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Polymer blends of poly(lactic acid) and starch for the production of films applied in food packaging: A brief review

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Polymers from Renewable Resources 2023年第2期14卷 108-153页

作者： Carneiro da Silva, Lucas Rafael Rios, Alessandro de Oliveira Campomanes Santana, Ruth Marlene Postgraduate Program in Mining Metallurgical and Materials Engineering Laboratory of Polymeric Materials Federal University of Rio Grande do Sul Rio Grande do Sul Brazil Postgraduate Program in Food Science and Technology Laboratory of Bioactive Compounds Federal University of Rio Grande do Sul Rio Grande do Sul Brazil

The limited degradation of synthetic polymers used in food packaging when discarded in the environment is a major concern for society. Therefore, industry and academia have sought to develop biodegradable and eco-friendly materials for single-use in packaging. An interesting alternative for the food industry is biodegradable polymeric films, which is why different biopolymers have been used in the production of sustainable packaging. It is worth mentioning that the use of biodegradable polymers is one of the most successful innovations in the industry to address issues related to the environment. Among the available raw materials, starch extracted from different renewable sources is very promising for this purpose, due to its abundance, low-cost compared to other polymers and ability to produce non-toxic films. However, when used alone, pure starch has many limitations, which can be overcome by developing a mixture with other polymers (polymer blends), preferably from renewable and biodegradable sources, such as poly(lactic acid) (PLA). In this context, the absence of literature reviews evidencing the results of the application of films in foods led us to write this article, given the importance of polymer blends produced with different types of starch (cassava, corn, pea, potato, rice and wheat) and the PLA matrix. According to the results, it is clear that polymer blends based on PLA/Starch for food packaging are very promising, already being part of the industries solutions, aiming to minimize the large volume of plastic waste of petrochemical origin discarded in nature. Obviously, as with any technology, more research is needed to further improve the performance of the films, and while much research has made great strides, there are still limitations that prevent the commercialization of these materials. © The Author(s) 2023.

关键词： Starch

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Effect of exposure to a light-emitting diode (LED) on the physicochemical characteristics of natural latex biomembranes used to treat diabetic ulcers

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Research on Biomedical engineering 2022年第3期38卷 901-911页

作者： Santana, Thamis Fernandes Oliveira, Rebeca Hannah de Melo dos Santos, Ludmila Evangelista Lima, Eunice Paloma Nascimento Faria, Sylvia de Sousa Fonseca, Marcos Augusto Moutinho da Silva, Jaqueline Rodrigues Tatmatsu-Rocha, José Carlos Gomes, Marília Miranda Forte Fleury Rosa, Mário Fabrício Fleury Rosa, Suélia de Siqueira Rodrigues Carneiro, Marcella Lemos Brettas Postgraduate Program in Biomedical Engineering University of Brasilia Federal District Brasilia Brazil Postgraduate Program in Materials Science and Engineering Federal University of Campina Grande Paraiba Campina Grande Brazil Department of Electrical Engineering University of Brasilia Federal District Brasilia Brazil Postgraduate Program in Biology Animal University of Brasilia Federal District Brasilia Brazil Medicine Faculty Physical Therapy Department Federal University of Ceara Ceara Fortaleza Brazil Postgraduate Technology and Health Program University of Brasília Federal District Brasília Brazil

