A preliminary study into the environmental and economic consequences of a sugar factory depithing operation

Bagasse stockpile operations have the potential to lead to adverse environmental and social impacts. Dust releases can cause occupational health and safety concerns for factory workers and dust emissions impact on the surrounding community. Preliminary modelling showed that bagasse depithing would likely reduce the environmental risks, particularly dust emissions, associated with large-scale bagasse stockpiling operations. Dust emission properties were measured and used for dispersion modelling with favourable outcomes. Modelling showed a 70% reduction in peak ground level concentrations of PM10 dust (particles with an aerodynamic diameter less than 10 μm) from operations on depithed bagasse stockpiles compared to similar operations on stockpiles of whole bagasse. However, the costs of a depithing operation at a sugar factory were estimated to be approximately $2.1 million in capital expenditure to process 100 000 t/y of bagasse and operating costs were 200 000 p.a. The total capital cost for a 10 000 t/y operation was approximately $1.6 million. The cost of depithing based on a discounted cash flow analysis was $5.50 per tonne of bagasse for the 100 000 t/y scenario. This may make depithing prohibitively expensive in many situations if installed exclusively as a dust control measure.

GNSS ambiguity resolution with controllable failure rate for long baseline network RTK

Many large-scale GNSS CORS networks have been deployed around the world to support various commercial and scientific applications. To make use of these networks for real-time kinematic positioning services, one of the major challenges is the ambiguity resolution (AR) over long inter-station baselines in the presence of considerable atmosphere biases. Usually, the widelane ambiguities are fixed first, followed by the procedure of determination of the narrowlane ambiguity integers based on the ionosphere-free model in which the widelane integers are introduced as known quantities. This paper seeks to improve the AR performance over long baseline through efficient procedures for improved float solutions and ambiguity fixing. The contribution is threefold: (1) instead of using the ionosphere-free measurements, the absolute and/or relative ionospheric constraints are introduced in the ionosphere-constrained model to enhance the model strength, thus resulting in the better float solutions; (2) the realistic widelane ambiguity precision is estimated by capturing the multipath effects due to the observation complexity, leading to improvement of reliability of widelane AR; (3) for the narrowlane AR, the partial AR for a subset of ambiguities selected according to the successively increased elevation is applied. For fixing the scalar ambiguity, an error probability controllable rounding method is proposed. The established ionosphere-constrained model can be efficiently solved based on the sequential Kalman filter. It can be either reduced to some special models simply by adjusting the variances of ionospheric constraints, or extended with more parameters and constraints. The presented methodology is tested over seven baselines of around 100 km from USA CORS network. The results show that the new widelane AR scheme can obtain the 99.4 % successful fixing rate with 0.6 % failure rate; while the new rounding method of narrowlane AR can obtain the fix rate of 89 % with failure rate of 0.8 %. In summary, the AR reliability can be efficiently improved with rigorous controllable probability of incorrectly fixed ambiguities.

Do prediction markets produce well-calibrated probability forecasts?

This article presents new theoretical and empirical evidence on the forecasting ability of prediction markets. We develop a model that predicts that the time until expiration of a prediction market should negatively affect the accuracy of prices as a forecasting tool in the direction of a ‘favourite/longshot bias’. That is, high-likelihood events are underpriced, and low-likelihood events are over-priced. We confirm this result using a large data set of prediction market transaction prices. Prediction markets are reasonably well calibrated when time to expiration is relatively short, but prices are significantly biased for events farther in the future. When time value of money is considered, the miscalibration can be exploited to earn excess returns only when the trader has a relatively low discount rate.

International entrepreneurship and firm performance over economic crisis

Small and medium firms (SMEs) that operate in global markets are vulnerable to external shocks in uncertain, hostile and volatile business environments given their limited resources and inexperience. In such environments entrepreneurial firms respond by making strategic choices to mitigate such vulnerabilities. This research examines one such important strategic choice – entrepreneurial posturing and its link to financial performance in Finnish SMEs during the global financial crisis. Findings suggest that the dimensions of entrepreneurial posturing have a differential effect on firm performance depending upon the severity of the business environment as well as the firm’s degree of internationalization. Implications for theory and practice are discussed and directions for future research provided.

