CT - DET - Artigos publicados em periódicos

URI Permanente para esta coleçãohttps://repositorio.ufrn.br/handle/1/182

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Dengue: prevenção e controle pelas ondas do rádio
(2014) Almeida Júnior, José Jailson de; Oliveira, Franklin Learcton Bezerra de; Araújo, Rayane Larissa Santos de; Brilhante, Magdalena Muryelle Silva; Silva, Dany Geraldo Kramer Cavalcanti e
INTRODUÇÃO: a dengue é uma doença viral que vem tomando grandes proporções mundialmente por possuir características endêmicas e epidêmicas, se alastrando por todo o mundo e provocando grande impac-to na saúde pública. OBJETIVO: apresentar as ações desenvolvidas nas rádios AM e FM do Projeto de Extensão Vigilância Ambiental em Saúde: ações integradas de controle da dengue no município de Santa Cruz/RN. MATERIAL E MÉTODOS: trata-se de um estudo descritivo do tipo relato de experi-ências sobre ações realizadas nas emissoras de rádio AM e FM do município de Santa Cruz/RN. RESULTADOS E DISCUSSÃO: as entrevistas tiveram boa repercussão, tendo em vista o público alcançado por meio das duas emissoras. CONCLUSÃO: acredita-se que o objetivo foi atingido, considerando que o programa de rádio proporciona um contato direto com o ouvinte, o que é reforçado com os apresentadores dos programas veicu-lados pelas emissoras
Estudo comparativo da atuação do enfermeiro no controle de dengue e febre chikungunya
(FapUNIFESP (SciELO), 2016) Almeida Júnior, José Jailson de; Oliveira, Franklin Learcton Bezerra de; Millions, Rejane Medeiros; Costa, Marcelo Viana da; Silva, Dany Geraldo Kramer Cavalcanti e
O objetivo deste estudo foi analisar a atuação dos enfermeiros das Estratégias de Saúde da Família no controle de dengue e febre chikungunya nos municípios de Parnamirim e Santa Cruz/RN. Trata-se de um estudo exploratório, descritivo, com abordagem qualitativa de tratamento e análise de dados. A coleta foi realizada entre novembro e dezembro de 2015 por meio de uma entrevista gravada, voltada às questões que abordam a ação da enfermagem e sua equipe no controle de dengue e febre chikungunya no campo de atuação da ESF. Utilizou-se como método de observação dos dados a análise de conteúdo de Bardin. Após análise, houve criação de duas categorias – educação em saúde e campanhas pontuais. Na primeira, os entrevistados informaram realizar palestras educativas, mas não explicam a metodologia usada e nem a participação popular, como também a articulação com o setor de endemias da cidade para fortalecer a discussão. Na segunda, algumas ações são assistencialistas de caráter campanhista/higienista, realizadas pelos enfermeiros dos municípios em campanhas de “higienização” e “limpeza”, as quais se mostram bastante presentes nas falas dos entrevistados. Há uma forte presença desse modelo enraizada tanto nas ações quanto na realização de atividades educativas, usando como metodologia a palestra. Além disso, há necessidade de se realizar mais estudos que aprofundem o tema abordado, a julgar por uma amostra pequena, especialmente no município de Parnamirim
Development of porous alumina membranes for treatment of textile effluent
(Taylor & Francis, 2015-02-27) Silva, Késia Karina de Oliveira Souto; Paskocimas, Carlos Alberto; Oliveira, Fernando R.; Nascimento, José Heriberto Oliveira do; Zille, Andrea
Ceramic porous membranes sintered at two different temperature using polyvinyl alcohol and ethylene glycol as binders, and composed of two types of α-alumina with different parti- cle sizes were investigated for the microfiltration of a textile effluent containing indigo dye, auxiliaries, heavy metals, oils, and solids. The physicochemical properties of the membranes and effluent were evaluated. X-ray diffraction, energy dispersive X-ray fluorescence spectros- copy, differential scanning calorimetry, and thermogravimetric analysis confirm that the thin membrane is composed of high crystalline and pure α-alumina. Scanning electron microscopy observation indicates that