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Production and characterization of polymeric nanocomposite foams based on starch and cellulose nanofibers from oil palm mesocarp fiber

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Applied Nanoscience (Switzerland) 2025年第2期15卷 1-11页

作者： Souza, Mariana Costa Gonçalves, Ana Paula Bispo da Silva Oliveira, Emanoel Igor dos Santos, Juscivaldo Passos Lazzari, Lídia Kunz Zattera, Ademir José José, Nadia Mamede Chemical Engineering Graduate Program Polytechnic School Federal University of Bahia Bahia Salvador Brazil Department of Education Federal Institute of Education Science and Technology Feira de Santana Bahia Brazil Postgraduate Program in Process Engineering and Technologies University of Caxias Do Sul Rio Grande Do Sul Caxias Do Sul Brazil

The demand for sustainable and eco-friendly materials has promoted studies over the years to explore different polymeric materials that meet requirements such as biodegradability and sustainability. In this context, biopolymer materials based on cellulose nanoparticles and starch from different botanical sources have been investigated, aiming to achieve satisfactory performance. The present study aims to develop and characterize cassava starch foams based on density, scanning electron microscopy (SEM), and three-point flexure tests, and to evaluate the effect of cellulose nanofibers obtained from palm mesocarp fibers using the ultrafine friction grinding method after different processing times, characterized by X-ray diffractometry (XRD), microscopy, and chemical composition, as a reinforcing filler. The chemical composition and scanning electron microscopy revealed the effectiveness of the cellulose isolation process, with the analysis of the chemical composition revealing a cellulose content of 55.70% in the fibers after pulping and bleaching, in addition to changes in the visual characteristics of the material after the process aimed at isolating the cellulose. After grinding, XRD showed an increase in crystallinity (76.1% at the maximum grinding time), along with typical microscopy images of cellulose nanofibers. The analysis of the obtained nanocomposites provided insights into the role of these nanostructures in the thermo-expanded starch matrix, indicating that the nanofibers promoted changes such as an increase in mechanical properties and crystallinity, which contributed to improving overall mechanical performance. A 67.48% increase in flexural strength was achieved for the formulation with cellulose nanofibers that underwent 150 min of grinding, without causing major variations in density. © King Abdulaziz City for Science and Technology 2025.

关键词： Starch

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Probabilistic Analysis of Low Power Factor in a Facility with High Integration of PV Generation 8

Probabilistic Analysis of Low Power Factor in a Facility wit...

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8th Southern Power Electronics Conference and the 17th Brazilian Power Electronics Conference, SPEC / COBEP 2023

作者： Pompermayer, Daniel Campos Fardin, Jussara Farias Postgraduate Program in Electrical Engineering Ppgee Federal University of Espírito Santo Ufes Vitória Brazil

ISBN: (纸本)9798350321128

This study introduces the ongoing development of a methodology to evaluate charges for excess reactive energy in an electrical facility due to a low power factor caused by the integration of photovoltaic (PV) generation. Real-world data from the Federal University of Espírito Santo, Brazil, were employed and clustered by season of the year, and whether falling in a business day, a holiday or during vacation period. The statistical distributions Johnson's SU and Proportional Reversed Hazard Logistic were selected to model consumption and generation patterns, while through a Monte Carlo simulation, the power factor violations and the charges for excess reactive energy for 2023 were estimated. It has been showed that the PV integration substantially lowers the power factor and increases the probability of violation, particularly during high generation periods. On the other hand, the carges for excess reactive energy are generally minimal, typically around 10% of PV integration savings. © 2023 IEEE.

关键词： Electric power systems energy management energy quality photovoltaic systems power factor

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Investigation of Polypropylene Fiber Reinforced Concrete After Elevated Temperature Using Color Quantification and Alkalinity Method 5th

Investigation of Polypropylene Fiber Reinforced Concrete Aft...

