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Impact of Latency and Packet Error on Communication in Centralized Microgrid Control: Modeling and Guidelines

IEEE Access 2025年 13卷 82732-82746页

作者： Lucaschaves, Lucas S. Callegari, Joao Marcus S. Araujo, Lucas S. Brandao, Danilo I. Universidade Federal de Minas Gerais Graduate Program in Electrical Engineering Belo Horizonte31270-901 Brazil Federal Center for Technological Education of Minas Gerais Department of Electrical Engineering Nepomuceno30575-180 Brazil

This paper proposes a novel dynamic model in the Laplace domain for an advanced ac microgrid with centralized secondary control. The model applies a centralized power-based control strategy and incorporates communication non-idealities such as latency and packet error. Packet loss and communication failure are considered herein as latency issues. The central controller incorporates an anti-aliasing filter that constrains the frequency of the transmitted signal and the packet transmission rate in compliance with Nyquist’s sampling theorem. The model is validated on a test bench, with experimental implementation of the communication system and central controller, and a real-time simulation of the electrical power system via hardware-in-the-loop. The impact of latency on the controller’s performance is evaluated through stability, control bandwidth, load rejection bandwidth, settling time, and rejection of packet errors. The results show that communication latency directly impacts the controller’s performance, affecting all analyzed performance metrics. Meanwhile, the cutoff frequency of anti-aliasing filter and packet transmission rate influence control stability, response dynamics, and the system ability to reject load variations and packet errors. Finally, the paper proposes a flowchart-based guideline for configuring the microgrid central controller and selecting communication technologies to implement ancillary services with predefined durations in advanced microgrids. © 2013 IEEE.

关键词： Signaling

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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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Inner-sphere adsorption of orthophosphates on amorphous aluminum hydroxide: The Laplace transform solution to a kinetic model involving first-order Taylor approximations to the Langmuir isotherm

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Separation and Purification Technology 2025年 369卷

作者： Nishimura, Thiago de Barros, Ivan Ricardo Benincá, Cristina Zanoelo, Everton Fernando Federal University of Paraná Graduate Program in Chemical Engineering PR Curitiba Brazil Federal University of Rio Grande Graduate Program in Technological and Environmental Chemistry Santo Antônio da Patrulha RS Brazil

The kinetics of interaction between orthophosphates and Al(OH)3 is of importance to remove phosphorus from wastewater and to understand its mobility and bioavailability in soils. In this study, the kinetics of adsorption of orthophosphates on amorphous Al(OH)3 was examined in an agitated vessel containing an aqueous solution with initial adsorbate concentrations (C0) ranging from ∼3 to 92 mg L−1, at ∼25 °C and pH ∼ 6.9. The soluble orthophosphates were rapidly adsorbed by inner-sphere complexation, but the adsorption capacity was limited to ∼13 mg of phosphorus per g of Al(OH)3. The yield of removal of adsorbing species from the liquid changed from ∼5 to 73 %. A novel reliable adsorption kinetic model was proposed by an original analytical solution of a system of differential equations from adsorbate balances. This solution by using Laplace transform was possible because a valid, robust and simplified procedure was suggested to describe the Langmuir isotherm by first-order Taylor approximations (R2 ∼ 0.93). By contrast to the usual kinetic modeling approaches for liquid–solid adsorption, the current model involves an effective adsorption rate constant (kCA = 3.840 × 10−4 L s−1) considered to be independent of C0. The rates of adsorbate transport from the bulk liquid to the internal adsorbent surface were supposed to be much slower than that of orthophosphates adsorption. ICP spectroscopy, XRD, SEM, EDX spectroscopy and gas adsorption analyses confirm that phosphorous was adsorbed on mesoporous amorphous Al(OH)3 with average pore size of 263 Å and specific surface area of ∼100 m2 g−1. A large independent set of adsorption data for P on Al(OH)3 was used to explain and validate the results. © 2025 Elsevier B.V.

关键词： Aluminum hydroxide

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Decoding microRNA arm switching: a key to evolutionary innovation and gene regulation

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Cellular and Molecular Life Sciences 2025年第1期82卷 1-23页