the membranes have smooth porous surface making it suitable for microfiltration applications. The membrane sintered at 1,450 ̊C exhibited higher water absorp- tion (WA) and apparent porosity than that sintered at 1,475 ̊C. The apparent specific gravity and flexural strength are in inverse correlation with the WA due to the enhanced densification of the membranes. The filtered effluent was evaluated using a membrane with an average pore size of 0.4 μm and a total porosity of 29.6%. The average values of rejection were 90% for color, 93% for suspended solids, 95% for turbidity, 60% for metals, and 73% for chemical oxygen demand. These results demonstrate that low-cost ceramic alumina membranes are a very promising advanced treatment for textile industrial effluents
Evaluation of aging in air of poly (ethylene terephthalat) in oxygen plasma
(Materials Research, 2015-10) Feitor, Michelle Cequeira; Alves Junior, Clodomiro; Bezerra, Clovis Medeiros; Sousa, Rômulo Ribeiro Magalhães de; Costa, Thercio Henrique de Carvalho
Polyester fabric samples – PET (poly (ethylene terephtalate)), were treated with oxygen plasma, in order to alter the hydrophilicity of such material. The process parameters: working pressure, current, tension and temperature were kept constant, varying only the treatment time. In order to evaluate the change caused on samples hydrophilicity, as well as the influence of the treatment time, the vertical wicking test was used. The samples were stored at standard temperature and pressure conditions, and their wettability were measured one day after the treatment and repeated after 30, 60 and 360 days, in order to check the stability of the effects produced. Scanning electron microscopy (SEM), Raman and ATR (Attenuated total reflection) spectroscopies were used to evaluate physical and chemical alterations on the samples surface. The results have shown a substantial improvement on the hydrophilicity of the treated samples compared to the non-treated sample.
Telmisartan decreases inflammation by modulating TNF-a, IL-10, and RANK/RANKL in a rat model of ulcerative colitis
(Pharmacological Reports, 2015-06) Silva, Késia Karina de Oliveira Souto; Guerra, Gerlane Coelho Bernardo; Araujo, Aurigena Antunes de; Lira, George A.; Melo, Maryanne N.; Fernandes, Daline; Silva, Arthur L.; Araujo Junior, Raimundo Fernandes de
Background: Telmisartan is an antihypertensive angiotensin II receptor blocker. This antihypertensive shows antiinflammatory activity. Purpose: In this study, the antiinflammatory activity of telmisartan was tested in an acetic acid (10%) model of ulcerative colitis (UC) in rats. Methods: Rats were given 1, 3, and 5 mg/kg/day of telmisartan orally for 3 days before induction of UC. The same doses were also administered 2 and 24 h after induction. Rats from the non-colitis and non- treated colitis groups were administered vehicle (saline, 5 ml/kg) orally and another group received sulfasalazine (50 mg/kg/day). Colons tissue was analyzed by macroscopic, by histopathology, by the immunohistochemical examination of RANKL/RANK pathway; by ELISA analysis of the levels of IL-10, TNF-a, myeloperoxidase (MPO) and malonaldehyde (MDA). Results: Telmisartan at 5 mg/kg reduced levels of MPO, MDA, TNF-a and increased of IL-10 (p < 0.05). Additionally, telmisartan reduced macroscopic damage, number of ulcers, and inflammatory and histopathological processes such as neutrophil infiltration, changes in cytoarchitecture, and necrosis. Immunohistochemistry revealed down-regulation of nuclear factor-kappaB receptor/nuclear factor- kappaB ligand (RANK/RANKL) in groups treated with sulfasalazine or telmisartan. Conclusion: Telmisartan exerts beneficial effects in an acetic acid model of colitis in rats. These effects may be due to accelerated termination of the acute inflammatory phase, indicated by decreased TNF-a and increased production of IL-10 and low expression of RANKL and RANK. 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp.
