEZ, J.; ASSUNCAO, M.; GUIMARAES, V.; LARA, A.L.; LEPINE-SZILY, A.; LICHTENTHALER, R.; LINARES, R.; MENDES JUNIOR, D.R.; PIRES, K.C.C.; SANTOS, O.C.B.; SERRA, A.S.; SHORTO, J.M.B. ; UMBELINO, U.; ZAGATTO, V.A.B.; ZEVALLOS, E.O.N.; ZAMORA, J.C.. Two-neutron transfer as a tool to study pairing correlations in nuclei. Journal of Physics: Conference Series, v. 2340, p. 1-5, 2022. DOI: 10.1088/1742-6596/2340/1/012040

    Abstract: A feasibility study of two-neutron transfer reactions, using 12C and 19F targets, was performed. In this experiment, a 6He beam at 20 MeV incident energy was delivered by the RIBRAS facility. The main goal of this work was to test the RIBRAS system, operated in a single-solenoid mode, to investigate (6He,α) reactions in light nuclei. The excitation function of the 14C nucleus, populated by the 12C(6He,α) reaction, was extracted from the data. Evidence of nn-transfer reactions populating the ground state and the first 0+ 1 state in 14C were observed. However, the present spectrum might have contribution from other reaction channels such as the 6He breakup. Future experiments with the RIBRAS dual-solenoid mode will improve the quality of the data by reducing a significant amount of background.

    Palavras-Chave: neutron transfer; pairing interactions; angular distribution

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  • IPEN-DOC 29042

    BEU, CASSIA M.L. ; LANDULFO, EDUARDO . Turbulence kinetic energy dissipation rate estimate for a low-level jet with Doppler lidar data: a case study. Earth Interactions, v. 26, n. 1, p. 112-121, 2022. DOI: 10.1175/EI-D-20-0027.1

    Abstract: Low-level jets are a recurrent feature of our study area in Ipero municipality of southeastern Brazil. They grow very near the surface as shown by this case study. These two aspects increase the needs for a realistic modeling of the low-level jet to simulate the atmospheric dispersion of industrial emissions. In this concern, we applied a recently proposed technique to estimate the turbulence kinetic energy dissipation rate of a low-level jet case with Doppler lidar data. This low-level jet remained for its entire lifetime (around 12 h) within a shallow layer (under 300 m); beyond this, we did not notice a remarkable directional shear as in other studies. Even for a shallow layer as for this study case, we observed strong spatiotemporal variability of the turbulence kinetic energy dissipation rate. We also detected a channel connecting the layers above and below the low-level jet that may be an exchange channel of their properties.

    Palavras-Chave: optical radar; turbulence; transverse energy; atmospheric circulation; boundary layers; jets

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  • IPEN-DOC 28994

    TRINDADE, FABIANE J.; DAMASCENO, SERGIO; OTUBO, LARISSA ; FELEZ, MARISSOL R.; FLORIO, DANIEL Z. de; FONSECA, FABIO C. ; FERLAUTO, ANDRE S.. Tuning of shape, defects, and disorder in lanthanum-doped ceria nanoparticles: implications for high-temperature catalysis. ACS Applied Nano Materials, v. 5, n. 7, p. 8859-8867, 2022. DOI: 10.1021/acsanm.2c00942

    Abstract: The design of nanomaterials by tailoring the size, shape, and surface chemistry has a significant impact on their properties. The fine-tuning of structural defects of ceria rod-like and cube-like-shaped nanoparticles was performed via La3+ doping in molar ratios of 0–70 mol %. Morphology control was achieved by varying the hydrothermal synthesis temperature. For LaxCe1–xO2–x/2 samples prepared at 110 °C, nanorod-like structures are obtained for x < 0.30 and a random morphology of interconnecting polyhedra is achieved for a larger x. The ceria fluorite crystalline structure is maintained at an x of up to 0.60, and both Raman and X-ray diffraction results indicate a high level of defects and disorder in the crystalline structure. For LaxCe1–xO2–x/2 samples prepared at 180 °C, cube-shaped particles are predominant for an x of up to 0.10; however, for x> 0.20, two fluorite phases with different lattice parameters are associated with two distinct shapes, cubes and rods The La concentration in nanocubes is limited to x = 0.10 even for samples prepared with higher nominal La concentrations, whereas the nanorods contain larger La concentrations. The demonstrated morphology and defect control on La-doped ceria nanoparticles are critical for applications such as high-temperature oxide catalysts.