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5th International Conference on Rehabilitation and Maintenance in Civil engineering, ICRMCE 2021

作者： Kencanawati, Ni Nyoman Murtiadi, Suryawan Nur, Zul Aida Postgraduate Study Program of Civil Engineering Mataram University Jl. Majapahit 62 Mataram83125 Indonesia

ISBN: (纸本)9789811693472

Concrete properties change when it is exposed to high temperature. Fire can reduce the strength and the stiffness of the concrete. Another visible thing is the change in the color of the concrete. Furthermore, a decrease in the alkaline degree of concrete can also occur at high temperatures. This study combines quantifying the value of the color change, quantifying the alkaline level, and evaluating the residual strength of post-fire concrete. Two concrete grades were prepared: 25 and 45 MPa and exposed to a high temperature of 300 and 700 ℃. The amount of 1.8, 2 and 2.5 kg/m3 of polypropylene fiber were added to the concrete. According to the temperature rise analysis, the farther the position from the concrete surface causes a decrease in temperature. The 2.5 kg/m3 fiber content shows more excellent post-fire mechanical performance because it provides the pores needed by concrete when water vapor pressure occurs due to high temperature;therefore, cracks in the cement paste can be avoided. Visually, the color change between grade 25 and 45 MPa are the same in each temperature;however, they have different coordinates as observed by the color test. Furthermore, the addition of 2.5 kg/m3 fiber to the concrete contributes a superior effect to prevent the decrease of the alkaline level during the fire. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Polypropylenes

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Truck Scheduling: A Case Study in the Automotive Sector

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International Journal of Applied and Computational Mathematics 2024年第2期10卷 1-24页

作者： de Oliveira, Caroline Maruchi Kleina, Mariana da Silva, Arinei Carlos Lindbeck Postgraduate Program in Production Engineering Federal University of Parana Av. Cel. Francisco Heráclito dos Santos 210 Paraná Curitiba 19011 Brazil

Logistic companies face several problems in their services, leading to increased time and costs in their operations. These issues could be mitigated if decision-making were based on models that consider resource optimization and respect process constraints. An example of this problem is the queues generated by trucks at docks for loading and unloading materials in the automotive sector. Therefore, this work studies truck scheduling with the inclusion of forbidden time windows for breaks. The aim is to propose a mathematical model in order to minimize the time spent by drivers within companies and to present exact and approximate solutions with the use of Operational Research techniques and algorithms. Methods and algorithms that adapt to this type of problem were identified. Then, the mathematical model was developed, computationally implemented in the LINGO and Gurobi software, and validated according to the case study conditions. A metaheuristic based on the Simulated Annealing algorithm was implemented in Visual Basic for Applications language, and used as a form of approximate resolution for problems larger than the ones solved optimally. Computational experiments were conducted to evaluate the performance of the model and metaheuristic proposed. The GAP between the metaheuristic solution and the optimal solution is less than 4% for all problems tested. For larger problems, with more than 10 trucks and 5 docks, Gurobi optimization software is not able to find the optimal solution in a feasible time. However, the metaheuristic is able to find good solutions for bigger problems in a reasonable time. Therefore, results proved the performance of the mathematical model, indicating that truck scheduling is an important tool for automotive companies, as it can help to improve efficiency and productivity. © The Author(s), under exclusive licence to Springer Nature India Private Limited 2024.

关键词： Forbidden time window Open Shop Simulated Annealing Truck scheduling

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Precipitation of Potassium from Domestic Sewage as Sylvite

Precipitation of Potassium from Domestic Sewage as Sylvite

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International Conference on Wider-Uptake of Water Resource Recovery from Wastewater Treatment, ICWRR 2024

作者： Schellin, Lucy Marta Froehner, Sandro José Postgraduate Program in Geology Federal University of Paraná PR Curitiba Brazil Department of Environmental Engineering Federal University of Paraná PR Curitiba Brazil

ISBN: (纸本)9783031633522

Potassium is a vital element for sustaining life on our planet, playing a crucial role in regulating fluid balance within cells and facilitating muscle contractions, including those of the heart. In plants, it governs the equilibrium of water absorption, serves as a fundamental component of structural tissues, and provides protection against pathogens, among other functions. Notably, a staggering 95% of the globally traded potassium is earmarked for fertilizer production. The deposits of this essential element are typically concentrated in specific geographical regions, often deep-seated, with distribution and logistics intricately tied to geopolitical considerations. A promising avenue for potassium recovery lies in exploring alternatives such as K-struvite precipitation and its combination with cellulose derived from vegetable waste. Cellulose, inherently containing potassium in its composition, makes it an attractive option. This study focuses on evaluating the mineralization of potassium using wood residues in the form of hygienic granules designed for animals and human urine, conducted at a temperature of 300 °C. The resulting mineral obtained was Sylvina, showcasing the potential for sustainable and efficient potassium retrieval. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Sewage

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Analysis of Brain Excitability After Transcranial Direct Current Stimulation and Brain-Computer Interface Based on Motor Imagery on a Post-stroke Patient 9th

Analysis of Brain Excitability After Transcranial Direct Cu...