Effect of cold plasma treatment on recycled polyethylene/kapok composites interface adhesion
(Composite Interfaces, 2018-11-26) Feitor, Michele Cequeira; Macedo, Murilo José Pereira; Mattos, Adriano Lincoln Albuquerque; Costa, Thércio Henrique de Carvalho; Ito, Edson Noriyuki; Melo, José Daniel Diniz
Composites from recycled polyethylene and kapok fibers were pre- pared using untreated and plasma-treated fibers. Flow properties, mechanical properties and fracture morphology were analyzed in order to evaluate the effects of cold plasma treatment on kapok fibers to improve interfacial bonding between fibers and matrix. Melt flow rate (MFR) measurements indicated a reduction in flow rate of the polymer with the addition of kapok fibers. Storage modulus increased with fiber addition and this effect was more significant when plasma- treated fibers were used. Tanδ obtained from viscoelastic characteriza- tion also suggested improvements in fiber/matrix interface as a result of plasma treatment. Addition of kapok fibers to polyethylene pro- duced a reduction in onset decomposition temperature determined from thermogravimetry curve. However, the decrease in temperature observed does not limit composite processing. Furthermore, the degree of crystallinity of polyethylene increased with the addition of untreated fibers and reduced when plasma treated fibers were added. Morphological analysis of failure surface by Field Emission Gun Scanning Electron Microscopy (FEGSEM) suggest that fiber/matrix adhesion was clearly improved when plasma treated fibers were used. Thus, the oxygen cold plasma treatment proved to be an effec- tive non-polluting approach to enhance matrix/fiber adhesion in poly- ethylene/kapok fiber composites, as opposed to chemical treatments.
Thin tin and tio2 film deposition in glass samples by cathodic cage
(Materials Research, 2015-04) Feitor, Michelle Cequeira; Sousa, Rômulo Ribeiro Magalhães de; Araújo, Francisco Odolberto de; Costa, Thercio Henrique de Carvalho; Nascimento, Igor Oliveira; Santos, Francisco Eroni Paes; Alves Júnior, Clodomiro
Thin nitride and titanium dioxide films were produced using an innovative technique called cathodic cage depositon. Uniformity, three-dimensionality and high rate deposition are some of the advantages of this technique. In this study we discuss the influences of temperature, treatment time and gaseous atmosphere on the characteristics of the deposited films. The TiN (titanium nitride) and TiO2 (titanium dioxide) films were produced using a high deposition rate of 2,5 μm/h at a work temperature and pressure of 400°C and 150 Pa respectively. EDS technique was used to identify the chemical composition of the thin film deposited, whilst Raman spectroscopy indicated the phases present confirmed by DRX analysis. The thickness of the deposited films was studied using electron microscopy scanning. The results based on the deposition parameters confirm the great efficiency and versatility of this technique, which allows a uniform three-dimensional film deposition on any material without the appearance of stress. Compared to other techniques, cathodic cage deposition enables deposition at lower temperatures
Novel synthesis of copper oxide on fabric samples by cathodic cage plasma deposition
(Polymers for Advanced Technologies, 2019-11-11) Feitor, Michele Cequeira; Fernades, Fernanda; Rocha Filho, Edglay; Souza, Ivan; Nascimento, Igor; Sousa, Rômulo; Almeida, Edalmy; Costa, Thércio; Naeem, Muhammad; Iqbal, Javed
The fabrics with copper or copper oxide deposition are of considerable interest because of exceptional antibacterial properties, which are useable in medical, textiles, and hygiene applications. Unfortunately, the conventional techniques take long pro-cessing time, complex equipment, and combination of several processing steps (nano-particles synthesis and their deposition on fabrics). In this novel study, cathodic cage plasma deposition assisted with copper cathodic cage is used for the synthesis of the copper oxide on polyester and polyamide fabrics. For the enhancement of synthesis efficiency, the effect of cathodic cage lid thickness is also investigated. The samples are assessed by using scanning electron microscopy, elemental dispersive spectros-copy, and X‐ray photoelectron spectroscopy. It is found that using cathodic cage plasma deposition, fabrics can be successfully synthesized by the copper oxide with comparatively small treatment time, cost‐effectively, and environmentally friendly. Interestingly, cathodic cage plasma treatment is already proved to be working effec- tively on industrial scale; thus, it is predicted to be of noteworthy importance for fab- rics processing on large‐scale garments manufacturing and hospitals.
