Tensile performance of braided composite rods for concrete reinforcement

The current work is concerned with the development of braided composite rods for civil engineering applications, namely for concrete internal reinforcement, as a steel substitute. The research study aims at understanding the tensile behaviour of composite rods reinforced by a textile structure – braided structure with core reinforcement. Seven types of braided composite rods were produced, varying the type of fibres used as a core reinforcement of a polyester braided structure. Eglass, carbon and HT polyethylene fibres were used in different combinations. The tensile properties of the braided reinforced composite rods were evaluated in order to identify the type(s) of fibre(s) to be used as core reinforcement. Results are compared to those of conventional materials used for concrete reinforcement, such as steel

Braided composite rods to reinforce concrete subjected to aggressive environments

The current work is concerned with the development of braided composite rods for civil engineering applications, namely for concrete internal reinforcement, as a steel substitute. The research study aims at understanding the tensile behaviour of composite rods reinforced by a textile structure – braided structure with core reinforcement. Seven types of braided composite rods were produced, varying the type of fibres used as a core reinforcement of a polyester braided structure. E-glass, carbon and HT polyethylene fibres were used in different combinations. The tensile properties of the braided reinforced composite rods were evaluated in order to identify the type(s) of fibre(s) to be used as core reinforcement. Results are compared to those of conventional materials used for concrete reinforcement, such as steel.Fundação para a Ciência e a Tecnologia (FCT) - projecto POCI/CTM/6086/2004, “Development of braided reinforced composite elements for concrete reinforcement and monitoring”

Hybrid composite rods for concrete reinforcement

The current work is concerned with the development of braided composite rods for civil engineering applications, namely for concrete internal reinforcement, as a steel substitute. The research study aims at understanding the tensile behaviour of composite rods reinforced by a textile structure – braided structure with core reinforcement.Seven types of braided composite rods were produced, varying the type of fibres used as a core reinforcement of a polyester braided structure. E-glass, carbon and HT polyethylene fibres were used in different combinations. The tensile properties of the braided reinforced composite rods were evaluated in order to identify the type(s) of fibre(s) to be used as core reinforcement. Results are compared to those of conventional materials used for concrete reinforcement, such as steel.This work is being funded by the FCT (Portugal) within the project POCI/CTM/6086/2004, Development of braided reinforced composite elements for concrete reinforcement and monitoring

Braided composite rods for civil construction applications

The use of fibre reinforced composite rods as concrete reinforcement material seems to be an effective solution to overcome durability problems of traditional steel reinforced concrete structures. The main advantages of fibre reinforced composite materials over steel include the excellent corrosive resistance, mechanical properties similar to steel, high strength-to-weight ratio and excellent fatigue resistance, among others [Alsayed et al, 2000], [Lees, J. M., 2001]. Typically, fibre reinforced composite rods are produced by pultrusion, although, besides this technique, composite rods can also be produced using braiding techniques [Kadioglu, F. & Pidaparti, R. M., 2005], [Saikia, B. et al, 2005]. Braiding is a low cost technique that allows in-plane multiaxial orientation, conformability, excellent damage tolerance and core reinforcement [Soebroto et al, 1990], the production of ribbed structures and a wide range of mechanical properties may be improved when the core braided fabrics are reinforced with the appropriate type of fibres [Fangueiro et al, 2004, 2005 & 2006]. The current research work deals with the development of braided reinforced composite rods for civil engineering applications, namely to reinforce concrete structures as a substitute of steel rebars. The mechanical properties of composite rods, produced by braiding, are influenced by the type of fibre used as braided fabric core reinforcement, among other parameters. The objective of this experimental work is to evaluate the influence of the type of core reinforcement fibres on the mechanical performance of braided reinforced composite rods. Several samples of braided reinforced composite rods were produced using polyester fibres, for the production of braided fabrics, E-glass, carbon and HT polyethylene fibres, as braided fabrics core reinforcement, and polyester resin as polymeric matrix. Braided reinforced composite rods were produced on a vertical braiding machine incorporating an impregnation system specially developed for this purpose. Different braided reinforced composite rods were produced maintaining the braided fabric structure and varying the type of core reinforcement fibre. Composite rods were reinforced with a single type of reinforcement fibres as well as with two and three types of fibres, varying the percentage of each type. In order to evaluate the volume fraction of the different braided reinforced composite rods produced, tests were performed according to the Portuguese Standard NP 2216/1988 (determination of mass loss by calcinations of glass fibre reinforced plastics).In order to evaluate the mechanical performance of the different braided reinforced composite rods produced, tensile tests were carried out according to ASTM D 3916-94 standard, with a crosshead speed of 5 mm/min. A post-load of 50KN was applied to the rods prior to performing the tensile tests. When compared to the steel rebars currently used in the construction industry, composite rods higher tensile strength. Current steel rebars, A235NL, A400NR/ER and A500NR/ER have values of tensile strength of 360 MPa, 460 MPa, and 550 MPa respectively. Composite rods present tensile strength higher than 550MPa. Even though the tensile strength braided reinforced composite rods is higher than that of steel rebars, composite rods have a lower modulus of elasticity when compared with the 210 GPa of steel rebars

