6,305 research outputs found
Wallum on the Nabiac Pleistocene barriers, lower North Coast of New South Wales
Wallum is widespread on coastal dunefields, beach ridge plains and associated sandy flats in northern NSW and southern Queensland. These sand masses contain large aquifers, and the wallum ecosystem is considered to be generally groundwater-dependent. This study describes the floristic composition and environmental relations of wallum on a Pleistocene barrier system at Nabiac (32˚ 09’S 152˚ 26’E), on the lower North Coast of NSW. Despite their minimal elevation and degraded relief, the Nabiac barriers maintain floristic patterns related to topography and hence groundwater relations. Comparative analyses identified the Nabiac wallum as representative of the ecosystem throughout large parts of its range in eastern Australia. The Nabiac wallum and nearby estuarine and alluvial vegetation supports species and communities of conservation significance. A borefield is proposed for development on the Nabiac barriers, thereby providing a valuable opportunity for research into mechanisms of groundwater utilisation by the wallum ecosystem
Wetland biodiversity in coastal New South Wales: the Wallis Lake catchment as a case study
The floristic composition and environmental relations of wetland vegetation in the Wallis Lake catchment (32˚ 09’S; 152˚ 20’E), area 1292 km2, on the lower North Coast of NSW are described. The catchment supports wetlands listed as Endangered Ecological Communities (NSW Threatened Species Conservation Act 1995) and plant species of high conservation value. A methodology of air photo interpretation, site-based sampling (114 quadrats) and landscape differentiation was developed. A total of 393 vascular plant taxa were recorded (including 10% exotics). Wetland vegetation formations and subformations including mangrove forest, swamp sclerophyll forest, wet heathland, chenopod shrubland, tussock grassland, sedgeland and rushland are described using numerical classification. 31 plant species of national or regional conservation significance are identified. Four Endangered Ecological Communities are discussed – Coastal Saltmarsh, Swamp Oak Floodplain Forest, Swamp Sclerophyll Forest on Coastal Floodplains, and Freshwater Wetlands on Coastal Floodplains. A key recommendation is the completion of reliable wetland vegetation and soil landscape mapping for all land tenures in the catchment – to assess wetland condition and conservation significance, and representation in formal conservation reserves, thereby directing future priorities for the protection of wetland biodiversity on both public and private lands. The methodology developed can be applied to the survey and conservation of wetland biodiversity in other parts of coastal NSW
A mathematical model of three-dimensional flow in a scraped-surface heat exchanger
We present a simple mathematical model of fluid flow in a Scraped-Surface Heat Exchanger (SSHE). Specifically we consider steady isothermal flow of a Newtonian fluid around a periodic array of pivoted scraper blades in a channel with one stationary and one moving wall, when there is an applied pressure gradient in a direction perpendicular to the wall motion. The flow is fully three-dimensional, but decomposes naturally into a two-dimensional transverse flow driven by the boundary motion and a longitudinal pressure-driven flow
Rewarding Creativity: Transformative Use in the Jazz Idiom
A crayon drawing from a five-year-old child likely produces a copyrighted work. Notating or recording two measures of a three year-old child depressing piano keys, while not conventionally pleasing to the ear, may nevertheless be worthy of a copyright.1 The artistic merit of a work is not a factor in determining originality. Simply stated, an author satisfies copyright formalities when she affixes an original work of authorship in a tangible medium.2 Case law indicates that the threshold requirement for the originality element of a copyright is a showing of some "minimal level of creativity."3 Few could disagree that the low threshold requirement for originality encourages creativity. An inherent unfairness exists, however, when copyright law shuns creative artists from attaining a copyright
Diagnostic analysis of RO desalting treated waste water
Diagnostic analysis of reverse osmosis membranes that were fed with Western treatment plant (WTP) recycled
water was investigated by both thermodynamic calculations and laboratory experiments in order to predict the
feasibility of RO desalting for WTP. The thermodynamic calculations suggested that RO recoveries of 80–85% were
feasible with careful control of feed water pH and the use of chemical additives such as antiscalants and chelating
agents, it also predicted the major minerals of concern to be silica, calcium fluoride, calcium carbonate, and calcium
phosphate. Following the thermodynamic simulations, diagnostic laboratory experiments were undertaken. The
experiments showed that the major contributor to scale formation was indeed calcium phosphate and possibly another
calcium based compound, which was strongly suspected to be calcium carbonate. Based on previously published
literature that indicated anti-scalants did not substantially decrease the scaling effect of calcium phosphate and laboratory tests that indicated controlling the pH to 6.4 in the feed water dramatically reduced scaling formation, it was suggested that the feed water could be controlled by pH adjustments only. Inter-stage pH correction was suggested as an optional technique to enhance the overall water recovery to above 95%
Strain-activated structural anisotropy in BaFe2As2
High-resolution single crystal neutron diffraction measurements are presented
probing the magnetostructural response to uniaxial pressure in the iron
pnictide parent system BaFe2As2. Scattering data reveal a strain-activated,
anisotropic broadening of nuclear Bragg reflections, which increases upon
cooling below the resolvable onset of global orthorhombicity. This anisotropy
in lattice coherence continues to diverge until a lower temperature scale---the
first-order onset of antiferromagnetism---is reached. Our data suggest that
antiferromagnetism and strong magnetoelastic coupling drive the
strain-activated lattice response in this material and that the development of
anisotropic lattice coherence under strain is the physical origin for the
anomalous nematic anisotropy in this compound.Comment: 5 pages, 4 figure
The planthopper genus Phylloscelis in the United States (Homoptera: Dictyopharidae)
The dictyopharid planthopper genus Phylloscelis is reviewed and a key to the four species provided. The morphology ofadult male and female P. pallescens Germar, P. atra Germar, P. rubra Ball, and P. pennata Ball is described and illustrated in detail. The species are separated principally by color patterns, wing venation, and features of the male and female external genitalia
Pyrazoline stereochemistry: use of nuclear magnetic resonance shift reagents with azo-compounds
Eu(fod)_3 shifts the n.m.r. spectra of cis-azo-compounds, shereas trans-azo-compounds remain almost unaffected; shifts obtained from pyrazolines have been related to their stereochemistry
Particle-Charge Spectrometer
An instrument for rapidly measuring the electric charges and sizes (from approximately 1 to approximately 100 micrometers) of airborne particles is undergoing development. Conceived for monitoring atmospheric dust particles on Mars, instruments like this one could also be used on Earth to monitor natural and artificial aerosols in diverse indoor and outdoor settings for example, volcanic regions, clean rooms, powder-processing machinery, and spray-coating facilities. The instrument incorporates a commercially available, low-noise, ultrasensitive charge-sensing preamplifier circuit. The input terminal of this circuit--the gate of a field-effect transistor--is connected to a Faraday-cage cylindrical electrode. The charged particles of interest are suspended in air or other suitable gas that is made to flow along the axis of the cylindrical electrode without touching the electrode. The flow can be channeled and generated by any of several alternative means; in the prototype of this instrument, the gas is drawn along a glass capillary tube (see upper part of figure) coaxial with the electrode. The size of a particle affects its rate of acceleration in the flow and thus affects the timing and shape of the corresponding signal peak generated by the charge-sensing amplifier. The charge affects the magnitude (and thus also the shape) of the signal peak. Thus, the signal peak (see figure) conveys information on both the size and electric charge of a sensed particle. In experiments thus far, the instrument has been found to be capable of measuring individual aerosol particle charges of magnitude greater than 350 e (where e is the fundamental unit of electric charge) with a precision of +/- 150 e. The instrument can sample particles at a rate as high as several thousand per second
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