Cents and Sustainability : Securing Our Common Future by Decoupling Economic Growth from Environmental Pressures

The focus of Cents and Sustainability is to respond to the call by Dr Gro Brundtland in the seminal book Our Common Future to achieve, 'a new era of economic growth - growth that is forceful and at the same time socially and environmentally sustainable'. With the 20th anniversary of Our Common Future in 2007, it is clearly time to re-examine this important work in a modern global context. Using the framework of ‘Decoupling Economic Growth from Environmental Pressures’, Cents and Sustainability investigates a range of new evidence and research in order to develop a deeper understanding of how, and under what conditions, this 'forceful sustainable growth' is possible. With an introduction by Dr Jim MacNeill (former Secretary General to the Brundtland Commission, and former Director, OECD Environment Directorate 1978 -1984), the book will carry forewords from Dr Gro Brundtland (former Chair of the World Commission on Environment and Development), Dr Rajendra Pachauri (Chief, Intergovernmental Panel on Climate Change (IPCC), and joint recipient of the 2007 Nobel Peace Prize on behalf of the IPCC), and Dr Kenneth Ruffing (former Deputy Director and Chief Economist of the OECD Environment Directorate 2000 - 2005). Beginning with a detailed explanation of decoupling theory, along with investigation into a range of issues and barriers to its achievement, the book then focuses on informing national strategies for decoupling. Then putting this into action the book focuses on five key areas of decoupling, namely greenhouse gas emissions, biodiversity, freshwater extraction, waste production, and air pollution, and in each case showing compelling evidence for significant cost effective reductions in environmental pressures. The book concludes with a detailed case study of the groundbreaking application of public interest litigation to combat air pollution in Delhi, India.

Considering the economic value of natural design elements at city scale

With increasing signs of climate change and the influence of national and international carbon-related laws and agreements, governments all over the world are grappling with how to rapidly transition to low-carbon living. This includes adapting to the impacts of climate change that are very likely to be experienced due to current emission levels (including extreme weather and sea level changes), and mitigating against further growth in greenhouse gas emissions that are likely to result in further impacts. Internationally, the concept of ‘Biophilic Urbanism’, a term coined by Professors Tim Beatley and Peter Newman to refer to the use of natural elements as design features in urban landscapes, is emerging as a key component in addressing such climate change challenges in rapidly growing urban contexts. However, the economics of incorporating such options is not well understood and requires further attention to underpin a mainstreaming of biophilic urbanism. Indeed, there appears to be an ad hoc, reactionary approach to creating economic arguments for or against the design, installation or maintenance of natural elements such as green walls, green roofs, streetscapes, and parklands. With this issue in mind, this paper will overview research as part of an industry collaborative research project that considers the potential for using a number of environmental economic valuation techniques that have evolved over the last several decades in agricultural and resource economics, to systematically value the economic value of biophilic elements in the urban context. Considering existing literature on environmental economic valuation techniques, the paper highlights opportunities for creating a standardised language for valuing biophilic elements. The conclusions have implications for expanding the field of environmental economic value to support the economic evaluations and planning of the greater use of natural elements in cities. Insights are also noted for the more mature fields of agricultural and resource economics.

