Assessing the validity of impact pathways for child labour and well-being in social life cycle assessment

Background, aim and scope: Assuming that the goal of social life cycle assessment (SLCA) is to assess damage and benefits on its ‘area of protection’ (AoP) as accurately as possible, it follows that the impact pathways, describing the cause effect relationship between indicator and the AoP, should have a consistent theoretical foundation so the inventory results can be associated with a predictable damage or benefit to the AoP. This article uses two concrete examples from the work on SLCA to analyse to what extent this is the case in current practice. One considers whether indicators included in SLCA approaches can validly assess impacts on the well-being of the stakeholder, whereas the other example addresses whether the ‘incidence of child labour’ is a valid measure for impacts on the AoPs.

Materials and methods: The theoretical basis for the impact pathway between the relevant indicators and the AoPs is analysed drawing on research from relevant scientific fields.

Results:   The examples show a lack of valid impact pathways in both examples. The first example shows that depending on the definition of ‘well-being’, the assessment of impacts on well-being of the stakeholder cannot be performed exclusively with the type of indicators which are presently used in SLCA approaches. The second example shows that the mere fact that a child is working tells little about how this may damage or benefit the AoPs, implying that the normally used indicator; ‘incidence of child labour’ lacks validity in relation to predicting damage or benefit on the AoPs of SLCA.

Discussion: New indicators are proposed to mitigate the problem of invalid impact pathways. However, several problems arise relating to difficulties in getting data, the usability of the new indicators in management situations, and, in relation to example one, boundary setting issues.

Conclusions: The article shows that it is possible to assess the validity of the impact pathways in SLCA. It thereby point to the possibility of utilising the same framework that underpins the environmental LCA in this regard. It also shows that in relation to both of the specific examples investigated, the validity of the impact pathways may be improved by adopting other indicators, which does, however, come with a considerable ‘price’.

Recommendations and perspectives: It is argued that there is a need for analysing impact pathways of other impact categories often included in SLCA in order to establish indicators that better reflect actual damage or benefit to the AoPs.

Modelling Australian business cycle fluctuations : a real business cycle approach

Provides a theoretical explanation of Australian macroeconomic fluctuations, identifies the major driving forces and measures the relative importance of different factors. The research shows that technology, the terms of trade and other real factors are the major driving forces behind Australian macroeconomic fluctations.

Drive cycle analysis of the performance of hybrid electric vehicles

 

Power-cycle-library-based control strategy for plug-in hybrid electric vehicles

It has been demonstrated that considering the knowledge of drive cycle as a priori in the PHEV control strategy can improve its performance. The concept of power cycle instead of drive cycle is introduced to consider the effect of noise factors in the prediction of future drivetrain power demand. To minimize the effect of noise factors, a practical solution for developing a power-cycle library is introduced. A control strategy is developed using the predicted power cycle which inherently improves the optimal operation of engine and consequently improves the vehicle performance. Since the control strategy is formed exclusively for each PHEV rather than a preset strategy which is designed by OEM, the effect of different environmental and geographic conditions, driver behavior, aging of battery and other components are considered for each PHEV. Simulation results show that the control strategy based on the driver library of power cycle would improve both vehicle performance and battery health.

Time and energy constraints in demanding phases of the annual cycle : an example of time limitation in refuelling migratory swans

The daily metabolizable energy intake of an animal is potentially limited by either the available feeding time or by its capacity to process energy. Animals are generally considered not to be time-limited but rather to be energy-processing-limited. This is concluded from the common observation that an animal's feeding time per day increases with a decrease in food density. We argue that such changes in feeding time are in theory also expected when no constraints are operating. Thus, a study of the constraints on energy intakes of free-living animals should be performed during demanding phases of the year. As an example, we collected data on time and energy budgets of Bewick's swan (Cygnus columbianus bewickii) refuelling during migration on fennel pondweed (Potamogeton pectinatus) tubers in two years differing two-fold in tuber biomass density. As predicted by time limitation, the feeding time (defined as the time with the head submerged) did not change in response to a change in food biomass density, both within and between years (averaging 12.2 h d⁻¹). Contrary to energy-processing limitation, and again in line with time limitation, the daily metabolizable energy intake varied, being greater in the year with high than in the year with low food densities. We conclude that more studies are needed of animals operating under demanding conditions before it can be assessed whether free-living animals are generally energy-processing- or time-limited.

