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Modern high-efficiency solid state lasers
2026 - WETTER, N. U.; PRADO, F. M.
This work reviews recent advancements in modern neodymium-doped solid-state lasers, with a particular emphasis on Nd:YLF. Key innovations include highly efficient passively Q-switched configurations and the demonstration of novel emission wavelengths. Nd:YLF lasers achieved record-breaking efficiencies in both traditional and in-band pumping schemes, with a notable demonstration of 41 mJ pulse energy and 46 MW peak power in a sub-nanosecond Q-switched system employing a Cr⁴⁺:YAG saturable absorber and a side-pumping scheme. Nd:YAG systems achieved 40 mJ pulse energy with an 18 ns duration, underscoring their suitability for laser designation applications. Additionally, new wavelengths at 863 nm and 1370 nm were demonstrated in Nd:YLF crystals, enabling applications such as blue light generation and astrophysical studies. Multichromatic emissions were also investigated, highlighting the potential of Nd-doped lasers to produce simultaneous outputs at multiple wavelengths. These findings emphasize the versatility, efficiency, and scientific importance of Nd-doped lasers, paving the way for further innovations in laser technology.
Oral cancer diagnosis via machine learning and micro-FTIR hyperspectral imaging
2026 - PERES, D. L.; SILVA, D. F. T.; GERMANO, G. C. M.; PEREIRA, T. M.; FELIPE, J. C.; MATOS, L. L. de; ZEZELL, D. M.
Oral squamous cell carcinoma (OSCC) remains a major global health challenge, and its early detection is essential for improving patient prognosis. Fourier-transform infrared (FTIR) hyperspectral imaging offers a powerful, label-free approach for probing biochemical alterations in biological tissues, providing rich spectral information that can support computational diagnosis. In this study, we evaluated the performance of a Random Forest classifier applied to FTIR hyperspectral images of OSCC and control oral tissues. After rigorous preprocessing and restriction of the analysis to the 1500-1750 cm−1 region—the portion of the fingerprint band with highest discriminative variability—the model achieved strong pixel-level performance, with high precision, recall, and an area under the ROC curve of 0.986. Image-level classification, a clinically relevant metric, yielded an accuracy of 0.86 across 96 samples, demonstrating the model’s reliability in assigning whole-sample labels. Feature importance analysis identified key vibrational modes associated with malignant transformation, notably the Amide I and Amide II bands, as well as lipid-related C=O stretching near 1735 cm−1. These findings indicate that Random Forest, combined with FTIR hyperspectral imaging, can robustly capture biologically meaningful spectral signatures and represents a promising complementary tool for OSCC screening and diagnostic support.
Controle de qualidade de um equipamento ultrassonográfico em um hospital universitário
2026 - OLIVEIRA, BRUNNO F. de; DONALD, GABRIELA G.; SILVA, ANDERSON M. B. da; AMORIM, PRISCILA S.; BARRETO, ISIS L. dos S.; CALDAS, LINDA V. E.; SOUZA, DIVANIZIA do N.
O presente estudo aborda o controle de qualidade em ultrassonografia em um hospital universitário de Sergipe, com foco na adequação dos procedimentos conforme a Instrução Normativa 96 da RDC 611/2022 da ANVISA, cuja implementação representa um avanço recente no cenário regulatório brasileiro. Embora programas de controle de qualidade em ultrassonografia já estejam consolidados em outros países, sua sistematização no Brasil ainda é um processo em consolidação. A ultrassonografia é um método de imagem não invasivo amplamente utilizado para o diagnóstico de patologias, como o câncer de mama. Portanto, o controle sistemático da qualidade dos exames ultrassonográficos é essencial para garantir a confiabilidade do diagnóstico e a segurança assistencial. Embora se reconheça a dependência do operador nesse método, o controle de qualidade constitui uma exigência técnica fundamental independentemente desse fator. As discussões deste artigo abrangem a análise de documentos normativos e a avaliação prática com um fantoma modelo 404GS LE, com ênfase no protocolo de controle de qualidade de exame de ultrassom mamário. Os testes foram realizados em três momentos (inicial, após seis meses e após oito meses), e incluíram avaliação de uniformidade da imagem, resolução axial e lateral, zona morta, profundidade de penetração, zona focal, exatidão das medidas e visualização de objetos anecoicos. No teste inicial, foram identificadas inconformidades nos parâmetros de uniformidade e resolução em dois dos transdutores avaliados. As inconformidades foram corrigidas, conforme constatado nos demais testes. Conclui-se que a implementação sistemática do controle de qualidade é fundamental para o monitoramento do desempenho dos equipamentos. Destacam-se, para a confiabilidade diagnóstica e a segurança dos exames, a manutenção preventiva ou corretiva dos equipamentos, o treinamento contínuo de seus operadores e a aplicação rigorosa das normativas vigentes.
