Bridging the research traditions of task/ego involvement and intrinsic/extrinsic motivation: Comment on Butler (1987).

In an experiment on the effects of different feedback conditions on motivationally relevant variables, R. Butler (see record 1988-21628-001) tested the hypothesis that the effects of feedback on intrinsic motivation would depend on whether that feedback promotes a task-involving or ego-involving orientation. She interpreted the findings as they relate to J. G. Nicholls's (see record 1984-28719-001) theory of task/ego involvement and our cognitive evaluation theory (E. L. Deci and R. M. Ryan, 1985). Although the data were very interesting, Butler failed to review a series of highly relevant studies, she misportrayed cognitive evaluation theory, and she drew conclusions that were not necessarily warranted given her experimental manipulations and data. This article provides a commentary on that research and presents a discussion of the relation between the two theories that Butler claimed to have tested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NMR Line Shape-Spin-Lattice Relaxation Correlation Study of Portland Cement Hydration

The proton free induction decay of a portland cement paste in an advanced stage of hydration can be roughly divided into three main components: (1) a component with a very short spin-spin relaxation time, T², representing the protons of the solid OH groups and the water of crystallization, (2) a component with an intermediate T, representing the bonded water in the gel phase, and (3) a third component with a relatively long T² representing the water in the micropores and layers. The dependences of the intensities, T²'s, and spin-lattice relaxation times (T¹'s) of these three components on the cement hardening time have been determined. The proton spin-lattice relaxation time of the "solid" component increases with hardening time whereas T¹ decreases for the other two components. The observed time dependence of the diffusion coefficient, D, of water in a tricalcium silicate paste supports the findings of the above correlation study.     

Critical Review of the Thermophysical Properties of Fast-Reactor Fuel

This paper identifies the fuel properties for which more data are needed for fast-reactor safety analysis. In addition, a brief review is given of current research on the vapor pressure over liquid UO₂ and (U, Pu)O_2-x the solid-solid phase transition in actinide oxides, and the thermal conductivity of molten urania.     

Fractoemission from Lead Zirconate-Titanate

We present measurements of the electron, positive ion, and photon emission accompanying the fracture in vacuum of poly-crystalline 95/5 lead zirconate-titanate. The intensities of the charged-particle components of this fractoemission are shown to depend strongly on the direction (relative to the direction of fracture) and magnitude of polarization. The most intense emission is observed when the fracture surfaces are perpendicular to the polarization direction. The emission intensity increases monotonically with polarization. These results are interpreted in terms of a model involving charge separation on the fracture surfaces leading to a microdischarge during fracture. Implications to the interpretation of triboluminesence effects are discussed.     

Hydrodynamic loadings due to the motion of large offshore structures

A very effective non-reflecting boundary condition is proposed for the three-dimensional finite element analysis of hydrodynamic loads on offshore structures under motion due to earthquake, waves or machinery forces. The effect of surface waves is considered and the analysis is conducted in the frequency domain. The structure is assumed to be sufficiently large such that the non-linear effect of drag force is negligible. The unbounded extent of water surrounding the structure is assumed to be incompressible. The boundary condition, which is derived for the general analysis of structure-water interaction, is found to depend on the frequency of excitation, the location of the truncation boundary and the depth of water in the far field. Through some simplified numerical examples, it is shown that the proposed technique is very efficient for a wide range of the frequency of excitation. Incorporation of the boundary condition into a finite element program requires practically no extra effort.     

Conversion of acrylonitrile-based precursors to carbon fibres

The progress of stabilization of two compositions of acrylic fibres with various orientations has been followed by a variety of techniques. The thermooxidative treatments for stabilization have been carried out in a continuous process and also in a batch process under free shrinkage, constant length and constant tension conditions. The morphological model of acrylic fibres consists of an alternating sequence of laterally ordered and laterally disordered regions along the fibre direction. This structure is consistent with the observations based on small-angle X-ray scattering of copper- impregnated precursor fibres and thermomechanical response, thermal stress development, calorimetry, wide- and small-angle X-ray scattering and sonic modu-lus measured at different extents of stabilization. Lateral as well as orientational order in these fibres can be increased markedly through a high-temperature deformation process prior to stabilization. An increase in perfection and extent of order is observed in the early stages of stabilization. There is also a simultaneous decrease in the orientation of the disordered phase at this stage and the extent of this decrease depends on the axial constraints imposed on the fibre. Little difference in the rate of stabilization is observed as measured by density or oxygen uptake for fibres with different extents of orientation, lateral order or restraint. Fibres containing itaconic add, a stabilization catalyst did show an increased rate of stabilization. Inferences have been drawn regarding additional research pertaining to achieving high order in precursor fibres, minimizing orientational relaxation during oxidative stabilization, and the techniques for monitoring the extents of the stabilization treatment and the changes in relevant morphological parameters.     

Long-term transients in a reactor under forced concentration cycling

In the approach to a cycle-invariant state in the forced feed concentration cycling of the CO oxidation over a NiO catalyst, a very long transient has been observed lasting 80 ks or more. This transient appears to be associated only with CO pretreatment of the catalyst and is not a general phenomenon. The slow convergence to the cycle-invariant state reported in certain modelling calculations in the literature appears to have a different cause.     

Comparing word fragment completion and cued recall with letter cues.

Cued recall with word stems as cues and fragment completion rely on different types of letter cues and also differ in the explicit–implicit nature of the retrieval orientation. Despite these differences, variables effective in one task may be effective in the other because both rely on letter cues. Two variables known to affect cued recall were manipulated: Lexical set size (number of words that fit the letter cue) and meaning set size (number of associates generated to the studied words). Across four experiments, subjects in each task were less likely to recover targets from larger lexical sets. However, meaning set size affected cued recall but not fragment completion. These results indicate that fragment completion and letter-cued recall are based on lexical search but that cued recall also involves a semantic search component. Furthermore, type of retrieval cue had a greater effect than type of retrieval orientation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)