Purpose: Natural latex biomembrane has shown high therapeutic potential for the treatment of diabetic ulcers when associated with phototherapy. In this study, physical and chemical alterations in the latex biomembranes were evaluated after exposure to light-emitting diode (LED) irradiation and after contact with NaCl solution. Methods: There were three experimental groups: natural latex biomembranes (1) in natura;(2) after 35 min of LED light irradiation;and (3) after immersion in NaCl 0.9 g% solution. The samples were analyzed by tensile strength test, thermogravimetry, contact angle wettability, and Fourier-transform infrared spectroscopy. Results: The biomembranes that were submitted to contact with NaCl aqueous solution or exposure to LED did not undergo impairment of mechanical resistance. The thermogravimetry analysis indicated that increasing temperature led to mass loss in all samples, referring to their decomposition temperatures. In the wettability test, biomembranes exposed to LED showed a significant reduction in the contact angle between 0 and 10 min, indicating an increase in hydrophilicity, suggesting water storage capacity. The Fourier-transform infrared spectrometry assay showed that there was a more significant reduction in vibration intensity after immersion in NaCl solution compared to untreated biomembranes. An increase in the intensity of the entire spectrum of biomembranes exposed to LED was observed in comparison with the other samples, which may be related to photodegradation caused by LED light irradiation. Conclusion: The biomembranes underwent significant changes in its chemical structure after being subjected to different types of exposure and maintained its elasticity and tensile strength properties, in addition to showing good water retention capacity after exposure to LED. Thus, it maintains many of its properties for application as a tissue-regenerating biomaterial, even when subjected to LED irradiation and a humid environment. © 20

关键词： Tissue regeneration

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Phase formation, microstructural and superconducting properties of YBCO added Ca-compounds extraction eggshells

Results in Materials

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Results in materials 2025年 26卷

作者： Yap, Siew Hong Awang Kechik, Mohd Mustafa Humaidi, Syahrul Mohd Shariff, Khairul Khaizi Baqiah, Hussien Chen, Soo Kien Lim, Kean Pah Mohd Zaid, Mohd Hafiz Yaakob, Yazid Abdul Karim, Mohd Khalis Talib, Zainal Abidin Loh, Zhi Wei Kamarudin, Aliah Nursyahirah Shaari, Abdul Halim Miryala, Muralidhar Superconductor & Thin Films Laboratory Department of Physics Faculty of Science Universiti Putra Malaysia UPM Serdang Selangor Darul Ehsan 43400 Malaysia Postgraduate Program (Physics) FMIPA Universitas Sumatera Utara Medan 20222 Indonesia Microwave Research Institute Universiti Teknologi MARA Selangor Shah Alam 40450 Malaysia Shandong Key Laboratory of Biophysics Institute of Biophysics Dezhou University No. 566 University Rd. West Shandong Dezhou China Department of Physics College of Natural Sciences Jeonbuk National University 567 Baekjedaero Deokjingu Jeollabukdo Jeonjusi 54896 South Korea Materials for Energy and Environmental Laboratory Superconducting Materials Group of Science & Engineering Shibaura Institute of Technology 3-7-5 Foxesu Koto-ku Tokyo 135-8548 Japan

For several decades now, the emergence and production of high-quality bulk rare-earth-based superconductors, particularly YBa2Cu3O7-δ (YBCO/Y-123), have been noteworthy advancements with potential implications in var... 详细信息

For several decades now, the emergence and production of high-quality bulk rare-earth-based superconductors, particularly YBa₂Cu₃O_7-δ (YBCO/Y-123), have been noteworthy advancements with potential implications in various fields. This unique research investigated the potential of using chicken eggshells as a source of calcium compounds (CaO, CaCO₃ and Ca(OH)₂) for the synthesis of YBCO. The green approach synthesis of YBCO added with Ca-compounds (0.0100 wt% ≤ x ≤ 0.6000 wt%) was conducted in a systematic manner via thermal treatment method. The crystal structure, surface morphology, and chemical composition of the specimens were characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and Energy Dispersive X-Ray Spectroscopy (EDX). The results showed the formation of orthorhombic Y-123 phase, Pmmm space group with the high-intensity peaks of Y-123. The addition of Ca-compounds proposed a different trend of grain degradations in the YBCO matrix system with the appearance of Ca-compounds' impurity phases. The superconducting properties such as electrical resistivity analyzed using electrical resistance measurement. Surprisingly, the superconducting parameters improved after Ca-compounds were added into the YBCO system. The hole concentration, p reached the highest value among all the specimens with the lowest superconducting transition width, ∼ΔT_c = 3.805 K (T_c-onset = 93.223 K and T_{c(R = 0)} = 89.418 K) for the lowest concentration of Ca-compounds i.e., 0.0375 wt%. This great finding targeted the green approach impurity materials into YBCO system that can usefully enhance the superconducting properties at high temperature which covers the idea of addition with deficient concentration Ca-compounds. © 2025

