Peter Rickwood

Boundary lines within petrologic diagrams which use oxides of major and minor elements

Use of some petrologic diagrams applied to analyses of volcanic rocks is unnecessarily difficult due to lack of data for construction of discriminant lines between rock series. Coordinates are provided for sufficient points to enable accurate plotting of the boundary lines within seven diagrams, viz.: (1) TAS - total alkalies (Na2O+K2O) vs. SiO2; (2) K2O vs. SiO2; (3) AFM; (4) Jensen; (5) KTP - K2OTiO2P2O5; (6) FMS - (FeO∗MgO) vs. SiO2; and (7) TAKTIP - K2O(Na2O+K2O) vs. TiO2P2O5. Different versions of these boundaries are collated to indicate their variable position, and it is demonstrated that inter-laboratory analytical precision suffices to account for almost all of their spread on the TAS and K2O vs. SiO2 diagrams.

Urban Structure and Energy—A Review

The nature and form of the urban environment is a critical determinant of the sustainability of our society, as it is responsible directly for a large proportion of consumed energy, and influences indirectly the patterns and modes of energy consumed in everyday activities. We examine the current state of research into the energy and greenhouse gas emissions attributable directly or indirectly to urban form. Specifically, we look at the embodied (construction) and operational energy attributable to the construction, maintenance and use of residential dwellings, and we review the literature on the relationship between urban structure and private travel behaviour. While there is clear evidence from both intra- and inter-city comparisons that higher density, transit-oriented cities have lower per-capita transport energy use, the effect of housing density on residential (in-house) energy use is less clear. More detailed research is needed to examine the relationships between urban form and overall energy use.

Urban Structure and Commuting in Australian Cities

Studies looking at the relationship between urban form and travel behaviour have generally considered spatial information at coarse metropolitan or local government area scales. We analyse ABS census data at the Collection District level for the metropolitan areas of the mainland Australian state capital cities, and at various spatial scales for an in-depth analysis of commuting in Sydney. The analyses suggest that the relationship between travel behaviour and urban form is complex, and that simple analyses of density alone are likely to overstate the effect of both metropolitan and neighbourhood scale population density on mode choice, but that these variables serve as useful proxies for more complex measures of urban structure.

Residential Operational Energy Use

Despite decades of debate in urban research about the effect of built form on household energy use, the empirical research on the topic is still far from conclusive. Many studies rely on small samples and fail to control for crucial variables such as household income. This article describes a detailed analysis of household energy use in Sydney that controls for major household demographic and income variables. The results demonstrate that appliance ownership, household size, dwelling size and dwelling type all affect energy consumption. Importantly, from a planning perspective, energy use in low-rise attached dwellings, after controlling for other factors, is estimated as 15–20 per cent lower than detached dwellings with the same number of bedrooms.

Methods for automatically analyzing humpback song units

This paper presents mathematical techniques for automatically extracting and analyzing bioacoustic signals. Automatic techniques are described for isolation of target signals from background noise, extraction of features from target signals and unsupervised classification (clustering) of the target signals based on these features. The only user-provided inputs, other than raw sound, is an initial set of signal processing and control parameters. Of particular note is that the number of signal categories is determined automatically. The techniques, applied to hydrophone recordings of humpback whales (Megaptera novaeangliae), produce promising initial results, suggesting that they may be of use in automated analysis of not only humpbacks, but possibly also in other bioacoustic settings where automated analysis is desirable.

Diamondiferous eclogite xenoliths in kimberlite

Abstract The physical properties of garnet in diamond-kyanite-eclogite and diamond-corundum-eclogite are presented for the first time, and are compared with garnet in six newly available diamond eclogites. Garnets from diamond-bearing eclogites do not constitute a separate subdivision, but plot in the compositional fields appropriate to their mineralogy and chemistry. Diamondiferous and graphite-bearing eclogites are neither chemically nor mineralogically different from eclogites without a carbon polymorph, except for the presence of the carbon phase. Diamondiferous eclogites are probably formed at depths of 190–555 km.

