Arc/gas electrode

A gas/arc electrode is disclosed for use under vacuum conditions where a first housing encloses a second housing, with an end of the second housing extending through an opening in the first housing and having an outlet orifice. Provisions are made for circulating a coolant through the first housing to surround and cool the second housing. An electrical current and a gas, such as argon, as passed through the second housing, with the current flowing through a narrow stream of the ionized gas flowing through the outlet orifice to a workpiece to be treated. The second housing forms a chamber which has a cross sectional area, in a plane perpendicular to the direction of gas flow, of at least ten times the cross sectional area of the outlet orifice such that a gas pressure can be maintained in the chamber to reduce erosion of the chamber walls

Maintenance of Androdioecy in the Freshwater Shrimp, Eulimnadia Texana: Field Estimates of Inbreeding Depression and Relative Male Survival

Androdioecy is a rare form of reproduction, only found in a few plant and animal species, wherein males co-exist with hermaphrodites. This particular form of mixed mating (mixtures of outcrossing and self-fertilization) is predicted to be evolutionarily unstable, with most androdioecious populations thought to be in a transition from hermaphroditism to dioecy, or vice versa. One well-studied androdioecious species is the freshwater clam shrimp Eulimnadia texana. A model by Otto et al. (1993), exploring the stability of this androdioecious system, predicts that males can co-exist with hermaphrodites when males fertilize an average of over twice the number of offspring that an average hermaphrodite produces in a lifetime. This value proportionally increases if males survive less well than hermaphrodites, and proportionally decreases with increased inbreeding depression. In the present study, we measured relative male longevity and inbreeding depression using laboratory-produced selfed and outcrossed eggs reared in the field. Males had lower survival than hermaphrodites in both mating treatments, but the survival difference was greater in the outcrossed relative to the selfed mating treatments (19 vs 9% difference). Inbreeding depression (6) was estimated at 0.58-0.69, depending on the level of selfing among the parents in the outcrossed treatments. Both estimates of relative male viability and inbreeding depression corresponded well with earlier laboratory estimates of these parameters. Thus the within-pond dynamics outlined in the model of Otto et al. (1993), which are driven by high inbreeding depression and high relative male fertility, may still explain the maintenance of androdioecy in these shrimp. Field estimates of male mating effectiveness are required as a final test of the accuracy of this model

Vacuum vapor deposition

A method and apparatus is described for vapor deposition of a thin metallic film utilizing an ionized gas arc directed onto a source material spaced from a substrate to be coated in a substantial vacuum while providing a pressure differential between the source and the substrate so that, as a portion of the source is vaporized, the vapors are carried to the substrate. The apparatus includes a modified tungsten arc welding torch having a hollow electrode through which a gas, preferably inert, flows and an arc is struck between the electrode and the source. The torch, source, and substrate are confined within a chamber within which a vacuum is drawn. When the arc is struck, a portion of the source is vaporized and the vapors flow rapidly toward the substrate. A reflecting shield is positioned about the torch above the electrode and the source to ensure that the arc is struck between the electrode and the source at startup. The electrode and the source may be confined within a vapor guide housing having a duct opening toward the substrate for directing the vapors onto the substrate

Organisational culture: A contemporary management perspective

Purpose: The purpose of this paper is to analyse the concept "organisational culture from a traditional and a more contemporary management perspective. Problem investigated: The concept organizational culture has assumed a very prominent place within the management literature and has been analysed from diverse multidisciplinary perspectives. Central to the importance attributed to the concept is the fact that it acts as a perceptual and behavioural determinant, which implies that it will have a significant impact on all human related institutional activities and thus the interest in the concept and its management. Researchers and management practitioners have come to assume that while the concept is difficult to manage in practice, it is possible to determine the prevailing culture of an institution, identify what is termed to be a desired culture for an institution and then analyse the cultural gap that exists. Based on the analysis conducted, it is further frequently assumed that the transition from the prevailing to a desired culture can be managed. A more contemporary management perspective, based on complexity theory, would appear to challenge the assumption of being able to actively manage the organisation's culture transformation process to ensure that a desired culture is manifest within the institution. The traditional and more contemporary approaches for dealing with the concept "organisational culture" are the focus of discussion and analysis in this paper. Methodology: A multidisciplinary literature review and analysis is undertaken to gain an insight of traditional and contemporary management theory and practice, as it relates to the concept "organisational culture" and its management. Findings: An important conclusion drawn from the study is that traditional paradigms of organisational culture management, that evolved within a more mechanistic manufacturing economy, is no longer effective for dealing with the unpredictable and disruptive changes of a highly complex, competitive and turbulent global services economy. It is suggested that a more contemporary complexity theory approach in dealing with the concept may in fact be more appropriate. Value of the research: Increasingly executives and managers are confronted with the complex realities associated with managing a modern day enterprise in a very turbulent and emerging global services economy. The concept organisational culture, as a perceptual and behavioural determinant, will have a multifaceted influence in the management of the enterprise and the insights derived from this research study could assist executives and managers in dealing with organisational culture as an emergent property, as opposed to a purposefully managed entity. Conclusion: A primary conclusion drawn from the study is that within a contemporary management setting the notion of organisational culture as an emergent, as opposed to actively managed, concept would appear to be more realistic. This would imply that executives and managers at best can attempt to influence its emergence and consequently its impact as a perceptual and behavioural determinant

Description of the fluctuating colloid-polymer interface

To describe the full spectrum of surface fluctuations of the interface between phase-separated colloid-polymer mixtures from low scattering vector q (classical capillary wave theory) to high q (bulk-like fluctuations), one must take account of the interface's bending rigidity. We find that the bending rigidity is negative and that on approach to the critical point it vanishes proportionally to the interfacial tension. Both features are in agreement with Monte Carlo simulations.Comment: 5 pages, 3 figures, 1 table. Accepted for publication in Phys. Rev. Let

In Extremis Leadership: A Study of the Effects in Different Contexts

When lives are at stake, astutely reading a situation (situation awareness) and belief in one’s ability to manage it (self-efficacy) are crucial leadership skills. Fire fighters, law enforcement officers and military leaders routinely enter dangerous, in extremis, situations. Data from these environments is difficult to capture, so there is a gap in the literature looking at the distinctness of these professions. We report on a survey of 514 military, firefighting, and law enforcement leaders examining their experiences during in extremis conditions. This study examines the moderating effect of four human qualities identified in that study (self-esteem, self-sacrifice, mental flexibility and altruism) on situation awareness and self-efficacy as they relate to performance in life threatening situations. We theorize and show in our research that differing priorities among the organizational missions give rise to disparities among the groups. Instead of routinely looking at all in extremis occupations as one population with identical roles, research into these differences should be explored further. Results thus seem relevant to most organizations facing lifethreatening situations, and each distinct group may benefit from different criteria for hiring, recruiting and training of personnel. The results may also be of interest to individuals facing tense, ambiguous, albeit less acute, circumstances