    Palavras-Chave: enzymes; angiotensin; catalysts; polypeptides; temperature dependence

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  • IPEN-DOC 28770

    ARAUJO, JOAO V. de S. ; MILAGRE, MARIANA X. ; KLUMPP, RAFAEL E. ; AYUSSO, VICTOR H. ; DONATUS, UYIME ; COSTA, ISOLDA . TSA anodising voltage effects on the near-surface coarse intermetallic particles in the AA2024-T3 and AA2198-T8 alloys. Corrosion Engineering, Science and Technology, v. 57, n. 4, p. 380-396, 2022. DOI: 10.1080/1478422X.2022.2071666

    Abstract: In this study, the behaviour of the micrometric particles of the AA2198-T8 alloy during anodising at various voltages and the effect of anodising voltage on the anodised surface morphology have been investigated in a tartaric-sulfuric acid anodising solution. The results were compared with that of the AA2024-T3 alloy. For the AA2198-T8 alloy, partial dissolution of these particles occurred at 0, 3 and 4 V. Besides, for potentials above 5 V, there is a preferential dissolution of the intermetallic particles. For the AA2024-T3 alloy, the results indicated a total dissolution of the micrometric particles at 0 V and a partial dissolution at 3 V, whereas above 4 V total dissolution occurred. Between 1 and 2 V, no dissolution was observed for both alloys. The preferential dissolution of the micrometric particles resulted in defects in the anodic film and cavities on the anodised surfaces.

    Palavras-Chave: aluminium alloys; intermetallic compounds; particle size; anodization; sulfuric acid; tartaric acid

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  • IPEN-DOC 28858

    JESUS, VIVIANE P. dos S.; VIEIRA, PAULA F.A.; CINTRA, RICARDO C.; SANTANNA, LUCIANA B.; ZEZELL, DENISE M. ; CASTILHO, MAIARA L.; RANIERO LEANDRO. Triple-negative breast cancer treatment in xenograft models by bifunctional nanoprobes combined to photodynamic therapy. Photodiagnosis and Photodynamic Therapy, v. 38, p. 1-9, 2022. DOI: 10.1016/j.pdpdt.2022.102796

    Abstract: Triple-negative breast cancer (TNBC) overexpresses the Epidermal Growth Factor Receptor (EGFR), a characteristic of different types of tumors, linked to worse disease prognosis and risk of recurrence. Conventional treatments are also aggressive and can be morbid.. Therefore, t improvement and development of new methods are notorious. Photodynamic Therapy (PDT) is an effective method for treating different types of cancer by using light radiation to activate a photosensitizing agent (drug) in molecular oxygen presence, promoting cell death., Improving drug uptake in target cells could contribute to PDT efficiency. Accordingly, we developed a bifunctional nanoprobe (BN), used in PDT as a a treatment method in vivo against breast cancer. The BN uses gold nanoparticles with active targeting through the Epidermal Growth Factor (EGF) protein and Chlorine e6 (Ce6) carriers. We evaluated the therapeutic efficacy of in vivo xenograft in 4 groups: Saline, BN, Ce6+PDT, and BN+PDT. As a result, we observed that the BN+PDT group exhibited an excellent effect with greater selectivity to tumor tissue and tissue damage when compared to the Saline, BN, and Ce6+PDT groups. The results indicate a potential impact on breast cancer treatment in vivo.. In conclusion, our data propose that the BN developed heightened PDT efficacy through cellular DNA repair effects and tumor microenvironment.

    Palavras-Chave: neoplasms; mammary glands; nanoparticles; photodynamic therapy; photosensitivity

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  • IPEN-DOC 29033

    GONCALVES, J.A.C. ; SOMESSARI, E.S.R. ; SOMESSARI, S.L. ; BUENO, C.C. . Transit dose measurements using alanine and diode-based dosimeters. Brazilian Journal of Radiation Sciences, v. 10, n. 2A, p. 1-9, 2022. DOI: 10.15392/bjrs.v10i2A.1828

    Abstract: The growing interest in low-dose (< 100 Gy) radiation processing applications has raised concerns about accurately measuring the absorbed dose in irradiated materials. Depending on the irradiator design, the transit time due to the radioactive source movement (or the product itself) until the stable irradiation position might affect the predicted absorbed dose. This work aims to evaluate the transit dose in a 60Co Gammacell 220-Nordion irradiator, which has radioactive sources settled at the bottom of a lead shielding. When the facility is on, the product and the dosimeter are mechanically guided down to the irradiation position, and hereafter the selected exposure time starts to be counted. At the end of irradiation, both product and dosimeter rise to the initial position enabling them to be gathered by the operator. The product is continuously irradiated at different dose rates during its fall and rise movement, preventing the transit dose from being obtained straightforward. The experimental approach adopted is to assess the transit time, and thus the transit dose, using an online diode-based dosimetry system previously calibrated against reference standard alanine dosimeters. The agreement between the transit doses attained with the diode (0.41 ± 0.02) Gy and alanine (0.38 ± 0.01) Gy validates the method herein proposed.