Integrating best estimate plus uncertainty analysis into model-based systems engineering
2026 - AVELAR, ALAN M.; SU, JIAN; GIOVEDI, CLAUDIA; CAMARGO, FABIO de; KLAMO, JOSEPH T.; YAKIMENKO, OLEG
The licensing of new nuclear reactors after the Fukushima accident presents significant challenges due to the complexity of nuclear systems and the stringent regulatory requirements involved. Model-based systems engineering (MBSE) has emerged as a useful approach for managing the development of such complex systems, while Best Estimate Plus Uncertainty (BEPU) methodologies have proven valuable within regulatory frameworks for safety evaluation. However, digital models and databases that are needed to provide evidence that the system meets the specified requirements are usually isolated in discipline-specific data repositories. To address this challenge, this article proposes a model breakdown structure (MBS) methodology, using a set of interconnectable models to seamlessly integrate MBSE, computer-aided engineering (CAE) models, and BEPU analysis. The Brazilian Multipurpose Reactor (RMB) served as the system of interest to exemplify the effectiveness of the proposed methodology. A requirement specification was linked to a finite element analysis (FEA) that estimates the peak cladding temperature in a slow loss of flow accident scenario. Additionally, key design factors are identified using design of experiments (DOE) and analysis of variance (ANOVA). Lastly, Wilks' theorem and Monte Carlo simulations are applied for uncertainty quantification. The results indicate that the 95/95 upper tolerance limit of the peak cladding temperature remains below the onset of nucleate boiling. Furthermore, the utilization of Wilks' theorem can reduce computational cost for uncertainty quantification, and the effect of sampling methods is negligible in Monte Carlo simulations with large sample sizes. This approach can enhance the verification and validation (V&V) of regulatory requirements in the licensing process of new reactors.
Physicochemical characterization of red pitaya (Hylocereus sp.) peel flour using FT-IR, Raman, and EPR spectroscopy
2026 - RONDAN-FLORES, LUZ M.; VILLAVICENCIO, ANNA L. C. H.; CASTRO, DIONE P. de; WETTER, NIKLAUS U.; GUNDU RAO, T. K.; CANAZA, EDWAR A.; CANO, NILO F.
To ensure food and fruit safety, it is essential to use accurate and appropriate techniques that allow irradiated products to be identified and labelled, thereby preventing their adulteration and that of their derivatives. In this context, in this study, we evaluated the physicochemical properties of γ-irradiated red pitaya peel flour from lab-prepared (PT) and commercial (PC) samples, using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Raman, and electron paramagnetic resonance (EPR) spectroscopic techniques, as well as thermal analysis (TGA/DSC). The moisture content ranged from 8.01% to 16.38%, with the highest values being 16.38% for the PC sample at 3.5 kGy and 10.56% for the PT sample at 7.5 kGy. FT-IR and Raman spectroscopy revealed differences in betalain concentrations, indicating that irradiation did not significantly alter the spectral profiles. However, chemical changes were detected in the PC sample compared to the PT sample. In the PT sample, at least three distinct paramagnetic centers were identified. A six-line EPR spectrum was assigned to Mn2+ ions (center I). Center II arises from at least two radical species, with the dominant radical exhibiting hyperfine interaction with one α-type and two nearly equivalent β-type protons and characterized by a g-value of 2.0023. The cellulosic component of the pitaya contributes to the formation of center III, which exhibits a g-value of 2.0027. In the PC sample, only center III was detected, with no evidence of Mn2+ signals.
