The impact of rain water on soil pore networks following irrigation with saline-sodic water

The soil pore network is an important factor affecting soil hydraulic conductivity (Ksat). In this study we examine the effect on the soil pore network of a Red Ferrosol caused by irrigation with good quality irrigation water (GQW), as well as saline-sodic water with varying sodium absorption ratios (SAR; 10, 50 and 120) and constant electrical conductivity (EC; 2 dS m-1), followed by application of distilled water (simulating rain water). The Ksat was measured for the different waters before and after applying the rain water to the soil. Soil samples were taken from different depths (1, 4 and 8 cm) for exchangeable cations measurement and the changes in ESP of the soil. Soil horizontal cross-sections were taken from the first 2 cm of the soil cores after drying with acetone and impregnation with polyester resin mixed with green fluorescent dye catalyst and hardener. These sections were polished and visualized under a microscope to investigate the changes in the soil pore network. By increasing the SAR of the water applied from 0.11 (GQW) to SAR 50 and 120, a significant reduction in Ksat was found, alongside a significant increase in the ESP of the soil from 3 to 10 and 11, respectively; this was most evident near the soil surface. After applying rain water, the Ksat reduced significantly approaching 0 mm h-1 where soil was treated with water of SAR 120. Visualisation of the soil pore network of the treated soils following the application of deionised water clearly showed a reduction in soil macroporosity where water quality of SAR ≥10 was applied, even where soils were non-sodic. Where irrigation occurred with good quality, low SAR water, this reduction was not evident

Radiation Induced Damage in GaAs Particle Detectors

The motivation for investigating the use of GaAs as a material for detecting particles in experiments for High Energy Physics (HEP) arose from its perceived resistance to radiation damage. This is a vital requirement for detector materials that are to be used in experiments at future accelerators where the radiation environments would exclude all but the most radiation resistant of detector types.Comment: 5 pages. PS file only - original in WORD Also available at http://ppewww.ph.gla.ac.uk/preprints/97/06

Preliminary Results for LP VPE X-Ray Detectors

Thick epitaxial layers have been grown using Low Pressure Vapour Phase Epitaxy techniques with low free carrier concentrations . This type of material is attractive as a medium for X-ray detection, because of its high conversion efficiency for X-rays in the medically interesting energy range.Comment: 4 pages. PS file only - original in WORD. Also available at http://ppewww.ph.gla.ac.uk/preprints/97/07

Selecting Site Suitable for Animal Waste Application using a Vector GIS

Due to the increase in the number and size of intensive animal industries (IAI) in many parts of the world including Australia, the disposal of animal waste has become a pressing environmental problem. Frequently the wastes generated at IAI are conveniently, favourably, and cost-effectively applied to the nearby agricultural fields to recycle manure nutrients. However, excessive application of wastes in the nearby fields without due consideration of site-specific factors (eg. slope, soil, and watercourses) has resulted in the run-off and leaching losses of manure nutrients causing agricultural non-point source (NPS) pollution (He and Shi, 1998). The agricultural NPS pollution has contributed significantly to the eutrophication and toxic blue green algae blooms in many river systems including Murray-Darling, where world's largest toxic riverine algal bloom was recorded in 1991 (Kuhn, 1993). Hence it has become crucial to develop an animal waste application guide (i.e. a site suitability map) by considering biophysical and socio-economic factors to minimise the environmental hazards. Developing such a map requires consideration of many factors and their spatial variability. Geographic information system (GIS)offers site suitability analysis techniques that are capable of processing large volumes of spatial data (Davis, 1996). The objective of this study is to develop a suitability map using a vector GIS, and to evaluate the factor sensitivity and aptness of this technique in selecting suitable sites for animal waste application

Quantifying landscape fragmentation in the Lockyer Valley Catchment, Queensland: 1973 – 1997

Fragmentation has become a central issue in landscape ecology and conservation. The breaking up of large land areas into smaller patches is known to influence many ecological patterns and processes. Thus, landscape fragmentation needs to be assessed and monitored. In this study of the Lockyer Creek Catchment in Queensland, landscape fragmentation was quantified using 1973 and 1997 Landsat images and other thematic layers. Landscape metrics (focusing on the size, shape, density, and isolation of woody vegetation) were calculated using the Patch Analyst (Grid) extension of ArcView GIS. The nature of fragmentation was further characterised based on landscape features including land use/cover, tenure, slope, as well as distance to roads and streams

Estimating the furrow infiltration characteristic from a single advance point

Management and control of surface irrigation, in particular furrow irrigation, is limited by spatio-temporal soil infiltration variability as well as the high cost and time associated with collecting intensive field data for estimation of the infiltration characteristics. Recent work has proposed scaling the commonly used infiltration function by using a model infiltration curve and a single advance point for every other furrow in an irrigation event. Scaling factors were calculated for a series of furrows at two sites and at four points down the length of the field (0.25 L, 0.5 L, 0.75 L and L). Differences in the value of the scaling factor with distance were found to be a function of the shape of the advance curves. It is concluded that use of points early in the advance results in a substantial loss of accuracy and should be avoided. The scaling factor was also strongly correlated with the furrow-wetted perimeter suggesting that the scaling is an appropriate way of both predicting and accommodating the effect of the hydraulic variability

On the puzzle of Bremsstrahlung as described by coaccelerated observers

We consider anew some puzzling aspects of the equivalence of the quantum field theoretical description of Bremsstrahlung from the inertial and accelerated observer's perspectives. More concretely, we focus on the seemingly paradoxical situation that arises when noting that the radiating source is in thermal equilibrium with the thermal state of the quantum field in the wedge in which it is located, and thus its presence does not change there the state of the field, while it clearly does not affect the state of the field on the opposite wedge. How then is the state of the quantum field on the future wedge changed, as it must in order to account for the changed energy momentum tensor there? This and related issues are carefully discussed.Comment: 29 pages, 1 figure; Revtex, minor changes, PACS correcte

Correction to: The hidden therapist: evidence for a central role of music in psychedelic therapy.

The article The hidden therapist: evidence for a central role of music in psychedelic therapy, written by Mendel Kaelen, Bruna Giribaldi, Jordan Raine, Lisa Evans, Christopher Timmerman, Natalie Rodriguez, Leor Roseman, Amanda Feilding, David Nutt, Robin Carhart-Harris, was originally published electronically on the publisher's internet portal