    Palavras-Chave: absorbed radiation doses; alanines; cobalt 60; dose rates; dosemeters; dose-response relationships; radiation monitoring

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  • IPEN-DOC 28500

    MAZZILLI, BARBARA P. ; LAVIERI, LETICIA G.S. ; SOARES, JOSIANE S. ; ROCHA, FLAVIO R. ; ANGELINI, MATHEUS ; FAVARO, DEBORAH I.T. . Trace and major elements, natural and artificial radionuclides assessment in bottom sediments from Tietê River basin, São Paulo State, Brazil: part III. Journal of Radioanalytical and Nuclear Chemistry, v. 331, n. 1, p. 129-144, 2022. DOI: 10.1007/s10967-021-08094-z

    Abstract: This paper aims at quantifying natural and artificial radionuclides, trace and major elements in sediments collected along the Tietê River basin. The results obtained for Cd, Cr, Cu, Ni and Zn, indicated that the region of “High Tietê” is highly polluted, followed by the region of “Middle Tietê” and the region of “Low Tietê” does not present evidence of contamination. The natural radionuclide concentrations were of the same order of magnitude of world average values and can be defined as basal levels of the region. Cesium-137 activity concentration ranged from 0.22 ± 0.08 Bq kg−1 to 0.96 ± 0.12 Bq kg−1.

    Palavras-Chave: rivers; sediments; contamination; elements; heavy metals; radioisotopes; trace amounts

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  • IPEN-DOC 29145

    BOIANI, N.F. ; TOMINAGA, F.K. ; BORRELY, S.I. . Toxicity removal of pharmaceuticals mixtures through electron beam irradiation. Brazilian Journal of Radiation Sciences, v. 10, n. 3B, p. 1-11, 2022. DOI: 10.15392/2319-0612.2022.1838

    Abstract: Contamination of the aquatic environment by pharmaceuticals is becoming a global phenomenon of growing concern. Pharmaceuticals are partially metabolized, resulting in the excretion and release of residual into sewage, unaltered or metabolites. The wastewater treatment plants are not designed to eliminate these compounds, leading the residues into the aquatic environment. Besides, pharmaceuticals are not detected individually but as a complex mixture. Advanced oxidative processes have been applied as an alternative or complement to conventional sewage treatment processes, aiming the degradation and removal of toxic pollutants. The objective of this study was to evaluate the toxicity removal of mixtures of pharmaceuticals subjected to electron beam treatment. The aqueous solutions of each pharmaceutical were diluted in ultra-pure water and prepared in three pharmaceuticals combinations: Propranolol + Fluoxetine + Sulfadiazine; Propranolol + Fluoxetine + Diclofenac; Acetylsalicylic acid + Fluoxetine + Metformin). Electron Beam Accelerator was applied for the irradiations and the absorbed doses were 2.5-5.0 kGy. Acute toxicity tests with Daphnia similis were performed to evaluate the toxicity, before and after irradiation.. The data analyzed showed toxicity removal efficiency around 80% for the mixture of Propranolol, Fluoxetine and Diclofenac; 75% for the mixture of Propranolol, Fluoxetine and Sulfadiazine; and 30% for the mixture of Acetylsalicylic acid, Fluoxetine and Metformin. According to the literature, this is a viable technology for the removal of toxicity from pharmaceuticals, and the results demonstrated the potential of electron beam irradiation in reducing the toxicity of pharmaceutical from different classes.

    Palavras-Chave: aquatic ecosystems; contamination; drugs; electron beams; environmental impacts; pollutants; radiation dose units; toxicity; waste water

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  • IPEN-DOC 28820

    MELO, CAMILA G. ; ROSA, JORGE M. ; BORRELY, SUELI I. ; PEREIRA, MARIA da C.C. . Toxicidade do efluente têxtil com corante reactive blue 21 submetido à irradiação por feixe de elétrons / Toxicity of reactive blue 21 dye textile effluent subjected to electron beam irradiation. Brazilian Journal of Development, v. 8, n. 4, p. 31191-31199, 2022. DOI: 10.34117/bjdv8n4-551