作者： Pinhal, Danillo Gonçalves, Leandro de B. Campos, Vinícius F. Patton, James G. Genomics and Molecular Evolution Laboratory Department of Chemical and Biological Sciences Institute of Biosciences DCQB IBB UNESP SP Botucatu CEP 18618-689 Brazil Structural Genomics Laboratory Graduate Program in Biotechnology Technological Development Center Federal University of Pelotas RS Pelotas Brazil Department of Biological Sciences Vanderbilt University Nashville 37232 TN United States

miRNA arm switching is a pivotal regulatory mechanism that allows organisms to fine-tune gene expression by selectively utilizing either the 5p or 3p strand of a miRNA duplex. This process, conserved across species, facilitates adaptive responses to developmental cues, environmental changes, and disease states. By dynamically altering strand selection, arm switching reshapes gene regulatory networks, contributing to phenotypic diversity and evolutionary innovation. Despite its growing recognition, the mechanisms driving arm switching—such as thermodynamic properties and enzyme-mediated processing—remain incompletely understood. This review synthesizes current findings, highlighting arm switching as a highly conserved mechanism with profound implications for the evolution of regulatory networks. We explore how this phenomenon expands miRNA functionality, drives phenotypic plasticity, and co-evolves with miRNA gene duplications to fuel the diversification of biological functions across taxa. © The Author(s) 2025.

关键词： Evolution of gene regulatory networks miRNA strand selection mechanisms Phenotypic plasticity in development Post-transcriptional gene regulation

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Exploring Carotenoid from Chlorella Sorokiniana as a Natural Alternative to Yellow Artificial Food Dyes: Stability and Application in Model System

SSRN

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SSRN 2025年

作者： Bianchini, Carlen Bettim Minatel, Gabriela Gomes Schappo, Flávia Barbosa Arend, Giordana Demaman de Mello Castanho Amboni, Renata Dias De Rosso, Veridiana Vera Nunes, Itaciara Larroza Graduate Program in Food Science Department of Food Science and Technology Federal University of Santa Catarina Florianópolis88034-001 Brazil Graduate Program in Food Engineering Department of Chemical Engineering and Food Engineering Federal University of Santa Catarina Florianópolis88040-900 Brazil Nutrition and Food Service Research Center Federal University of São Paulo Santos11015-020 Brazil

This study investigated ultrasound-assisted extraction using ethanol from Chlorella sorokiniana-derived carotenoids and encapsulation by co-crystallization. The carotenoid extract was quantified and identified (HPLC-DAD) and its encapsulation efficiency was assessed. Co-crystals were analyzed for FTIR spectra, morphology (SEM) and stability (moisture, water activity, carotenoid content, and color) over 90 days. Their potential as a natural dye in gelatin was also evaluated. Lutein and β-carotene were the major carotenoids, with an encapsulation efficiency of 53%. FTIR analysis of the co-crystals demonstrated characteristic functional groups of sucrose and carotenoids, while SEM revealed a porous structure with particles diameters ranging from 2 μm to 20 μm. Over storage, moisture, and water activity increased, while carotenoid content decreased. Yellow remained stable in co-crystals for 90 days, whereas gelatin powder showed reduced red and yellow colors. The color of the ready-to-serve gelatin remained stable for seven days. Co-crystals can replace artificial dyes and sugar in gelatin. © 2025, The Authors. All rights reserved.

关键词： Ethanol

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Bovine bone–based activated carbon composite containing nanomagnetite as a catalyst for photo-Fenton reactions

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Environmental Science and Pollution Research 2025年 1-18页

作者： Guidolin, Thays de Oliveira Polla, Mariana Borges Rodriguez, Adriane de Assis Lawisch Wermuth, Tiago Bender Eller, Sarah de Oliveira, Tiago Franco Pereira, Fabiano Raupp da Cas Viegas, Alexandre Montedo, Oscar Rubem Klegues Cechinel, Maria Alice Prado Arcaro, Sabrina Universidade Do Extremo Sul Catarinense SC CriciúmaCEP 88806-000 Brazil Laboratório de Engenharia Ambiental Universidade de Santa Cruz Do Sul RS Santa Cruz Do SulCEP 96815-900 Brazil Graduate Program in Health Sciences Federal University of Health Sciences of Porto Alegre RS Porto AlegreCED 90050-170 Brazil Institute of Physics Federal University of Rio Grande Do Sul 9500 RS Porto AlegreCEP 91501-970 Brazil Department of Chemical and Food Engineering Federal University of Santa Catarina SC FlorianópolisCEP 88040-900 Brazil

Magnetic composites (MC) prepared from magnetite nanoparticles (MNP) and activated carbon from bovine bone (AC) in different proportions (75/25, 50/50, and 25/75) were used as catalysts in the photo-Fenton process to degrade methylene blue (MB) in aqueous solution. The materials were prepared by the citrate–nitrate sol–gel synthesis method and used as catalysts in the photo-Fenton process. The photocatalytic tests were performed in a cylindrical reactor with a 4.13-cm internal diameter and 300-mL maximum capacity, equipped with 9.9-W visible light lamps. The specific surface area of the MC increased by up to 1138.39% with the addition of AC. Morphological analysis confirmed the anchoring of MNPs on the AC surface. The band gap values of the materials ranged from 1.16 to 1.55 eV and increased proportionally with the addition of AC to the MC compositions. MC-75/25 and MC-50/50 presented predominantly superparamagnetic behavior, while for MC-25/75 superparamagnetic and superimposed paramagnetic phases were observed. All samples showed good reduction of the MB concentration, exceeding 80% after 10 cycles of use. The mineralization advanced extensively to simple organic acids, proving the non-generation of harmful by-products and the efficiency of this photocatalytic system. The use of magnetic composites favored the efficient separation of the catalyst without causing secondary pollution, in addition to increasing the stability and reusability of the catalysts. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Bone