关键词： Ca-compounds Critical temperature Grains degradations Hole concentration Superconducting transition width

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Substitution effect of (Mn, Ti) to the dielectric properties of barium-strontium hexaferrite for absorbing electromagnetic waves

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AIP Conference Proceedings 2011年第1期1454卷 282-285页

作者： Repi, V. Vekky R. Manaf, Azwar Postgraduate Program of Materials Science Faculty of Mathematics and Natural Science Universitas Indonesia Jakarta 10430 Jalan Salemba Raya 4 Indonesia Faculty of Engineering and Science Department of Engineering Physics Universitas Nasional Jakarta 12520 Indonesia

The objective of this work is to evaluate the ability of Mn-Ti substituted barium-strontium hexaferrite to absorb high frequency electromagnetic wave. To accomplish this objective, Mn-Ti substituted barium strontium hexaferrite of Ba0.5Sr0.5Fe12-x(Mn0.5Ti0.5)x with x = 0.1, x=0.3, x=0.5 were prepared through mechanical alloying route. Phase identification of the material obtained from XRD pattern indicating that the material is single phase for all variations of x. Coercivity and the remanent obtained by analyzing the hysteresis curve. The lowest coercivity at x = 0.5 for 77.86 kA/m but also lower the remanent of 0.088 kA/m. Dielectric properties of the material traced by calculating the value of permittivity and permeability of the material that was obtained with the parameters of the scattering vector network analyzer (VNA) in the 8GHz to 12GHz range. © 2012 American Institute of Physics.

关键词： Barium-strontium hexaferrite Electromagnetic wave absorber Mechanical alloying Permittivity and permeability

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Morphological Characterization of Brazil Nut Tree (Bertholletia excelsa) Fruit Pericarp

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Journal of Renewable materials 2019年第7期7卷 683-692页

作者： Gustavo P.Petrechen Marcos Arduin JoséD.Ambrósio Materials Science and Engineering Postgraduate Program Federal University of São CarlosSão CarlosBrazil Center of Characterization and Materials Development Federal University of São CarlosSão CarlosBrazil Department of Botany Federal University of São CarlosSão CarlosBrazil Citlab-Science Innovation and Technology LaboratorySorocabaBrazil

This article presents the overall morphological structure of the Brazil nut tree(Bertholletia excelsa)fruit pericarp,from macro to nano *** acquired knowledge would be used for the development of new applications,like using the materials as fillers for biocomposites,or as a hierarchical architecture model for *** research was performed using stereo and light microscopy and conventional and force field emission scanning electron *** pericarp presents three layers:the exocarp,a dark gray,brittle and fragile outer layer;the mesocarp,a beige,dry,rigid,impermeable and fibrous intermediate layer;and the endocarp,an inner layer with similar characteristic as the exocarp,but formed next to the ***,the exocarp and the endocarp presented minor regions of sclereids,fibers and vascular cell bundles,inside major regions of parenchyma *** mesocarp presents a structure of fiber cells regions alternating with sclereids and vascular cells regions,arranged in a composite like arrangement,with the fibers cells bundles acting as randomly oriented disperse phases in a sclereid cells *** arrangement was associated with the mesocarp relative superior proprieties,indicating a great material for using as fillers for biocomposites or in biomimetics applications.

关键词： Bertholletia excelsa brazil nut fruit pericarp morphological structure microscopy

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Microwave-assisted hydrothermal synthesis of NiO-Ce1-xEuxO2-δ powders for fuel cell catalytic anodes

Microwave-assisted hydrothermal synthesis of NiO-Ce1-xEuxO2-...

