Understandings of sustainable corporate governance by Australian managed investment schemes and some implications for small-scale forestry in Australia

This study reveals that managers of Australian managed investment schemes understand sustainable corporate governance as a mix of financial, natural environment and social outcomes. The managers that were interviewed prioritized financial aspects of business performance but acknowledged that sustained financial performance was only possible if positive natural environment outcomes and positive social outcomes were also sustained. In this context, the managers expressed qualified support for the development of small-scale forestry in Australia

Intensification of coffee systems can increase the effectiveness of REDD mechanisms

In agricultural production systems with shade trees, such as coffee, the increase in greenhouse gas (GHG) emissions from production intensification can be compensated for, or even outweighed, by the increase in carbon sequestration into above-ground and below-ground tree biomass. We use data from a long-term coffee agroforestry experiment in Costa Rica to evaluate the trade-offs between intensification, profitability and net greenhouse gas emissions through two scenarios. First, by assessing the GHG emissions associated with conversion from shaded to more profitable full-sun (un-shaded) systems, we calculate the break-even carbon price which would need to be paid to offset the opportunity cost of not converting. The price per tCO2e of emissions reduction required to compensate for the coffee production revenue foregone varies widely from 9.3 to 196.3 US$ amongst different shaded systems. Second, as an alternative to intensification, production area can be extended onto currently forested land. We estimate this land-use change required to compensate for the shortfall in profitability from retaining lower intensity coffee production systems. For four of the five shade types tested, this land-use change causes additional GHG emissions >5 tCO2e ha−1 yr−1 resulting in net emissions >8 tCO2e ha−1 yr−1 for the whole system. We conclude that instead, by intensifying production, mechanisms similar to REDD that are based on reducing emissions through avoided land-use change (REAL) could play a major role in increasing the climate change mitigation success of agroforestry systems at the same time as aiding REDD through reducing pressure for further forest conversion to agriculture

A Novel Neurotrophic Drug for Cognitive Enhancement and Alzheimer's Disease

Currently, the major drug discovery paradigm for neurodegenerative diseases is based upon high affinity ligands for single disease-specific targets. For Alzheimer's disease (AD), the focus is the amyloid beta peptide (Aß) that mediates familial Alzheimer's disease pathology. However, given that age is the greatest risk factor for AD, we explored an alternative drug discovery scheme that is based upon efficacy in multiple cell culture models of age-associated pathologies rather than exclusively amyloid metabolism. Using this approach, we identified an exceptionally potent, orally active, neurotrophic molecule that facilitates memory in normal rodents, and prevents the loss of synaptic proteins and cognitive decline in a transgenic AD mouse model

Machinability of a near beta titanium alloy

In this paper, the machinability of a near beta Ti25Nb3Mo3Zr2Sn titanium alloy with different heat treatment histories has been investigated in terms of cutting force, chip temperature and chip formation. A solution treatment was performed followed by ageing at different temperatures for the near beta alloy. It has been shown that the same alloy behaves differently during machining at various cutting speeds after different heat treatment

A case-study on the mechanism of flank wear during laser-assisted machining of a titanium alloy

In recent years, researchers have been investigating various technologies including laser-assisted machining (LAM) to improve the machinability of titanium alloys which is considered to be one of the difficult-to-cut materials. The LAM process involves heating the titanium workpiece with a laser beam of sufficient power to soften the material before it engages with the cutting tool. Benefits of LAM include significant reduction in cutting forces as well as better surface finish. However, as diffusion wear is the most dominant tool wear mechanism associated when machining titanium alloys, the effect of the additional heat from laser preheating on the cutting tool life is not clearly understood. Therefore, this paper aims at investigating the tool life of an uncoated carbide tool during LAM of Ti-6Al-4V alloy, as well as identifying the principal flank wear mechanisms involved during the cutting process. It was found that the tool life was reduced by about 8% when machining the workpiece with laser preheating. Moreover, it was found that the carbon from the cutting tool diffused into the titanium built-up edge formed in the vicinity of the cutting zone from where it was carried out through the chips. This considerably weakened the cutting edge of the tool resulting in accelerated tool wear. Copyright © 2017 Inderscience Enterprises Ltd

