2,454 research outputs found
Finite element modeling and operational modal analysis of a historical masonry mosque
Finite Element Modeling (FEM) and Operational Modal Analysis (OMA) is herein presented for the historical masonry Kütahya Kurşunlu Mosque within the framework of its seismic performance assessment. The historical structure is located in Turkey which has a high-level seismic activity. A FEM strategy was adopted to construct a numerical model of the structure considering a simplified three-dimensional geometry and a macro-modeling approach for the masonry. A representative numerical model of the existing structure was calibrated and improved according to the OMA results obtained from ambient vibration measurements, performed in-situ. The ambient vibration measurements were operated by using two triaxial accelerometers, that one of the accelerometers was regulated as a reference station whereas the other accelerometer was relocated to seven different points on the top of the walls. Identification of the experimental modal parameters was achieved by performing two different signal processing methodologies, namely the Enhanced Frequency Domain Decomposition (EFDD) and the Stochastic Subspace Identification - Unweighted Principal Components (SSI-UPC). Results obtained from both methods were compared in terms of the Modal Assurance Criterion (MAC) which considers the mode shapes derived in a specific range of frequency. The SSI-UPC method was employed in achieving the experimental modal response of the structure and the results were compared with the eigenvalue analysis results of the preliminary numerical model. A calibration process was carried out in terms of minimizing the difference between the experimental and numerical modal response by a trial and error approach and an average error of 4.9% was calculated for the modal frequencies of the first four global modes of vibration
An early sex difference in the relation between mental rotation and object preference
Accumulating evidence suggests that males outperform females on mental rotation tasks as early as infancy. Sex differences in object preference have also been shown to emerge early in development and precede sex-typed play in childhood. Although research with adults and older children is suggestive of a relationship between play preferences and visuospatial abilities, including mental rotation, little is known about the developmental origins of this relationship. The present study compared mental rotation ability and object preference in 6- to 13-month-old infants. We used a novel paradigm to examine individual differences in infants’ mental rotation abilities as well as their differential preference for one of two sex-typed objects. A sex difference was found on both tasks, with boys showing an advantage in performance on the mental rotation task and exhibiting greater visual attention to the male-typed object (i.e., a toy truck) than to the female-typed object (i.e., a doll) in comparison to girls. Moreover, we found a relation between mental rotation and object preference that varied by sex. Greater visual interest in the male-typed object was related to greater mental rotation performance in boys, but not in girls. Possible explanations related to perceptual biases, prenatal androgen exposure, and experiential influences for this sex difference are discussed
Diversidade florística em quintais agroflorestais de agroecossistemas familiares da comunidade Nova Canaã, Rio Preto da Eva-AM.
Este trabalho teve por objetivo verificar a diversidade de espécies cultivadas em pomares caseiros de agroecossistemas, onde trabalhavam agricultores familiares da comunidade Vila Canaã
Charmonium Suppression by Comover Scattering in Pb+Pb Collisions
The first reports of and production from experiment NA50 at
the CERN SPS are compared to predictions based on a hadronic model of
charmonium suppression. Data on centrality dependence and total cross sections
are in good accord with these predictions.Comment: 9 pages, latex, 6 figures, epsf, figure added and text modified to
clarify result
Produção de leite de búfalas murrah e mediterrâneo em sistema silvipastoril, associado a pastejo rotacionado intensivo de Brachiaria humidicola e suplementação alimentar, na pequena propriedade da Amazônia Oriental.
Biochar/Zinc Oxide Composites as Effective Catalysts for Electrochemical CO2 Reduction
Novel electrocatalysts based on zinc oxide (ZnO) and biochars are prepared through a simple and scalable route and are proposed for the electrocatalytic reduction of CO2 (CO2RR). Materials with different weight ratios of ZnO to biochars, namely, pyrolyzed chitosan (CTO) and pyrolyzed brewed waste coffee (CBC), are synthesized and thoroughly characterized. The physicochemical properties of the materials are correlated with the CO2RR to CO performance in a comprehensive study. Both the type and weight percentage of biochar significantly influence the catalytic performance of the composite. CTO, which has pyridinic- and pyridone-N species in its structure, outperforms CBC as a carbon matrix for ZnO particles, as evidenced by a higher CO selectivity and an enhanced current density at the ZnO_CTO electrode under the same conditions. The study on various ZnO to CTO weight ratios shows that the composite with 40.6 wt % of biochar shows the best performance, with the CO selectivity peaked at 85.8% at -1.1 V versus the reversible hydrogen electrode (RHE) and a CO partial current density of 75.6 mA cm-2 at -1.3 V versus RHE. It also demonstrates good stability during the long-term CO2 electrolysis, showing high retention in both CO selectivity and electrode activity
Diversidade florística em quintais agroflorestais de quatro localidades, Parintins - Amazonas.
O objetivo deste trabalho foi verificar a diversidade das espécies em pomares caseiros no assentamento de Vila Amazônia
Selectivity for CO2 over CH4 on a functionalized periodic mesoporous phenylene-silica explained by transition state theory
Efficient separation of CO2/CH4 is critical in biogas upgrading, requiring highly selective adsorbents. Based on the adsorption energies of 0.30 and 0.14 eV, previously calculated by dispersion corrected density functional theory for adsorption/desorption of CO2 and CH4 on the functionalized periodic mesoporous phenylene-silica material APTMS@Ph-PMO, respectively, transition state theory rates were derived and used to simulate the adsorption/desorption rates of these two gases on APTMS@Ph-PMO. The latter yielded an estimation of initial CO2/CH4 selectivity at various temperatures. At T= 298 K, selectivity of 32.2 agrees to an experimental value of 26.1, which validates the method used for evaluating CO2/CH4 adsorption selectivities. 2017 Elsevier B.V. All rights reserved
Using pre-selected variants from large-scale whole-genome sequence data for single-step genomic predictions in pigs
Multi-line ssGBLUP evaluation using preselected markers from whole-genome sequence data in pigs
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