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9th Latin American Congress on Biomedical engineering, CLAIB 2022 and 28th Brazilian Congress on Biomedical engineering, CBEB 2022

作者： Silva, Leticia Lima, Jéssica Schreider, Sheila Delisle-Rodriguez, Denis Krishnan, Sridhar Bastos-Filho, Teodiano Postgraduate Program in Electrical Engineering Universidade Federal do Espirito Santo Vitoria Brazil Postgraduate Program in Biotechnology Universidade Federal do Espirito Santo Vitoria Brazil Edmond and Lily Safra International Institute of Neurosciences Instituto Santos Dumont Macaiba Brazil Department of Electrical Computer and Biomedical Engineering Toronto Metropolitan University Toronto Canada

ISBN: (纸本)9783031494062

Stroke is a neurological syndrome that may cause severe cognitive and motor impairments for survival. Alternative rehabilitation techniques have been developed to recover lower-limb movements and gait of post-stroke patients, such as Motor Imagery (MI)-based Brain-Computer Interfaces (BCIs), Virtual Reality (VR), and robotic devices. Transcranial Direct Current Stimulation (tDCS) is a non-invasive technique to stimulate the brain and modulate cortical excitability. This study aims to analyze the short-term effects of tDCS compared to sham stimulation before a lower-limb MI-BCI pedaling training (through a robotic monocycle) task in a patient with subacute stroke. We studied a post-stroke patient with 2 months of ischemic stroke and right hemiparesis who was submitted to the following tasks: active pedaling, sham tDCS and MI-BCI, and tDCS and MI-BCI. We evaluated the relative power around the foot area (Cz electrode), and a significant (p-value © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Brain computer interface

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Fire effects on itacolomi quartzites from stonework historical buildings: implications for conservation of the cultural heritage

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Journal of Building Pathology and Rehabilitation 2024年第2期9卷 1-12页

作者： Fransozo, Hélder Luís Lima, Gustavo Filemon Costa de Gouveia, Antonio Maria Claret da Silva Bezerra, Augusto Cesar Postgraduate Program in Materials Engineering Federal University of Ouro Preto Ouro Preto 35400-000 Brazil Department of Transport Engineering Federal Center for Technological Education of Minas Gerais Belo Horizonte 30421-169 Brazil

Fires can be a real threat to stone-built cultural heritages, and understanding the behavior of stones under thermal stress is strategic knowledge for efficient restoration and conservation management. In Ouro Preto, settled as a world heritage site by UNESCO, and Mariana, a living register of Brazilian colonial history, fire events are a critical factor threatening the historical stonework buildings. Ouro Preto and Mariana architecture is home to Baroque art based on Itacolomi quartzite record centuries-old Brazilian Portuguese stone mansory techniques. Therefore, this research aims to characterize the effects of fire in Itacolomi quartzites and its respective implications for Ouro Preto and Mariana stone-built heritages. Itacolomi quartzite blocks were sampled from three different mining areas, and characteristics such as aesthetics, mineralogy, and strength were observed before and after the fire experiment. A GRION furnace following the NBR 5628:2001 was applied for the fire experiment. Micromorphology and mineralogy variations were observed through scanning electron microscopy coupled with an energy-dispersive spectrometer and an X-ray diffraction. Compressive strength was used to assess the mechanical behavior after the fire. Significant aesthetics variations were observed after the fire experiment. Fe-oxidation and dehydroxylation of phyllosilicates seem to inflict aesthetic and mineralogical changes in quartzite samples. Compressive strength in quartzite blocks varies from 11.69 to 38.95 MPa before and 11.89 to 22.80 MPa after the fire experiment. This research shows that Itacolomi quartzites are susceptible to fire effects, and variations in mineralogy and strength should be considered in terms of restoration and conservation of the historical stone-built heritages. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.

关键词： Building materials Fire damage quartzites Stone buildings

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Classification and tracking of items on a moving conveyor belt using convolutional networks and image processing

Classification and tracking of items on a moving conveyor be...

