Characterization of tempered martensite embrittlement using hardness measurement

A series of experiments were carried out on three commercial steels to explore the possibility for characterizing tempered martensite embrittlement (TME) by Rockwell, macro-, and micro-Vickers hardness tests. The results indicate distinct hardness peaks in two steels and an inflection in the other around the TME temperature. A new analytical approach for examining the slope of hardness-tempering temperature plots appears to reveal the TME phenomenon more sensitively. Dilatometric examinations substantiate that the temperature of hardness peak/inflection occurs beyond the second stage of tempering.     

Author index,vol. 70 (1994/1995)

Author index, vol. 70 (1994/1995)     

Airborne scatterometers: investigating ocean backscatter under low and high-wind conditions

Attempting to understand and predict weather on a local and global basis has challenged both the scientific and engineering communities. One key parameter in understanding the weather is the ocean surface wind vector because of its role in the energy exchange at the air-sea surface. scatterometers, radars that measure the reflectivity of a target offer a tool with which to remotely monitor these winds from tower-, aircraft-, and satellite-based platforms. This paper introduces three current airborne scatterometer systems, and presents data collected by these instruments under low-, moderate-, and high-wind conditions. The paper focuses on airborne scatterometers because of their ability to resolve submesoscale variations in wind fields. Discrepancies between existing theory and the observations are noted and the concerns in measuring low-wind speeds discussed. Finally, the application of using this technology for estimating the surface-wind vector during a hurricane is demonstrated     

A general interaction analysis for large deformations

A method is presented for the finite element analysis of the interaction of geometrically and materially non-linear bodies. Interaction is considered at predefined interfaces. Equations for interaction forces are assembled via static condensation, and the solution for these forces is utilized for the full analysis of the problem. An interface function using the interpolating functions is defined to maintain the equilibrium of interaction forces and the displacement compatibility at the interface nodes. The method permits large rotations and slipping as well as the occurrence of new contacts at the interfaces. Additionally, solutions can be found using high- or low-order elements and when nodes at either side of the interface are not aligned.     

Fatal accident to a horse from a narrow transverse beam in the box door

It is reported on the fatal accident of a horse due to a cross-beam too low above the door of the stable, in which the animal suffered several skull fractures and a tear of the musculus longus capitis from the base of the skull. The aim of this article is, to supply a contribution to the establishment of minimal requirements for the housing of horses, in this case for the request of the minimum height of stable doors and ceilings as well as for constructions on horse transporters. On the grounds of this example, the natural behaviour of horses is discussed at the hand of the literature and the efforts are shown to improve the existing inadequacies in the housing and transport of horses with regard to the judicial situation. In the light of section 2 of the animal protection law, as to the construction of horse stables the importance is especially emphasized to consider the panic behaviour in connection with abrupt flight reactions as physiologic in the prevention of accidents.     

Interactions of stimulus attributes, base rates, and feedback in recognition.

Continuous old-new recognition was studied in relation to 3 factors that have been relatively neglected in previous research-stimulus attributes, old-new base rates, and informative feedback following responses. Under all conditions, both hits and false alarms increased over trials and all measures of recognition depended strongly on stimulus properties, notably interitem similarity. In contrast to expectations based on earlier results, both hit and false-alarm levels proved independent of old-new base rate when tests were given without feedback; with feedback added, false-alarm rates tended to approach true old-stimulus base rates with some types of stimuli, though not with words. The findings are compatible, in general, with current composite-memory models and were predicted in detail by an array-similarity model deriving from categorization theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three-dimensional anatomical model-based segmentation of MR brainimages through principal axes registration

Model-based segmentation and analysis of brain images depends on anatomical knowledge which may be derived from conventional atlases. Classical anatomical atlases are based on the rigid spatial distribution provided by a single cadaver. Their use to segment internal anatomical brain structures in a high-resolution MR brain image does not provide any knowledge about the subject variability, and therefore they are not very efficient in analysis. The authors present a method to develop three-dimensional computerized composite models of brain structures to build a computerized anatomical atlas. The composite models are developed using the real MR brain images of human subjects which are registered through the principal axes transformation. The composite models provide probabilistic spatial distributions, which represent the variability of brain structures and can be easily updated for additional subjects. The authors demonstrate the use of such a composite model of ventricular structure to help segmentation of the ventricles and cerebrospinal fluid of MR brain images. Here, a composite model of ventricles using a set of 22 human subjects is developed and used in a model-based segmentation of ventricles, sulci, and white matter lesions. To illustrate the clinical usefulness, automatic volumetric measurements on ventricular size and cortical atrophy for an additional eight alcoholics and 10 normal subjects were made. The volumetric quantitative results indicated regional brain atrophy in chronic alcoholics