Modified 2D stylus profilometry and its application to frictional analyses in sheet metal forming operations

Frictional conditions at contact interfaces can have a large influence on the success of some sheet metal forming operations. Topographic surface characterisation is a useful tool for obtaining data necessary for some tribological analyses, and it is proposed that a standard two-dimensional (2D) profilometer can be modified to provide inexpensive three-dimensional (3D) data without any significant loss of performance. A scanning white light interferometer is used to verify this hypothesis, and the results show that while the new profilometry technique is less accurate at low contact areas, it is sufficiently accurate for some purposes. Surface maps are created and the results used to calculate the real contact areas, bearing area curves and hydrodynamic lift pressures for a drawing-quality steel.     

Serological responses in Lyme disease: the influence of sex, age, and environment

Social workers in a rehabilitation hospital established an outreach service through which volunteers with previous amputations visited patients with recent amputations, acting as role models and offering emotional support and information. Volunteers received in-depth training and continued with their own system of support. Patients who were visited had strong positive responses to the program. Critical components of the program were developing a collaborative partnership between volunteers and social workers; demonstrating credibility to health care professionals; linking emotional support, information, and affirmation; providing benefits to both patient and volunteer; and strengthening linkages among patient, community, and institution.     

Thermodynamics controlling the proeutectoid ferrite transformations in Fe-C-Mn alloys

The portion of the Fe-C-Mn phase diagram which is relevant to the proeutectoid ferrite transformation has been reexamined. Several tie-lines have been determined using an experimental method designed to promote rapid equilibration and these are shown to be in good agreement with tie-lines estimated from thermodynamic data. The same thermodynamic information has been used to compute paraequilibrium phase boundaries.     

Partition of manganese during the proeutectoid ferrite transformation in steel

The late stages of the isothermal proeutectoid ferrite reaction in Fe-C-Mn have been investigated theoretically and experimentally. For the growth of grain-boundary allotriomorphs three temporal regimes must be recognized. In the early regime the grain-size is infinite with respect to the diffusion length of carbon so the growth is parabolic. The middle regime involves the cumulative impingement of the carbon fields from opposite sides of the grains. This regime ends as the carbon activity approaches substantial uniformity through the ferrite and austenite. The final stage involves the extremely slow approach of the manganese towards uniform activity as well. These temporal regimes must be further subdivided into high and low super saturation regions. In the low supersaturation region segregation of manganese must occur at all times, while in the high supersaturation region it must occur significantly only for late times. The growth rates and the diffusion profiles for the third temporal regime have been calculated on a local equilibrium model and compared with the metallographic and microprobe results for alloys within the two regions of supersaturation. The agreement between theory and experiment is in all cases good.     

Insonation and impedance analysis in graft surveillance

Seventy consecutive patients with infrainguinal bypass grafts entered a 1-year graft surveillance programme involving colour duplex scanning, direct graft insonation and computer-assisted impedance analysis. Graft patients with a positive duplex scan, high frequencies on graft insonation or an impedance value above 0.50 subsequently underwent arteriography. Sixteen patients were excluded before the initial surveillance visit. The 54 remaining patients with grafts (30 vein, 24 synthetic) underwent a total of 137 surveillance visits, with 21 grafts confirmed to be 'at risk'. The sensitivity of an impedance value above 0.55 in identifying these grafts was 86 per cent, rising to 95 per cent when combined with graft insonation. Duplex scanning did not identify any abnormalities in 11 grafts that were either shown by arteriography to be 'at risk' or occluded before arteriography. Impedance measurement and graft insonation are simple screening techniques with a high sensitivity (when combined), which identify 'at risk' infrainguinal grafts. Positive graft insonation or an impedance value over 0.55 will identify all 'at risk' vein grafts while minimizing the number of unnecessary arteriograms.     

Salient-feature coding operations in spatial precuing tasks.

Addressed the issue of whether the principle discovered by the present authors (see record 1986-13527-001) that when 2-dimensional symbolic stimuli are assigned to finger responses, the translation between stimuli and responses operates according to a salient-features coding principle also applies to situations in which the stimuli are spatial locations assigned compatibly to response locations. Three experiments were conducted with 96 undergraduates and used vertical stimulus and response arrangements that allowed finger movements to be similar for different hand placements. Exp I provided evidence for spatial coding on the basis of the salient top–bottom feature of the arrangements. Although spatial coding predominated, evidence for coding on the basis of a distinction between hands also was obtained. Exp II showed that hand coding was not used when the hand distinction failed to correspond with the salient feature of the stimulus display. Exp III indicated that when the hand distinction did correspond with the salient stimulus feature, hand coding occurred only when the hands were turned inward. It is concluded that compatibly assigned spatial-location stimulus and response sets are coded in terms of their salient features, much as are the stimulus and response sets when the assignments are less compatible. (16 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Novel techniques for the thermal management of space-based,high-power microwave tubes

This work is based in part on a study (M.F. Rose et al., 1989) by the authors to determine the applicability of several concepts to the cooling of high-power linear microwave tubes operating in space under a variety of conditions. The authors focus on: direct radiation to space, beam exit to space, thermal storage, secondary coolant loops/heat pipes and the use of supercritical hydrogen as a coolant with subsequent ejection to space. Each of these techniques is evaluated within the framework of a neutral particle beam weapons system or other limited duty cycle device which might lay dormant for long periods of time, come to life, and function reliably for a specified time. System impact for each technique is estimated in terms of impact on weight, volume, spacecraft interaction, and ease of implementation     

Split-Plot and Multi-Stratum Designs for Statistical Inference

It is increasingly recognized that many industrial and engineering experiments use split-plot or other multi-stratum structures. Much recent work has concentrated on finding optimum, or near-optimum, designs for estimating the fixed effects parameters in multi-stratum designs. However, often inference, such as hypothesis testing or interval estimation, will also be required and for inference to be unbiased in the presence of model uncertainty requires pure error estimates of the variance components. Most optimal designs provide few, if any, pure error degrees of freedom. Gilmour and Trinca (2012 Gilmour, S. G., and Trinca, L. A. (2012), “Optimum Design of Experiments for Statistical Inference” (with discussion), Applied Statistics, 61, 345–401.[Crossref], [Web of Science ®] , [Google Scholar]) introduced design optimality criteria for inference in the context of completely randomized and block designs. Here these criteria are used stratum-by-stratum to obtain multi-stratum designs. It is shown that these designs have better properties for performing inference than standard optimum designs. Compound criteria, which combine the inference criteria with traditional point estimation criteria, are also used and the designs obtained are shown to compromise between point estimation and inference. Designs are obtained for two real split-plot experiments and an illustrative split–split-plot structure. Supplementary materials for this article are available online.