Rational approach for the analysis of segmental reinforced soil walls based on kinematic constraints

The paper presents an analytical method for the solution of reinforced soil walls in which the wall facing has a structural role. The three-component (soil–reinforcement–wall) system is statically indeterminate, and hence cannot be solved by equilibrium equations alone. The paper follows up on the work of Baker and Klein [2004. An integrated limiting equilibrium approach for design of reinforced soil retaining structures part I – formulation. Geotextiles and Geomembranes 22, 119–150] where an interaction model, incorporating factors that divide forces between the reinforcement layers and the wall, was introduced to solve the statically indeterminate system. In the current work, the division factors are resolved such that the kinematic constraints of compatibility between the reinforcement layers and the wall are satisfied. This is achieved by solving an optimization problem in which the objective function includes the relative displacement between the reinforcement layers and the wall. The resultant system is fully coupled whereby upper reinforcement layers are affected by the behavior of lower layers. As such, the method overcomes the limitation of the original framework in which the top-down procedure omits such coupling. A non-dimensional parametric study was conducted on walls with 10 face blocks (9 reinforcement layers). Results are given in a normalized manner for cases in which the reinforcement pullout stiffness is uniform and linearly increasing with depth. Analysis results show that in cases where the wall is relatively stiff compared to the reinforcement, the upper reinforcement layers are clearly affected by the lower layers (this is a direct outcome of the fully coupled system). On the other hand, when the relative stiffness of the wall is low, the system behavior tends towards that of a hinged system, which is statically determinate. In this case the solution becomes independent of the reinforcement pullout stiffness. Analysis results indicate that current design codes, which do not explicitly consider the structural role of the facing in the calculation procedure, may be overconservative in certain cases. This result supports the argument for introducing the structural role of the facing into design procedures.     

The attentional white bear phenomenon: The mandatory allocation of attention to expected distractor locations.

The authors devised a prestimulus-probe method to assess the allocation of attention as a function of participants' top-down expectancies concerning distractor and target locations. Participants performed the flanker task, and distractor locations remained fixed. On some trials, instead of the flanker display, either 2 simultaneous dots or a horizontal line appeared. The dot in the expected distractor location was perceived to occur before the dot in the expected empty location, and the line appeared to extend from the expected distractor location to the expected empty location, suggesting that attention is allocated to expected distractor locations prior to stimulus onset. The authors propose that a process-all mechanism guides attention to expected locations of all stimuli regardless of task demands and that this constitutes a major cause for failures of selective attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fabrication and Characterization of Three‐Dimensional Silver‐Coated Polymeric Microstructures

A method is reported for fabricating complex 3D silver‐coated polymeric microstructures. The approach is based on the creation of a crosslinked polymeric microscaffold via patterned multiphoton‐initiated polymerization followed by surface‐nucleated electroless deposition of silver. The conductivity and reflectivity of the resulting silver–polymer composites and the nanoscale morphology of the deposited silver are characterized. Sub‐micrometer thick layers of silver can be controllably deposited onto surfaces, including those of 3D microporous forms without occluding the interior of the structure. The approach is general for silver coating crosslinked polymeric structures based on acrylate, methacrylate, and epoxide resins and provides a new path to complex 3D micrometer‐scale devices with electronic, photonic, and electromechanical function.     

Transient flow in response to a pressure pulse in gas chromatography

The analysis of flow through a gas chromatography column has traditionally assumed the presence of steady-state conditions. However, when rapid changes in inlet pressure are introduced, a significant transient period is observed, leading to a failure of the steady-state model. Through the introduction of a one-dimensional continuity equation into the basic set of equations, a nonlinear partial differential equation is derived to describe the evolution of pressure profiles in a capillary gas chromatography column. A numerical solution is used to solve the differential equation for the case of a pulse injection under isothermal conditions, and comparisons with experimental holdup and retention times show very good agreement.     

The teacher's pet phenomenon: Rate of occurrence, correlates, and psychological costs.

The teacher's pet phenomenon was investigated in 80 5th-grade Israeli classrooms. Pets were identified through students' sociometric nominations in 80% of the classrooms: exclusive pets in 26% and unexclusive pets in 54% of the classrooms. Pets tended to be girls rather than boys, of Ashkenazi rather than Sephardi origin, very good (but not necessarily the best) students academically, and perceived as charming, socially skilled, and compliant. Teachers who had pets were found to hold somewhat more authoritarian attitudes than teachers who did not have pets, and the rate of occurrence of the pet phenomenon was higher in religious than in secular schools. Students' affective reactions to their teachers were more positive in classrooms without pets, and most negative in exclusive-pet classrooms. Potential favoritism in assigning teacher grades to exclusive pets was also investigated: No overall favoritism was found, but a trace of favoritism by more authoritarian teachers was discovered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correction to: The Implications of Post-Fire Physical Features of Cylindrical 18650 Lithium-Ion Battery Cells

Fire Technology - The original publication of the article unfortunately contained a mistake in Figure 2c.     

Nutritional Value of Seven Freshwater Fish Species From the Brazilian Pantanal

This study determined the proximate composition and fatty acid profile of the lipid fraction in muscle tissue (fillet) of seven fish species from the Miranda River, Brazil. Total lipid content had the largest coefficient of variation among species (73%), while protein content had the smallest (4.5%), allowing Pimelodus argenteus (mandi-prateado) to be categorized as lean fish; Pimelodus maculatus (mandi-amarelo), Hemisorubim platyrhynchos (jurupoca), and Pinirampus pirinampu (barbado) as species with medium fat content, and Paulicea luetkeni (jaú) and Surubim lima (jurupensém) as fatty fish. In all the species investigated, palmitic acid (23.76–25.99%) was the predominant saturated fatty acid. Oleic acid (16.09–32.90%) was the most abundant monounsaturated fatty acid. Total omega-6 polyunsaturated fatty acids (5.99–15.56%) were the predominant polyunsaturated fatty acids, except in Ageneiosus brevifilis (palmito), in which total omega-3 polyunsaturated fatty acids predominated (10.30%). All the species had favorable indices of nutritional quality for total lipids, with respect to human consumption.     

Leading by example: The case of leader OCB.

The importance of leading by personal example or role modeling for effective leadership has been recognized in many leadership theories. However, leaders' ability to influence group behavior through exemplary behavior has received little attention in empirical work. This study explores leading by example through theoretical development and empirical testing of a moderated mediation model of the potential effects of leader organizational citizenship behavior (OCB). This model suggests that a leader's OCB may promote group OCB directly and indirectly by enhancing the group's belief that OCB is worthy. It also specifies the moderators of the direct and indirect effects of leader OCB on group OCB. Data from 683 members of 67 intact work groups, 67 group managers, and their supervisors support the hypothesized model. The theoretical and practical implications of these findings are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)