Analysis and evaluation of shape memory alloy wires behaviour in weft-knitted fabrics
(Trans Tech Publications, 2012-11) Medeiros, José Ivan de; Fangueiro, Raul
It is widely acknowledged within the textile engineering community that Shape Memory Alloys (SMA), exhibit great potential for several applications. This paper presents the research undertaken at the University of Minho aiming to study the behaviour of weft-knitted fabrics produced with SMA nitinol® wires. SMA nitinol® wires of type B (which shows shape memory effect at body temperature) of 50, 127 and 210 µm diameters have been used to produce weftknitted fabrics with different loop types, e.g. stitch, tuck and miss. The influence of the loop type on the performance of the weft-knitted fabric, in terms of energy absorption, has been analyzed. Tensile tests were carried out according to ISO1462 standard, using a H100KS Hounsfield universal testing instrument. The results aim to help future applications of SMA in the development of new textile materials
Analysis of energy absorption for NiTi wires under different diameters and loop types
(The Textile Machinery Society of Japan, 2013) Medeiros, José Ivan de; Fangueiro, Raul
This paper presents the research undertaken at the University of Minho aiming to study the behaviour of 3D weft-knitted structures using Shape Memory Alloy (SMA) wires and elastomeric yarns, in order to produce dynamic structures as a support to answer specific situations and applications. Several samples were produced using NitinolR wires in different diameters and loop types. The Tensile tests were carried out being based to NP EN ISO 2062: 1993 standards, using a H100KS Hounsfield Universal Testing Instrument. The results showed that The 50 μm wire showed to be too thin to this propose;moreover, The 210 μm NiTi wire showed to be hard to process on the knitting machine due to its high stiffness;The 127 μm NiTi wire showed to be the best among them, due to the process and energy absorption ratio. Finally, for both NiTi wires in different diameters studied, tuck loop showed to have the highest energy absorption capacity
Cotton fabric bleached with seawater: mechanical and coloristic properties
(Scielo, 2019) Ferreira, Iêda Letícia Souza; Medeiros, José Ivan de; Steffens, Fernanda; Oliveira, Fernando Ribeiro
The textile industry needs a high volume of water to carry out its processes, which among them; textile chemical finishing is the main responsible for high water expenditure. However, nowadays there is a worldwide concern regarding the scarcity of fresh water. This research aims to study the use of seawater in the cotton bleaching process and compare the results obtained with the bleaching process made with distilled water. The characterization of the substrates was performed through the following analyses: reflectance spectrophotometry, white degree (oBerger), wettability, tensile strength, elongation, scanning electron microscopy and dispersive energy spectroscopy. The bleaching with seawater presented good whiteness index, high tensile strength values and excellent hydrophilicity, which suggest that it may be possible to perform this process in cotton fabric using seawater
Influence of silane coupling agent on shear thickening fluids (STF) for personal protection
(Elsevier, 2019-10) Santos, Thiago Félix dos; Santos, Caroliny Minely da Silva; Aquino, Marcos Silva de; Ionesi, Dorin; Medeiros, José Ivan de
The present work studied the influence of silane coupling agent in non-Newtonian fluid, in the impact resistance, adhesion and flexibility results. The results of stab performance for Kevlar samples impregnated with silane agent showed results significantly higher than others samples non impregnated, such results are closely associated with the formation of siloxane bonds due to the coupling agent. The impact resistance properties of all samples were tested using drop tower testing, and the flexibility was testes beyond bending angle test. SEM and FTIR analyses were used to verify the chemicals compositions and to evaluate qualitatively the presence of nanoparticles samples. Abrasion test were realized to verify the influence of silane agent of the resistance adhesive of non-Newtonian fluid under samples. The Kevlar samples impregnated with STF and coupling silane presented best flexibility (angle of bending = 30.33◦), a significant increase on the dissipation kinetic (penetration depth) in comparing to the others and resistance adhesive of non-Newtonian fluid under samples. Therefore, practically this property remained unalterable in relation to Kevlar samples with STF and Kevlar control