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Chitosan-geopolymer composites: A synergistic approach to sustainable and functional materials

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Ceramics International 2025年

作者： Silva, Angelo Oliveira Colombo, Paolo Hotza, Dachamir Graduate Program in Chemical Engineering Federal University of Santa Catarina SC Florianópolis 88040-900 Brazil Department of Industrial Engineering University of Padova Padova 35131 Italy

The combination of chitosan, a natural biopolymer, with geopolymers, a class of inorganic materials, represents a promising strategy to develop sustainable and high-performance composites for various applications. This review explores the current state of research on chitosan-geopolymer composites, focusing on two primary methods of incorporation: pre-geopolymerization and post-geopolymerization. Key findings highlight how chitosan addition impacts the properties of geopolymers, with potential applications in civil construction materials and environmental remediation. The review also discusses the challenges of process optimization, scalability, and long-term performance, identifying future research directions to enhance the effectiveness of these materials. This work aims to provide a comprehensive overview for researchers and engineers interested in the development and application of innovative, eco-friendly materials. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Chitosan Composites Geopolymer Sustainable materials

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Phenomenological modeling of H2S adsorption in fixed-bed columns: Operational variables effect over column performance and scale-up

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chemical engineering Journal 2025年 515卷

作者： Costacurta da Silva, Pedro Guilherme Alves, Helton José da Silva, Eliane Soares Machado, Bruna Borba, Carlos Eduardo Scheufele, Fabiano Bisinella Federal Technological University of Paraná - UTFPR Campus Toledo Cristo Rei 19 Vila Becker PR Toledo85902-490 Brazil Materials and Renewable Energy Laboratory - LABMATER Federal University of Paraná – UFPR Setor Palotina Rua Pioneiro 2153 PR Palotina85950-000 Brazil Graduate Program of Chemical Engineering West Paraná State University Rua da Faculdade 645 PR Toledo85903-000 Brazil

This study investigates the adsorption of H2S onto babassu-derived biochar in a fixed-bed column through a phenomenological model. Lab-scale experiments were conducted under varying operational conditions (H2S concentration, flow rate, and temperature) to assess their effect over equilibrium, kinetics, thermodynamics and fluid dynamics of the process, by applying external film diffusion, overall diffusion (linear driving force – LDF), and adsorption on adsorbent sites. Langmuir isotherm confirmed favorable monolayer adsorption, while LDF model described diffusion-controlled kinetics. Process simulations suggested optimization strategies, including lowering H2S concentrations, reducing flow rates, and adjusting bed height. The lab-scale data were used to simulate a real-scale adsorber under typical industrial conditions. The study revealed operational challenges, mainly due to high flow rates and H2S concentrations, which led to a "concentration hammer" effect, resulting in reduced bed efficiency. The analysis of commercial-scale data highlighted operational inefficiencies, such as premature breakthrough time and reduced bed utilization efficiency (η 2S inlet concentrations below 500 ppm, flow rates between 300–1000 mL min−1, and temperatures up to 35 °C. Simulations based on lab-scale parameters suggested potential process modifications, including using higher bed heights, operating dual columns in parallel, and implementing H2S concentration and flow control systems. This work demonstrates the effectiveness of phenomenological modeling in understanding the complex dynamics of H2S adsorption, supporting both scale-up and optimization of industrial-scale systems through predictive simulations and minimized experimentation. © 2025 Elsevier B.V.

