Promoting investment in the water sector

Australian governments are the primary investors, infrastructure owners and operators in the Australian water sector. Population growth, historic underinvestment in water infrastructure, water security, climate change and increasing environmental and public health regulation mean that considerable investment in the sector is needed in the future. Significant capital expenditure is required to renew ageing assets and expand networks. Given the challenging fiscal environment for governments in the short to medium term, now is an opportune time for governments to consider where public investment in the water sector is most needed, where efficiency gains can be made and whether additional private investment in the sector could usefully free up current public investment for application in other sectors such as health and education. This paper examines a number of the regulatory barriers to greater private sector participation in the sector. It includes a set of recommendations to governments to facilitate increased private sector investment in the short term and broader reform in the medium to long term

Evaluation of photografted charged sites within polymer monoliths in capillary columns using contactless conductivity detection

Capacitively coupled contactless conductivity detection (C4D) is presented as a novel and versatile means of visualising discrete zones of charged functional groups grafted onto polymer based monoliths. Monoliths were formed within 100 μm UV transparent fused silica capillaries and photografting methods were subsequently used to graft a charged functional monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) onto discrete regions of the “generic” monolith using a photomask. Post-modification monolith evaluation involves scanning the C4D detector along the length of the monolith to obtain a profile of the exact spatial location of grafted charged functionalities with millimetre accuracy. The methodology was extended to the visualisation of several zones of immobilised protein (bovine serum albumin) using photografted azlactone groups to enable covalent attachment of the protein to the monolith at precise locations along its length. In addition, the extent of non-specific binding of protein to the ungrafted regions of the monolith due to hydrophobic interactions could be monitored as an increase in background conductivity of the stationary phase. Finally, the technique was cross-validated using fluorescence microscopy by immobilising green fluorescent protein (GFP) in discrete zones and comparing the profiles obtained using both complementary techniques

On the impact of powder cohesion on the bulk properties of a powder bed in Additive Manufacturing using Discrete Element Method (DEM) simulations

In powder based Additive Manufacturing (AM) a uniform and compact spread of particles is required which can then be accurately fused layer by layer to form final products. As powders are spread, several parameters control the quality of the final powder bed layer; namely, spreader type, powder grain shape, powder characteristics and ambient manufacturing conditions. Utilising discrete element method (DEM) simulations this paper investigates the effect of cohesion on the quality of the powder bed post spreading. However, only cohesion due to the formation of liquid bridges as a result of moisture content of the powder is considered in this work. Simulations are run with a realistic spreader (geometry of which was created from data points from manufacturing equipment used within industry), alongside realistic particle shapes created via Multi-Sphere Approximations (MSA) of models derived from powder X-ray microtomography images, see Figure 1. A random selection of powder particles is chosen and used within simulations, with the resolution of these particles being controlled via a surface smoothing factor [1] to ensure an acceptable balance of accuracy and computational cost. Simulations are run with an appropriate subset of the total number of particles to yield a statistically accurate representation of the grain population to identify the effects of cohesion on the final quality of the powder bed layer. In this paper for the first time, the relationship between the moisture content and powder bed quality is investigated and the simulation results indicate that the cohesion has a strong effect on the powder bed quality which is quantified via a surface roughness parameter and powder's bulk density

Why 'scaffolding' is the wrong metaphor : the cognitive usefulness of mathematical representations.

The metaphor of scaffolding has become current in discussions of the cognitive help we get from artefacts, environmental affordances and each other. Consideration of mathematical tools and representations indicates that in these cases at least (and plausibly for others), scaffolding is the wrong picture, because scaffolding in good order is immobile, temporary and crude. Mathematical representations can be manipulated, are not temporary structures to aid development, and are refined. Reflection on examples from elementary algebra indicates that Menary is on the right track with his ‘enculturation’ view of mathematical cognition. Moreover, these examples allow us to elaborate his remarks on the uniqueness of mathematical representations and their role in the emergence of new thoughts.Peer reviewe