Efficient silver nanoparticles deposition method on DBD plasma-treated polyamide 6,6 for antimicrobial textiles
(IOP Publishing, 2021-04-10) Silva, Késia Karina de Oliveira Souto; Ribeiro, Ana Isabel; Senturk, Dilara; Modic, Martina; Cvelbar, Uros; Dinescu, Gheorghe; Mitu, Bogdana; Nikiforov, Anton; Leys, Christophe; Kuchakova, Irina; Vanneste, M.; Heyse, P.; Vrieze, Mike de; Souto, António P.; Zille, Andrea
Several methods for silver nanoparticles (AgNPs) deposition on dielectric barrier discharge (DBD) plasma treated and not treated polyamide 6,6 fabric were tested for the production of durable antibacterial textiles. Ultrasound-assisted, dip-coating, exhaustion at 70 ̊C and spray deposition methods were applied. The treated fabrics were analysed in terms of coating uniformity, plasma effect, nanoparticles concentration onto the fabrics and nanoparticles release. Scanning electron microscope (SEM), energy dispersive X-ray (EDX), atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectrometry (ICP-OES) and reflectance spectroscopy(%R) were performed. In the fabrics impregnated with AgNPs by dip coating or spray methods there are no significant differences in the plasma treated and untreated samples. Ultrasound tip and exhaustion at 70 ̊C presented higher AgNPs loading. Better AgNPs distribution, higher concentration and less agglomeration were observed in the plasma treated samples and an improved controlled release as well. The plasma treated fabrics with AgNPs deposited with the ultrasound method showed the highest concentration of nanoparticles onto the fabrics as well as the lowest NPs agglomeration. However, this deposition is limited to certain areas of the fabric, the samples were not uniform. The exhaustion method showed the best equilibrium between the NPs distribution and state of agglomeration
Characterization and acidic properties of AlMCM-41 prepared by conventional and post-synthesis alumination
(Australian Journal of Chemistry, 2015) Nascimento, Rubens Maribondo do; Costa, Maria José Fonseca; Chellappa, Thiago; Araujo, Antonio Souza de; Fonseca, Viviane Muniz; Fernandes Júnior, Valter José; Pacheco, Jose G. A.
The catalysts analysed in the current work are variations of MCM-41. The properties of these highly ordered mesoporous aluminosilicates were adjusted by an isomorphous substitution of Si by a trivalent cation, in this case Al3þ, generating catalysts of the AlMCM-41 type. The materials were synthesized with a silicon/aluminium ratio of 40, through two methods of impregnation of the metal: conventional and post-synthesis alumination. With the aim of determining the density of the acid sites of the Al40MCM-41 prepared by post-synthesis and conventional alumination, studies of the adsorption of n-butylamine probe molecule were carried out. Further, the studied material was characterized by thermogravimetry measurements, providing the profile of decomposition of the samples, which allowed calculation of the densities of the acid sites. The model-free kinetic algorithms were applied in order to determinate conversion and apparent activation energy. Comparison of energy-dispersive X-ray fluorescence and X-ray photoelectron spectroscopy measurements indicated that the post-synthesis method was more favourable based on the metal positioning, ‘anchored’ in the surface of the catalyst. The textural properties of the calcined Al40MCM-41 prepared by post-synthesis and conventional alumination were characterized by X-ray diffraction, N2 isothermal adsorption measurements (Brunauer– Emmett–Teller and Barrett–Joyner–Halenda), transmission electron microscopy, and X-ray photoelectron spectroscopy.
Surface modification of tool steel by cathodic cage TiN deposition
(Taylor and Francis, 2019-09-11) Feitor, Michelle Cequeira; Barbosa, M. G. C.; Viana, Bartolomeu C.; Santos, F. E. P.; Fernandes, Fernanda de Melo; Costa, Thércio Henrique de Carvalho; Naeem, Muhammad Salman; Sousa, R. R. M.