Embedding nature into cities – a case study of economic lessons from Singapore

Built environment design around the world faces a number of 21st Century challenges such as rising urban heat island effect and rising pollution, which are further worsened by consequences of climate change and increasing urban populations. Such challenges have caused cities around the globe to investigate options that can help to significantly reduce the environmental pressures from current and future development, requiring new areas of innovation. One such area is ‘Biophilic Urbanism’, which refers to the use of natural elements as design features in urban centres to assist efforts to address climate change issues in rapidly growing economies. Singapore is an illustration of a thriving economy that exemplifies the value of embedding nature into its built environment. The significance of urban green space has been recognised in Singapore as early as the 1960s when Lee Kuan Yew embarked on the ‘Garden City’ concept. 50 years later, Singapore has achieved its Garden City goal and is now entering a new era of sustainability, to create a ‘City in a Garden’. Although the economics of such efforts is not entirely understood, the city of Singapore has continued to pursue visions of becoming a biophilic city. Indeed, there appears to be important lessons to be learned from a city that has challenged the preconceived notion that protecting vegetation in a city is not economically viable. Hence, this paper will discuss the case study of Singapore to highlight the drivers, along with the economic considerations identified along the way. The conclusions have implications for expanding the notion of biophilic urbanism, particularly in the Australian context by discussing the lessons learned from this city. The research is part of Sustainable Built Environment National Research Centre, and has been developed in collaboration with the Curtin University Sustainability Policy Institute.

Viewpoint : social and economic dimensions of involving savanna communities in carbon management systems

In this paper we discuss the social, economic and institutional aspects of the development of carbon management systems within Australia's tropical savannas. Land-use values in savanna landscapes are changing as a result of changing economic markets, greater recognition of native title, and growing social demands and expectations for tourism, recreation and conservation. In addition, there is increasing interest in developing markets and policy arrangements for greenhouse gas abatement, carbon sequestration and carbon trade in savannas. We argue that for carbon management to lead to national greenhouse outcomes, attention must be paid to social, economic and institutional issues in environmental planning and policy arrangements. From an economic perspective, the financial impact of carbon management on savanna enterprises will depend on appropriate and available policy mechanisms, unit price for carbon, landscape condition, existing management strategies and abatement measurements used. Local social and cultural features of communities and regions may enhance or constrain the implementation of carbon abatement strategies, depending on how they are perceived. In terms of institutional arrangements, policies and plans must support and enable carbon management. We identify three areas that require priority investigation and adjustment: regional planning arrangements, property rights, and rules for accounting at enterprise and regional scales. We conclude that the best potential for managing for carbon will be achieved while managing for range of other natural resource management outcomes, especially where managing for carbon delivers collateral benefits to enterprises.

Are in vitro estimates of cell diffusivity and cell proliferation rate sensitive to assay geometry?

Cells respond to various biochemical and physical cues during wound–healing and tumour progression. In vitro assays used to study these processes are typically conducted in one particular geometry and it is unclear how the assay geometry affects the capacity of cell populations to spread, or whether the relevant mechanisms, such as cell motility and cell proliferation, are somehow sensitive to the geometry of the assay. In this work we use a circular barrier assay to characterise the spreading of cell populations in two different geometries. Assay 1 describes a tumour–like geometry where a cell population spreads outwards into an open space. Assay 2 describes a wound–like geometry where a cell population spreads inwards to close a void. We use a combination of discrete and continuum mathematical models and automated image processing methods to obtain independent estimates of the effective cell diffusivity, D, and the effective cell proliferation rate, λ. Using our parameterised mathematical model we confirm that our estimates of D and λ accurately predict the time–evolution of the location of the leading edge and the cell density profiles for both assay 1 and assay 2. Our work suggests that the effective cell diffusivity is up to 50% lower for assay 2 compared to assay 1, whereas the effective cell proliferation rate is up to 30% lower for assay 2 compared to assay 1.

Perceived obstacles to multi-storey timber-frame construction : an Australian study

The contemporary default materials for multi-storey buildings – namely concrete and steel – are all significant generators of carbon and the use of timber products provides a technically, economically and environmentally viable alternative. In particular, timber’s sustainability can drive increased use and subsequent evolution of the Blue economy as a new economic model. National research to date, however, indicates a resistance to the uptake of timber technologies in Australia. To investigate this further, a preliminary study involving a convenience sample of 15 experts was conducted to identify the main barriers involved in the use of timber frames in multi-storey buildings. A closed-ended questionnaire survey involving 74 experienced construction industry participants was then undertaken to rate the relative importance of the barriers. The survey confirmed the most significant barriers to be a perceived increase in maintenance costs and fire risk, together with a limited awareness of the emerging timber technologies available. It is expected that the results will benefit government and the timber industry, contributing to environmental improvement by developing strategies to increase the use of timber technologies in multi-storey buildings by countering perceived barriers in the Australian context.

