Matéria (Rio de Janeiro)最新文献_第4页

Effect of printing parameters on mechanical properties and processing time of additively manufactured parts 打印参数对增材制造零件力学性能和加工时间的影响

Matéria (Rio de Janeiro) Pub Date : 2023-07-21 DOI: 10.1590/1517-7076-rmat-2023-0111

Y. Gonzalez, Jorge Mario Mendoza, Jair Restrepo Durán, Luis Carlos Tapia Vertel, J. D. Rhenals-Julio

引用次数: 0

Delivery kinetics of natural active agents by PVA hydrogels intended for wound care 用于伤口护理的聚乙烯醇水凝胶的天然活性剂递送动力学

Matéria (Rio de Janeiro) Pub Date : 2023-07-17 DOI: 10.1590/1517-7076-rmat-2023-0071

Isis Siqueira Fernandes, Laís da Costa Saboia, Vinicius Soares Gonçalves, Jorge Luiz Siqueira da Costa Neto, A. Moreira, Natália Dias Souza, Alexandre Miguel do Nascimento, D. Chaves, L. Rosado, L. Silva, G. Bauerfeldt, A. Middea, R. N. Oliveira

{"title":"Delivery kinetics of natural active agents by PVA hydrogels intended for wound care","authors":"Isis Siqueira Fernandes, Laís da Costa Saboia, Vinicius Soares Gonçalves, Jorge Luiz Siqueira da Costa Neto, A. Moreira, Natália Dias Souza, Alexandre Miguel do Nascimento, D. Chaves, L. Rosado, L. Silva, G. Bauerfeldt, A. Middea, R. N. Oliveira","doi":"10.1590/1517-7076-rmat-2023-0071","DOIUrl":"https://doi.org/10.1590/1517-7076-rmat-2023-0071","url":null,"abstract":"Acute wound dressings can be based on PVA hydrogels, which present many characteristics of an ideal dressing, e.g., fluid uptake, a moisturized environment, etc. The lack of antimicrobial properties leads to the addition of natural active agents. The present work aims to manufacture and compare PVA gels loaded with Barbatimão bark extract, Leucaena bark extract, Aloe vera, and Lavender essential oil. They were characterized by FTIR, swelling tests, SEM, actives release. There were interactions between PVA and the active agents. The addition of Leucaena and Barbatimão increased the PVA ability to swell, but the opposite was found for Aloe vera and Lavender essential oil. PVA-Lavender essential oil samples presented interconnected pores, while samples with essential oil or extracts presented high crystallinity. Lavender essential oil and Aloe vera presented the highest release. The Barbatimão and Leucaena samples’ release may be related to the samples’ swelling, but the initial release of Aloe vera and Lavender samples was diffusion controlled by swelling. Their long-term release was dose-dependent for Aloe vera, while it was a non-Fickian diffusion for Lavender essential oil related to the hydrogel’s relaxation step. There is a synergistic effect when Aloe vera and Lavender essential oil are loaded in PVA hydrogels.","PeriodicalId":18246,"journal":{"name":"Matéria (Rio de Janeiro)","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91204901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of zinc sulphate in microstructure and strength properties of blended cementitious concrete system 硫酸锌对混合胶凝混凝土体系微观结构和强度性能的影响

Matéria (Rio de Janeiro) Pub Date : 2023-07-10 DOI: 10.1590/1517-7076-rmat-2023-0128