The aim of this work is to investigate the effect of titanium nitride coating for various treatment times (0.5–4 h) by cathodic cage plasma deposition (CCPD) on surface properties of AISI D6 tool steel. The obtained results depict micrometric-sized TiN film deposition under all processing condition with improved surface hardness and corrosion resistance. Raman and EDS analysis are used to calculate N/Ti ratios for stoichiometric calculations of samples. This study depicts that the surface properties of tool steel can be effectively improved by TiN film deposition using CCPD, with low processing time, low processing temperature and better uniformity, as compared to conventional techniques. Additionally, the problems associated with the conventional TiN films such as pores and voids are eliminated. This technique is compatible with industrial-scale applications, and thus results from this study are expected to be beneficial for the surface engineering industry
Study of High-Density Polyethylene (HDPE) kinetics modification treated by Dielectric Barrier Discharge (DBD) plasma
(MDPI, 2020-10-21) Feitor, Michelle Cequeira; Medeiros Neto, João Freire de; Souza, Ivan Alves de; Targino, Talita Galvão; Diniz, Gutembergy Ferreira; Libório, Maxwell Santana; Sousa, Rômulo Ribeiro Magalhães; Costa, Thércio Henrique de Carvalho
In this work, the plasma was used in the dielectric barrier discharge (DBD) technique for modifying the high-density polyethylene (HDPE) surface. The treatments were performed via argon or oxygen, for 10 min, at a frequency of 820 Hz, voltage of 20 kV, 2 mm distance between electrodes, and atmospheric pressure. The efficiency of the plasma was determined through the triple Langmuir probe to check if it had enough energy to promote chemical changes on the material surface. Physicochemical changes were diagnosed through surface characterization techniques such as contact angle, attenuated total reflection to Fourier transform infrared spectroscopy (ATR-FTIR), X-ray excited photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Plasma electronics temperature showed that it has enough energy to break or form chemical bonds on the material surface, impacting its wettability directly. The wettability test was performed before and after treatment through the sessile drop, using distilled water, glycerin, and dimethylformamide, to the profile of surface tensions by the Fowkes method, analyzing the contact angle variation. ATR-FTIR and XPS analyses showed that groups and bonds were altered or generated on the surface when compared with the untreated sample. The AFM showed a change in roughness, and this directly affected the increase of wettability
Optical-electrical properties and thickness analysis of TiO2 thin films obtained by magnetron sputtering
(Springer Science and Business Media LLC, 2020-09-23) Feitor, Michelle Cerqueira; S. Sobrinho, V. S.; Miranda Neto, José Queiroz de; Lima, L. L. F.; Souza, Iedo A; Libório, Maxwell Santana; Queiroz, José César Augusto de; Sousa, Rômulo Ribeiro Magalhães de; Almeida, Érika Oliveira de; Costa, Thércio Henrique de Carvalho
The study of thin films with properties that meet specific needs and improve people’s quality of life has been the focus of many researchers. However, knowing and controlling the production techniques of these films have been a challenge for the industry of optical-electronic devices, functional coatings, and energy conservation. The thickness of thin films is a parameter that influences the optical and electrical characteristics of these materials, thus being one of the most important information in the plasma deposition process. Because of the need for precision in measuring the thickness of thin transparent films, this work proposes to evaluate the Swanepoel methods (envelope) and the PUMA, computational method, from optical transmittance curves and compare them with the measurements directly made by microscopy. Scanning electronics for thin films of TiO2 deposited by magnetron sputtering in different conditions. The results of this study showed that the PUMA method is capable of calculating film thicknesses of a few hundred nanometers and with few interference fringes. The PUMA method showed convergence with high precision for films produced with 30 and 60 min of treatment and a difference of 17% for films with 120 min of deposition concerning the measurements made by microscopy
Statistical study of performance properties to impact of Kevlar® woven impregnated with Non-Newtonian Fluid (NNF)
(Elsevier, 2020-05) Santos, Thiago Felix dos; Santos, Caroliny Minely da Silva; Aquino, Marcos Silva de; Oliveira, Fernando R.; Medeiros, José Ivan de