Stratigraphy and Geochemistry of Paleocene-Aged Bauxites from North Mississippi

Bauxite is a heavily-mined aluminum ore that forms through the relative depletion of silica to aluminum. In North Mississippi, bauxite occurring within the Upper Midway and Lower Wilcox groups has been the subject of study for over a century. Despite the abundance and duration of research, controversy surrounds the subjects of bauxite genesis and economic value. The last detailed study of North Mississippi bauxite was in the 1980’s, so the goal of this project is to apply newly available technologies and modern hypotheses on bauxite formation to refine and obtain new data. Fieldwork observations yielded pisoliths, horizonation, and possible rhizoliths, which support a lateritic genesis at the most well exposed outcrop, which is located in Pontotoc County and mapped as the Upper Midway Group. Additionally, stratigraphic trends in percentages of SiO2, Al2O3, and Fe2O3 at this location closely resembled that of a typical lateritic bauxite profile reflecting the depletion of SiO2 and enrichment of Fe2O3 upsection. Abundances of chromium (Cr) and nickel (Ni) as well as percentages of zirconium (Zr), gallium (Ga), and chromium (nickel) (Cr(Ni)) determined the bauxite protolith was acidic and/or sedimentary and that bauxites were of the high-iron lateritic variety. This aligned with the occurrence of siderite (iron carbonate) in the interpreted protolith as well as ratios of lanthanum to yttrium that indicated an acidic paleoenvironment throughout the section. Lastly, stable isotope data confirmed prior hypotheses of a warm paleoclimate and indicated subaerial exposure of the interpreted parent material. A comparison with the reworked bauxite of the Lower Wilcox Group found that pisoliths were different in regards to structure and chemistry, supporting the hypothesis that these originated in a separate event or under different conditions

Millennial-Scale Instability in the Geomagnetic Field Prior to the Matuyama-Brunhes Reversal

Changes in the Earth's magnetic field have global significance that reach from the outer core extending out to the uppermost atmosphere. Paleomagnetic records derived from sedimentary and volcanic sequences provide important insights into the geodynamo processes that govern the largest geomagnetic changes (polarity reversals), but dating uncertainties have hindered progress in this understanding. Here, we report a paleomagnetic record from multiple lava flows on Tahiti that bracket the Matuyama‐Brunhes (M‐B) polarity reversal ∼771,000 years ago. Our high‐precision ^(40)Ar/^(39)Ar ages constrain several rapid and short‐lived changes in field orientation up to 33,000 years prior to the M‐B reversal. These changes are similar to ones identified in other less well‐dated lava flows in Maui, Chile, and La Palma that occurred during an extended period of reduced field strength recorded in sediments. We use a simple stochastic model to show that these rapid polarity changes are highly attenuated in sediment records with low sedimentation rates. This prolonged 33,000 year period of reduced field strength and increased geomagnetic instability supports models that show frequent centennial‐to‐millennial‐scale polarity changes in the presence of a strongly weakened dipole field

The Effects of Facial Expression on Out-Group Discrimination

The current paper sought to test the hypothesis that the facial expression of smiling would mitigate the effects of out-group discrimination. Study 1 examined the influence of facial expression (smiling or frowning), gender (man or woman), and race (Black or White) on resource allocation decisions. Participants were shown arrays of facial photographs. The arrays all contained eight photographs and were counterbalanced to contain all combinations of the variables of interest (i.e., each group had a smiling man of each race, a smiling woman of each race, a frowning man of each race, and a frowning woman of each race). The participants were asked to imagine that the photographs were taken of other college students. They were then asked to allocate hypothetical extra credit points among the photographs. The Black participants tended to show out-group discrimination regardless of the facial expression of the photographs. The White participants demonstrated no form of discrimination when the targets were smiling, but actually favored the frowning Black targets over the frowning White targets. In Study 2, a second group of participants rated the photographs used in Study 1 across 15 different attributes. The number of points allocated to each photograph in Study 1 and the ratings from Study 2 were then explored though bivariate correlations. All of the attributes with the exception of Dominance were highly correlated with the number of points the photographs received in Study 1. The results are discussed in terms of halo effects and cultural display rules for emotions