关键词： Flow interactions

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Valorization of Spondias bahiensis waste: Ultrasound-assisted extraction, in vitro phenolics bioaccessibility, and effect on the stability of lipid-protein oxidation in pre-cooked goat meatballs

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Food Bioscience 2025年 69卷

作者： da Silva Ferreira, Valquíria Cardoso de Santana Neto, Deocleciano Cassiano Fernandes Santos, Miriane Moreira da Silva, Anna Júllia Bezerra de Azevedo Moura, Gleyce Swellen Santos Ribeiro, José Evangelista Lima, Marcos dos Santos Magnani, Marciane Silva, Fábio Anderson Pereira da Department of Management and Agro-industrial Technology Federal University of Paraíba Paraíba Bananeiras Brazil Post-graduate Program in Food Engineering Department of Chemical Engineering Federal University of Paraná Brazil Post-graduate Program in Food Science and Technology Department of Food Engineering Technology Center Federal University of Paraíba Paraíba Joao Pessoa 58051-900 Brazil Department of Food Engineering Technology Center Federal University of Paraíba Paraíba Joao Pessoa 58051-900 Brazil

This study aimed to optimize the ultrasound-assisted extraction of phenolic compounds from the bagasse of umbu-cajá (Spondias bahiensis), a native Brazilian fruit, and to assess their bioaccessibility. Additionally, the influence of different concentrations of the umbu-cajá bagasse (SBB) extract on the oxidative stability of pre-cooked goat meatballs was investigated over a 10-day refrigerated storage period by quantifying lipid oxidation products. A central composite rotational design determined the optimal ethanol concentration, sonication time, and bagasse-solvent ratio. The optimized extract was applied to meatballs at two concentrations: EX2 (meatballs with 7.0 g/100 g of added SBB extract) and EX4 (meatballs with 13.7 g/100 g of added SBB extract). A control treatment (no antioxidant) and BHT-treated meatballs (0.02 g/100 g) were included as references. Meatballs were evaluated by measuring instrumental color, peroxide value, TBARS, carbonyl compounds, and through simulated digestion. Optimal extraction conditions were 55 % ethanol, 20 min of sonication, and a 1:36.8 bagasse-to-solvent ratio (m/v). The extract showed high antioxidant activity and bioaccessibility of catechin (1243.75 %), epicatechin gallate (918.75 %), procyanidins B2 (915.38 %), gallic acid (319.76 %) and procyanidins B1 (136.36 %). SBB extract slowed lipid oxidation until day 10 and protein oxidation until day 5 but did not inhibit color change. The meatballs had low content of oxidative compounds and high antioxidant capacity in the intestinal fraction, indicating that SBB extract can partially or totally replace the synthetic preservative. © 2025

关键词： Antioxidant Goat meat In vitro gastrointestinal digestion Oxidation Phenolic compounds Umbu-cajá

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A comprehensive evaluation of the use of graphene enriched cutting fluids on the surface integrity of very poor-grindability materials

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Wear 2025年

作者： de Oliveira, Déborah de Paiva, Raphael Lima de Souza Ruzzi, Rodrigo Jackson, Mark James Gelamo, Rogério Valentim Machado, Alisson Rocha da Silva, Rosemar Batista University of Brasília Department of Mechanical Engineering DF Brasília Brazil Federal University of Piauí School of Mechanical Engineering PI Teresina Brazil Federal University of Uberlandia School of Mechanical Engineering MG Uberlandia Brazil Kansas State University College of Technology and Aviation SalinaKS United States Federal University of Triângulo Mineiro Institute of Technological and Exact Sciences MG Uberaba Brazil Pontifícia Universidade Católica do Paraná Mechanical Engineering Graduate Program PR Curitiba Brazil

The use of graphene has stood out in recent years in different fields due to the wide applicability based on its properties. Specifically, multilayer graphene can be highlighted as a good lubricant, it possesses low shear resistance between layers and has good thermal conductivity. Those characteristics are well suitable for cutting fluids, especially considering the grinding process which presents high friction, elastic and plastic deformations, and the intense occurrence of plowing, thereby resulting in high specific cutting energy. However, studies have shown the use of graphene on cutting fluids can be influenced by many factors, including delivery methods, particle concentrations and even the workpiece material. Thus, a comprehension of how graphene particles added to the cutting fluid interact at the abrasive-chip interface is important for its correct use and the achievement of high-quality surfaces. In this sense, this work aims to investigate the use of multilayer graphene enhanced cutting fluids delivered during the grinding process for three different very poor-grindability materials: Inconel 625, Inconel 718 and SAE 52100 hardened steel. Different multilayer graphene concentrations (0.05–0.1 wt%) were added in the same base fluid and tested under different flow rates. The influence of graphene was assessed in terms of grinding power, surface roughness and morphology (SEM images). The experimental results showed that for the lower hardness material (Inconel 625), graphene promoted intense plowing and adhered material on the ground surface, while for the SAE 52100 steel, minor effects were generated on the surface affecting its integrity. For Inconel 718, that possesses both high hardness and ductile responses, the presence of graphene in the cutting fluid provides a great improvement in cutting, resulting in 15 % and 27 % reduction in surface roughness values and grinding power, respectively, even for a low cutting fluid flow rate. © 2025 Elsevier B.V.

关键词： Grinding (machining)

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