Systems design of high performance stainless steels II. Prototype characterization

Within the framework of a systems approach, the design of a high performance stainless steel integrated processing/structure/property/performance relations with mechanistic computational models. Using multicomponent thermodynamic and diffusion software platforms, the models were integrated to design a carburizable, secondary-hardening, martensitic stainless steel for advanced gear and bearing applications. Prototype evaluation confirmed the predicted martensitic transformation temperature and the desired carburizing and tempering responses, achieving a case hardness of R _c 64 in the secondary-hardened condition without case primary carbides. Comparison with a commercial carburizing stainless steel demonstrated the advantage of avoiding primary carbides to resist quench cracking associated with a martensitic start temperature gradient reversal. Based on anodic polarization measurements and salt-spray testing, the prototype composition exhibited superior corrosion resistance in comparison to the 440C stainless bearing steel, which has a significantly higher alloy Cr concentration. This revised version was published online in June 2006 with corrections to the Cover Date.     

Relative versus absolute measures of explicit attitudes: Implications for predicting diverse attitude-relevant criteria.

The authors report 4 studies exploring a self-report strategy for measuring explicit attitudes that uses "relative" ratings, in which respondents indicate how favorable or unfavorable they are compared with other people. Results consistently showed that attitudes measured with relative scales predicted relevant criterion variables (self-report of behavior, measures of knowledge, peer ratings of attitudes, peer ratings of behavior) better than did attitudes measured with more traditional "absolute" scales. The obtained pattern of differences in prediction by relative versus absolute measures of attitudes did not appear to be attributable to differential variability, social desirability effects, the clarity of scale-point meanings, the number of scale points, or overlap with subjective norms. The final study indicated that relative measures induce respondents to consider social comparison information and behavioral information when making their responses more than do absolute measures, which may explain the higher correlations between relative measures of attitudes and relevant criteria. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Organization of visual short-term memory.

The authors examined the organization of visual short-term memory (VSTM). Using a change-detection task, they reported that VSTM stores relational information between individual items. This relational processing is mediated by the organization of items into spatial configurations. The spatial configuration of visual objects is important for VSTM of spatial locations, colors, and shapes. When color VSTM is compared with location VSTM, spatial configuration plays an integral role because configuration is important for color VSTM, whereas color is not important for location VSTM. The authors also examined the role of attention and found that the formation of configuration is modulated by both top-down and bottom-up attentional factors. In summary, the authors proposed that VSTM stores the relational information of individual visual items on the basis of global spatial configuration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A wreath product group approach to signal and image processing .I.Multiresolution analysis

We propose the use of spectral analysis on certain noncommutative finite groups in digital signal processing and, in particular, image processing. We pay significant attention to groups constructed as wreath products of cyclic groups. Within this large class of groups, our approach recovers the discrete Fourier transform (DFT), the Haar wavelet transform, various multichannel pyramid filter banks, and other aspects of multiresolution analysis as special cases of a more general phenomenon. In addition, the group structure provides a rich algebraic structure that can be exploited for the analysis and manipulation of signals. Our approach relies on a synthesis of ideas found in the early work of Holmes (1987, 1990), Karpovsky and Trachtenberg (1985), and others on noncommutative filtering, as well as Diaconis's (1989) spectral analysis approach to understanding data     

Varieties of developmental reading disorder: genetic and environmental influences

There is widespread support for the notion that subgroups of dyslexics can be identified who differ in their reading profiles: Developmental phonological dyslexia is characterized by poor nonword reading, while developmental surface dyslexia is distinguished by a particular difficulty in reading irregular words. However, there is much less agreement about how these subtypes, and particularly the surface dyslexic pattern, are to be accounted for within theoretical models of the reading system. To assist in addressing this issue, the heritability of reading deficits in dyslexic subtypes was examined using a twin sample. Subjects' scores on (a) an exception word reading task and (b) a nonword reading task were used to create a subtype dimension, and surface and phonological dyslexic subgroups were selected from the ends of this distribution. Reading deficits were found to be significantly heritable in both subgroups. However, the genetic contribution to the group reading deficit was much greater in the phonological dyslexics than in the surface dyslexics. The finding of differential genetic etiology across subtypes suggests that there is at least partial independence in the development of the cognitive processes involved in reading exception words and nonwords. Also, the results support accounts of surface dyslexia which emphasize a strong environmental contribution.     

Relationship between acute diarrhoea and low plasma levels of vitamin A and retinol binding protein

OBJECTIVE: We studied possible sex differences of the effect of fenofibrate on serum lipoproteins. Twenty-three patients with primary hypercholesterolaemia (10 postmenopausal women and 13 aged-matched men) were treated with slow-release fenofibrate for 96 weeks. RESULTS: Steady state lipoprotein concentrations were reached after 12 and 24 weeks of treatment in women and men, respectively. During the subsequent follow-up the lipoprotein concentrations remained constant. In women total and low-density lipoprotein (LDL) cholesterol decreased from 299 to 234 mg.dl-1 and from 210 to 151 mg.dl-1, respectively, and in men from 265 to 233 mg.dl-1 and from 192 to 160 mg.dl-1. The decrease in triglycerides was also more pronounced in women (-42%) than in men (-18%). High-density lipoprotein (HDL) cholesterol increased significantly in women from 53 to 63 mg.dl-1 but not in men (45 to 50 mg.dl-1). Since the changes in LDL and HDL cholesterol occurred in opposite directions, the decrease in LDL/HDL cholesterol ratio was accentuated in both groups. However, this ratio was decreased almost twofold in women (-41%) compared to men (-23%). Although the serum concentrations of fenofibric acid were 1.3-fold higher in women than in men, which was probably due to the higher body weight in men (1.2-fold), this difference can hardly explain the favorable effect on lipoproteins in women. CONCLUSION: The present study indicates that fenofibrate might be very effective by reducing the concentrations of atherogenic lipoproteins in postmenopausal women.     

Viking gas chromatograph-mass spectrometer

The Mars viking gas chromatograph-mass spectrometer is described. The system is designed to determine the composition of the Martian atmosphere and detect and identify chemical compounds vaporized or pyrolyzed from the Martian soil. Construction details, performance data, data processing methods, and references to manufacturing and test procedures are also provided.     

Spatially resolved photoluminescence and transmission spectra of HgCdTe

We report new high-resolution scanning photoluminescence (PL) experiments in the mid-infrared (IR) portion of the spectrum. The samples investigated were Hg_0.7Cd_0.3Te epilayers grown on Cd_0.96Zn_0.04Te substrates. The influence of macrodefects and the annealing of samples on the PL signal were studied. Transmission spectra were used to map the optical path variations of the epilayer.     

Selecting Landmarks for Localization in Natural Terrain

We describe techniques to optimally select landmarks for performing mobile robot localization by matching terrain maps. The method is based upon a maximum-likelihood robot localization algorithm that efficiently searches the space of possible robot positions. We use a sensor error model to estimate a probability distribution over the terrain expected to be seen from the current robot position. The estimated distribution is compared to a previously generated map of the terrain and the optimal landmark is selected by minimizing the predicted uncertainty in the localization. This approach has been applied to the generation of a sensor uncertainty field that can be used to plan a robot's movements. Experiments indicate that landmark selection improves not only the localization uncertainty, but also the likelihood of success. Examples of landmark selection are given using real and synthetic data.