    Abstract: O setor têxtil se destaca na economia de muitos países e por questões ambientais relacionadas à sua cadeia produtiva. A etapa de beneficiamento secundário, em especial o processo de tingimento, além de consumir muita água, utiliza inúmeros insumos químicos, gerando efluentes com potencial tóxico e desequilíbrio às condições de vida do corpo receptor. Diante disso, o objetivo do estudo foi avaliar a toxicidade do efluente têxtil, com o corante Reactive Blue 21, antes e após tratamento por irradiação com feixe de elétrons. O efluente do tingimento otimizado com o corante Reactive Blue 21 foi submetido à irradiação por feixe de elétrons e, posteriormente, avaliado e comparado à amostra sem tratamento, em relação a sua toxicidade aguda com os organismos Daphnia similis e Vibrio fischeri. Os resultados apontaram maior sensibilidade da bactéria luminescente Vibrio fischeri ao efluente, com um valor de CE50 de 0,43% para a amostra sem tratamento e de 8,89%. Já o microcrustáceo Daphnia similis, apresentou para a amostra sem tratamento 4,79% e 12,64% de CE50.O processo de tratamento por irradiação se mostrou eficaz para a redução da toxicidade no efluente analisado, com uma eficácia de mais de 60% no tratamento para ambos os organismos.

    Palavras-Chave: ionizing radiations; toxicity; dyes; textile industry; liquid wastes; materials testing

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  • IPEN-DOC 28662

    YAMAGATA, CHIEKO ; LEME, DANIEL R. ; RODRIGUES, VANESSA G. ; ERETIDES, GABRIEL T. ; RODAS, ANDREA C.D.. Three routes for the synthesis of the bioceramic powder of the CaO-MgO-SiO2 system. Ceramics International, v. 48, n. 7, p. 9681-9691, 2022. DOI: 10.1016/j.ceramint.2021.12.169

    Abstract: We report three routes for the synthesis of CaO-MgO-SiO2 (CMS) bioceramic powder using different Si sources and synthesis procedures. The ceramic powders were synthesized from Na2SiO3 waste solution by the sol-gel process combined with co-precipitation (synthesis route I and synthesis route II), and from TEOS (tetraethyl orthosilicate) by conventional sol-gel (synthesis route III). Ceramic powders of the CMS multiphase system were obtained, including diopside, wollastonite, akermanite, monticellite and merwinite, which are suitable for application as biomaterial. These powders were sintered at 1200 °C for 2 h to obtain the CMS ceramics. The ceramics mostly contained diopside and wollastonite crystalline phases. Those ceramics when submitted to cytotoxicity tests revealed to be non-cytotoxic, according to ISO10993-5:2009. The ceramics were tested for in vitro bioactivity while soaked in simulated body fluid (SBF) solution. After 14 days, the presence of hydroxyapatite particles on the surface of ceramics was confirmed by Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) micrographs. The surfaces were completely covered with hydroxyapatite, after 21 days. In summary, CaO-MgO-SiO2 (CMS) ceramic powder derived from three routes of synthesis have potential application in the biomedical area. However, further in-vitro and in-vivo studies are needed.

    Palavras-Chave: synthesis; ceramics; biological materials; sol-gel process; coprecipitation

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  • IPEN-DOC 28865

    SANTOS, CALINE O.; SANTOS, BIANCA F.S.; REZENDE, YARA R.R.S.; SILVA, ANDERSON M.B.; CALDAS, LINDA V.E. ; SOUZA, DIVANIZIA N.; SILVA, RONALDO S.; REZENDE, MARCOS V.S.. Thermoluminescence and optically stimulated luminescence of Ba-doped Al2O3 produced by a modified sol-gel route. Radiation Physics and Chemistry, v. 198, p. 1-5, 2022. DOI: 10.1016/j.radphyschem.2022.110194

    Abstract: This work features the synthesis and characterization of Al2O3 phosphors doped with different concentrations of barium. The samples are produced by a modified sol-gel route, with glucose used as a chelating agent. The luminescent response of the phosphors is also evaluated through their thermoluminescence (TL) and optically stimulated luminescence (OSL). These optical properties are characterized with pellets obtained from the addition of Teflon to the phosphors. Through the TL analysis carried out with a heating rate of 10 °C/s, the samples reveal two intense TL glow peaks with different glow curve shapes when varying the dopant concentration of all the samples. By means of the TL emission curves of the pellets, activation energies associated with the transfer processes of the materials are determined. The phosphors present typical exponential OSL decay curves with a predominance of fast and medium components, indicating that the traps have a high photoionization cross section for blue light-emitting diodes.

    Palavras-Chave: dosimetry; thermoluminescence; aluminium oxides; luminescence; optical fibers; stimulated emission

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