Wind tunnel investigations at transonic Mach numbers

Investigation utilizes static and fluctuating pressure measurements and oil flow visualization techniques to analyze perturbed flow environments of three-dimensional protuberances and the surrounding structure. Significant findings are given

Balancing soil nutrient availability on commercial organic farms

Soils from two commercial farms were analysed for cation exchange capacities with the aim of improving the balance of available nutrients at soil level, and to support the basic organic principle of maintaining and improving the long-term fertility and microbiological activity of the soil

Experimental program to investigate transonic flow around protuberances

Transient and steady state aerodynamic flow of turbulent boundary layers are investigated for generalized cylindrical projections and several specific configurations used on the Saturn 5 launch vehicle. A transonic wind tunnel gave generalized information

X-Y plotter adapter developed for SDS-930 computer

Graphical Display Adapter provides a real time display for digital computerized experiments. This display uses a memory oscilloscope which records a single trace until erased. It is a small hardware unit which interfaces with the J-box feature of the SDS-930 computer to either an X-Y plotter or a memory oscilloscope

York Digital Library : an ecological view of interactions and systems

This case study of York Digital Library examines the development of a digital library of images at the University of York. In particular, it examines the project phase of the Fedora-based digital library and its provision of service to the History of Art department. The case study examines the technical, cultural, and human interactions of the digital library using the metaphor of an ecosystem. This approach is based on earlier work by the Repositories Research Tea

Investigation of electronic switches for analog and hybrid computation technical note no. 6

Analog switching circuits for analog and hybrid computer

Numerical simulation of natural convection in a spherical container due to cooling at the center (idealization of the Lal/Kroes experiment)

Natural convection in a spherical container with cooling at the center was numerically simulated using a numerical fluid dynamics computer program. The numerical analysis was simplified by assuming axisymmetric flow in the spherical container, with the symmetry axis being a sphere diagonal parallel to the gravity vector. This axisymmetric spherical geometry was intended as an idealization of the proposed Lal/Kroes crystal growing experiment to be performed on Spacelab. Results were obtained for a range of Rayleigh numbers from 25 to 10,000. The computed velocities were found to be approximately proportional to the Rayleigh number over the range of Rayleigh numbers investigated

Emission within a Damped Lyman Alpha Absorption Trough: the Complex Sight Line Towards Q2059-360

We present new spectroscopic observations of the quasar Q2059-360, confirming the existence of an emission feature within the Damped Lyman Alpha (DLA) absorption trough. By observing also at slit positions offset from the quasar, we show that the emission is spatially extended by at least a few arcseconds, and hence confirm that the feature seen must be due to emission rather than unusual absorption characteristics. We find that the DLA trough is very close in redshift to the broad Lyman~$\alpha$ emission line of the QSO, with the result that the DLA absorption removes much of the peak region of that line. Despite the similarity of the redshifts of the DLA and the QSO, the lack of high-ionization lines of the DLA system and the unresolved widths of the corresponding metal lines indicate that the DLA cloud is not an associated system. The emission feature has a large velocity offset of +490 km/s with respect to the DLA system, and is resolved in velocity, comprising two components with a separation of ~ 300 km/s. We consider three possibilities: (1) Both emission and absorption occur within an object similar to the high redshift Lyman-break galaxies; (2) The emission feature arises from an object distinct from both the DLA absorber and the QSO, perhaps a young star-forming galaxy or a proto-galactic clump. It could be associated with the DLA absorber and perhaps the QSO in a compact group or cluster; (3) The redshifts are such that the emission feature could be due to Narrow Line Region filaments of the QSO, if the DLA absorption covers a sufficiently small angular size to allow the filaments to be seen beyond the edge of the DLA cloud.Comment: 10 pages, 6 figures. Accepted for publication in MNRA