The biotite-prehnite association

Abstract Prehnite interleaved with biotite in altered diorite from S.E. Queensland and elsewhere has a lens-shaped form which bows the enclosing mica cleavages. Despite the first description of the texture in 1918 and identification of the prehnite in 1936 only a few references to the intergrowth can be found. Genetic considerations usually involve K metasomatism of hornblende or the crystallization of prehnite and biotite in place of amphibole. Although it appears as if the prehnite developed by replacement of the biotite, volume considerations for both the phyllosilicates mitigate against the simple insertion of Ca 2 Al for K(Mg,Fe) 3 within the basic sheet structure. At present it is suggested that the prehnite developed in response to deuteric reactions.

Association of BMI and interpregnancy BMI change with birth outcomes in an Australian obstetric population: A retrospective cohort study

Objective To assess maternal and neonatal outcomes associated with increasing body mass index (BMI) and interpregnancy BMI changes in an Australian obstetric population. Methods A retrospective cohort study from 2008 to 2013 was undertaken. BMI for 14 875 women was categorised as follows: underweight (≤18 kg/m2); normal weight (19–24 kg/m2); overweight (25–29 kg/m2); obese class I (30–34 kg/m2); obese class II (35–39 kg/m2) and obese class III (40+ kg/m2). BMI categories and maternal, neonatal and birthing outcomes were examined using logistic regression. Interpregnancy change in BMI and the risk of adverse outcomes in the subsequent pregnancy were also examined. Results Within this cohort, 751 (5.1%) women were underweight, 7431 (50.0%) had normal BMI, 3748 (25.1%) were overweight, 1598 (10.8%) were obese class I, 737 (5.0%) were obese class II and 592 (4.0%) were obese class III. In bivariate adjusted models, obese women were at an increased risk of caesarean section, gestational diabetes, hypertensive disorders of pregnancy and neonatal morbidities including macrosomia, large for gestational age (LGA), hypoglycaemia, low 5 min Apgar score and respiratory distress. Multiparous women who experienced an interpregnancy increase of ≥3 BMI units had a higher adjusted OR (AOR) (CI) of the following adverse outcomes in their subsequent pregnancy: low 5-min Apgar score 3.242 (1.557 to 7.118); gestational diabetes mellitus (GDM) 3.258 (1.129 to 10.665) and hypertensive disorders of pregnancy 3.922 (1.243 to 14.760). These women were more likely to give birth vaginally 2.030 (1.417 to 2.913). Conversely, women whose parity changed from 0 to 1 and who experienced an interpregnancy increase of ≥3 BMI units had a higher AOR (CI) of caesarean section in their second pregnancy 1.806 (1.139 to 2.862). Conclusions Women who are overweight or obese have a significantly increased risk of various adverse outcomes. Interpregnancy weight gain, regardless of parity and baseline BMI, also increases various adverse outcomes. Effective weight management strategies are needed.

The bedrock topography of the botany basin, New South Wales

Abstract The bedrock topography of the Botany Basin has been determined from seismic‐sparker records made in Botany Bay and Bate Bay, and from seismic‐refraction and gravity measurements on the Kurnell Peninsula. Supplementary information has been obtained from boreholes both on land and in the sea. The Cooks and Georges Rivers formerly constituted the main drainage of the Basin and flowed generally southeastwards (beneath the present Kurnell Peninsula) and joined the Port Hacking River east of Cronulla. The depth of the bedrock channel of the former Georges River is 75–80 m b.s.l. at Taren Point, 90–95 m beneath the Kurnell Peninsula and 110–115 m at its junction with the Port Hacking River channel. The bedrock channel of the former Cooks River is about 30 m b.s.l. at Kyeemagh, its present entrance to Botany Bay, and it joined the Georges River at a location now 90 m b.s.l. beneath the Kurnell Peninsula. A second drainage system existed in the north and east of Botany Bay and generated the present mouth ...

The impact of rising oil prices on the transport sector

Abstract Oil is the dominant motorized transportation fuel used in most countries, including Australia. Many other oil-derived products and services are important to the functioning of the Australian economy. It makes sense, then, that this issue of Australian Planner focuses on the risks associated with scarce and/or expensive oil. This paper provides background information about oil consumption in Australia, and reviews the available information on price elasticities for the major oil end-uses. Based on this review, the impact of higher oil prices is assessed, and short- and long-run policy options are discussed. Reducing fuel used for private motoring, and preparing emergency adaptation plans to cope with sudden oil price spikes are identified as the major areas on which planners should focus.