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2024 International Conference on Artificial Intelligence, Computer, Data Sciences, and Applications, ACDSA 2024

作者： De Goes, Angelo Leite Medeiros Neto, Adriao Duarte Doria Andrade, Matheus Gomes Diniz De Oliveira, Thiago Theiry Federal University of Rio Grande Do Norte Electrical and Computer Engineering Postgraduate Program Natal Brazil Federal University of Rio Grande Do Norte Computer Engineering Natal Brazil

ISBN: (纸本)9798350394528

The prolonged waiting time at supermarket checkout lines poses a significant challenge to the shopping experience, impacting customer satisfaction and operational efficiency. This paper presents a prototype that addresses this issue by utilizing computer vision and deep learning. The model, incorporating convolutional neural networks such as YOLO v4 tiny and YOLO v5 small, along with tools like OpenCV and Roboflow for dataset management, achieves a remarkable 98% mean average precision for two-class detection. It efficiently detects, classifies, tracks, and counts items on a mobile supermarket conveyor belt. Additionally, we introduce a versatile framework designed for seamless integration into real-world applications. It comprises a customizable monitoring application and simulator that facilitates synthetic image data generation. Managing diverse items in a supermarket presents a major challenge for data gathering, labeling, and training. In that sense, the importance of customizable monitoring and simulation tools is highlighted, emphasizing their practical role. Our findings demonstrate the feasibility of maintaining a minimal 0% to 2.85% precision tradeoff while using half of the data as synthetic for two-class detection, indicating potential practicality in supermarkets with proper scaling. In summary, this study brings tangible benefits to both customers and retailers, offering a potential to streamline, speed up, and cut costs in the supermarket checkout process. © 2024 IEEE.

关键词： Deep learning

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Proposal of Serious Games for a Socially Assistive Robot Based on Eye Contact and Visual Attention of Children with Autism Spectrum Disorder 9th

Proposal of Serious Games for a Socially Assistive Robot ...

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9th Latin American Congress on Biomedical engineering, CLAIB 2022 and 28th Brazilian Congress on Biomedical engineering, CBEB 2022

作者： Negri, Yuri Panceri, João Freitas, Éberte Schreider, Sheila Caldeira, Eliete Bastos-Filho, Teodiano Electrical Engineering Department Federal University of Espirito Santo Av. Fernando Ferrari 514—Goiabeiras ES Vitória29075-910 Brazil Postgraduate Program in Electrical Engineering Federal University of Espirito Santo Vitoria Brazil Automation and Control Engineering Department Federal Institute of Espirito Santo Linhares Brazil Postgraduate Program in Biotechnology Federal University of Espirito Santo Vitoria Brazil

ISBN: (纸本)9783031494062

Eye contact is one of the main human skills, and a prerequisite of verbal language. However, children with Autism Spectrum Disorder (ASD) often have an important deficit in this skill, compromising their entire cognitive and social development. This work shows the development of two Serious Games (SGs), based on the concept of Child-Robot Interaction (CRI), for the exercise and improvement of eye contact and visual attention, as well as concepts such as imitation and emotion recognition. For face detection and eye movement monitoring, an open source development framework of machine learning named MediaPipe was used. Tests with children with ASD will be conducted, and it is expected these SGs have a positive impact regarding the improvement of both eye contact and visual attention for these children. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Serious games

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Building Information Modeling Applied to Daylight Dynamic Simulation Considering Local and Global Climate Change

SSRN

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SSRN 2024年

作者： Michelon, Michelli Gongalves Miri, Majid da Rocha Menezes, Leonardo Junior Ramos, Greici Barata, Marcio Santos Zemero, Bruno Ramos Postgraduate Program in Architecture and Urbanism Federal University of Para Brazil Sweco AB Sweden Postgraduate Program in Mechanical Engineering Federal University of Para Brazil Postgraduate Program in Civil Engineering Federal University of Santa Catarina Brazil

The EN 17037:2018 standard, titled "Daylight in Buildings", is recognized as a step in the right direction concerning daylighting and has been used as the basis for the recently revised Brazilian standard. In this context, this study aims to delve into the understanding of the daylight performance in buildings in Brazil by analyzing the advancements and challenges in NBR 15215/15575:2022. Two methods will be employed: the computational daylight performance simulation method and the abacus method, following the revision of NBR 15575:2022, in a Housing of Social Interest (HIS) located in the city of Belem, Brazil. Since it is a digital prototype and not a physical one, the reliability of the simulations was verified by comparing the results obtained with the abacus method, which also allowed for an analysis of the case study using this alternative approach from the standard. The study aims to identify the best workflow for applying the standard, based on an investigation of dynamic simulation software and the impact of future-urban weather files, seeking to propose improvements to the standard. The results demonstrate the efficiency and accuracy of building information modeling, specifically the AftabRad plugin, for dynamic simulations in accordance with normative criteria, as well as the need to include urban weather files in the standard. © 2024, The Authors. All rights reserved.

关键词： Climate change

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