Archana Murugan, Ramasamy Vasudevan

{"title":"Influence of zinc sulphate in microstructure and strength properties of blended cementitious concrete system","authors":"Archana Murugan, Ramasamy Vasudevan","doi":"10.1590/1517-7076-rmat-2023-0128","DOIUrl":"https://doi.org/10.1590/1517-7076-rmat-2023-0128","url":null,"abstract":"In recent decades, greenhouse gas emission and global warming are the major threat to climatic change variability. The quality of concrete can be enhanced by the addition of a supplementary cementitious material to portland cement. In this study, fly ash is utilized as a supplemental cementitious material (SCM). The purpose of this research is to test and study the mechanical and thermal properties of blended concrete containing ordinary portland cement, fly ash and zinc sulphate as well as to investigate the microstructure in order to study the influence of zinc sulphate on the hydration process of concrete. This research mainly focused on the changes occurring in the strength, retarding mechanism, setting time, mineralogy, and microstructure caused by the addition of zinc sulphate in concrete. Ordinary portland cement, fly ash, pulverized fly ash and zinc sulphate are used in the blended concrete. The varied proportions of fly ash and zinc sulphate in the mix are 15%, 30%, 45%, and 60% respectively. The strength characteristics can be increased by fly ash pulverization. Hence the research focuses in exploring the addition of fly ash, pulverized fly ash and zinc sulphate anhydride to the concrete mix.","PeriodicalId":18246,"journal":{"name":"Matéria (Rio de Janeiro)","volume":"93 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73928933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Rehabilitation of damaged RC exterior beam-column joint using various configurations of CFRP laminates subjected to cyclic excitations 利用循环激励下不同结构的碳纤维布层合板修复受损的RC外梁柱节点

Matéria (Rio de Janeiro) Pub Date : 2023-07-10 DOI: 10.1590/1517-7076-rmat-2023-0110

Gopalakrishnan Palanisamy, Vidhya Kumarasamy

{"title":"Rehabilitation of damaged RC exterior beam-column joint using various configurations of CFRP laminates subjected to cyclic excitations","authors":"Gopalakrishnan Palanisamy, Vidhya Kumarasamy","doi":"10.1590/1517-7076-rmat-2023-0110","DOIUrl":"https://doi.org/10.1590/1517-7076-rmat-2023-0110","url":null,"abstract":"In this research, an investigational study on the use of CFRP laminates with 4 types of configurations (Series-A: laminated with confinement wrap, Series-B: single flat & L wrap, Series-C: confinement wrap, and Series-D: double flat & confinement wrap) to repair partially damaged reinforced cement composite column-beam joints is presented. The project’s primary goal was to examine how retrofitting configurations affected the behaviour of repaired RC column-beam junctions when subjected to cyclic loads (FL + RL). To examine the effectiveness of repairs for enhancing the stiffness, strength capacity, and behaviour of damaged RC joints (Partially – 25%, 50%, and 75%), seventeen samples were fabricated and investigated. Cyclic loading was used to test the control specimen all the way to failure. Sixteen samples were subjected to a load level that was around 75% of the projected pre-failure load (26 kN) under seismic condition. The maximum load, ductility index, and load versus displacement were all used to analyse the data. Also, CFRP debonding and the failure modes due to fracture pattern were observed. The findings highlighted the significance of repairing and improving joint performance. All repaired joints have increased strength that is virtually as strong as the beam-column joint’s actual shear strength. As a result, compared to the reference specimen, the Series-D joints had a substantially greater strength capacity (30.77%).","PeriodicalId":18246,"journal":{"name":"Matéria (Rio de Janeiro)","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78085269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

™Small steam turbine operating at low pressure for generating electricity in the Amazon ™小型汽轮机运行在低压发电在亚马逊

Matéria (Rio de Janeiro) Pub Date : 2023-07-07 DOI: 10.1590/1517-7076-rmat-2023-0059

Davi Cavalcante de Oliveira, J. Vaz, Marcelo de Oliveira e Silva, Edson Bruno Soares de Abreu, M. Galhardo, Leonam Ferreira de Araújo

{"title":"™Small steam turbine operating at low pressure for generating electricity in the Amazon","authors":"Davi Cavalcante de Oliveira, J. Vaz, Marcelo de Oliveira e Silva, Edson Bruno Soares de Abreu, M. Galhardo, Leonam Ferreira de Araújo","doi":"10.1590/1517-7076-rmat-2023-0059","DOIUrl":"https://doi.org/10.1590/1517-7076-rmat-2023-0059","url":null,"abstract":"Abstract In the Amazon, local electrical energy production is very important due to the large number of isolated communities, usually far from the conventional grid. In this context, steam turbines are relevant technologies to be used in the region, since waste biomass is widely available in several communities, besides, where sustainable agricultural activities take place, such as the use of açaí seeds, sugarcane bagasse, among others. Currently, there are not many relevant studies in the literature for small steam turbines operating at low pressure, conditioned to the reality of the Amazon region. Hence, the main goal of this work is to develop an experimental study of a small steam turbine operating at low pressure, in order to apply it to small energy demand, typically found in the Amazon. We developed measurements on the behavior of mechanical and electrical powers in relation to the shaft rotational speed of the small steam turbine, taking into account pressures of 0.1, 0.2 and 0.3 MPa. We concluded that the preliminary experimental survey, made in this work, demonstrates a good mechanical behavior of the small turbine and could be an alternative for electricity generation system to supply small demands in isolated communities in the Amazon, taking advantage of biomass from sustainable agricultural activities.","PeriodicalId":18246,"journal":{"name":"Matéria (Rio de Janeiro)","volume":"4 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89951943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of low content of steel fibre on concretes produced with recycled coarse aggregates with varying densities 低含量钢纤维对不同密度再生粗骨料混凝土的影响