Seasonal winds drive water temperature cycle and migration patterns of Southern Australian giant crab Pseudocarcinus gigas

The giant crab Pseudocarcinus gigas occurs along the continental shelf break of southern Australia. During the summer alongshore winds cause cooler water to upwell onto the shelf, and the crabs move from deeper water onto the shelf where there is more food. The combination of a preferred thermal niche and a depth-stratified food supply defines the favorable foraging environments that enhance the growth of P. gigas. Climate change is expected to cause a southerly shift of the austral subtropical high-pressure belt, and modelers have predicted more upwelling-favorable winds. The associated increase in the circulation of cooler water across the shelf is likely to provide P. gigas with an increased access to benthic food resources and their growth rate may increase in some regions.

Textural fractography of fatigue failures under variable cycle loading

A new concept of counting time at fatigue processes is proposed, aimed to reach fractographic compatibility in cases of different loading sequences. Values of cycle effectivity are summarized to give the new reference time. The improvement is shown in application - textural fractography of three specimens loaded by constant cycle, constant cycle with periodic overloading, and a random block, respectively. In contrast to the conventional crack growth rate, the reference crack growth rate is related to common morphologic features of all fracture surfaces.

Cell cycle sensing of oxidative stress in saccharomyces cerevisiae by oxidation of a specific cysteine residue in the transcription factor Swi6p

Yeast cells begin to bud and enter S phase when growth conditions are favourable during G1 phase. When subjected to some oxidative stresses, cells delay entry at G1 allowing repair of cellular damage. Hence, oxidative stress sensing is coordinated with the regulation of cell cycle. We identified a novel function of the cell-cycle regulator of Saccharomyces cerevisiae, Swi6p, as a redox sensor through its cysteine residue at position 404. When alanine was substituted at this position, the resultant mutant, C404A, was sensitive to several reactive oxygen species and oxidants including linoleic acid hydroperoxide, the superoxide anion and diamide. This mutant lost the ability to arrest in G1 phase upon treatment with lipid hydroperoxide. The Cys404 residue of Swi6p in wild-type cells was oxidised to a sulfenic acid when cells were subjected to linoleic acid hydroperoxide. Mutation of Cys404 to Ala abolished the down-regulation of expression of the G1 cyclin genes CLN1, CLN2, PCL1 and PCL2 that occurred when cells of the wild type were exposed to the lipid hydroperoxide. In conclusion, oxidative stress signaling for cell-cycle regulation occurs through oxidation of the G1/S-speicific transcription factor Swi6p and consequently leads to suppression of the expression of G1-cyclins and delay in cells entering the cell cycle.

Life cycle cost analysis of silicon and organic building integrated photovoltaic systems (BiPV)

Despite the undisputed benefits associated with photovoltaic (PV) technology, the financial barrier acts as the major hurdle before it is seen as a commercial competitive form of renewable energy. Many studies have been performed outlining the life cycle energy benefits of PV technology. However, there has been limited number of studies dedicated to the life cycle cost impacts. The aim of this paper is to identify whether life cycle cost analysis is the best approach to determining the cost contributors or savings associated with this technology. This paper has been structured similarly to previous life cycle energy studies to consider the cost implications involved within each area of the products lifecycle. Amongst many new developments, traditional silicon based units have been challenged by the introduction of new organic systems; and recent studies highlight that these systems offer major cost reductions. Based on an analysis of current literature, this paper identifies that the recent growth and development of both organic and silicon based systems have had a considerable effect on the cost of PV cells. The competitive nature of the renewable energy market will also impact on a life cycle cost analysis; and any potential findings will valid for a limited timeframe.