Computational modeling of CyberKnife® system using the Monte Carlo method
2026 - GRANJA, ALINE A. C.; ANTUNES, PAULA C. G.; JESUS, GABRIELA R. S.; CARDOSO, PEDRO H. B.; SHORTO, JULIAN M. B.
The accuracy required in small-field dosimetry for stereotactic radiosurgery imposes limitations on the conventional dosimetric calibration protocols used in radiotherapy. This study presents the development and validation of a computational model of the CyberKnife® system using the Monte Carlo method with the MCNP6 code. The main objective is to establish a validated computational model that enables future research and clinical applications in stereotactic radiosurgery. The model was developed to validate the 60 mm conical collimator, and the results were compared with experimental data from percentage depth dose (PDD) and lateral dose profile (LDP) curves at depths of 10 cm and 20 cm. The analyses revealed the influence of field size and photon-source characteristics on the dose distribution, with good agreement between simulated and measured data within the established tolerance limits. These findings demonstrate that the proposed model accurately reproduces the CyberKnife® beam behavior and serves as a robust and promising tool for investigating treatment variables, supporting therapeutic planning, and optimizing stereotactic radiosurgery protocols.
Eu3+ complex as an efficient luminescent sensitizer for NIR-emitting core-shell ZnxMgySnO4:Cr3+ persistent luminescence materials
2026 - FRANCISCO, LEONARDO H. C.; MOREIRA, RENAN P.; SALVADOR, FRANCINE F. S.; FELINTO, MARIA C. F. C.; TEIXEIRA, VERONICA C.; MALTA, OSCAR M. L.; RODRIGUES, LUCAS C. V.; BRITO, HERMI F.
This work presents the development of core–shell ZnxMgySnO4:Cr3+ (40 and 80% Mg) persistent luminescent (PersL) materials prepared by the ceramic method and decorated with the [Eu(tta)3(H2O)2] complex via microwave-assisted silanization, with promising optical properties in the near-infrared (NIR) range. The crystal structure of the prepared materials showed overlapping Mg2SnO4 and Zn2SnO4 patterns, along with SnO2, with increasing Mg content. FESEM and TEM microscopy revealed polycrystalline particles with well-defined surfaces and a silica shell in the 5–10 nm range. The optical properties were investigated by UV–vis and synchrotron spectroscopies (VUV, XANES-XEOL, and XRF). The persistent luminescent materials exhibit a noticeable increase in band gap energy with higher Mg content, intense, broadband NIR emission centered at 780 nm from the Cr3+ ion in a weak crystal-field environment, as well as longer PersL decay time with a higher Mg/Zn ratio. Core–shell materials decorated with the Eu3+-complex indicate energy transfer to the Cr3+ ion, resulting in NIR luminescence sensitization by UV and X-ray excitation. Therefore, we demonstrate an effective strategy to sensitize NIR emission by utilizing a highly efficient Eu3+ complex in core–shell persistent luminescent materials, which exhibit notable structural and optical properties and hold promise for optical imaging and photonic applications.
Optical flow-based forecasting of surface irradiance using cloud motion vectors in Brazil
2026 - XAVIER, RODRIGO de S.; PRETTO, LUCAS R. de; PEREIRA, ANDRE L. V.; MARTINS, FERNANDO R.
The energy transition is driving the integration of renewable energy sources with an intrinsic relationship with meteorological and climatic conditions. In this context, it is essential to develop tools that support the growth of the share of intermittent renewable sources, such as solar energy, in the electrical grid. This research developed a short-term forecasting model to predict surface solar irradiance at four different locations in Brazil. The forecasting model uses the Farnebäck optical flow method to track cloud motion in GOES-16 satellite images. We compared the predicted results with actual data collected at SONDA network stations during different seasons of the year. The methodology showed the lowest RMSE values during winter in Cachoeira Paulista (SP), with 0.13 for a 30-minute forecast horizon and 0.11 for a 120-minute horizon. The highest RMSE deviation was observed during autumn, with 0.39 in 30 minutes and 0.41 in 120 minutes at the same site. These findings are consistent with research in tropical regions of South America, indicating the potential utility of this approach in the field.