Matéria (Rio de Janeiro) Pub Date : 2023-06-30 DOI: 10.1590/1517-7076-rmat-2023-0109

A. Figueiredo, I. Pietra, Luís Antônio Guimarães Bitencourt Júnior

引用次数: 1

Concreto de cimento Portland dopado com quitosana: propriedades mecânicas e microestrutural 壳聚糖掺杂硅酸盐水泥混凝土的力学和微观结构性能

Matéria (Rio de Janeiro) Pub Date : 2023-06-23 DOI: 10.1590/1517-7076-rmat-2023-0037

J. B. D. Silva, Rafaela Miranda da Silva, Andresa de Freitas Silva, Emanuel Laurertan Tavares França, E. P. Hernández, Patrícia Maria Albuquerque de Farias

{"title":"Concreto de cimento Portland dopado com quitosana: propriedades mecânicas e microestrutural","authors":"J. B. D. Silva, Rafaela Miranda da Silva, Andresa de Freitas Silva, Emanuel Laurertan Tavares França, E. P. Hernández, Patrícia Maria Albuquerque de Farias","doi":"10.1590/1517-7076-rmat-2023-0037","DOIUrl":"https://doi.org/10.1590/1517-7076-rmat-2023-0037","url":null,"abstract":"RESUMO A construção civil exerce função importante no consumo de energia em todo o mundo e influência, de forma significativa, o consumo total de recursos naturais e as emissões de CO2. A utilização de materiais renováveis está intrinsecamente relacionada à pesquisa e à inovação. A reutilização, a reciclagem, bem como o desenvolvimento de novos materiais e a descoberta de novas aplicações para materiais renováveis já conhecidos, podem contribuir de maneira expressiva para o desenvolvimento sustentável. A quitosana (CS) é um biopolímero com uma estrutura química e características únicas aliadas à sua farta disponibilidade como derivado da quitina, fazem com que suas possibilidades de aplicação nos mais diferentes campos tecnológicos, tenha se expandido consideravelmente. No presente trabalho, a utilização da quitosana para produção de concretos por meio de teores ótimos é investigada. Os valores de quitosana incorporados na dosagem foram 0,1%; 0,3% e 0,4%, com relação à massa de cimento. Os diferentes concretos obtidos foram submetidos a ensaios de propriedades mecânicas e microestrutural. Os resultados mostraram que a microestrutura foi favorecida com a utilização da quitosana. Bem como, apresentaram resultados favoráveis à incorporação dos teores utilizados de quitosana (se desatacando as amostras com 0,1% de substituição), sendo positivos quanto às propriedades mecânicas para a maioria das técnicas utilizadas, o que indica fortemente que a quitosana pode ser considerada como material promissor a ser incorporado na produção de concreto.","PeriodicalId":18246,"journal":{"name":"Matéria (Rio de Janeiro)","volume":"2011 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82600416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development and characterization of bacterial cellulose membrane incorporated with Witch hazel extract 含金缕梅提取物的细菌纤维素膜的制备与表征

Matéria (Rio de Janeiro) Pub Date : 2023-06-23 DOI: 10.1590/1517-7076-rmat-2023-0008

Maria Luiza Molin, Bruna Segat, Michele Cristina Formolo Garcia, A. P. Pezzin, M. L. L. Silveira, A. Schneider

