Comparisons of the RETRAN two-phase flow model with experimental data

The RETRAN computer program was designed for thermal-hydraulic analysis of nuclear steam supply systems at steady-state and off-normal conditions. A homogeneous equilibrium mixture model (HEMM) of two-phase flow is used in the program. The constitutive models for wall friction, two-phase friction multiplier, heat transfer coefficient, and critical heat flux are compared with steady-state experimental data in this report. The void fraction predicted by the HEMM is also compared with data. The results of the data comparisons indicate that the constitutive models are accurate representations and that the RETRAN numerical scheme provides an excellent framework for data comparisons.     

Etching methods for indium oxide/tin oxide films

Methods are described for etching patterns in conducting indium-tin oxide films on glass substrates. For patterns requiring maximum definition and resolution hydriodic acid is preferred, whereas hydrofluoric acid or zinc and hydrochloric acid are useful for other purposes.     

Isolation of a spotted fever group rickettsia from the Pacific Coast tick, Ixodes pacificus, in Oregon

A rickettsia of the spotted fever group was isolated on three occasions from Ixodes pacificus in western Oregon. These isolations, and additional evidence furnished by complement fixation tests on guinea pigs inoculated with other Oregon ticks of this species, indicate that the association of this rickettsia with the Pacific Coast tick may be widespread. This is the first isolation of a spotted fever group rickettsia from I. pacificus. Because the Oregon isolates are mildly virulent for guinea pigs they resemble the Western U and Rickettsia montana strains of rickettsiae. However, preliminary evidence from cross-immunofluorescence tests of mouse antisera suggests the Tillamook and Grants Pass strains are antigenically different from all known spotted fever group agents.     

Whose fault is it anyway? A practical illustration of human factors in process safety

Major process accidents have typically occurred not through a single failure, but through a combination of events, some of which had contributors from past actions and failures (latent or unrevealed failures). People are integral and key features of business systems; therefore systems, tools, and equipment should be designed with the potential capabilities and limitations of people in mind. This paper demonstrates the benefits of using human factors approaches to improve system safety and reliability. Practical examples from past experience are quoted and a framework for human error prediction is described. Guidance is given on the practicalities of deriving recommendations from these types of studies.     

Macroscopic balance equations for two-phase flow models

The macroscopic, or overall, balance equations of mass, momentum, and energy are derived for a two-fluid model of two-phase flows in complex geometries. These equations provide a base for investigating methods of incorporating improved analysis methods into computer programs, such as RETRAN, which are used for transient and steady-state thermal-hydraulic analyses of nuclear steam supply systems. The equations are derived in a very general manner so that three-dimensional, compressible flows can be analyzed. The equations obtained in this report supplement the various partial differential equation two-fluid models of two-phase flow which have recently appeared in the literature. The primary objective of the investigation is the macroscopic balance equations. The flow-field model equations required by the balance equations are not discussed nor have applications and numerical solution techniques been considered.     

The dietary potential of the common nettle

A leaf protein concentrate prepared from the young leaves of the common nettle (Urtica dioica) failed to support normal growth in young rats; supplementation with methionine produced a protein efficiency ratio greater than that of casein. A nettle leaf wholemeal, providing 66% of the dietary protein, supported normal growth in young guinea-pigs, mice and rats. Chicks receiving the whole nettle meal as their sole dietary protein grew at only half the rate of chicks given a standard commercial diet. A nettle meal-induced hypercholesterolaemia in mature guinea-pigs and kidney hypertrophy in mice and guinea-pigs should perhaps be interpreted as a caution against the indiscriminate introduction of nettles into the human diet.     

Novel microwave GaAs field-effect transistors

A technology is described for the fabrication of Schottky-barrier f.e.t.s with electrodes on either or both sides of a submicrometre thick single-crystal layer of GaAs. Preliminary d.c. and microwave results are given together with possible advantages of these novel f.e.t. structures.     

Hop maturation and resin formation. Effects of extended harvestings on subsequent hop crops

Commercial harvestings of hops (Humulus lupuhlus L, var., Pride of Ringwood) were conducted over a 5 week period encompassing normal harvest time. The effect on yield and α-acid content of the crop was determined, as was the effect on the subsequent crop. Although the yields of hops and α-acid from the first crop were found to plateau for at least 4 weeks, beginning 2 weeks prior to normal harvest, the time of harvesting exercised a significant effect on the yield for the following season. The magnitude of the effect was generally found to correlate with the length of time between training and harvesting of the initial crop, i.e. the shorter the time, the lower the yield of the subsequent crop.