Analysis of strain-rate dependent mechanical behavior of single chondrocyte : a finite element study

Various studies have been conducted to investigate the effects of impact loading on cartilage damage and chondrocyte death. These have shown that the rate and magnitude of the applied strain significantly influence chondrocyte death, and that cell death occurred mostly in the superficial zone of cartilage suggesting the need to further understand the fundamental mechanisms underlying the chondrocytes death induced at certain levels of strain-rate. To date there is no comprehensive study providing insight on this phenomenon. The aim of this study is to examine the strain-rate dependent behavior of a single chondrocyte using a computational approach based on Finite Element Method (FEM). An FEM model was developed using various mechanical models, which were Standard Neo-Hookean Solid (SnHS), porohyperelastic (PHE) and poroviscohyperelastic (PVHE) to simulate Atomic Force Microscopy (AFM) experiments of chondrocyte. The PVHE showed, it can capture both relaxation and loading rate dependent behaviors of chondrocytes, accurately compared to other models.

Modelling the economic benefits of gold standard care for chronic wounds in a community setting

Chronic leg ulcers are costly to manage for health service providers. Although evidence-based care leads to improved healing rates and reduced costs, a significant evidence-practice gap is known to exist. Lack of access to specialist skills in wound care is one reason suggested for this gap. The aim of this study was to model the change to total costs and health outcomes under two versions of health services for patients with leg ulcers: routine health services for community-living patients; and care provided by specialist wound clinics. Mean weekly treatment and health services costs were estimated from participants’ data (n=70) for the twelve months prior to their entry to a study specialist wound clinic, and prospectively for 24 weeks after entry. For the retrospective phase mean weekly costs of care were $AU130.30 (SD $12.64) and these fell to $AU53.32 (SD $6.47) for the prospective phase. Analysis at a population level suggests if 10,000 individuals receive 12 weeks of specialist evidence-based care, the cost savings are likely to be AU$9,238,800. Significant savings could be made by the adoption of evidence-based care such as that provided by the community and outpatient specialist wound clinics in this study.

Exploration of mechanisms underlying the strain-rate-dependent mechanical property of single chondrocytes

Based on the characterization by Atomic Force Microscopy (AFM), we report that the mechanical property of single chondrocytes has dependency on the strain-rates. By comparing the mechanical deformation responses and the Young’s moduli of living and fixed chondrocytes at four different strain-rates, we explore the deformation mechanisms underlying this dependency property. We found that the strain-rate-dependent mechanical property of living cells is governed by both of the cellular cytoskeleton (CSK) and the intracellular fluid when the fixed chondrocytes is mainly governed by their intracellular fluid which is called the consolidation-dependent deformation behavior. Finally, we report that the porohyperelastic (PHE) constitutive material model which can capture the consolidation-dependent behavior of both living and fixed chondrocytes is a potential candidature to study living cell biomechanics.

A comparison of mathematical models for phase separation in high-rate LiFePO4 cathodes

We construct a two-scale mathematical model for modern, high-rate LiFePO4cathodes. We attempt to validate against experimental data using two forms of the phase-field model developed recently to represent the concentration of Li+ in nano-sized LiFePO4crystals. We also compare this with the shrinking-core based model we developed previously. Validating against high-rate experimental data, in which electronic and electrolytic resistances have been reduced is an excellent test of the validity of the crystal-scale model used to represent the phase-change that may occur in LiFePO4material. We obtain poor fits with the shrinking-core based model, even with fitting based on “effective” parameter values. Surprisingly, using the more sophisticated phase-field models on the crystal-scale results in poorer fits, though a significant parameter regime could not be investigated due to numerical difficulties. Separate to the fits obtained, using phase-field based models embedded in a two-scale cathodic model results in “many-particle” effects consistent with those reported recently.