Model analysis of plasma incineration system of radioactive waste
2026 - GONCALVES, MAX F. S.; MASSI, MARCOS; ROSA, RODRIGO de A.; COUTO, ANTONIO A.; MOL, MARCOS P. G.
Nuclear waste management represents a challenge due to the hazardous characteristics. The most efficient alternative is to prevent improper disposal, thereby avoiding environmental harm and optimizing the resources needed for transport and storage, which in turn minimizes the associated costs. Therefore, the objective of this study is to evaluate the use of plasma technology in waste management for radioactive waste. To understand the impact of implementing a plasma reactor in the radioactive waste management systems, various scenarios were created to analyse the behaviour, particularly in terms of disposal costs for this waste, in this studied case. In light of the present work, the methodology, positive results and analyses may encourage further studies for the development of plasma systems with greater capacity and plasma processes designed to treat low-level radioactive waste. It is essential to acknowledge a limitation in this study, which is the existence of various factors and experimental conditions that can influence the performance of the plasma thermal process. There is also a need for test procedures specifically designed to evaluate the immobilization of radioactive waste.
Color etching as a tool for phase identification in an AA1100–25 vol.% B4C metal matrix composite
2026 - ARAUJO, JOAO V. de S.; MORAIS, NATHANAEL W.; COSTA, ISOLDA
A color-etching methodology was applied to an AA1100–25 vol.% B4C composite to enhance phase identification under optical microscopy. A solution of 50% (v/v) phosphoric acid in deionized water was used at − 5 °C under a constant current density of 0.02 A cm−2. As a result, the aluminum matrix appeared pink, the B4C particles dark brown, TiB2 interfacial layers formed distinct contours around the B4C reinforcement, and the Si-rich inclusions exhibited a bright blue hue. These contrasts made the interfaces between the B4C particles and the aluminum matrix clearly distinguishable. Complementary SEM and EDS analyses confirmed the presence of TiB2 at the Al/B4C interfaces and Si-rich phases within the matrix. The proposed methodology provides a rapid and reliable means of identifying secondary phases and interfacial layers in Al–B4C composites.
α-SiC-induced embrittlement in WC-(Co, Ni) hardmetals
2026 - MIRANDA, FABIO; SANTOS, MARCELO O. dos; MARTINEZ, LUIS G.; OLIVEIRA, RENE R. de; BATALHA, GILMAR F.; ROSSI, JESUALDO L.
This study systematically investigates the effect of adding α-SiC (0, 0.7, 1.3, and 3.2 wt%) on the microstructure, residual stresses, and mechanical performance of WC-11(Co, Ni)-based hardmetal processed by liquid-phase sintering at 1400 °C. A slight increase in hardness was observed, rising from 12.64 to 13.24 GPa with the addition of 0.7 wt% α-SiC. However, the transverse rupture strength (TRS) dropped by approximately 71% (from 1219 ± 114 MPa to 355 ± 87 MPa) at 1.3 wt% α-SiC, far exceeding the 10–20% losses typically associated with conventional grain growth inhibitors. Fracture toughness (KIC) decreased by 57% (from 26.0 ± 5.6 to 11.2 ± 1.9 MPa m1/2), accompanied by a transition from the Palmqvist crack regime to the radial-median crack regime, indicating pronounced embrittlement. Densification was progressively impaired, with the apparent density falling by 3.4%. XRD and SEM analyses revealed the underlying degradation mechanism: partial dissolution of α-SiC t promotes the formation of brittle Co0.85Si0.15, Co₂Si and Ni₂Si silicides, which consume the ductile binder phase, promote abnormal WC grain growth, and intensify compressive residual stresses (from −150 to −1000 MPa). These combined effects result in a pronounced reduction in mechanical strength and toughness. These combined effects result in a marked loss of mechanical strength and toughness. Overall, the results demonstrate that α-SiC, under the evaluated conditions, does not function as an effective reinforcement or grain growth inhibitor, but rather promotes microstructural instability through binder modification, silicide formation, and increased residual stresses, underscoring the need for careful control of composition and processing parameters for industrial applications.
