Microphysical properties of cold frontal rainbands

Observations have been obtained within an intense (precipitation rates > 50 mm h−1 ) narrow cold-frontal rainband (NCFR) embedded within a broader region of stratiform precipitation. In situ data were obtained from an aircraft which flew near a steerable dual-polarisation Doppler radar. The observations were obtained to characterise the microphysical properties of cold frontal clouds, with an emphasis on ice and precipitation formation and development. Primary ice nucleation near cloud top (−55◦ C) appeared to be enhanced by convective features. However, ice multiplication led to the largest ice particle number concentrations being observed at relatively high temperatures (> −10◦ C). The multiplication process (most likely rime splintering) occurs when stratiform precipitation interacts with supercooled water generated in the NCFR. Graupel was notably absent in the data obtained. Ice multiplication processes are known to have a strong impact in glaciating isolated convective clouds, but have rarely been studied within larger organised convective systems such as NCFRs. Secondary ice particles will impact on precipitation formation and cloud dynamics due to their relatively small size and high number density. Further modelling studies are required to quantify the effects of rime splintering on precipitation and dynamics in frontal rainbands. Available parametrizations used to diagnose the particle size distributions do not account for the influence of ice multiplication. This deficiency in parametrizations is likely to be important in some cases for modelling the evolution of cloud systems and the precipitation formation. Ice multiplication has significant impact on artefact removal from in situ particle imaging probes.

Changes in sewage sludge carbon forms along a treatment stream

The behaviour and fate of macronutrients and pollutants in sewage sludge applied to the land are affected by the chemical composition of the sludge organic matter, which in turn is influenced by both sewage source and by sewage treatment processes. In this study, 13C nuclear magnetic resonance (NMR) spectroscopy was used to characterise the organic matter of sludges collected at three different points along the treatment stream of a municipal sewage works with a domestic catchment. Sludge at the first point, an undigested liquid (UL) sludge, had a substantially different composition to the anaerobically digested (AD) and dewatered sludge cake (DC) materials, which were similar to each other. In particular, the UL sludge contained more alkyl C than the AD or DC sludges. All three sludges were found to contain mobile alkyl C that is poorly observed using the cross polarisation (CP) technique, necessitating the use of the less sensitive, but more quantitatively reliable direct polarisation (DP) technique to obtain accurate distributions of C types.

High-precision measurements of the co-polar correlation coefficient: non-Gaussian errors and retrieval of the dispersion parameter µ in rainfall

The co-polar correlation coefficient (ρhv) has many applications, including hydrometeor classification, ground clutter and melting layer identification, interpretation of ice microphysics and the retrieval of rain drop size distributions (DSDs). However, we currently lack the quantitative error estimates that are necessary if these applications are to be fully exploited. Previous error estimates of ρhv rely on knowledge of the unknown "true" ρhv and implicitly assume a Gaussian probability distribution function of ρhv samples. We show that frequency distributions of ρhv estimates are in fact highly negatively skewed. A new variable: L = -log10(1 - ρhv) is defined, which does have Gaussian error statistics, and a standard deviation depending only on the number of independent radar pulses. This is verified using observations of spherical drizzle drops, allowing, for the first time, the construction of rigorous confidence intervals in estimates of ρhv. In addition, we demonstrate how the imperfect co-location of the horizontal and vertical polarisation sample volumes may be accounted for. The possibility of using L to estimate the dispersion parameter (µ) in the gamma drop size distribution is investigated. We find that including drop oscillations is essential for this application, otherwise there could be biases in retrieved µ of up to ~8. Preliminary results in rainfall are presented. In a convective rain case study, our estimates show µ to be substantially larger than 0 (an exponential DSD). In this particular rain event, rain rate would be overestimated by up to 50% if a simple exponential DSD is assumed.

Electronic properties of liquid hydrogen fluoride: A sequential quantum mechanical/Born-Oppenheimer molecular dynamics approach

The electronic properties of liquid hydrogen fluoride (HF) were investigated by carrying out sequential quantum mechanics/Born-Oppenheimer molecular dynamics. The structure of the liquid is in good agreement with recent experimental information. Emphasis was placed on the analysis of polarisation effects, dynamic polarisability and electronic excitations in liquid HF. Our results indicate an increase in liquid phase of the dipole moment (similar to 0.5 D) and isotropic polarisability (5%) relative to their gas-phase values. Our best estimate for the first vertical excitation energy in liquid HF indicates a blue-shift of 0.4 +/- 0.2 eV relative to that of the gas-phase monomer (10.4 eV). (C) 2010 Elsevier B.V. All rights reserved.

Electronic properties of a methane-water solution

Electronic properties of a methane-water solution were investigated by a sequential quantum mechanical/molecular dynamics approach. Upon hydration methane acquires an induced dipole moment of similar to 0.5 +/- 0.2 D. This is related to polarisation effects and to weak methane-water hydrogen bond interactions. From gas phase to solution, the first vertical excitation and ionisation energies of methane are red-shifted by 0.45 +/- 0.25 and 0.87 +/- 0.40 eV, respectively. We also report results for the dynamic polarisability of methane in water. In comparison with water, no difference was found for the average monomeric dipole moment of water molecules in close interaction with methane. (c) 2011 Elsevier B.V. All rights reserved.

