843 research outputs found
Numerical validation of compressive strength prediction for hollow concrete blocks
The results of a numerical modeling program to evaluate the behavior of hollow concrete blocks under
uniaxial compression are addressed. It has been considered appropriate to use interface elements to
represent the confinement effect at the top and bottom of blocks. The response of the numerical
simulations is compared with experimental data of masonry units. Laboratory tests were carried out
utilizing standard flat platens and brush platens to evaluate the confinement effect due block
geometry. The elastic and inelastic parameters compressive strength, tensile strength, stress-strain
relationships and fracture energy were acquired from concrete samples that constitute the blocks.
The results from the theoretical analysis are discussed with respect to the ability to reproduce the
experimental tests. Good agreement between experimental and numerical results was found for the
peak load
Triaxial compression tests on bedding mortar samples looking at confinement effect analysis
This paper presents an analysis of the mechanical behavior of bedding mortar samples under
triaxial compression tests. When masonry is subjected to vertical loads, mechanical
interactions between blocks and bedding mortar at the joints induce lateral tension and
compression stresses. Thus, the mortar layer is submitted to a triaxial stress state that
modifies its mechanical properties and behavior under confinement effects. This
phenomenon may affect the failure mode of masonry and almost no information about this
subject is found in literature. Here, test procedures are detailed and results are discussed. In
addition to the compressive strength test results, also elastic modulus and Poisson ratio
values are addressed. Significant differences were observed among triaxial and uniaxial
standard test results. The obtained mortar behavior under different levels of lateral pressure
is compared with test results done by other researchers in order to produce relevant
conclusions for different mortar compositions.SĂŁo Paulo State Research Support
Foundation (FAPESP)Brazilian Research Support Foundation (CAPES
Superfluid phase transition and strong-coupling effects in an ultracold Fermi gas with mass imbalance
We investigate the superfluid phase transition and effects of mass imbalance
in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation)
crossover regime of an cold Fermi gas. We point out that the Gaussian
fluctuation theory developed by Nozi\`eres and Schmitt-Rink and the -matrix
theory, that are now widely used to study strong-coupling physics of cold Fermi
gases, give unphysical results in the presence of mass imbalance. To overcome
this problem, we extend the -matrix theory to include higher-order pairing
fluctuations. Using this, we examine how the mass imbalance affects the
superfluid phase transition. Since the mass imbalance is an important key in
various Fermi superfluids, such as K-Li Fermi gas mixture, exciton
condensate, and color superconductivity in a dense quark matter, our results
would be useful for the study of these recently developing superfluid systems.Comment: 7 pages, 4 figures, Proceedings of QFS-201
Rmi1 stimulates decatenation of double Holliday junctions during dissolution by Sgs1-Top3
double Holliday junction (dHJ) is a central intermediate of homologous recombination that can be processed to yield crossover or non-crossover recombination products. To preserve genomic integrity, cells possess mechanisms to avoid crossing over. We show that Saccharomyces cerevisiae Sgs1 and Top3 proteins are sufficient to migrate and disentangle a dHJ to produce exclusively non-crossover recombination products, in a reaction termed "dissolution." We show that Rmi1 stimulates dHJ dissolution at low Sgs1-Top3 protein concentrations, although it has no effect on the initial rate of Holliday junction (HJ) migration. Rmi1 serves to stimulate DNA decatenation, removing the last linkages between the repaired and template DNA molecules. Dissolution of a dHJ is a highly efficient and concerted alternative to nucleolytic resolution that prevents crossing over of chromosomes during recombinational DNA repair in mitotic cells and thereby contributes to genomic integrity
Anthropomorphizing brands: The role of attributed brand traits in interactive CSR communication and consumer online endorsements
Consumers tend to relate to brands in similar ways as they relate to individuals and groups. However, relatively little is known about the attribution of human traits to brands in online contexts. The current research focused on the role of attributed brand traits in interactive corporate social responsibility (CSR) communication and positive electronic wordâofâmouth intentions. Results of an online survey (N = 174) revealed that higher levels of perceived interactivity were associated with stronger attributions of morality, sociability, and competence traits to brands. Yet only attributed brand morality was associated with consumers' willingness to endorse the brand and its CSR message on social networking sites. These findings underline the importance of brands' openness to dialogue regarding the pr
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