Influence of pulp industry dregs on the physical and mechanical properties of mortar
2026 - CESAR, LUIS F. M.; ALBAS, AGDA E. de S.; LIMA, NELSON B. de; AKASAKI, JORGE L.; MORAES, JOAO C. S.
This study examined the constituents and evaluated the effects of incorporating a pulp industry residue (dregs) on the physical and mechanical properties of mortar. The properties of the mortar constituents were evaluated using thermogravimetry–differential scanning calorimetry (TG-DSC), energy-dispersive spectroscopy (EDS), X-ray Fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and tests specified in standards NBR 16605 (2017), NBR 11579 (2013), and NM 18 (2012). The hardened mortar was evaluated through mechanical testing (NBR 7215 2019), water absorption testing (NBR 9778 2005), and mercury intrusion porosimetry. XRD data from dregs treated at different temperatures were analyzed using the Rietveld refinement method. The specific gravities of the cement, dregs, and sand were 3.13, 2.58 and 2.62 g/cm3, respectively. The main chemical elements detected in the dregs (> 1 atom%) were Ca, Mg, Mn, Si, Na, S, and Al. Thermal analysis revealed two endothermic events: the evaporation of sulfur-containing compounds and the decomposition of calcium magnesium carbonate. Lattice parameters were obtained for the Ca0.87Mg0.13(CO3)2 phase, observed in the dregs treated at 100 and 500 °C, and for the CaO and MgO phases, observed after treatment at 750 °C. To evaluate compressive strength, water absorption, and porosity, mortars were prepared under three distinct conditions: one without dregs; four with dregs added to the mixture, keeping the cement and sand contents constant; and four with dregs as a partial replacement for Portland cement, keeping the sand content constant. Compressive strength decreases with increasing dregs content, with a more pronounced reduction when Portland cement is replaced by dregs than when dregs are added. Incorporating 40 wt% dregs reduced compressive strength by 73% under the Substitution condition and 52% under the Addition condition, relative to the reference mortar without dregs. This reduction in compressive strength is associated with increased water absorption and porosity as the dregs content increases.
Impact of high-energy milling synthesis on the electrostriction performance of Ce0.9Zr0.1O2
2026 - MARQUES, LARISSA S.; FERLAUTO, ANDRE S.; FONSECA, FABIO C.; KABIR, AHSANUL; KOUKOULIS, DIMITRIOS; ISLAM, KHONDOKER N.; ESPOSITO, VINCENZO; FLORIO, DANIEL Z. de
Electrostrictors have the capacity to unidirectionally convert electrical energy into a mechanical response. The best electrostrictors known so far have a high content of toxic lead (Pb) in their composition. To solve this environmental issue, research efforts shifted to lead-free electrostrictor compositions, such as the ceria-based compounds. Ceria-based materials present “giant” electrostriction, and amongst them, Ce0.9Zr0.1O2 can be a suitable lead-free substitute. To advance in the implementation of green chemistry principles for electromechanically active materials and to determine the ramifications of its employment on functional properties of fluorite-based CeO2 - ZrO2 mixed oxides, we successfully synthesized a Ce0.9Zr0.1O2 solid solution using a high-energy milling-assisted method. Nanometric milled powders exhibit the fluorite structure and a homogeneous dispersion of Zr in the ceria matrix that is preserved after sintering dense pellets. Soft X-ray absorption measurements reveal the predominance of Ce4+ species and the limited presence of oxygen vacancies in Ce0.9Zr0.1O2. Impedance spectroscopy measurements reveal highly resistive behavior, characterized by a strong overlap of grain and grain boundary contributions. The Ce0.9Zr0.1O2 dielectric constant measured at room temperature is twice that of undoped ceria, εr ≈ 66, which is related to improved electromechanical response. Longitudinal electrostriction measurements support this assessment, reaching values of up to 1.7⋅10−17 m2 V−2 near the kHz frequency.
