Waste avoidance and reuse strategies for residential buildings in Australia

Introduction The Beyond Waste Fund is an initiative managed by Sustainability Victoria to help businesses avoid waste sent to landfill. The fund supports innovations that focus on waste avoidance, reduction and reuse, leading to improved resource management, and better environmental outcomes. As part of the Beyond Waste Fund, a partnership between Burbank Australia, the Housing Industry Association (HIA), and the Centre for Design at RMIT University was established to conduct a research study aiming at reducing the waste generated in the construction phase of building by the volume residential building sector in Australia. The major steps in this project were to: 1.    Establish a waste audit methodology 2.    Undertake and assess an initial waste audit on a typical volume-built house 3.    Develop waste avoidance strategies 4.    Assess the efficacy of waste avoidance strategies by undertaking a final waste audit on a typical volume build-house, which utilises the identified strategies. This report presents the final outcomes of this study, outlining the goal and scope of the study, the waste audit methodology and initial audit results, waste avoidance strategies, final audit results and an assessment on the efficacy and implementation of waste avoidance strategies

Systematic review of greenhouse gas emissions for different fresh food categories

This paper presents the results of a systematic literature review of greenhouse gas emissions for different food categories from life cycle assessment (LCA) studies, to enable streamline calculations that could inform dietary choice. The motivation for completing the paper was the inadequate synthesis of food greenhouse gas emissions available in the public domain. The paper reviewed 369 published studies that provided 1,718 global warming potential (GWP) values for 168 varieties of fresh produce. A meta-analysis of the LCA studies was completed for the following categories: fresh vegetables (root vegetables, brassica, leaves and stems); fresh fruits, (pepo, hesperidium, true berries, pomes, aggregates fruits and drupes); staples (grains, legumes, nuts, seeds and rice); dairy (almond/coconut milk, soy milk, dairy milk, butter and cheese); non-ruminant livestock (chicken, fish, pork); and ruminant livestock (lamb and beef). The meta-analysis indicates a clear greenhouse gas hierarchy emerging across the food categories, with grains, fruit and vegetables having the lowest impact and meat from ruminants having the highest impact. The meta-analysis presents the median, mean, standard deviation, upper and lower quartile, minimum and maximum results for each food category. The resultant data enables streamline calculations of the global warming potential of human diets, and is illustrated by a short case study of an Australian family’s weekly shop. The database is provided in the Appendix as a resource for practitioners. The paper concludes with recommendations for future LCA studies to focus upon with respect to content and approach

The greenhouse gas profile of a “Hungry Planet”:quantifying the impacts of the weekly food purchases including associated packaging and food waste of three families

The United Nations Food and Agricultural Organisation (FAO) have estimated that 1.3 billion tonnes of food is wasted across the supply chain, while food security emerges as one of the leading challenges facing a growing global population. Life cycle assessment (LCA) can illustrate the environmental implications of food production, consumption and waste. In 2005, Peter Menzel and Faith D’Aluisio presented a photographic study in “Hungry Planet – What the World Eats” documenting what thirty families across twenty-four countries ate during the course of one week. The weekly food purchasing inventories of three of these families have been combined with LCA data to report the greenhouse gas intensity of these food purchases. The greenhouse gas emission profile including those of 128 varieties of fresh food, along with data on packaging material production and household food waste, have been used in the calculations. The paper will present the findings illustrating the contribution each component has: food, packaging and food waste; and will also discuss the implications for food packaging desig