In situ impedance spectroscopy study of the electrochemical corrosion of Ti and Ti-6Al-4V in simulated body fluid at 25 degrees C and 37 degrees C

The corrosion resistance of Ti and Ti-6Al-4V was investigated through electrochemical impedance spectroscopy, EIS, potentiodynamic polarisation curves and UV-Vis spectrophotometry. The tests were done in Hank solution at 25 degrees C and 37 degrees C. The EIS measurements were done at the open circuit potential at specific immersion times. An increase of the resistance as a function of the immersion time was observed, for Ti (at 25 degrees C and 37 degrees C), and for Ti-6Al-4V (at 25 degrees C), which was interpreted as the formation and growth of a passive film on the metallic surfaces. (C) 2009 Elsevier Ltd. All rights reserved.

Study of electrochemical behavior of azoles for AISI 430 stainless steel in H(2)SO(4) 1 mol L(-1)

Corrosion is an undesirable process that occurs in metallic materials. Studied was the effect of inhibiting Benzotriazole (BTAH), Benzimidazole (BZM) and Indole in different concentrations-for the stainless steel (SS) AISI 430 in H(2)SO(4) mol The techniques employed this research were: anodic potenciostatic polarisation, electrochemical impedance spectroscopy, optical microscopy and scanning electron microscopy The curves of anodic polarisation showed that BTAH, BZM and Indol act as corrosion inhibitors for 430 SS, at concentrations of 1x10(-3) and 5x10(-4) mol L(-1) but do not inhibit corrosion for concentrations equal to or less than 1x10(-4) mol L(-1). The in-crease of the efficiency in relation to the inhibitory substances studied followed this order: Indol

For goodness sake! Postlogographically de-(dis)positioning education research

How are education researchers and their research now positioned? Where are education research and researchers now positioned in the public/private debate? What is the position of practitioner research in these circumstances? My paper introduces 'post logography' as a researching trope for perturbing structuralist analytic methods towards interpreting post structuralising complexities that challenge the 'positioning' of education/research/researchers.

I discuss interpreting researching with and in (with-in) educating as intertwining ways, for turning the analytical objectivity that 'positions' subjective 'facts' as essentialised 'goods', towards exploring generative states of 'goodness'.

Education and its research are typically cast as separate constructs (like teaching and outcomes) for defining the subjectification of educational objects as valuable 'goods' - especially those with private economic value.

I argue that researched educational 'goods' are mostly teaching and outcomes focussed, and mainly privately positioned, whereas researching with-in educating for 'goodness' concerns a public disposition of exploring-learning-generativity for social knowing-acting.

I am theorising that through postlogographically de-positioning the predominance of 'facts' as private 'goods', and thereby recognising interpretive states concerning and generating 'goodness', the reductive polarisation of education/research, public/private, theorist/practitioner turns towards understanding complex continua for exploring-learning-generativity, which introduce new horizons of significance for social knowing-acting.

Doing justice' : stories of everyday life in disadvantaged schools and neighbourhoods

I worked as a school administrator in 'disadvantaged schools' for many years. In this study I asked colleagues from sixteen schools in the northern and western suburbs of Adelaide to co - theorise about changes in their neighbourhood, school populations and programs, now that their schools are no longer recognised by policy as 'disadvantaged1. I explore the use of narrative method and arts based approaches by constructing a 'literary' research text that uses conventional sociological forms together with images, poetry and personal stories. I use anthropological and geographical theoretical constructs to look at the changing material, economic, cultural and social landscapes and the mosaic of inequalities in the city of Adelaide. I suggest that this is not a simple binary polarisation, although large numbers of people are similarly positioned by de-industrialisation and the diminishing social wage. After examining the literature on poverty in Australia, I am eventually prepared to call this space class, understanding that this is a sociological metaphor. Through a theorisation of each school as a 'place' within a specific neighbourhood, I look at the similarities and differences across sites. I suggest that 'disadvantaged schools' are similarly positioned as sites for the mediation of social inequalities, and that this can be readily seen in the time consuming 'housework' of discipline and welfare. I indicate how each school is differently able to 'do more with less', because of their unique neighbourhood and its narratives, knowledges, histories, teleologies and people. I show that the common coercive regimes of market devolution, new public management and the 'distributive curriculum' frame the work of teachers, students and administrators in ways that are not conducive to 'doing justice', despite the policy rhetoric of equity and community. I provide evidence that the neoliberal imaginary of context free schooling enshrined in effective schools literatures is Utopian and irrational. I argue that the capacity of the school to 'generate context' is always paradoxically dependent on 'context derived'. I discuss the notion of 'doing justice' and the benefits of 'disadvantaged schools' having a local set of principles that guide their decisions and actions and provide evidence that the school administrator's understandings of 'doing justice' are important. I also suggest that, despite being increasingly isolated and hindered by policy directions, the majority of the sixteen schools continue to work for and with principles of justice and equity, drawing on a range of emotional and intellectual resources and deep, longstanding commitments. I conclude by speculating on the kinds of policy and research agendas that might take account of both the commonalities and differences amongst 'disadvantaged schools', and what might be included in a comprehensive and systematic approach to 'doing justice'.