Formation of dysprosium doped yttria (YDy) powders with EPR response
2026 - SANTOS, S. C.; RODRIGUES JR, O.; CALDAS, L.
From rare-earth (RE) based oxides, yttria (Y2O3) has unique solid-state characteristics, and as doped with RE-ions, exhibits excellent spectroscopic properties. However, its potentiality in radiation dosimetry field has been rarely explored. Based on this context, the present paper reports an alternative hydrothermal synthesis based on low temperature and environmental pressure to form dysprosium doped yttria (YDy) nanoparticles with potential application in radiation dosimetry. According to the results, YDy compositions with up to 2 at%Dy exhibited cubic C-type form, rounded-like shape, and narrow particle size distribution with the average size inferior to 700 nm. In addition, by Electron Paramagnetic Resonance (EPR), it was seen that the EPR response of the YDy nanoparticles relied on the content of dysprosium, while the YDy composition containing 0.1 at%Dy exhibited the maximum spin concentration 23.1027s.mm−3 among all compositions. These innovative findings are useful processing parameters to advance toward the formation of shaped bodies by additive manufacturing, and use in solid state dosimetry.
Novel chemometric Raman approach for spatially resolved quantification of graft distribution in anion exchange membranes
2026 - BERECZKI, ALLAN; BARBOSA, ANDREY da S.; WETTER, NIKLAUS U.; DEKEL, DARIO R.; SANTIAGO, ELISABETE I.
Precise control of the graft distribution, represented by the degree of grafting (DoG), in anion exchange membranes (AEMs) prepared by radiation-induced grafting (RIG), is critical for alkaline fuel cells' performance, especially aiming to improve water management. However, current methods offer only bulk or qualitative assessments of DoG, limiting the ability to understand and optimize local membrane properties. In this work, we present a novel Raman-based chemometric method for the spatially resolved quantification of DoG using micro-Raman spectroscopy. By applying classical least squares (CLS) fitting to decompose Raman spectra into contributions from the polymer base and grafted side chains, we establish a direct correlation between CLS scores and the local DoG. This approach enables, for the first time to our knowledge, the use of a multivariate technique for quantitative mapping of grafting profiles across the membrane cross-section using a widely accessible and non-destructive technique. The method is validated on membranes with known grafting levels and applied to asymmetric DoG AEMs, revealing detailed insights into spatial variations in functionalization. Moreover, the approach is broadly applicable to any grafted copolymer system with side-chain functionalization, beyond the specific membranes studied here. By combining spatially resolved measurement with rigorous chemometric analysis, this technique offers a robust tool for the design and optimization of next-generation ion-conducting membranes in electrochemical energy systems.
Post-column derivatization high-performance liquid chromatography-ultraviolet-ultraviolet (HPLC-UV) method for the detection of Kryptofix 2.2.2 content in Positron Emission Tomography (PET) tracers
2026 - XU, LEI; DONG, ZHENHAO; ZHANG, HONG; GOMES, ANTONIO A.; ROSSI, WAGNER de; WANG, JING; NARIO, ARIAN P.; HE, QINGGANG
A post-column derivatization high-performance liquid chromatography-ultraviolet (HPLC-UV) method was developed to determine Kryptofix 2.2.2 (K2.2.2) in PET tracers. This method utilizes the specific complexation between K2.2.2 and Pb2+, forming a stable 1:1 host-guest complex. The complexation produces a bathochromic shift in UV absorption maximum (from 210 nm to 254 nm), enabling sensitive detection. This approach addresses the limitations of poor performance and narrow applicability associated with direct single-method detection of K2.2.2. The chromatographic conditions were optimized (column flow rate: 0.7 mL·min−1; derivatization reagent flow rate: 0.7 mL·min−1; Pb2+ concentration: 50 μg·mL−1) and the method was validated. The results exhibited excellent linearity (1–100 μg·mL−1, r2 > 0.999), high reproducibility (relative standard deviation (RSD) < 5%), and a low detection limit (0.5 μg·mL−1). The method successfully quantified K2.2.2 in [18F]FDG, [18F]AV45 and [18F]DPA714, achieving spiked recoveries of 89%–105%. Additionally, the method remained unaffected by interference from common sample components such as sodium chloride and sodium ascorbate. This method provides a novel and efficient quality control tool for the simultaneous analysis of radiochemical purity and K2.2.2 content in diverse PET tracers.