Tensile properties of braided composite rods

The current work is concerning the development of braided reinforced composite rods for civil engineering applications, namely for concrete internal reinforcement. The research study aims to understand the mechanical behaviour of braided reinforced composite rods produced from an innovative technique. Seven types of braided reinforced composite rods were produced, varying the type of fibres used as a core reinforcement of a polyester braided fabric. E-glass, carbon, HT polyethylene fibres were used in different combinations. The mechanical properties of the braided reinforced composite rods were evaluated under tensile in order to identify the type(s) of fibre(s) to be used as core reinforcement. Results are compared to those of conventional materials used for concrete reinforcement, such as steel.(undefined

Evidence that the degree of obstructive sleep apnea may not increase myocardial ischemia and arrhythmias in patients with stable coronary artery disease

There is controversy regarding whether obstructive sleep apnea is responsible for triggering myocardial ischemia, arrhythmias and heart rate variability in patients with coronary artery disease. OBJETIVE: The objective of this study was to identify relationships between sleep apnea, myocardial ischemia and cardiac arrhythmia in patients with coronary artery disease. METHODS: Fifty-three patients with stable coronary disease underwent simultaneous polysomnography and electrocardiographic Holter recording. The apnea-hypopnea index (AHI) was defined as the number of apneas/hypopneas per hour of sleep. Patients were divided into a Control group (AHI15, n=23 pts) and an Apnea group (AHI>;15, n=30 pts). A subgroup of 13 patients with an AHI>;30 (Severe Apnea group) was also studied. We analyzed ischemic episodes (ST-segment depressions >;1 mm, >; 1 min), heart rate variability and the occurrence of arrhythmias during wakefulness and sleep. RESULTS: Baseline clinical characteristics among the groups were similar except for higher blood pressure in the Apnea groups (

Estimulação cognitiva e aprendizagem infantil: revisão de literatura / Cognitive stimulation and child learning: literature review

A cognição é uma função psicológica atuante na aquisição do conhecimento, é a maneira como o cérebro percebe, aprende, pensa e recorda determinado conhecimento que é captado pelos sentidos. Considerada aspecto fundamental para a aprendizagem infantil, sua estimulação traz efeitos benéficos para o desenvolvimento infantil. Este estudo tem como objetivo demonstrar a importância da estimulação cognitiva para a aprendizagem infantil. Trata-se de uma revisão narrativa de literatura, realizada no mês de julho de 2019, através do Portal de Aperfeiçoamento de Pessoal de Nível Superior (Capes). Foram empregados os descritores: Estimulação Cognitiva, Educação Infantil, Aprendizagem Infantil e Escola, foram encontrados 131 artigos sendo selecionados 6 para compor este estudo. Os resultados obtidos evidenciaram a importância da estimulação cognitiva para a aprendizagem infantil, bem como para o desenvolvimento global da criança e seus benefícios para o desempenho escolar. Foi possível observar que aspectos socioeconômicos e culturais, bem como o nível de escolaridade dos pais podem influenciar o desenvolvimento cognitivo da criança. a importância do educador como facilitador de intervenções e a necessidade de investimento em sua formação para que possa executá-las coerentemente de acordo com o nível de desenvolvimento de cada criança, respeitando sua idade e suas singularidades, além de atuar em conjunto com a família e com demais profissionais para que a criança possa se beneficiar de um desenvolvimento integral e com qualidade

Effect of hydrogel containing Achyrocline satureioides (Asteraceae) extract–loaded nanoemulsions on wound healing activity

Achyrocline satureioides (Lam.) DC extract–loaded nanoemulsions have demonstrated potential for wound healing, with promising effects on keratinocyte proliferation. We carried out the first in vivo investigation of the wound healing activity of a hydrogel containing A. satureioides extract– loaded nanoemulsions. We prepared hydrogels by adding the gelling agent (Carbopol® Ultrez) to extract-loaded nanoemulsions (~250 nm in diameter) obtained by spontaneous emulsification. The final flavonoid content in formulation was close to 1 mg/mL, as estimated by ultra-fast liquid chromatography. Permeation/retention studies using porcine ear skin showed that flavonoids reached deeper layers of pig ear skin when it was damaged (up to 3.2 g/cm2 in the dermis), but did not reach the Franz-type diffusion cell receptor fluid. For healing activity, we performed a dorsal wound model using Wistar rats, evaluating the lesion size, anti-inflammatory markers, oxidative damage, and histology. We found that extract-loaded formulations promoted wound healing by increasing angiogenesis by ~20%, reducing inflammation (tumor necrosis factor ) by ~35%, decreasing lipid damage, and improving the re-epithelialization process in lesions. In addition, there was an increase in the number of blood vessels and hair follicles for wounds treated with the formulation compared with the controls. Our findings indicate that the proposed formulation could be promising in the search for better quality healing and tissue reconstruction

ATLANTIC-PRIMATES: a dataset of communities and occurrences of primates in the Atlantic Forests of South America

Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1–6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km 2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km 2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the The Authors. Ecology © 2018 The Ecological Society of Americ