Comparison of statistical methods in MR imaging

The problem of recovering the true underlying scene from a noisy image is considered. Several methods are compared empirically by applying them to magnetic resonance (MR) images. It turns out that a simple method, the Gaussian window filter, gives good results. This method requires only “instantaneous” processing.     

Nylons: A review of the literature on products of combustion and toxicity

The literature on polyamides was reviewed to determine the nature and extent of information available on these materials which are commonly used in consumer and industrial applications. This review was limited to aliphatic polyamides normally called nylon and excludes aromatic polyamides such as Nomex and bicomponent polymers consisting of nylon and other polymers. The review was further limited to those publications in English through June 1984. Typical pyrolysis products from a broad range of nylons do not appear to differ greatly. Many of the decomposition products detected in vacuum pyrolysis experiments appear as products of thermal degradation in inert and air atmospheres. In air, a general reduction in the quantities of heavier hydrocarbons is noted along with an increase in the production of CO, CO₂, H₂O, NH₃, HCN and NO_x. The toxicity of the thermal degradation products from various types of nylon has been evaluated by nine different protocols. Reported LC₅₀ values range from 10.8 m l^?1 to 61.9 mg l^?1. Dyes apparently do not affect the materials' combustion products toxicity but an increase in the amount of backcoating on a nylon fabric increases toxicity. Time to death measurements show that volatile products from nylons are less toxic than those from rayons or cotton, while the blending of wool with nylon greatly increases the toxicity of the thermal decomposition products. In general, however, the overall toxicity of the thermal degradation products from nylon do not appear to be greatly different than those from many other polymeric materials. Large-scale test results are ambiguous, and it is difficult to interpret the results in terms of a single component in a multicomponent system.     

Experimental study of cryogen spray properties for application in dermatologic laser surgery

Cryogenic sprays are used for cooling human skin during laser dermatologic surgery. In this paper, six straight-tube nozzles are characterized by photographs of cryogenic spray shapes, as well as measurements of average droplet diameter, velocity, and temperature. A single-droplet evaporation model to predict average spray droplet diameter and temperature is tested using the experimental data presented here. The results show two distinct spray patterns--sprays for 1.4-mm-diameter nozzles (wide nozzles) show significantly larger average droplet diameters and higher temperatures as a function of distance from the nozzle compared with those for 0.5-0.8-mm-diameter nozzles (narrow nozzles). These results complement and support previously reported studies, indicating that wide nozzles induce more efficient heat extraction than the narrow nozzles.     

Mythmaking and Knowledge Sharing: Living organizational myths and the broadening of opportunity structures for knowledge sharing in a Scandinavian engineering consultant company

With examples from Scandiaconsult, a Scandinavian engineering consultant company, this paper is an exploration of some of the constructive mythological aspects of living knowledge emerging in the symbolic interaction of organizational work life. Framed within the overall challenge of organizational knowledge sharing, and the approach of the communal resource as a (partial) solution to that, we more specifically look at ways of broadening the opportunity structures for knowledge sharing through the twin principles of organizational myths and rituals – as processes whereby people can identify and tap into the reservoir of living knowledge in the organization life, often in the realm of the informal or shadow organization. We explore in what ways the myths and rituals can leverage knowledge sharing especially in the face of distributed work environments inhabited by multiplex interested knowledge workers, and in our case with the additional challenge of mergers and acquisitions. We argue that active mythmaking is very far from manipulation or plain rhetoric, but rather a complex and interwoven processes of displaying cultural premises and transforming barriers and misbelieves into trustworthy relationships, and thus rendering possible conditions for lowering the costs of knowledge sharing. The mythmaking, of course, has to be deeply interwoven with the already existing mythic reservoir.     

Dauerschwingfestigkeit der technischen Titanlegierungen TiAl 5 Sn 2,5 und TiAl 6 V 4

Dauerschwingversuche an Flachproben aus geschmiedeten und gewalzten Blechen zweier Titanlegierungen unter Planbiegung sowie an Rundproben aus geschmiedeten Stangen unter Zug-Druck-, Umlaufbiege- und Verdrehwechselbelastung. Einfluß von Probenform und -fertigung sowie Wärmebehandlung und Beanspruchungsart auf die Wechselfestigkeit. Ermittlung der Kerbwirkungszahlen. Metallographische Untersuchungen über die Ursachen der Lebensdauerstreuungen und Ausbreitung von Dauerbruchanrissen. Vergleich der Ergebnisse mit Angaben im Schrifttum.     

The digital transformation of management consulting companies: a qualitative comparative analysis of Romanian industry

Information Systems and e-Business Management - Digital transformation affects all industries. This study targets how management consulting companies address this phenomenon. Based on a survey of...