METROCLIMA-MASP
2026 - ANDRADE, MARIA de F.; MARQUES, MARCIA T. A.; MEDEIROS, JOSE A. G. de; SOUTO-OLIVEIRA, CARLOS E.; FRANCO, MARCO A.; KUMAR, PRASHANT; DOMINGUES, LUCAS G.; LEONARDO, NOELE F.; YAMASOE, MARCIA A.; MORALES-ESPINOZA, LESLIE L.; LANDULFO, EDUARDO
Cities account for over half of global greenhouse gas (GHG) emissions, yet monitoring is very limited, especially in the Global South. A GHG monitoring network was established in 2019 in São Paulo, the largest metropolitan area in the Southern Hemisphere. Five sites were strategically selected, including four measuring surface mole fraction of carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4): Pico do Jaraguá (PDJ; –23.46°, −46.77°), IAG (–23.56°, −46.73°), UNICID (–23.54°, −46.56°), and ICESP (–23.56°, −46.67°). The fifth site, CIENTEC (–23.65°, −46.62°), was dedicated to measuring CO2 fluxes within a vegetated area. At IAG, δ13C-CO2 was also measured. The results revealed the influence of local sources, vegetation, and surface characteristics on GHG patterns. The elevated, forested site of PDJ provided urban background GHG levels, while urban core sites were heavily affected by traffic and biomass burning. CO2 levels increased across the city, with annual growth rates of 4.86 ± 2.84 ppm at UNICID (from 2021 to 2024), 4.92 ± 0.56 ppm at IAG (from 2021 to 2024), and 1.67 ± 0.38 ppm at PDJ (2019–2024). CH4 levels were more stable, exhibiting minor seasonal variability and no clear trend at PDJ. At UNICID, strong CO2-CO correlations (r > 0.9) during traffic peaks suggested emissions dominated by combustion, while weaker correlations during outside peak hours (r < 0.7) indicated the uptake of CO2 by the vegetation. Diurnal CO2 patterns across stations reflected the balance between human activity and biogenic processes, driven by photosynthesis and respiration, emphasizing the role of vegetation in modulating urban CO2 levels. These results highlight the importance of urban GHG measurements for understanding emission dynamics, assessing the influence of urban structure and meteorology, and supporting mitigation strategies at the city scale. This work clearly highlights the need to establish similar networks across Latin America to fill this critical data gap, which is key for developing effective climate mitigation strategies.
Effective compatibilization of poly(L-lactic acid)/poly(butylene adipate-co-terephthalate) blends via low-dose gamma irradiation
2026 - COSTA, FERNANDA A. T. da; DUFRESNE, ALAIN; PARRA, DUCLERC F.
This study addresses the critical challenge of compatibilizing immiscible poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) blends. The aim is to investigate low-dose gamma irradiation (3–5 kGy) as an efficient and clean method to enhance the interfacial adhesion and overall performance of these biodegradable polymer blends, overcoming the limitations of conventional compatibilization techniques. PLA pellets were subjected to gamma irradiation at 3 and 5 kGy before being melt-blended with PBAT in a 50/50 wt% ratio using a twin-screw extruder. The resulting blends were comprehensively characterized to evaluate their molecular, mechanical, morphological, thermal, and rheological properties. Low-dose gamma irradiation induced controlled chain scission in PLA, reducing its molecular weight. This modification significantly improved the compatibility of PLA/PBAT blends, leading to a more homogeneous morphology with elongated PBAT domains. Consequently, the mechanical properties were enhanced, with the 3 kGy irradiated blend showing a 7.7% increase in yield stress and an 8.6% increase in elongation at break compared to the non-irradiated blend. Furthermore, the thermal stability of the blend irradiated at 3 kGy improved, with the onset degradation temperature increasing by 5.3 °C. Low-dose gamma irradiation is a highly effective and promising strategy for compatibilizing PLA/PBAT blends. The controlled degradation of PLA enhances interfacial adhesion, leading to a synergistic improvement in mechanical and thermal properties without the drawbacks of high-dose irradiation or chemical additives. This method offers a scalable and environmentally friendly pathway to develop high-performance, fully biodegradable materials for sustainable packaging and other advanced applications.
