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

Investigation of weld joint detection capabilities of a coaxial weld vision system

This report describes the second phase of a series of evaluations of a vision-based welding control sensor for the Space shuttle Main Engine Robotic Welding System. The robotic welding system is presently under development at the Marshall Space Flight Center. This evaluation determines the factors influencing the minimum joint gap required for consistent detection of the weld joint

Efficient solutions of self-consistent mean field equations for dewetting and electrostatics in nonuniform liquids

We use a new configuration-based version of linear response theory to efficiently solve self-consistent mean field equations relating an effective single particle potential to the induced density. The versatility and accuracy of the method is illustrated by applications to dewetting of a hard sphere solute in a Lennard-Jones fluid, the interplay between local hydrogen bond structure and electrostatics for water confined between two hydrophobic walls, and to ion pairing in ionic solutions. Simulation time has been reduced by more than an order of magnitude over previous methods.Comment: Supplementary material included at end of main pape

Implications for welfare, productivity and sustainability of the variation in reported levels of mortality for laying hen flocks kept in different housing systems: A meta-analysis of ten studies

Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports. Cumulative mortality (CM) was higher in flocks with intact beaks (χ2 = 6.03; df 1; p = 0.014) than in those with trimmed beaks. Most data were available for free-range systems (2,823 flocks), where producer recorded CM at 60–80 weeks of age averaged 10% but with a range from 0% to 69.3%. Life cycle assessment showed that the main effect of increased levels of hen mortality is to increase the relative contribution of breeding overheads, so increasing environmental burdens per unit of production. Reducing CM to levels currently achieved by the 1st quartile could reduce flock greenhouse gas emissions by as much as 25%. Concurrently this would enhance hen welfare and better meet the expectation of egg consumers. More research to understand the genetic x environment interaction and detailed records of the causes of mortality is required so that improved genotypes can be developed for different systems and different breeds can be better managed within systems

Molecular oxygen densities from rocket measurements of Lyman-alpha absorption profiles

Molecular oxygen density measurements in upper atmosphere by absorption spectroscopy using solar Lyman alpha radiatio

Investigation of the D and E region during the IQSY Final report, 1964 - 1965

Nike-Apache rocket measurements of lower ionosphere during International Quiet Sun Yea

Density fluctuations and the structure of a nonuniform hard sphere fluid

We derive an exact equation for density changes induced by a general external field that corrects the hydrostatic approximation where the local value of the field is adsorbed into a modified chemical potential. Using linear response theory to relate density changes self-consistently in different regions of space, we arrive at an integral equation for a hard sphere fluid that is exact in the limit of a slowly varying field or at low density and reduces to the accurate Percus-Yevick equation for a hard core field. This and related equations give accurate results for a wide variety of fields

Identification Strategies in Survey Response Using Vignettes

In this paper we explore solutions to a particular type of heterogeneity in survey data which is manifest in the presence of individual-specific response scales. We consider this problem in the context of existing evidence on cross-country differences in subjective life satisfaction, and in particular the extent of cross-country comparability. In this instance observed responses are not directly comparable, and inference is compromised. We utilise two broad identification strategies to account for scale heterogeneity. Keeping the data fixed, we consider a number of estimators based on alternative generalisations of the ordered response model. We also examine a number of alternative approaches based on the use of additional information in the form of responses on one or more additional questions with the same response categories as the self-assessment question. These additional questions, referred to as anchoring vignettes, can under certain conditions, be used to correct for the resultant biases in model parameters

Sequential simulation model development

Sequential simulation (SqS) is a physical form of simulation that recreates care pathway trajectories rather than single episodes of care. Current physical simulation in health care focuses on specific tasks or particular teams and settings. However, the patient perspective is a journey through the care system and not an isolated component. To date, SqS has been used for a range of applications, including training multidisciplinary teams on end-of-life care, developing integrated care approaches, quality improvement projects, designing new models of care, evaluating new interventions, and improving care of the deteriorating patient in an acute setting, to name but a few. Many applications are possible, and therefore the design process can be lengthy and complex. This article outlines an approach the author took over a 3-year period to generate a usable SqS model through empirical and theoretical data. The model draws on process, observational, survey, and evaluative data to generate an understanding of the key components that constitute the design process of an SqS. This approach resulted in an empirically and theoretically driven model that can be used and refined by others in the field of health-care simulation