4,099 research outputs found

    Are Muslims the New Catholics? Europe’s Headscarf Laws in Comparative Historical Perspective

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    In this paper a biologically-inspired model for partly occluded patterns is proposed. The model is based on the hypothesis that in human visual system occluding patterns play a key role in recognition as well as in reconstructing internal representation for a pattern’s occluding parts. The proposed model is realized with a bidirectional hierarchical neural network. In this network top-down cues, generated by direct connections from the lower to higher levels of hierarchy, interact with the bottom-up information, generated from the un-occluded parts, to recognize occluded patterns. Moreover, positional cues of the occluded as well as occluding patterns, that are computed separately but in the same network, modulate the top-down and bottom-up processing to reconstruct the occluded patterns. Simulation results support the presented hypothesis as well as effectiveness of the model in providing a solution to recognition of occluded patterns. The behavior of the model is in accordance to the known human behavior on the occluded patterns

    The Apology: An Introduction to the Dynamics of the Moral Life

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    In this article I propose to reflect upon four themes that seemingly underpinned Socrates moral enterprise as adumbrated in the context of his trial: (1) ethical naturalism; (2) the moral life as a response to a divine call; (3) the social context of the moral life; and (4) the role of critical thinking in the moral life. This was developed at the time of the Sophists who espoused moral relativism, denying any basis for absolute moral standards. And their scepticism led them to adopt an atheistic attitude. Socrates, in contrast, recognized the importance of a societal context for the unfolding of the moral life. He engaged in a relentless pursuit of the good. And, finally, he was open to the operation of transcendence in his life

    Gap solitons in spatiotemporal photonic crystals

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    We generalize the concept of nonlinear periodic structures to systems that show arbitrary spacetime variations of the refractive index. Nonlinear pulse propagation through these spatiotemporal photonic crystals can be described, for shallow nonstationary gratings, by coupled mode equations which are a generalization of the traditional equations used for stationary photonic crystals. Novel gap soliton solutions are found by solving a modified massive Thirring model. They represent the missing link between the gap solitons in static photonic crystals and resonance solitons found in dynamic gratings.Comment: 3 figures, submitte

    Evaluation of Multiple Corrosion Protection Systems for Reinforced Concrete Bridge Decks

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    The performance of corrosion protection systems for reinforcing steel in concrete is evaluated. In addition to conventional and conventional epoxy-coated reinforcement, the corrosion protection systems tested include epoxy coatings with improved adhesion to the underlying steel, conventional and conventional epoxy-coated reinforcement used in conjunction with concrete containing one of three corrosion inhibitors, DCI-S, Rheocrete 222+, or Hycrete, epoxy-coated reinforcement with a microencapsulated calcium nitrite primer, multiple-coated reinforcement with a layer of zinc between the epoxy and steel, and pickled 2205 duplex stainless steel. The systems are evaluated using bench-scale and field tests. Two bridges in Kansas, cast with 2205 stainless steel, are monitored using corrosion potential mapping. Epoxy-coated and multiple-coated bars are evaluated to determine the effect of corrosion loss and time on the disbondment of the epoxy coating. Conventional, galvanized, and epoxy-coated reinforcement are evaluated using impressed current to determine the corrosion loss required to crack concrete for each system. A finite element model is developed to represent general and localized corrosion, and the results are used to develop a relationship between concrete cover, bar diameter, and area of bar corroding, and the corrosion loss required to crack concrete. An analysis of pore solutions expressed from cement pastes containing corrosion inhibitors is performed, with pH and selected ion concentrations measured from solutions collected one and seven days after casting. The results obtained from bench-scale and field test specimens are used to estimate cost effectiveness for each system under a 75-year service life. The results show epoxy coatings significantly reduce the corrosion rate compared to conventional reinforcement. Corrosion inhibitors significantly reduce corrosion rates in uncracked concrete. In cracked concrete, corrosion inhibitors also reduce corrosion rates, but their relative effectiveness is reduced. Specimens containing Hycrete exhibit the lowest corrosion rates; however, field specimens containing Hycrete also show signs of scaling. Epoxies with improved adhesion exhibit no improvement over conventional epoxy-coated reinforcement in terms of corrosion rate or disbondment of the epoxy coating. Multiple-coated iv reinforcement exhibits significantly less disbondment than epoxy-coated reinforcement. Pickled 2205 reinforcement exhibits the least corrosion among all systems tested. Testing of conventional and galvanized reinforcement indicates galvanized reinforcement requires more than twice as much corrosion loss to crack the surrounding concrete compared to conventional reinforcement. An analysis of pore solution extracted from cement pastes containing inhibitors indicates an elevated sulfate content in pore solution collected from specimens containing Hycrete. Increased sulfate levels may explain the reduced strength and critical chloride corrosion threshold observed in concrete containing Hycrete. Elevated sulfate levels are also observed in pore solutions collected 7 days after casting from cement paste containing Rheocrete. An economic analysis of a 0.216-m (8.5-in.) thick bridge deck over a 75-year design life indicates that corrosion protection systems using either coated or stainless steel reinforcement are significantly more cost-effective than any of the systems containing conventional reinforcement

