CHARACTERIZATION OF HEAVY OIL BY CAPILLARY SUPERCRITICAL FLUID CHROMATOGRAPHY

Using supercritical CO₂ as the mobile phase with a 30m × 100μ ID SPB-5 capillary column and temperature of 90°C, high boiling fractions of heavy oils could be characterized. A linear restrictor placed as close as possible to the flame ionization detector jet prevented the characteristic spiking often observed in these systems, and also allowed the study of high molecular weight material without plugging of the restrictor. The boiling points of model saturate and aromatic compounds correlate with retention time providing the capability to study heavy oils without exposing them to the high temperatures necessary in gas chromatography. Individual peaks can be resolved for the n-paraffins in waxes up to C₉₀. Primary production, fireflood and steamflood heavy oils and bitumens were compared by this technique.     

Aviation software guidelines

Regulatory authorities in the US and Europe have received two documents crucial to aviation software developers. The first one, DO-248B, clarifies existing software guidelines for airborne systems and equipment certification, and the other, CNS/ATM (a counterpart to DO-178B) provides new guidance for non-airborne communication and navigation systems.     

AMYLASE ACTIVITY AND ENDOSPERM HARDNESS OF HIGH LYSINE BARLEYS

Several of the high lysine barleys selected by the Udy dye binding method have altered proportions of the main protein fractions. These varieties also vary considerably in endosperm hardness measured as the amount of electrical energy required for milling. A few have endosperms requiring a higher milling energy than that of the parental variety, but five high lysine varieties have soft endosperms typical of barleys that malt readily. In addition the high lysine selections differ markedly in β-amylase and diastatic activity. Mutant R 1508 with the highest grain lysine has very low diastatic activity, whereas R 56 and Hiproly have diastatic activities equivalent to that of a known high diastase barley. α-Amylase activity of high lysine barleys also ranges widely and tends to be inversely related to diastatic activity.     

Using the Perceptual Cycle Model and Schema World Action Research Method to generate design requirements for new avionic systems

The Schema World Action Research Method (SWARM) has previously been used as a means to explore the underlying decision‐making processes involved in retrospective incident reports. The approach has been fruitful in capturing all interacting processes involved in managing incidents. This paper proposes that SWARM may also be used prospectively within the early phases of the design lifecycle for new behavioral‐based intervention strategies. Six pilot interviews were conducted to explore pilots' perceptual cycle processing when faced with a suspected engine oil leak. The aim was to explore whether there may be any deficiencies within current practise and explore ways in which pilots may be better supported in dealing with abnormal system parameters such as this. A number of design recommendations are proposed for a new avionic system capable of supporting and guiding pilots through the decision‐making process.     

Oxidation of electrodeposited black chrome selective solar absorber films

X-ray photoelectron spectroscopy and Auger electron spectroscopy were used to study the composition and oxidation of electrodeposited black chrome films. The outer layer of the film is Cr₂O₃ and the inner layer is a continuously changing mixture of chromium and Cr₂O₃. Initially, approximately 40 vol.% of the chromium was combined as Cr₂O₃ and the percentage of Cr₂O₃ increased to greater than 60 vol.% after heat treatment for only 136 h at 250°C. After 3600 h at 400°C the percentage of Cr₂O₃ increased to as high as 80 vol.%. The thermal emittance decreased approximately linearly with increasing oxide content whereas the solar absorptance remained constant until the percentage of Cr₂O₃ exceeded approximately 70%. Oxidation was slower when the Cr³⁺ concentration in the plating bath was reduced from 16 to 8 g 1^?1 and when black chrome was deposited on stainless steel rather than on sulfamate nickel.     

Comparative methods for the determination of the gap state density in magnetron-sputtered hydrogenated amorphous silicon

A comparative study of three methods for determining the density of states N(E) in material with the same structure and chemical composition is presented. The three techniques are measurements of the field effect, the Schottky capacitance and conductance as a function of voltage and the Schottky capacitance and conductance versus frequency at zero bias. The difference between the N(E) deduced from a field effect measurement and those deduced from the other methods is found to be due to the technique itself and not to a difference in material properties. This difference can be greater than a decade.We also report here, for the first time, changes in the midgap density of states of hydrogenated amorphous silicon (a-Si:H) produced by r.f. magnetron sputtering with variation in the hydrogen pressure from 0.2 to 2.0 mTorr and for substrate temperatures between 170 and 260 °C. There is a sharp decrease in the density of states followed by a rise as the hydrogen pressure is increased. Magnetron-sputtered a-Si:H is shown to be a good quality material because of its low N(E) and its performance in devices.     

The Wechsler Object Assembly subtest and bodily concerns.

This study tried to evaluate a hypothesis drawn from clinical impressions and from suggestive incidental data of prior research that concerns about body intactness will be reflected in a Wechsler subtest pattern where the Object Assembly (OA) score is lower than those of other subtests. OA scores were found to be significantly lower in children with bodily concerns than in a control group, and there were no other significant differences on other WISC subtests. Rorschachs of adult patients with low and high OA scores were compared and there was a significantly greater percentage of Rorschach responses indicating bodily concern in the group scoring low in OA. These findings are discussed in relation to the assessment of cognitive processes and ego functions in diagnostic testing, the process of clinical inference and prior research on body image. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-dimensional homotopy curve tracking on a shared-memory multiprocessor

Results are reported for a series of experiments involving numerical curve tracking on a shared-memory parallel computer. Several algorithms exist for finding zeros or fixed points of nonlinear systems of equations that are globally convergent for almost all starting points, that is, with probability one. The essence of all such algorithms is the construction of an appropriate homotopy map and then the tracking of some smooth curve in the zero set of this homotopy map. HOMPACK is a mathematical software package implementing globally convergent homotopy algorithms with three different techniques for tracking a homotopy zero curve, and has separate routines for dense and sparse Jacobian matrices. The HOMPACK algorithms for sparse Jacobian matrices use a preconditioned conjugate gradient algorithm for the computation of the kernel of the homotopy Jacobian matrix, a required linear algebra step for homotopy curve tracking. A parallel version of HOMPACK is implemented on a shared-memory parallel computer with various levels and degrees of parallelism (e.g., linear algebra, function, and Jacobian matrix evaluation), and a detailed study is presented for each of these levels with respect to the speedup in execution time obtained with the parallelism, the time spent implementing the parallel code, and the extra memory allocated by the parallel algorithm.     

Controlling digital signature services using a smartcard

In this paper a number of requirements for the corporate user of digital signature technology have been identified. These appeared at first sight to be demanding security controls and usability requirements over and above those assumed of normal signature systems.However, once the requirements were fully analyzed, an approach was described which not only met the additional requirements, but did so while at the same time reducing the likely implementation cost, by reducing the burden placed on the smartcard, and increasing the effective performance be delegating signature processing to a shared server.This approach appears therefore to be unique in raising levels of security, usability and performance while at the same time reducing potential implementation costs and adhering to external standards. It should therefore be of extreme interest to all corporate users who wish to enter the world of electronic commerce backed by digital signature and non-repudiation.     

The Anatomy of Housing Stress in Sydney

The issue of housing affordability is now the focus of a number of policy interventions in Australian metropolitan areas. In this article data from the ABS 1996 Census and 1999 National Housing Survey are used to unpack the geography of Sydney's unaffordability problem at the local level and looks at the numbers, distribution and characteristics of low income households in housing stress.