The Sintering Behaviour of Al-Mg-Si-Cu-(Sn) Powder Metallurgy Alloys

The current, commercially available, press and sinter Al-Mg-Si-Cu alloys are based on wrought or cast alloy compositions and have not been tailored for the press and sinter process. The limited development of the Al-Mg-Si-Cu alloys for the press and sinter process can be partly attributed to a poor understanding of the effects of processing conditions on the sintering behaviour. The primary objective of this work was to investigate and understand the effects of processing conditions on the sintering behaviour of Al-Mg-Si-Cu-(Sn) alloys. Dilatometry was used in conjunction with other experimental techniques to elucidate and understand the expansion and shrinkage events that occur during the liquid-phase sintering of Al-Mg-Si-Cu-(Sn) powder metallurgy alloys. Samples were uni-axially pressed from elemental metal powder blends, de-waxed, and then sintered in a horizontal push-rod dilatometer to record the dimensional changes in the pressing direction. The processing conditions examined included the alloy composition, temperature, green density and atmosphere. A liquid forms during heating due to reactions between the alloying elements and the aluminium. This liquid is initially non-wetting on the oxide layer of the aluminium particles, resulting in separation of the particles, which is manifested by expansion of the sample. The oxide is reduced as sintering progresses, alleviating the non-wetting conditions. When more liquid forms, further expansion occurs, despite the improved wetting conditions. It is proposed that atmospheric oxygen and/or nitrogen can react with the liquid, forming a solid phase (‘shell’) at the liquid-vapour interfaces. These shells prevent the liquid from wetting the particles, resulting in further expansion and preventing shrinkage. Unbalanced diffusivities (the Kirkendall effect) between the aluminium and silicon contribute to the expansion. A mechanism is proposed to account for the transition to shrinkage, whereby the shells at the liquid-vapour interface rupture when there is a rapid increase in the volume of contained liquid. The liquid then flows out and over the shells, onto the aluminium substrate, causing shrinkage. Magnesium and nitrogen delay the transition to shrinkage by facilitating nitride shell formation at the solid-liquid interface. Silicon and tin cause an earlier transition to shrinkage by increasing the liquid volume. In addition, tin promotes shrinkage by segregating to the liquid-vapour interfaces, limiting the thickness of the shells at the liquid-vapour interfaces. The two dominant liquid-phase shrinkage mechanisms during the sintering of Al-Mg-Si-Cu-(Sn) alloys are rearrangement and pore-filling. Contact-flattening is not a dominant shrinkage mechanism, but may occur concurrently with the other mechanisms. If contact flattening occurs, a decrease in the pressure of isolated pores increases the total shrinkage rate. Nitrogen increases the shrinkage rate during rearrangement by restricting grain-growth. Magnesium increases the shrinkage rate during rearrangement by reducing the solid-liquid interface energy. Magnesium and nitrogen are essential for the formation of nitride within isolated pores, which decreases the pore pressure and increases the contribution of contact-flattening on the total shrinkage rate. Silicon reduces the beneficial influence of magnesium during rearrangement by diluting the magnesium content in the liquid. Silicon increases the pore-filling rate due to an increase in the liquid volume. Magnesium increases the pore-filling rate by facilitating aluminium nitride formation within isolated pores and by increasing the pore-filling. Tin additions can decrease the pore-filling rate due to its segregation to the liquid-vapour interface, limiting the consumption of nitrogen within isolated pores

A taxonomy of common engineering activities and competencies

In this paper, we address the lack of a unified approach to understanding engineering practice by developing and presenting a taxonomy of common engineering activities. The taxonomy consists of 86 common engineering activities linked to 17 engineering competencies and the 11 International Engineering Alliance graduate attributes. The list of activities was developed using a six-step process, including multiple systematic literature searches and surveying engineers. The taxonomy provides a critical foundation for better understanding what engineers do, particularly in the Australian and New Zealand context. The taxonomy has potential utility in both engineering practice research and engineering education curriculum reform

The BeLongEng Project – protocol and baseline data for a prospective longitudinal cohort study of engineers in Australia and New Zealand

CONTEXTEngineering practice research focusses on what engineers do (Stevens, Johri, & O’Connor, 2014). There is continued interest in the future of engineering work, and how engineering curriculum can respond to these future changes. Despite this interest, the empirical evidence on how engineering practice has changed is scant (Mazzurco, Crossin, Chandrasekaran, Daniel, & Sadewo, 2021; Stevens et al., 2014; Trevelyan, 2007).PURPOSEThe aim of the BeLongEng Project is to provide empirical evidence for policy change in engineering education and engineering practice. The goal of this paper is to describe the study protocol and baseline cohort, including analysis of the cohort’s demographics.APPROACHThe BeLongEng Project is a prospective longitudinal cohort study. Data waves will be collected over a 20-year time horizon using an online survey. In the baseline survey, collected in 2022, data were collected on participants’ demographics, psychometric factors and the engineering activities they undertake at work.OUTCOMESWe summarise the survey design, recruitment method, ethics, and data management protocols. The baseline cohort includes 889 participants. Participants were more likely to be women or female, from New Zealand, and be higher qualified, relative to the engineering population across Australia and New Zealand.CONCLUSIONSThe BeLongEng Project has recruited a large cohort of engineers living in or who studied in Australian and New Zealand who will be followed prospectively to explore trends and relationships for engineering work, and the context in which the participants work. The project represents a significant opportunity for engineering education academics to draw upon empirical research to better understand the practice of engineers, and how this practice is changing

Resource efficiency in the food manufacturing sector: DIRECT, a co-designed online tool.

International audienc