Water Quality Relationships to Concentrations of Pfiesteria-like Organisms in Virginia Estuaries for 1998

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large number of zero counts; and; c) there were no marked changes involving increasing abundance during the study that could be related to environmental factors

Water Quality Relationships to Concentrations of Pfiesteria-like organisms in Virginia Estuaries for 1998.

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large number of zero counts; and; c) there were no marked changes involving increasing abundance during the study that could be related to environmental factors

Embodied energy of Sliver® modules

Sliver® solar cells, invented and developed at the ANU, allow a reduction in the consumption of silicon by a factor of 5 to 12 compared with state of the art conventional crystalline silicon modules, resulting in a decrease in the number of wafers that need to be processed to produce a kW rated system by a factor of 15 to 30. Both of these features reduce the embodied energy of Sliver® modules. We have calculated an energy payback time of 1.5 years for Sliver® modules compared to 4.1 years for conventional crystalline silicon modules. The equivalent greenhouse gas emissions embodied in Sliver® modules also compares favourably to emissions from fossil fuel sources used for the generation of electricity in Australia

Modelling of silver modules incorporating a lambertian rear reflector

Modules incorporating cells which are bifacial and narrow can make use of rear reflectors to capture most of the incident sunlight while covering only a fraction of the module area with cells. Sliver® cells, invented and developed at the ANU, meet these criteria. In this paper we analyse the performance limits of such modules for the case where a diffuse (lambertian) reflector is used. The analysis is carried out for various cell thicknesses, cell spacings and reflectivities of the lambertian reflector. The results show that excellent performance can be realised despite the simplicity of the structure. A module with a 50% coverage with 70µm thick cells can capture up to 84% of the light entering the module. Importantly, the performance of this kind of module is insensitive to module orientation. The results of the analytical model are compared with ray tracing studies and measurements and are shown to be in good agreement. It is concluded that significant module cost reductions can be achieved for only modest reductions in performance by covering half or less of the module surface with cells

Characterisation of the thermal response of Silver® cells and modules

Sliver cells, invented and developed at The Australian National University, are long, thin, narrow, and bifacial. They are constructed from high-grade mono-crystalline silicon. Solar modules that incorporate Sliver cells are significantly different in their construction and performance characteristics to conventional crystalline silicon modules. In Sliver modules, the cells are usually spaced apart to make use of the bifacial nature of the Sliver cells. A scattering reflector on the rear of the module is used to trap most of the incident light within the module structure. However, a fraction of the incident sunlight will not be absorbed by the cells and will instead be coupled out of the module. While this loss of incident radiation results in a reduction in module efficiency, it also results in a proportional reduction in heat generation within the module. This leads to lower module operating temperatures compared with conventional modules of similar efficiencies

The effect of bifacial Sliver® Module orientation on energy production

The Sliver® solar cell technology has the principal features of reduced silicon consumption (down by a factor ~12), a reduced number of wafers that need to be processed per kW (down by a factor of ~30), high efficiency (~19%) and perfect bifacial response. The bifacial response of cells allows a wide range of innovative Sliver® module designs that cannot be achieved using conventional technology (monofacial modules). This work examines the relative performance of monofacial and bifacial modules in a variety of mounting configurations

Influence of reactive ion etching on the minority carrier lifetime in P-type Si

Quasi-steady-state photoconductance (QSSPC) and deep level transient spectroscopy (DLTS) were used to characterize the recombination properties of reactive ion etched p-type Si. The effective lifetime of the plasma-processed samples degraded after etching, with the densities of recombination centers increasing linearly with etch time, before reaching a plateau. Evidence is provided for the long-range (> 2 µm) migration of defects in the samples plasma-etched at room temperature. The relationship between rf power and lifetime degradation is also discussed. A defect with energy position at (0.31 ± 0.02) eV was detected by DLTS in RIE p-Si, whereas no defect level was measured in n-type Si. We demonstrate that this energy level could be used to adequately model the injection-dependence of the measured carrier lifetimes using the Shockley-Read-Hall model

Filling a blank on the map: 60 years of fisheries in Equatorial Guinea

Despite a scarcity of pertinent information, it has been possible to reconstruct time series of marine fisheries catches for Equatorial Guinea from 1950 to 2010 using per capita fish consumption and population numbers for small-scale fisheries, catch rates and number of vessels for industrial fisheries and discard rates to estimate the discarded bycatch. Small-scale fisheries, industrial large-scale fisheries, domestic and legal and illegal foreign fisheries and their discards are all included. Total catches were estimated at 2.7 million tonnes over the time period considered, of which 653 000 t were caught domestically compared to 187 000 t reported by FAO. This shows that fisheries have more importance for Equatorial Guinea's food security than the official data suggest. In contrast to what is suggested by official figures, fisheries were shown to be strongly impacted by civil and political unrest; notably, they declined overall because of civil and political conflicts, socio-demographic dynamics, and a growing role of the newly discovered oil resources, which directly and indirectly threaten the food security of the people of Equatorial Guinea

Collapse Models

This is a review of formalisms and models (nonrelativistic and relativistic) which modify Schrodinger's equation so that it describes wavefunction collapse as a dynamical physical process.Comment: 40 pages, to be published in "Open Systems and Measurement in Relativistic Quantum Theory," F. Petruccione and H. P. Breuer eds. (Springer Verlag, 1999