Paths to Buddhahood : the "sudden" and "gradual" awakening models in Mah ̄y n̄a and Vajray n̄a Buddhism

Examines the graduated paths of Mah ȳn̄a and Vajrayn̄a Buddhism and the instantaneous paths of Ch'an/Zen, rDzogs chen and Mahm̄udr.̄ The main contention between these approaches relates to how the mental defilements are to be purified and how the positive qualities of Buddhahood are to be realised. After comparing and examining the paths it is argued that the polarisation of the "sudden" and "gradual" approaches is the result of the critical philosophies of late Indian and Tibetan Buddhism, rather than a real spiritual dilemma for adherents of either path.

Research paradigms in environmental education : post war reconciliation?

Methodological self-reflection is an aspect of research rigour. Yet the "politics of method" perspective has been slow to take hold in North American environmental education. While arguments have been made concerning the need for deliberation about and congruence among the political theories of substance and method, polarisation of quantitative and qualitative researchers has tended to persist. This presentation provides an outline of the issues arising at a recent forum which aimed to transcend this polarisation of research in environmental education.

Monitoring the corrosion of concrete reinforcement using control curves

Corrosion testing (half-cell and LPR) was carried out on a number reinforced concrete panels which had been taken from the fascia of a twenty five year old high rise building in Melbourne, Australia. Corrosion, predominantly as a result of carbonation of the concrete, was associated with a limited amount of cracking. A monitoring technique was established in which probe electrodes (reference and counter) were retro-fitted into the concrete. The probe electrode setup was identical for all panels tested. It was found that the corrosion behaviour of all panels tested closely fitted a family of results when the corrosion potential is plotted against the polarisation resistance (Rp). This enabled the development of a so-called 'control curve' relating the corrosion potential to the Rp for all of the panels under investigation. This relationship was also confirmed on laboratory samples, indicating that for a fixed geometry and experimental conditions a relationship between the potential and polarisation resistance of steel can be established for the steel-concrete system. Experimental results will be presented which indicate that for a given monitoring cell geometry, it may be possible to propose criteria for the point at which remediation measures should be considered. The establishment of such a control curve has enabled the development of a powerful monitoring tool for the assessment of a number of proposed corrosion remediation techniques. The actual effect of any corrosion remediation technique becomes clearly apparent via the type and magnitude of deviation of post remediation data from the original (preremediation) control curve.

Transient response analysis of steel in concrete

A new approach is presented for the analysis of galvanostatically induced transients allowing for the rapid evaluation of the corrosion activity of steel in concrete. This method of analysis is based on the iterative fitting of a non-exponential model based on a modified KWW (Kohlrausch–Williams–Watt) formalism. This analysis yields values for the parameters related to corrosion such as the concrete resistance, polarisation resistance, interfacial capacitance and β, the non-ideality exponent.

On the electrochemical response and interfacial properties of steel–Ca(OH)2 and the steel–concrete system measured using galvanostatic pulses

The interfacial properties of the steel–concrete system are examined via a new approach for evaluation of galvanostatic pulse data. This methodology allows for rapid determination of the corrosion activity of steel, and readily yields values for parameters related to corrosion such as the polarisation resistance and interfacial capacitance. The method of analysis is based on the iterative fitting of a non-exponential model based on a modified Kohlrausch–Williams–Watt (KWW) formalism. The transient behaviour of steel in concrete is non-exponential in its form and, when analysed this way, an exponent β can be determined characterising the exponential non-ideality of the transient. This non-ideality parameter is found to differ significantly for actively corroding and passive specimens, thereby serving as a useful index to the level of corrosion being experienced. Furthermore, the investigation of the interfacial characteristics of the system, previously unobtainable in a reproducible manner via other electrochemical methods, reveal information regarding the kinetic factors governing corrosion of steel in concrete.

The corrosion inhibition mechanism of new rare earth cinnamate compounds — electrochemical studies

A combination of linear polarisation resistance (LPR) and cyclic potentiodynamic polarisation (CPP) measurements demonstrated that the lanthanum-4 hydroxy cinnamate compound could inhibit both the cathodic and anodic corrosion reactions on mild steel surfaces exposed to 0.01 M NaCl solutions. However, the dominating response was shown to vary with inhibitor concentration. At the concentrations for which the highest level of protection was achieved, both REM-4 hydroxy cinnamate (REM being lanthanum and mischmetal) displayed a strong anodic behaviour for mild steel and their inhibition performance, including their resistance against localised attack, improved with time.

Electrochemical impedance spectroscopy (EIS) measurements and modelling were carried out so as to propose a simple electrical model and correlate the extracted parameters to the inhibition mechanism put forward for REM-cinnamate based compounds. The results supported the high corrosion inhibition performance of the compounds as well as the build-up of a protective film with time. Based on a two-layer model the results suggested that the upper layer of the inhibitor film seemed to offer less resistance to the diffusion of electrochemically active species than the highly resistive inner layer at the film/metal interface.