Ultraviolet chambers based on integrating spheres for use in artificial weathering

Laboratory ultraviolet (UV) chambers are widely used to obtain weathering data for a wide range of commercial polymer products including coatings, textiles, elastomers, plastics, and polymeric composites. Although numerous improvements have been made in the design of UV chambers over the last 80 years, the reproducibility of the exposure results from these chambers has remained elusive. This lack of reproducibility is attributed to systematic errors in their design, operation, and control which prevent direct comparisons of the performance of materials exposed in the same environment, comparisons of the performance of the same material exposed in different laboratories, and the comparison of field and laboratory results. This paper describes an innovative UV chamber design based on integrating sphere technology that greatly reduces the magnitude of these errors, as well as provides additional experimental capabilities. Presented at the 79th Annual Meeting of the Federation of Societies for Coatings Technology, on November 4–7, 2001, in Atlanta, GA. Building Materials Division. Gaithersburg, MD. Freeport, TX.     

Une architecture massivement parallèle intégrée

This paper presents a new massively parallel MIMD architecture, halfway between the Connection Machine and hypercubes based on 32-bit processors. It is built from specific 8-bit processors arranged in a 2-D grid and communicating by message transfers. We discuss the communication problems, the instruction set of the basic processing unit, the programmation of the whole array and the use of a high level data-flow language.     

Forty-Five Years After Broadbent (1958): Still No Identification Without Attention.

According to D. E. Broadbent's (1958) selective filter theory, people do not process unattended stimuli beyond the analysis of basic physical properties. This theory was later rejected on the basis of numerous findings that people identify irrelevant (and supposedly unattended) stimuli. A careful review of this evidence, however, reveals strong reasons to doubt that these irrelevant stimuli were in fact unattended. This review exposed a clear need for new experiments with tight control over the locus of attention. The authors present 5 such experiments using a priming paradigm. When steps were taken to ensure that irrelevant stimuli were not attended, these stimuli produced no priming effects. Hence, the authors found no evidence that unattended stimuli can be identified. The results support a modern version of Broadbent's selective theory, updated to reflect recent research advances. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Life task appraisals, spouse involvement in strategies, and daily affect among short- and long-term married couples.

The purpose of this study was to examine predictors and consequences of spouses' involvement in each others' strategies for pursuing important personal goals called life tasks. Husbands and wives within 39 short- and long-term marriages described five life tasks and provided appraisals of whether each was shared with their spouse. Participants later completed 14 consecutive diary entries recording daily life task pursuit strategies, the extent of spouse involvement in each, and measures of positive and negative affect. Results indicated that interdependence in life task appraisals prospectively predicted greater spouse involvement, and greater spouse involvement was associated with more positive affect for that day. Life task appraisals may provide avenues for understanding couples' strategies for dealing with goals or stressors and how those strategies affect mood. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

In situ regeneration of the Ni-based catalytic reformer of a 5 kW PEMFC system

The paper reports the results of on-site regeneration catalytic bed of the natural gas reformer in a 5 kW PEM fuel cell system. The Ni catalyst previously poisoned by sulphur from the available natural gas, could be re-activated by injection of pure water steam, following the method developed for industrial reformers using the same metal catalyst: this method was shown to be perfectly efficient, provided no natural gas was fed during the operation. Results of the tests conducted are presented and discussed in relation to published data on S-sorption on Ni surfaces.     

Behavioral response to naturally occurring stress in cyclothymia and dysthymia.

Outlines an approach to epidemiologic-type life-stress studies that involves the intensive study of smaller groups of well-defined disordered individuals across the course of the response. On the basis of their previous research, the authors suggest that cyclothymia may be characterized by poor regulation of biologic and behavioral variation and that this condition may be exaggerated by stress. To extend the evidence on poor regulation generated in laboratory studies of cortisol functioning, 31 cyclothyme patients and 24 normal controls (median age 19.3 yrs) were asked to provide daily ratings of moods and events over 28 consecutive days. Data show that Ss with cyclothymia showed prolonged duration of recovery of behavioral levels compared to controls. Findings support a notion of weak inhibitory modulation in certain CNS systems that control biologic and behavioral variables related to affective disorder. It is suggested that the prolonged duration of behavioral change in cyclothymia is unlikely to be the consequence of concurrent depression and that the nature of prolonged recovery to stress in cyclothymia reflects the operation of an endogenous regulatory process, as opposed to a cognitive appraisal bias. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A parametric interpolator with confined chord errors, acceleration and deceleration for NC machining

Parametric interpolation has many advantages over linear interpolation in machining curves. Real time parametric interpolation research so far has addressed achieving a uniform feed rate, confined chord errors and jerk limited trajectory planning. However, simultaneous consideration of confined chord errors that respect the acceleration and deceleration capabilities of the machine has not been attempted. In this paper, the offline detection of feed rate sensitive corners is proposed. The velocity profile in these zones is planned so that chord errors are satisfied while simultaneously accommodating the machine's acceleration and deceleration limits. Outside the zone of the feed rate sensitive corners, the feed rate is planned using the Taylor approximation. Simulation results indicate that the offline detection of feed rate sensitive corners improves parametric interpolation. For real time interpolation, the parametric curve information can be augmented with the detected feed rate sensitive corners that are stored in 2×2 matrices.