    Multiple Corrosion Protection Systems for Reinforced Concrete Bridge Components

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    the rapid macrocell, Southern Exposure, cracked beam, and linear polarization resistance tests. The systems include bars that are pretreated with zinc chromate to improve the adhesion between the epoxy and the reinforcing steel; two epoxies with improved adhesion to the reinforcing steel; one inorganic corrosion inhibitor, calcium nitrite; two organic corrosion inhibitors; an epoxy-coated bar with a primer containing microencapsulated calcium nitrite; the three epoxy-coated bars with improved adhesion combined with the corrosion inhibitor calcium nitrite; and multiple coated bars with an initial 50-μm (2-mil) coating of 98 percent zinc and 2 percent aluminum followed by a conventional epoxy-coating. The systems are compared with conventional uncoated reinforcement and conventional epoxy-coated reinforcement. The results presented in this report represent the findings obtained during the first half of a 5-year study that includes longer-term ASTM G 109 and field tests. In the short-term tests used to date, the epoxy-coatings evaluated provide superior corrosion protection to the reinforcing steel. The results also indicate that the bars will continue to perform well in the longer term, although the tests do not evaluate the effects of long-term reductions in the bond between the epoxy and the reinforcing steel. The corrosion rate on the exposed regions of damaged epoxy-coated reinforcement is somewhat higher than the average corrosion rate on the surface of uncoated reinforcement subjected to similar exposure conditions. The use of concrete with a reduced water-cement ratio improves the corrosion performance of both conventional and epoxy-coated reinforcement in uncracked concrete but has little effect in cracked concrete. Increased adhesion between the epoxy and reinforcing steel provides no significant improvement in the corrosion resistance of epoxy-coated reinforcement. It appears that corrosion inhibitors in concrete and the primer coating containing microencapsulated calcium nitrite improve the corrosion resistance of the epoxy-coated steel in uncracked concrete, but not in cracked concrete. The zinc coating on the multiple coated bars acts as a sacrificial barrier and provides some corrosion protection to the underlying steel in both uncracked and cracked concrete. The degree of protection, however, cannot be evaluated based on the results available to date

    Highly conductive Sb-doped layers in strained Si

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    The ability to create stable, highly conductive ultrashallow doped regions is a key requirement for future silicon-based devices. It is shown that biaxial tensile strain reduces the sheet resistance of highly doped n-type layers created by Sb or As implantation. The improvement is stronger with Sb, leading to a reversal in the relative doping efficiency of these n-type impurities. For Sb, the primary effect is a strong enhancement of activation as a function of tensile strain. At low processing temperatures, 0.7% strain more than doubles Sb activation, while enabling the formation of stable, ~10-nm-deep junctions. This makes Sb an interesting alternative to As for ultrashallow junctions in strain-engineered complementary metal-oxide-semiconductor device

    Divergence-time estimates for hominins provide insight into encephalization and body mass trends in human evolution

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    Quantifying speciation times during human evolution is fundamental as it provides a timescale to test for the correlation between key evolutionary transitions and extrinsic factors such as climatic or environmental change. Here, we applied a total evidence dating approach to a hominin phylogeny to estimate divergence times under different topological hypotheses. The time-scaled phylogenies were subsequently used to perform ancestral state reconstructions of body mass and phylogenetic encephalization quotient (PEQ). Our divergence-time estimates are consistent with other recent studies that analysed extant species. We show that the origin of the genus Homo probably occurred between 4.30 and 2.56 million years ago. The ancestral state reconstructions show a general trend towards a smaller body mass before the emergence of Homo, followed by a trend towards a greater body mass. PEQ estimations display a general trend of gradual but accelerating encephalization evolution. The obtained results provide a rigorous temporal framework for human evolution

    Marriage, religion and human flourishing: how sustainable is the classic Durkheim thesis in contemporary Europe?

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    This paper draws on the three waves of the European Values Survey across five countries (Great Britain, Italy, the Netherlands, Northern Ireland, Spain and Sweden) to investigate the relationship between indicators of positive psychology (conceptualised as feelings of happiness and satisfaction with life), religiosity (conceptualised as self-assigned religious affiliation and self-reported religious attendance) and marital status. The results demonstrate that religiosity is, in general, positively correlated with both indicators of positive psychology. Further, across all waves and all countries, the pattern emerges that those respondents who are married are likely to report higher levels of happiness and greater satisfaction in life. These data provide contemporary support for the classic Durkheim thesis linking the two institutions of marriage and religion with human flourishing
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