Super-speed centrifugation at sea using a gimballed platform

The use of a super-speed centrifuge at sea for the recovery of suspended solids or interstitial pore fluids requires a stabilizing platform. In this report, we describe a simple platform gimball and magnetic rotor stabilizer that have been fitted to a Sorvall model SS_?3 super-speed centrifuge. In principle, any centrifuge of comparable weight (86 kg) could be easily adapted for use at sea with gimbals of similar design.The magnetic rotor coupler is designed to eliminate rotor precession when the centrifuge is operated at sea. This attachment is particularly useful when the Sorvall SS_?3 (equipped with a conventional rotor) is used to recover interstitial pore fluids.     

Aborigines and land in Northern Australian development

Northern Australian development has been based primarily on land ownership and the commercial exploitation of resources. Aborigines, lacking legally recognised tenure to land, have largely been excluded from this process. Their priorities for development have rarely been considered. Aboriginal land rights legislation theoretically transforms this situation. But, because of external pressures, Aboriginal land owners have to a large extent continued to follow the conventional development path through the establishment of enterprises. Factors such as physical isolation, lack of management expertise and the demands for reciprocity in Aboriginal society have inhibited the success of such enterprises. This paper, focusing primarily on Aboriginal pastoral operations, discusses these issues and illustrates some alternative forms of land and resource use which suggest that Aboriginal development priorities have a stronger social orientation.     

Random vectors and spatial analysis by geostatistics for geotechnical applications

Geostatistics is extended to the spatial analysis of vector variables by defining the estimation variance and vector variogram in terms of the magnitude of difference vectors. Many random variables in geotechnology are in vectorial terms rather than scalars, and its structural analysis requires those sample variable interpolations to construct and characterize structural models. A better local estimator will result in greater quality of input models; geostatistics can provide such estimators: kriging estimators. The efficiency of geostatistics for vector variables is demonstrated in a case study of rock joint orientations in geological formations. The positive cross-validation encourages application of geostatistics to spatial analysis of random vectors in geoscience as well as various geotechnical fields including optimum site characterization, rock mechanics for mining and civil structures, cavability analysis of block cavings, petroleum engineering, and hydrologic and hydraulic modelings.     

Simultaneous solutions for photometric and spectroscopic observations of TX UMa

B andV light curves for one epoch and radial velocity curves of three different epochs have been analyzed to revise the solution of TX UMa. The solution has been adjusted simultaneously in the light curves and radial velocity curves by the method of Wilson and Devinney's differential correction. The primary star's surface rotation rate to synchronous rate is determined as 1.768 from one of the radial velocity curves. The absolute dimension of the system has been deduced based on the simultaneous solution. The primary star is well fitted to the evolutionary track for a single star while the secondary star, while filling its Roche lobe, is fitted to the evolutionary track for a close binary system.     

Venus cloud microphysics

Because sulfuric acid does not wet sulfur, composite drops in the atmosphere of Venus cannot have sulfur “cores,” but must instead have sulfur coats. Both components then communicate with the vapor phase. Drops that are fully coated with sulfur are immune to coalescence; this sets a limit to growth that may explain “Mode 3” particles. The sulfur coating is probably responsible for the anomalously low refractive indices derived from entry-probe nephelometer data. There appears to be about an order of magnitude less elemental sulfur than sulfuric acid in the clouds.     

Application of Spectroscopic Diagnostics to Early Observations with the SOHO Coronal Diagnostic Spectrometer

The Coronal Diagnostic Spectrometer (CDS) has as a scientific goal the determination of the physical parameters of the solar plasma using spectroscopic diagnostic techniques. Absolute intensities and intensity ratios of the EUV spectral emission lines can be used to obtain information on the electron density and temperature structure, element abundances, and dynamic nature of different features in the solar atmosphere. To ensure that these techniques are accurate it is necessary to interface solar analysis programs with the best available atomic data calculations. Progress is reported on this work in relation to CDS observations.     

On the cooling of the moon by solid convection

If a molten, or partially molten, lunar core exists at present, constraints would be placed on the viscosity of the solid mantle and the distribution of radioactive heat sources. Models in which the heat sources have been concentrated near the surface would rapidly solidify if the effective viscosity was equal to, or less than, 10²² cm² s⁻¹. Retention of most of the heat sources throughout the mantle would permit present day solid convection to occur without cooling the core.