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Symposium on Nanotechnology General Session - 225th ECS Meeting

作者： Medeiros, A.L. Martinelli, A.E. Melo, D.M.A. Orlandi, M.O. Macedo, D.A. Materials Science and Engineering Postgraduate Program UFRN Natal59072-970 Brazil Institute of Chemistry UNESP Araraquara14801-907 Brazil Department of Materials Engineering UFPB João Pessoa58051-900 Brazil

ISBN: (纸本)9781607685869

CeO2-based materials doped with rare earth (TR+3) can be used as alternative to traditional NiO-YSZ anodes in solid oxide fuel cells as they have higher ionic conductivity and lower ohmic losses compared to YSZ. Moreover, they allow fuel cell operation at lower temperatures (500-800°C). In the anode composition, the concentration of NiO acting as catalyst in YSZ provides high electrical conductivity and high electrochemical activity of reactions, promoting internal reform in the cell. In this work, NiO - Ce1-xEuxO2-δ compounds (x = 0.1, 0.2 and 0.3) have been synthesized by microwave-assisted hydrothermal method. The materials were characterized by TG, XRD, TPR and SEM-FEG techniques. The refinement of data obtained by X-ray diffraction showed the presence of ceria doped with europium crystallized in a cubic phase with fluorite structure, in addition to the presence of NiO. The microwaveassisted hydrothermal method showed significant reduction in the average particle size and good mass control of phase compositions compared to other chemical synthesis techniques. © The Electrochemical Society.

关键词： Nickel oxide

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S3M: A suggestion mechanism for semantic web service composition 15

S3M: A suggestion mechanism for semantic web service composi...

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21st Brazilian Symposium on Multimedia and the Web, WebMedia 2015

作者： Busanello Da Silva, Diogo P. Weber, Mathias Henrique Siqueira, Frank Department of Informatics and Statistics Federal University of Santa Catarina Florianópolis Brazil Postgraduate Program on Materials Science and Engineering Federal University of Santa Catarina Florianópolis Brazil

ISBN: (纸本)9781450339599

Web Service composition is a complex and error-prone process that requires the support of software tools in order to become feasible. Composition tools can help a developer to select compatible services from vast service repositories, taking into account characteristics such as port compatibility, availability, cost, and so on. This paper describes S3M, a service suggestion mechanism that, coupled with the CVFlow workflow editor, helps developers to select services and to build compositions. Service suggestions are given to the user taking into account the semantic description of Web Services in SAWSDL format. © 2015 ACM.

关键词： Websites

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Microstructure and wear resistance of spray-formed supermartensitic stainless steel

Microstructure and wear resistance of spray-formed supermart...

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作者： Zepon, Guilherme Kiminami, Claudio Shyinti Filho, Walter José Botta Bolfarini, Claudemiro Postgraduate Program in Science and Materials Engineering Federal University of São Carlos - UFSCar São Carlos SP Brazil Department of Materials Engineering Federal University of São Carlos - UFSCar São Carlos SP Brazil

Since the early 90's the oil industry has been encouraging the development of corrosion and wear resistant alloys for onshore and offshore pipeline applications. In this context supermartensitic stainless steel was introduced to replace the more expensive duplex stainless steel for tubing applications. Despite the outstanding corrosion resistance of stainless steels, their wear resistance is of concern. Some authors reported obtaining material processed by spray forming, such as ferritic stainless steel, superduplex stainless steel modified with boron, and iron-based amorphous alloys, which presented high wear resistance while maintaining the corrosion performance. The addition of boron to iron-based alloys promotes the formation of hard boride particles (M2B type) which improve their wear resistances. This work aimed to study the microstructure and wear resistance of supermartensitic stainless steel modified with 0.3 wt. (%) and 0.7 wt. (%) processed by spray forming (SF-SMSS 0.3%B and SF-SMSS 0.7%B, respectively). These boron contents were selected in order to improve the wear resistance of supermartensitic stainless steel through the formation of uniformly distributed borides maintaining the characteristics of the corrosion resistant matrix. SF-SMSS 0.7%B presents an abrasive wear resistance considerably higher than spray-formed supermartensitic stainless steel without boron addition (SF-SMSS). © 2013.