This investigative work was carry out through a factorial planning, using Design of Experiment (DoE) in order to evaluate the impact performance properties of Kevlar® woven structure impregnated with Non-Newtonian Fluids (NNF). Pull out and drop tower tests were performed. The pull out test showed that Kevlar® strength values with NNF composition 3 were better (10.55 N) when compared to others (1 and 2). The drop tower test showed that woven samples with highest concentration of NNF nanoparticles (3OR) exhibited the best behavior with respect to the penetration depth for P1 (19.5%) and S1 (48.0%) knife blade geometries. Thus, evidencing best residual energy dissipation when compared to the others. Results also showed that the composition (1, 2 and 3) of NNF as well as the orientation of the woven layers can be used to improve impact performance properties. Therefore, the impact protection performance depends on the friction between the yarns (pull out), the knife blade geometry and mainly the composition of the NNF which, in turn, is directly related to the nanoparticle and agent content of silane coupling present in the composition of the Non- Newtonian Fluid. Finally, this study also demonstrates that the use of statistical analysis promoted the improvement for obtaining and effectiveness of the behavior of lightweight impact protection textile structures
Study of the reuse potential of the sisal fibers powder as a particulate material in polymer composites
(Elsevier, 2019-09) Melo, Kátia Moreira de; Santos, Thiago Felix dos; Santos, Caroliny Minely da Silva; Fonseca, Rubens Tavares da; Lucena, Nestor Dantas de; Medeiros, José Ivan de; Aquino, Marcos Silva de
The present work studied the reuse of sisal fiber powder, contaminated by industrial oil, resulting from the activities of a Brazilian textile industry. With the objective of reusing the contaminated sisal fiber powder residue, harmful to the environment, this work evaluate the potential of the use this sisal powder as reinforcement in composites. Natural fibre reinforced polymer composites became more attractive structural materials due to their high specific strength, lightweight and biodegradability properties. The mechanical behaviour of polyester resin based natural polymeric composites, made by using experimental planning (granulometry of sisal powder, fiber content and with or without styrene). Thus, combination of analysis of variance (ANOVA), response surface methodology (RSM) and experimental methods allowed evaluated, analyzed and validated the mechanical properties. The results obted showed that the waste from the sisal industry exhibits potential application in reinforcing composite materials Thus, different values of mechanical properties can be obtained by different interactions of the entry variables. Thus, the condition that exhibited high results of mechanical behavior independent of the addition of styrene were the particle size and fiber content 1680m and 2.5%, respectively. Therefore, the best results were stress (0.59 MPa), strain (5.68%), tenacity (2.01 E-05 MJ/m3) and energy at break (14 J) for the composite reinforced with sisal powder
Seawater as an alternative to dye cotton fiber with reactive dyes
(SAGE Publications, 2020-11-11) Ferreira, Iêda Letícia de Souza; Medeiros, José Ivan de; Steffens, Fernanda; Oliveira, Fernando Ribeiro
The textile industry is a sector completely dependent on water for its full functioning; on the other hand, water represents a very high cost in the production process. The textile chemical processing area is mainly responsible for the large consumption of water. On the opposite side of this high consumption there is an evident water crisis world-wide. That fact has led to many problems to textile companies, mainly for the preparation, dyeing and printing sectors. This present work focuses on an ecologically friendly alternative for cellulosic fiber dyeing processes using seawater. Dyeing cotton fabrics with reactive dye in three primary colors (blue, yellow and red) was performed, and the results compared with processes using distilled water. Samples dyed with seawater exhibit good uniformity, intense color (color strength – K/S) and excellent washing and rubbing fastness properties compared to the conventional process. It was possible to observe also that the use of seawater did not affect the mechanical properties of the substrate. Thereby, it was verified that the use of seawater presents as a potential and important alternative to applications in the textile dyeing process

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