Effects of level of cooperative choice by the other player on choices in a prisoner's dilemma game: Part I.

In a Prisoner's Dilemma type game, Ss (male and female students) were asked to make repeated choice between 2 alternatives, R and B, where R is presumably the cooperative and B the competitive choice. While believing that they were playing persons of the same sex, Ss actually played a simulated partner who, for ? of the group, chose 83% random R and, for the other ?, 83% random B for 30 trials. Thereafter for 60 trials, the simulated partner chose according to a strategy of 83% matching, 17% mismatching the choices of S. The purpose of this procedure was to determine the effects of initial level of simulated cooperation on S's own level of cooperation. The results failed to demonstrate that the level of simulated cooperation employed functioned to determine choice by S. Ss had been stratified according to a test of character which failed to predict choice. However, a 2nd scoring formula employed on this test did significantly distinguish the amount of R choice emitted by S and deserves further examination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A test of the censure-deficit model and its relation to premorbidity in the performance of schizophrenics.

This investigation incorporated controls suggested by the Rodnick-Garmezy model of schizophrenic behavior with the task most frequently employed in disconfirmatory studies, in order to assess the tenability of the latter. A number of hypotheses derived from Rodnick and Garmezy, concerned with premorbid history of patients (Goods and Poors) and normals, reinforcement conditions (reward, punishment, and nonevaluation) and sex of E (parental surrogates), were tested in a 3×3×2 design with reaction time (RT) as the dependent variable. None of the hypotheses was supported. Instead, punishment led to fastest performance for all groups, and all Ss tended to perform faster for male than for female Es. This research is consistent with the results of the disconfirmatory studies rather than those of Rodnick-Garmezy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Godunov-Type Solutions for Transient Flows in Sewers

This work is part of a long term project which aims at developing a hydraulic model for real-time simulation of unsteady flows in sewers ranging from gravity flows, to partly gravity–partly surcharged flows to fully surcharged flows. The success of this project hinges on the ability of the hydraulic model to handle a wide range of complex boundaries and to provide accurate solutions with the least central processing unit time. This first paper focuses on the development and assessment of two second-order explicit finite-volume Godunov-type schemes (GTS) for unsteady gravity flows in sewers, but with no surcharging. Traditionally, hydraulic transients have been modeled using the method of characteristics (MOC), which is noted for its ability to handle complex boundary conditions (BCs). The two GTS described herein incorporate BCs in a similar manner to the MOC. The accuracy and efficiency of these GTS schemes are investigated using problems whose solution contains features that are relevant to transient flows in sewers such as shock, expansion, and roll waves. The results show that these GTS schemes are significantly faster to execute than the fixed-grid MOC scheme with space-line interpolation, and in some cases, the accuracy produced by the two GTS schemes cannot be matched by the accuracy of the MOC scheme, even when a Courant number close to one and a large number of grids is used. Furthermore, unlike the MOC solutions, which exhibit increasing numerical dissipation with decreasing Courant numbers, the resolution of the shock fronts was maintained by the GTS schemes even for very low Courant numbers (0.001).     

TWO-PHASE FLOW PRESSURE CHANGE ACROSS SUDDEN EXPANSIONS IN DUCT AREAS

A new model to calculate the two-phase flow pressure change across a sudden expansion in a duct area was developed and checked against data measured with mixtures of air and water, aqueous glycerol, watery calcium nitrate and with refrigerant R 12. In the model all relevant physical parameters are included and, in contrast to equations in the literature, the entrainment of liquid in the gas stream is considered. The predictions are validated for a wide range of conditions, pipe diameters and physical properties typically encountered in industrial pipe line systems: Calculations based on the new approach are sufficiently accurate for engineering purposes.     

Self-trapping of electrons in liquid nitrogen

A possibility of electron self trapping in nitrogen is discussed. It is found that electrons are free when injected in liquid N₂ near the triple point and localized inside bubbles and in the gaseous phase, far enough from the critical point. On the saturation line near the critical point a transition of electrons from bound to free states takes place     

A microfabricated suspended-tube chemical reactor for thermally efficient fuel processing

We present a suspended-tube chemical reactor/heat exchanger for high-temperature fuel processing in micro energy conversion systems, primarily for hydrogen production in portable fuel cell systems. This reactor, designed to thermally isolate a high-temperature reaction zone, consists of four free-standing silicon nitride tubes comprising two independent U-shaped fluidic channels. Portions of the tubes are encased in silicon to enable heat exchange between the fluids in these channels. A thin-film platinum resistor is embedded for localized heating and temperature sensing. This paper describes the design and fabrication process for the MEMS fuel processor. Fluidic testing, thermal characterization up to 825/spl deg/C, and preparation of catalyst washcoats in the reactor microchannels are discussed. In addition, results from catalytic autothermal butane combustion and ammonia cracking in the reactor are presented.     

Numerical dissipation and the bottleneck effect in simulations of compressible isotropic turbulence

The piece-wise parabolic method (PPM) is applied to simulations of forced isotropic turbulence with Mach numbers ∼0.1 … 1. The equation of state is dominated by the Fermi pressure of an electron-degenerate fluid. The dissipation in these simulations is of purely numerical origin. For the dimensionless mean rate of dissipation, we find values in agreement with known results from mostly incompressible turbulence simulations. The calculation of a Smagorinsky length corresponding to the rate of numerical dissipation supports the notion of the PPM supplying an implicit subgrid scale model. In the turbulence energy spectra of various flow realisations, we find the so-called bottleneck phenomenon, i.e., a flattening of the spectrum function near the wave number of maximal dissipation. The shape of the bottleneck peak in the compensated spectrum functions is comparable to what is found in turbulence simulations with hyperviscosity. Although the bottleneck effect reduces the range of nearly inertial length scales considerably, we are able to estimate the value of the Kolmogorov constant. For steady turbulence with a balance between energy injection and dissipation, it appears that C ≈ 1.7. However, a smaller value is found in the case of transonic turbulence with a large fraction of compressive components in the driving force. Moreover, we discuss length scales related to the dissipation, in particular, an effective numerical length scale Δ_eff, which can be regarded as the characteristic smoothing length of the implicit filter associated with the PPM.     

Monomeric and dimeric phenolic acids released from cell walls of grasses by sequential treatment with sodium hydroxide

Cell walls of tall fescue Festuca arundinacea Schreb and coastal bermudagrass Cynodon dactylon L Pers were treated sequentially with increasing concentrations of sodium hydroxide (0·1 M to 10 M) to release monomeric and dimeric phenolic acids. (E)-p-Coumaric and (E)-ferulic acids were the major monomers released. Most of the saponifiable feruloyl groups (97% for tall fescue, 89% for coastal bermudagrass) were released with 0·1 M sodium hydroxide. Much lower proportions of saponifiable p-coumaroyl groups (67% for tall fescue, 46% for coastal bermudagrass) were released with this treatment. The major dimers from both grasses were 4,4′-dihydroxy-α-truxillic, 4,4′-dihydroxy-3-methoxy-α-truxillic, and 4,4′-dihydroxy-3,3′-dimethoxy-α-truxillic acids, and were mainly released with 0·1 M sodium hydroxide. Similar proportions of the monomers and dimers were released from the cell walls of each grass with the 0·1 M and 1 M sodium hydroxide sequential treatments. It is probable that most if not all of the monomers and dimers released by the sequential alkali treatments were originally ester linked to the cell walls. If it is assumed that the cell wall bound dimers are formed photochemically from p-coumaroyl and feruloyl groups during plant growth, it is calculated that, for the two grasses, between 12 and 17% of the monomer units were converted to dimers.