Glass waste powder addition used as mitigator of concrete alkali-silica reaction

The recycled aggregates from demolition of concrete structures affected by alkali silica reaction as well as the potentially reactive natural aggregates are often a matter of great concern and fear in case of new structures construction. Thus, to encourage the recycling and use of some potential reactive aggregates under scientific basis, this paper presents an experimental study where suspected alkali-silica reactive recycled aggregates was used. The main goal of this study is evaluate the influence of waste glass powder addition as mitigator of the concrete expansive reaction. In a first phase, the level of expansibility of different aggregates was identified using accelerated tests in mortars bars, method ASTM C1260 and an adapted accelerated test on specimens of 40 x 40 x 160 mm. In a second phase, tests were performed on concrete mixtures, according to CMBT method, with 100% recycled reactive coarse aggregates and powder addition, such as the glass powder and metakaolin. The powder additions percentages were incorporated at 20%, 40% and 60% of cement weight. The results of mortars bars test showed opposite results according to the method applied, i.e. , the same aggregates considered as harmless by the adapted method are considered reactive by the ASTM method, if the same expansion limit of 0,10% for 16 days was adopted for both methods. Finally, the concrete results obtained with CMBT method showed that glass powder and metakaolin had a significant mitigation effect in alkali-aggregate reaction development

Reinforced and prestressed concrete hollow beams under torsion

Recently a new rational theoretical model for beams under torsion has been proposed. This model, called Softened Membrane Model for Torsion (SMMT), is able to predict well the global behaviour of reinforced and prestressed concrete solid beams under torsion. This paper presents a study in order to check the SMMT for reinforced and prestressed concrete hollow beams under torsion. Theoretical predictions from SMMT are compared to some experimental results of hollow beams available in the literature and also with the predictions of another theoretical model previously proposed from the authors. It is shown that SMMT, with some corrections, is able to predict satisfactorily the overall behaviour of reinforced and prestressed concrete hollow beams under torsion

Quantification and source identification of atmospheric particulate polycyclic aromatic hydrocarbons and their dry deposition fluxes at three sites in Salvador Basin, Brazil, impacted by mobile and stationary sources

The present work has aimed to determine the 16 US EPA priority PAH atmospheric particulate matter levels present in three sites around Salvador, Bahia: (i) Lapa bus station, strongly impacted by heavy-duty diesel vehicles; (ii) Aratu harbor, impacted by an intense movement of goods, and (iii) Bananeira village on Maré Island, a non vehicle-influenced site with activities such as handcraft work and fisheries. Results indicated that BbF (0.130-6.85 ng m-3) is the PAH with highest concentration in samples from Aratu harbor and Bananeira and CRY (0.075-6.85 ng m-3) presented higher concentrations at Lapa station. PAH sources from studied sites were mainly of anthropogenic origin such as gasoline-fueled light-duty vehicles and diesel-fueled heavy-duty vehicles, discharges in the port, diesel burning from ships, dust ressuspension, indoor soot from cooking, and coal and wood combustion for energy production.O presente trabalho apresenta o estudo sobre 16 HPAs prioritários em material particulado atmosférico de três sítios próximos a Salvador-BA: (i) Estação da Lapa, estação de ônibus da Região Metropolitana de Salvador; (ii) Porto de Aratu, impactado por intenso movimento de matérias-primas e (iii) Bananeira, localizado na Ilha de Maré, vilarejo que tem como principais atividades a pesca e artesanato. Resultados mostraram que o BbF (0,130-6,85 ng m-3) foi o HPA com as concentrações mais elevadas em Aratu e Bananeira e CRY (0,075-6,85 ng m-3) apresentou nível mais elevado na Lapa. As fontes de HPAs nos sítios estudados foram principalmente de origem antrópica, tais como veículos de pequeno e grande portes, carregamentos do porto, ressuspensão de partículas do solo, queima de diesel das embarcações e a queima de carvão e madeira para produção de energia.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FINEPFAPESBPRONEXRECOMBIONordeste GenerationANEELFAPES

Influence of cavosurface angle on the stress concentration and gaps formation in class V resin composite restorations

The study aimed to evaluate the influence of cavosurface angle on stress concentration and gap formation in class V restorations. Cylindrical cavities 3 mm in diameter were prepared in forty-five bovine incisors, changing only the angle of the bur in relation to the flat surface of the tooth. The cavities maintained the same volume (17.67 mm³). The samples were divided according to the cavosurface angle, into three groups (n = 15): 90°, 120°, 135°. After adhesive application (Futurabond U, VOCO), the cavity was filled with bulk placement of a resin composite (GrandioSO, VOCO). The teeth were analyzed with stereomicroscopy. Data of marginal gap formation were statistically analyzed with a one-way analysis of variance (ANOVA) followed by Tukey tests (significance level: α = 0.05). Finite element analysis (FEA) was used to study residual stress in these geometries and to correlate those stresses with experimentally measured gap formation. The elastic modulus and polymerization shrinkage were determined for FEA. Residual shrinkage stresses were expressed in maximum principal stress (MPS). There was a significant difference in the gap formation among the groups (p = 0.001). A significantly lower marginal gap formation was found for 120° and 135° angles, with no significant difference between them. The cavosurface angle at 90° caused substantially higher stresses, in the restoration interface, with greater marginal gap. For the 120° and 135° angles, the stress concentrations were smaller and were located in the dental structure. The cavosurface angle influenced the marginal gap formation and stress concentration

Rapid determination of flavonoids and phenolic acids in grape juices and wines by RP-HPLC/DAD: Method validation and characterization of commercial products of the new Brazilian varieties of grape.