Application of advanced oxidation processes for remediation of rubber industry wastewater
2026 - ULLAH, ZAFRAN; TIAN, ZHEN-YU; JOSEPH, COLLIN G.; GUILHEN, SABINE N.; TEO, SIOW H.; GANSAU, JUALANG A.; SARBATLY, ROSALAM; ALIAS, KARTINI; SUBHRAMANIYUN, PRETIBAA; KHAN, MUHAMMAD N.; IQBAL, MUHAMMAD S.
Rubber is an industrial material valued worldwide for its remarkable elasticity and versatility. It has become an essential material among the several various sectors, contributing to technological progress and improving the quality of everyday life. In the twenty-first century, increasing global awareness over rubber pollution has highlighted the significant attention towards the ecological footprint and sustainability challenges associated with rubber materials. The manufacturing of rubber is known to produce effluents that are difficult to treat with existing technologies. These effluents are known to have a high chemical oxygen demand (COD) and biological oxygen demand (BOD) alongside organic toxic pollutants. However, the new advanced oxidation processes (AOPs) for treating such wastewater have shown promise alongside AOPs that produce high amounts of hydroxyl radicals. This paper analyzes other prominent techniques such as Fenton and photo-Fenton, photocatalysis, ozonation, and electrochemical oxidation, aimed at treating rubber industry effluents. These techniques are found to be highly effective against resistant pollutants and aid in increasing biodegradation efficiency. The Fenton processes, alongside AOP technologies, pose some operational challenges and are not advanced enough to have cost-effective and efficient solutions. The combination of AOPs with biological processes and other recent studies have been shown to be effective, but more research needs to be done on their economic viability. We have also emphasized the important role of hybrid synergistic systems and AI in improving the effectiveness of AOPs for achieving better waste management practices in the rubber industry.
Integrated twin-screw extrusion and organosolv pretreatment efficiently enhances cellulose-to-glucose conversion and lignin recovery from corn cobs
2026 - JOSE, ALVARO H. M.; RODRIGUES, BRUNA G.; MOURA, ESPERIDIANA A. B.; MOTTA, JOAO V. S.; MOREIRA, RENATA; RODRIGUES, RITA C. L. B.
Efficient conversion of lignocellulosic biomass into bioproducts depends on optimized pretreatment strategies that enhance the accessibility of structural macromolecules. However, individual methods often face limitations regarding cellulose-to-glucose conversion and lignin recovery. This study evaluated an integrated approach combining twin-screw extrusion, organosolv fractionation, and enzymatic hydrolysis using corn cobs as feedstock. A factorial design applied to the extrusion process identified optimal conditions (144 °C, 11 rpm), resulting in a cellulose-to-glucose conversion of 92.6 wt% after enzymatic hydrolysis. In the subsequent organosolv step, treatment time was the most influential factor for improving cellulose digestibility. A second factorial design identified optimal conditions (60 min, 20.1 wt% solids), yielding the highest glucose conversion (93.0 ± 1.2 wt%) and enabling recovery of 45.4% of the solubilized lignin. Additionally, increasing solids loading from 10 to 15 wt% during enzymatic hydrolysis improved glucose productivity by 23.7%. These findings demonstrate that integrating twin-screw extrusion and organosolv pretreatment effectively enhances sustainable valorization of corn cobs.

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