6,198 research outputs found

    ASSESSING STEEL STRAINS ON REINFORCED CONCRETE MEMBERS FROM SURFACE CRACKING PATTERNS

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    The measurement of steel strains in reinforced concrete structures is often critical to characterise stresses and forces along the member. In this scope, this manuscript describes the development of a method to assess steel strains inside concrete members using solely surface measurements. These measurements were obtained using photogrammetry and image processing. The technique was validated using two concrete ties monitored using strain gauges placed inside the steel bars. The experimental results showed that one of the most important parameters affecting the accuracy of the technique is the measurement of crack widths, whereas the concrete strain has little effect on the final results. The technique is particularly advantageous since it is non-contact and does not impact on the bond conditions. It also does not require accessing the reinforcements. As a main conclusion, this work showed the feasibility of estimating strains inside the structure. This will benefit in the near future from further improvements namely in what concerns camera resolutions.Australian Research Council Discovery Early Career Researcher Award (DE150101703); Faculty of Engineering & Information Technologies

    Hábitos Alimentares Durante a Gravidez em Mulheres com Parto Muito Pré-Termo: Uma Análise Exploradora

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    Introduction: Preterm birth is increasing worldwide, representing a major cause of death and long-term loss of human potential among survivors. Some morbidities during pregnancy are well-known risk factors for preterm labor, but it is not yet known whether deviations from adequate dietary patterns are associated with preterm delivery. Diet may be an important modulator of chronic inflammation, and pro-inflammatory diets during pregnancy were reported to be associated with preterm birth. The aim of this study was to assess the food consumption during pregnancy of Portuguese women giving birth very prematurely and the association between the food consumption and the major maternal morbidities during pregnancy related with preterm delivery. Material and methods: A single-center cross-sectional observational study including consecutive Portuguese women giving birth before 33 weeks of gestation was conducted. Recall of eating habits during pregnancy was obtained within the first week after delivery, using a semi quantitative food frequency questionnaire validated for Portuguese pregnant women. Results: Sixty women with a median age of 36.0 years were included. Of these, 35% were obese or overweight at the beginning of pregnancy, 41.7% and 25.0% gained excessive or insufficient weight during pregnancy, respectively. Pregnancy-induced hypertension was present in 21.7% of cases, gestational diabetes in 18.3%, chronic hypertension in 6.7%, and type 2 diabetes mellitus in 5.0%. Pregnancy-induced hypertension was significantly associated with increased daily consumption of pastry products (31.2 vs 10.0 g, p = 0.022), fast food (39.6 vs 29.7 g, p = 0.028), bread (90.0 vs 50.0 g, p = 0.005), pasta, rice and potatoes (225.7 vs 154.3 g, p = 0.012). In a multivariate analysis, only bread consumption maintained a significant, albeit weak, association (OR = 1.021; 1.003 - 1.038, p = 0.022). Conclusion: Pregnancy-induced hypertension was associated with increased consumption of pastry products, fast food, bread, pasta, rice, and potatoes, although only bread consumption had a weak but statistically significant association with pregnancy-induced hypertension in a multivariate analysis.info:eu-repo/semantics/publishedVersio

    Osmolality of Elemental and Semi-Elemental Formulas Supplemented with Nonprotein Energy Supplements

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    Elemental and semi-elemental formulas are used to feed infants with short bowel syndrome, who may not be able to tolerate feeds of more than 310 mOsm kg(-1). The present study aimed to measure the osmolality of elemental and semi-elemental formulas at different concentrations, with and without the addition of nonprotein energy supplements

    Avaliação do sistema radicular de Lima Ácida Tahiti em dois sistemas de manejo.

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    Para que as plantas cítricas tenham longevidade é necessário que o sistema radicular possa se desenvolver sem limitações. Rezende et al. (2002) registram o desenvolvimento prejudicado do sistema radicular de citros nos solos coesos dos Tabuleiros Costeiros, com as plantas geralmente exibindo sistema radicular superficial e enovelamento da raiz principal. A utilização de práticas de manejo de solo como, uso de coberturas vegetais e subsolagem, melhoram a morfologia da planta, uma melhor distribuição do sistema radicular permite explorar maior volume de solo para absorção de nutrientes e principalmente de água em profundidade. A produção citrícola nos Tabuleiros Costeiros, onde predominam Latossolos Amarelos e Argissolos Amarelos, caracterizados como profundos, ácidos e com presença de horizontes coesos (Jacomine et al., 1977), é realizada praticamente sem uso de irrigação, pois a região dispõe de uma distribuição de chuvas regular durante 9 a 10 meses/ano (CNPMF, 1993). Práticas culturais, como a utilização de leguminosas nas entrelinhas e herbicidas nas linhas, em áreas subsoladas a 0,50 m de profundidade, que foram capazes de aumentar o volume do sistema radicular dos citros neste ecossistema entre 68 e 148% e a produção de frutos entre 28 e 40%, respectivamente (Carvalho et al.,1999). O objetivo deste trabalho foi avaliar o sistema radicular da Lima Ácida Tahiti, verificando a capacidade das raízes de explorar o solo, comparando dois sistemas de cultivo.pdf 220

    Comparison of the C-mediating killing activity and C-activating properties of mouse monoclonal and polyclonal antibodies against Trypanosoma cruzi

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    A Mouse polyclonal antiserum against Trypanosoma cruzi or its IgG and IgM fractions and five monoclonal antibodies (two IgM, two IgG1 and one IgG2a) recognize and combine with membrane components of trypomastigote forms of the parasite as revealed by immunofluorescence. Although all these antibodies sensitize trypomastigotes and prepare them to activate the complement (C) system, as measured by consumption of total C, C4, B and C3, only the polyclonal antiserum or its IgG, IgM and Fabμ fragments were able to induce trypanosome lysis by the alternative C pathway

    Impurity-enhanced Aharonov-Bohm effect in neutral quantum-ring magnetoexcitons

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    We study the role of impurity scattering on the photoluminescence (PL) emission of polarized magnetoexcitons. We consider systems where both the electron and hole are confined on a ring structure (quantum rings) as well as on a type-II quantum dot. Despite their neutral character, excitons exhibit strong modulation of energy and oscillator strength in the presence of magnetic fields. Scattering impurities enhance the PL intensity on otherwise "dark" magnetic field windows and non-zero PL emission appears for a wide magnetic field range even at zero temperature. For higher temperatures, impurity-induced anticrossings on the excitonic spectrum lead to unexpected peaks and valleys on the PL intensity as function of magnetic field. Such behavior is absent on ideal systems and can account for prominent features in recent experimental results.Comment: 7 pages, 7 figures, RevTe
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