A method for rapid determination of phenolic compounds by reversed-phase high-performance liquid chromatography (RP-HPLC), using a new column of faster resolution was validated and used to characterize commercial products produced with new grape Brazilian varieties of Northeast of Brazil. The in vitro antioxidant activity was also measured. The method showed linearity (R > 0.9995), good precision (CV% < 2.78), recovery (91.8?105.1%) and limits of detection (0.04?0.85 mg L-1 ) and quantification (0.04?1.41 mg L-1 ) according to other methods previously published with the difference of a run time of only 25 min. The results obtained in the characterization of the samples differed for juices and wines from other world regions, mainly because of the high values of (-)-epigallocatechin and trans-caftaric acid. The products analyzed showed high antioxidant activity, especially the wine samples with values higher than those from wines of different regions of the worl

Study of efficiency time of recombinant DNA insulin via accelerated life testing and interval censoring.

This paper aims to study the efficiency of recombinant DNA insulin via models for accelerated life tests. The potency loss of these insulin products was evaluated periodically, subject to the conditions of temperature of 8?C, 25?C and 37?C. Insulin samples with potency at less than 100% were considered unfit for consumption, which characterizes the event of interest. Samples suitable for consumption were considered to be censored. The response variable was observed periodically for 736 days. For data analysis, statistical models of stress-response regression were used. The deterministic part of these models is the Arrhenius model because the stress variable is the temperature, while the probabilistic part was comprised of the Exponential, Weibull, and Log-normal models. The techniques of accelerated life tests proved adequate to address the time of potency loss of the insulin for the various temperature levels. The times of occurrence of the events were treated in three different ways, which were compared in this study. First, interval censoring was considered, or only the upper and lower limits of the interval in which the failure occurred were known. Then, the midpoint of this interval was considered as a failure time. Finally, only the lower limit of the interval in which the failure occurred was considered. According to the results, it is concluded that the use of the interval lower limit is more appropriate for estimating the reliability curves, as the estimates are closer to those using interval censoring then using the midpoint of the interval. For the specific case of the recombinant DNA insulin data, it was observed that the Arrhenius-Weibull model and the Arrhenius-lognormal are suitable for adjusting the data. It follows also that the temperature affects the power of the insulin: The higher the temperature are, the lesser the efficiency

The consequences of growth hormone-releasing hormone receptor haploinsufficiency for bone quality and insulin resistance

Objective Growth hormone (GH)/insulin-like growth factor (IGF) axis and insulin are key determinants of bone remodelling. Homozygous mutations in the GH-releasing hormone receptor (GHRHR) gene (GHRHR) are a frequent cause of genetic isolated GH deficiency (IGHD). Heterozygosity for GHRHR mutation causes changes in body composition and possibly an increase in insulin sensitivity, but its effects on bone quality are still unknown. The objective of this study was to assess the bone quality and metabolism and its correlation with insulin sensitivity in subjects heterozygous for a null mutation in the GHRHR. Patients and methods A cross-sectional study was performed on 76 normal subjects (68.4% females) (N/N) and 64 individuals (64.1% females) heterozygous for a mutation in the GHRHR (MUT/N). Anthropometric features, quantitative ultrasound (QUS) of the heel, bone markers [osteocalcin (OC) and CrossLaps], IGF-I, glucose and insulin were measured, and homeostasis model assessment of insulin resistance (HOMAIR) was calculated. Results There were no differences in age or height between the two groups, but weight (P = 0.007) and BMI (P = 0.001) were lower in MUT/N. There were no differences in serum levels of IGF-I, glucose, T-score or absolute values of stiffness and OC, but insulin (P = 0.01), HOMAIR (P = 0.01) and CrossLaps (P = 0.01) were lower in MUT/N. There was no correlation between OC and glucose, OC and HOMAIR in the 140 individuals as a whole or in the separate MUT/N or N/N groups. Conclusions This study suggests that one allele mutation in the GHRHR gene has a greater impact on energy metabolism than on bone quality.NIH, National Institutes of Health USA [1 R01 DK065718]FAPITEC/SE, BrazilCAPESFAEP

Vulnerability of Brazilian municipalities to hantavirus infections based on multi‑criteria decision analysis

Background: Hantavirus infection is an emerging zoonosis transmitted by wild rodents. In Brazil, high case-fatality rates among humans infected with hantavirus are of serious concern to public health authorities. Appropriate preventive measures partly depend on reliable knowledge about the geographical distribution of this disease. Methods: Incidence of hantavirus infections in Brazil (1993–2013) was analyzed. Epidemiological, socioeconomic, and demographic indicators were also used to classify cities’ vulnerability to disease by means of multi-criteria decision analysis (MCDA). Results: From 1993 to 2013, 1752 cases of hantavirus were registered in 16 Brazilian states. The highest incidence of hantavirus was observed in the states of Mato Grosso (0.57/100,000) and Santa Catarina (0.13/100,000). Based on MCDA analysis, municipalities in the southern, southeastern, and midwestern regions of Brazil can be classified as highly vulnerable. Most municipalities in northern and northeastern Brazil were classified as having low vulnerability to hantavirus cardiopulmonary syndrome. Conclusions: Although most human infections by hantavirus registered in Brazil occurred in the southern region of the country, a greater vulnerability to hantavirus was found in the Brazilian Midwest. This result reflects the need to strengthen surveillance where the disease has thus far gone unreported

Ordenamento do Território e Planeamento Ambiental : investigação e prática

A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.O CIGPT fundado pelos Geógrafos Helena Calado e João Porteiro desenvolveu nas duas últimas décadas um esforço considerável na investigação e prática do Ordenamento Territoria