{"title":"Development and characterization of bacterial cellulose membrane incorporated with Witch hazel extract","authors":"Maria Luiza Molin, Bruna Segat, Michele Cristina Formolo Garcia, A. P. Pezzin, M. L. L. Silveira, A. Schneider","doi":"10.1590/1517-7076-rmat-2023-0008","DOIUrl":"https://doi.org/10.1590/1517-7076-rmat-2023-0008","url":null,"abstract":"Bacterial cellulose (BC) has stood out in the biomedical field for its biocompatibility, non-toxicity and high liquid absorption capacity. Thus, studies have been conducted aiming at the functionalization of BC with sub-stances that add properties, such as anti-inflammatory and antimicrobial action. Hamamelis virginiana plant extract is known for its astringent, anti-inflammatory and antimicrobial properties. Thus, the present work aimed to incorporate aqueous (AE) and glycolic (GE) extracts of witch hazel in different concentrations to BC, aiming at its application as a curative. BC membranes incorporated with the extracts were characterized by thermo - gravimetric analysis (TGA), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and antimicrobial activity. The TGA results indicated a reduction in thermal stability and the appearance of a new stage of degradation in the samples that underwent incorporation. Furthermore, the FTIR showed the presence of aromatic compounds not found in the BC, corroborating the TGA. The micrographs revealed that the incorporation of the extracts resulted in the formation of a film on the surface of the membranes, covering the nanofibers. These results show that incorporating the aqueous and glycol extracts in the BC membrane was successful. However, despite the crude extracts’ antimicrobial potential, antimicrobial activity in the function - alized BC samples was not observed.","PeriodicalId":18246,"journal":{"name":"Matéria (Rio de Janeiro)","volume":"317 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78291470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Optimization of boriding process on AISI 1015 steel using response surface methodology 用响应面法优化aisi1015钢渗硼工艺

Matéria (Rio de Janeiro) Pub Date : 2023-06-16 DOI: 10.1590/1517-7076-rmat-2023-0086

Surya Raj Gopala Krishnan, Prince Muthiah, Maniraj Jaganathan

引用次数: 0

Structure and mechanical behavior of lignosulfonate-treated piassava (Attalea funifera) fibers 木质素磺酸处理木薯纤维的结构和力学性能

Matéria (Rio de Janeiro) Pub Date : 2023-06-16 DOI: 10.1590/1517-7076-rmat-2023-0041

Paula Lage Agrize, Beatriz Dantas Lourenço da Silva, Betina Carvalho Veiga, Camila Aparecida Abelha Rocha, F. G. Garcia Filho, Fábio de Oliveira Braga

{"title":"Structure and mechanical behavior of lignosulfonate-treated piassava (Attalea funifera) fibers","authors":"Paula Lage Agrize, Beatriz Dantas Lourenço da Silva, Betina Carvalho Veiga, Camila Aparecida Abelha Rocha, F. G. Garcia Filho, Fábio de Oliveira Braga","doi":"10.1590/1517-7076-rmat-2023-0041","DOIUrl":"https://doi.org/10.1590/1517-7076-rmat-2023-0041","url":null,"abstract":"The use of natural lignocellulosic fiber (NLF) biocomposites for the construction industry has been growing over the years, due to technical and environmental advantages. However, fiber-matrix incompatibility remains a major challenge. Various surface treatments have been investigated to improve fiber-matrix bonding, including sodium lignosulfonate (SLS), a potentially effective and environmentally friendly chemical. In this study, SLS treatment protocols were applied to piassava fibers to evaluate their influence on the fibers. Thermogravimetric Analysis (TG/DTG), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM/EDS), Fourier-transform Infrared Spectroscopy (FTIR), moisture absorption measurements and tensile tests were performed to character - ize the modifications. Results demonstrated, for the first time, the efficiency of SLS to remove extractives from the piassava surface. In general, partial degradation of the cellulosic structure was observed, noticeable by the slight drop in crystallinity index (from 42.80 to 39.82%), and an increase in the TG residual mass (from 21.35 to 31.90%), along with changes in DTG curves. However, a particular SLS treatment using ultrasonic bath was able to fully clean the surface preserving the cellulosic structure, and increasing the strength of fibers (from 386 ± 140 MPa to 524 ± 126 MPa).","PeriodicalId":18246,"journal":{"name":"Matéria (Rio de Janeiro)","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87270051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0