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There have been a large number of papers on the surface tensions of metals since Keene published his critical review in 1993. Consequently, current data for both the surface tensions of metals and their temperature dependencies have been critically assessed and recommended values are given. Experimental uncertainties can arise from two sources: systematic errors associated with the experimental methods (typically ±2%) and changes in surface tension arising from oxygen contamination of the specimen. Uncertainties arising from the latter can be variable. [ABSTRACT FROM AUTHOR]

The diffusion of Os in Ni is characterised by measuring interdiffusion coefficients in the binary Ni-Os system, in the temperature range 1200-1350°C. The results are compared with data for Ni-Re. Theoretical calculations indicate that Os should display a diffusion coefficient comparable with Re, among the lowest displayed by elements from the d-block transition elements. The authors' experimental findings confirm these predictions, and suggest that alloying with Os is likely to improve the high temperature properties of the nickel-based superalloys. [ABSTRACT FROM AUTHOR]

Powder consumption, Q s, is an important process variable in the continuous casting of steel but there is no agreement on the factors affecting Q s. This study seeks to identify those factors which have an effect on Q s. A large database containing powder consumption values and casting conditions, mould flux and steel composition data from a large number of steelworks has been analysed using statistical techniques to identify those factors which have significant effect on powder consumption. The following parameters, in decreasing order, were found to be significant (at the 95% confidence level): casting speed, viscosity, stroke length, oscillation frequency and break temperature. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 63-year-old woman with spiny keratoderma. She was suffering from the problem of itchy lesions on her palms for more than ten years, but was ignoring medical treatment for it. She also had faced several other health problems in past including diabetes, valvular heart disease, and congestive heart failure.

Thermophysical properties for the solid and liquid phases of several Ni based superalloys (CMSX-4, CMSX-10, CM186LC, IN 738 and Rene 80) have been measured. The following properties were measured: heat capacity and enthalpy, thermal expansion coefficient and density, thermal diffusivity, viscosity and surface tension. Analysis of these measurements showed that that γ' phase (Ni3Al) affected the values for the following properties; Cp, enthalpy, electrical resistivity, thermal diffusivity and conductivity. Relationships have been identified between properties and the γ' phase content (which can be represented by mass% Al in the alloy). These relations were then used to calculate property values of the alloys from chemical composition. Other relations were developed to estimate the viscosities and surface tensions of Ni based superalloys. The predicted property values were found to be in good agreement with the measured values. [ABSTRACT FROM AUTHOR]

A computerized task was used in two studies to examine the influence of stimulants, sedatives, and fatigue on single-target and divided-attention responses in different parts of the visual field. The drug effects were evaluated over time with repeated behavioral and subjective measures against ascending and descending drug levels. In the first study, 18 fully rested participants received placebo, alprazolam (0.5 mg), and dextroamphetamine (10 mg). Alprazolam impairs performance, whereas dextroamphetamine induces enhancement and tunnel vision. Study 2 exposed 32 participants to fatigue and no fatigue with a repeated-measures crossover design. Four independent groups subsequently received placebo, dextroamphetamine (10 mg), caffeine (250 mg), or alcohol (.07%). Under fatigue, stimulants have no performance-enhancing effects, whereas impairment from alcohol is severe. Under no fatigue, alcohol has a modest effect, caffeine has no effect, and dextroamphetamine significantly enhances divided-attention performance coincident with tunnel vision. Participants rate all drug effects more stimulating and less sedating while fatigued. Implications for transportation safety are discussed. Actual or potential applications of this research include driver and pilot training. [ABSTRACT FROM AUTHOR]