关键词： Wear resistance

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Electrical properties of lanthanum silicate apatite electrolytes prepared by an innovative chemical route

Electrical properties of lanthanum silicate apatite electrol...

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Symposium on Nanotechnology General Session - 225th ECS Meeting

作者： Macedo, G.L.S. Macedo, D.A. Rajesh, S. Martinelli, A.E. Figueiredo, F.M.L. Marques, F.M.B. Nascimento, R.M. Department of Chemical Engineering UFRN Natal59078-970 Brazil Department of Materials Engineering UFPB João Pessoa58051-900 Brazil Dept. of Materials and Ceramic Eng. CICECO University of Aveiro 3810-193 Portugal Materials Science and Engineering Postgraduate Program UFRN 59078-970 Brazil

ISBN: (纸本)9781607685869

This work reports the synthesis of apatite-type lanthanum silicate powders with nominal composition La10Si6O27 by an innovative chemical route which combines co-precipitation and sol-gel approaches. The herein proposed synthetic procedure is advantageous in reducing energy consumption and processing time, key elements to decrease the total manufacturing cost. The asprepared powder was calcined between 500 and 900 °C. Structure of the calcined powders, characterized by X-ray diffraction (XRD) and Rietveld refinement, indicated the formation of apatite crystalline lanthanum silicate with minor amount of L2O3 at 900 °C. The apatite powder was further analyzed by scanning electron microscopy (SEM). The effect of sintering temperature, ranging from 1400 to 1450 °C, on the electrical properties was investigated by impedance spectroscopy. Electrical measurements were recorded in the 400-800 °C temperature range. The lanthanum silicate electrolyte sintered at 1450 °C exhibited total electrical conductivity (σ700 °C = 2.12 × 10-3 ***-1) comparable with samples from literature prepared by sol-gel and freeze drying methods and sintered at 1500 °C. The results in the present study demonstrate that the co-precipitation method combined with a solgel approach is a promising alternative route to synthesize lanthanum silicate powders. © The Electrochemical Society.

关键词： Powders

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Impact Of WC Addition And High-Energy Milling Time On The Properties Of Cu-WC Composite Powders

Impact Of WC Addition And High-Energy Milling Time On The Pr...

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2024 European Powder Metallurgy Congress and Exhibition, Euro PM 2024

作者： Queiroz e Silva, Thalita Mashhadikarimi, Meysam Vieira, Pâmala Samara Marques, Anderson Costa Dos Santos Vasconcelos, Gabriel Dos Santos, Lucas Marques Materials Science and Engineering Postgraduate Program Federal University of Rio Grande do Norte Natal59078-970 Brazil School of Science and Technology Federal University of Rio Grande do Norte Natal59078-970 Brazil

ISBN: (纸本)9781899072583

Composites formed by a copper matrix, reinforced by a ceramic and refractory material, stand out due to their relevance in electrical conductor applications. In this context, this study investigated the hardening of copper powder with the addition of different concentrations of tungsten carbide (5, 10, 15 and 20% by weight) prepared by high-energy milling (HEM) for 1, 2, 5, 10 and 20 hours. The powders were characterized by SEM, XRD and Vickers microhardness. The results showed that the milling method was efficient for obtaining Cu-WC composites, with strong bonds between the phases. The diffractograms showed characteristic copper and tungsten carbide peaks, with no secondary phases. The Vickers microhardness value is directly related to the amount of WC and the milling time;consequently, the 20% WC composite powder milled for 20 hours had a microhardness of 251 HV, exceeding the values of the other powders. © European Powder Metallurgy Association (EPMA)

关键词： Microhardness

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