Crystallisation kinetics of some archetypal ionic liquids: isothermal and non-isothermal determination of the Avrami exponent

The properties of ionic liquids give rise to applications in diverse technology areas including mechanical engineering, mining, aerospace and defence. The arbitrary physical property that defines an ionic liquid is a melting point below 100 degrees C, and as such, an understanding of crystallisation phenomena is extremely important. This is the first report dealing with the mechanism of crystallisation in ionic liquids. Assuming crystallisation of the ionic liquids is a thermal or mass diffusion-controlled process, the values of the isothermal Avrami exponent obtained from three different ionic liquids with three different anions and cations all indicate that growth occurs with a decreasing nucleation rate (n = 1.8-2.2). For one of the ionic liquids it was possible to avoid crystallisation by fast cooling and then observe a devitrification upon heating through the glass transition. The isothermal Avrami exponent of devitrification suggested growth with an increasing nucleating rate (n = 4.1), compared to a decreasing nucleation rate when crystallisation occurs on cooling from the melt (n = 2.0). Two non-isothermal methods were employed to determine the Avrami exponent of devitrification. Both non-isothermal Avrami exponents were in agreement with the isothermal case (n = 4.0-4.15). The applicability of JMAK theory suggests that the nucleation event in the ionic liquids selected is a random stochastic process in the volume of the material. Agreement between the isothermal and non-isothermal techniques for determining the Avrami exponent of devitrification suggests that the pre-exponential factor and the activation energy are independent of thermal history. The heating rate dependence of the glass transition enabled the calculation of the fragility index, which suggests that the ionic liquid is a "strong" glass former. This suggests that the temperature dependence of the rate constant could be close to Arrhenius, as assumed by JMAK theory. More generally, therefore, it can be concluded that there is nothing unusual about the crystallisation mechanism of the ionic liquids studied here

Portfolio assessment in engineering: Student perspectives on effective implementation

Dargusch, JM ORCiD: 0000-0003-4208-9843; Harris, LR ORCiD: 0000-0002-7379-3676; Taylor, BA ORCiD: 0000-0002-8229-3964Learning professional skills through exposure to real-world contexts demands sophisticated assessment practices. However, complex and often novel genres can be daunting for undergraduate students. This study examined student perspectives as they engaged in Portfolio assessment for the first time within a core undergraduate engineering unit. 42 students were surveyed (27%) with 11 participating in a follow-up telephone interview. Students rated content derived from their contributions to team projects as the most valuable component of their portfolio in terms of demonstrating the unit learning outcomes and developing the skills and dispositions needed in professional practice. The team structure of many learning opportunities encouraged students to collaborate and to draw on each other as instructional resources. The data indicated it is highly worthwhile for instructors to develop static resources that reduce students' need to contact instructors with trivial questions, though lecturer contact was deemed essential and effective for comprehending more complex tasks

A study on laser assisted machining of Ti10V2Fe3Al alloy with varying laser power

Laser-assisted machining (LAM) is a promising technique to improve the machinability of various difficult-to-machine materials such as steels, nickel and titanium alloys and metal-matrix composites. Most of the research studies are focused on analyzing the effect of various cutting parameters such as cutting speeds, feed rates and depth of cut at a constant laser power despite being reported that the maximum benefit of the LAM technique can be realised when all parameters including laser power are optimised. Therefore, the primary objective of this paper is to assess the effect of laser power on the cutting temperature and cutting forces including force fluctuations during the machining of Ti10V2Fe3Al alloy. A cutting force reduction of at least 10 % was found using the assistance of a 1,600 W laser beam between cutting speeds of 55-140 m/min. Nevertheless, it was concluded that a power of 800-1200 W for the laser beam is best suited during LAM of Ti10V2Fe3Al alloy within a cutting speed range of 55-100 m/min. Further, higher cutting speeds were recommended when employing a higher power laser beam to avoid problems such as chatter and chip pile-up