Influence of deformation conditions and texture on the high temperature flow stress of magnesium AZ31

The evolution of hot working flow stress with strain is examined in torsion, uniaxial compression and channel die compression. The flow stress was found to be strongly dependent on texture and deformation mode. At low strains this dependency accounted for a difference in flow stress of up to a factor of two. At higher strains the influence of texture and deformation mode was less marked. The stresses corresponding to an equivalent strain of 0.5 were modelled using a power law expression with an activation energy of 147 kJ/mol and a strain rate exponent of 0.15. The influence of texture and deformation mode on flow stress is rationalised in terms of the influence of prismatic slip, twinning and dynamic recrystallisation on deformation stress and structure.

The high court on vicarious liability

Vicarious liability (respondeat superior) is a venerable common law doctrine which holds an employer liable for the torts of employees, regardless of the fault of the employer. An employer's liability for the torts of its employees can represent a significant financial obligation and can affect both hiring and operational decisions of businesses. Vicarious liability is a prominent theme in the background of much litigation and is often the reason for litigating the issue of whether or not a worker is an employee. Vicarious liability may also arise through other relationships, such as partnership and agency. Two recent decisions by the High Court of Australia have drawn attention to the issue of vicarious liability. These decisions illuminate the High Court's view of vicarious liability's two main streams: negligence (Hollis v Vabu Pty Ltd) n2 and intentional tort (NSW v Lepore). [*2] n3

Section 46 of the Trade Practices Act-has the High Court made a "u-turn" on "taking advantage"?

Examination of High Court decisions on misuse of market power in regard to the element of "taking advantage" reveals inconsistency of application. Whilst being consistent regarding the need for a connection between the market power and the impugned conduct, the High Court has not been consistent regarding the degree of connection required. Two streams have developed, one supporting a high degree of connection, the other a lower degree before a firm is found to have "taken advantage" of its market power. Added to this has been the development of the "rational business explanation" which, it is argued, is either used as a defence to a s 46 action or is premised on the higher threshold of connection. Initially the high Court supported the lower threshold. In later decisions, whilst expressing support for the earlier decisions, in application the High Court favoured the higher threshold and at one point the rational business explanation. This trend appears to have been reversed with the most recent High Court decision which indicates substantive support for the earlier s 46 decisions.

The high court and the utility of multiple judgments

Recently, the High Court has been criticised for its supposed increasing tendency to deliver multiple majority judgments. Ostensibly this impairs the capacity for the Court to clarify and unify the law, thereby making it more difficult for citizens to plan and coordinate their affairs. This criticism of the High Court is unsound. First, there is no evidence to suggest that the High Court is now more fragmented than it has been during other periods of its history. Secondly, the precise reasoning process (and the underlying jurisprudence reflected by this) is a cardinal aspect of the development of precedent and legal principle. Convergence in conclusion only is of little utility and does not promote certainty and clarity in the law. One cannot make an informed assessment of the impact and breadth of a decision without an understanding of the (actual) premise underpinning the decision. It is for this reason that legislation is such a poor vehicle for declaring the law and why in recent decades there has been an increasing degree of reliance on extraneous material to assist in the interpretation of legislation. Conclusion without (genuine) reasons is not highly instructive. Coerced agreement, no matter how subtle, is undesirable. The High Court should resist calls to deliver more single majority judgments.

A lawyer's lawyer joins the high court of Australia

In November 2005, Susan Crennan was sworn in as the 45th justice of the High Court of Australia. This follows a brief two year period as a justice of the Federal Court of Australia. In this article, the author recounts the debate leading up to the latest appointment regarding what type of justice should be appointed to the Court, and reviews Crennan's Federal Court judgments in an attempt to provide some insight on the type of High Court justice Crennan will be. What is for certain is that Crennan is enchantingly mysterious.

What explains dissent on the High Court of Australia? An empirical assessment using a cointegration and error correction approach

This article examines the factors influencing the annual dissent rate on the High Court of Australia from its first full year of operation in 1904 up to 2001 within a cointegration and error correction framework. We hypothesize that institutional factors, socioeconomic complexity, and leadership style explain variations in the dissent rate on the High Court of Australia over time. The institutional factors that we consider are the Court's caseload, whether it had discretion to select the cases it hears, and whether it was a final court of appeal. To measure socioeconomic complexity we use the divorce rate, urbanization rate, and real GDP per capita. Our main finding is that in the long run and short run, caseload and real income are the main factors influencing dissent. We find that a 1 percent increase in caseload and real income reduce the dissent rate on the High Court of Australia by 0.3 percent and 0.6 percent, respectively, holding other factors constant.

Alarmed, but not alert in the "war on terror"? The High Court, Thomas V Mowbray and the Defence Power

The article examines the judgment in Thomas v. Mowbray by the High Court in Australia handed down during the so called 'War on Terror'. According to the author, (i) the High Court de-emphasized the importance of the difference between war and peace in fixing the scope of the defence power in the Australian Constitution in a manner which was inconsistent with its earlier celebrated decision in the Communist Party Case in 1950 during the Cold War; and (ii) failed to apply a sufficiently rigorous test of proportionality in characterising the impugned Commonwealth laws. The article discuss the legal background and social implications of the High Court's decision, using the Communist Party Case in 1950 as a point of comparison.

Hail to the chief! Leadership and structural change in the level of consensus on the High Court of Australia

This article identifies structural breaks in dissenting and single opinions on the High Court of Australia and uses a recent method proposed by Caporale and Grier (2002) to examine the effect of leadership on variations in the dissent rate between 1904 and 2001. Although there has been much speculation about the effectiveness of different Chief Justices in obtaining consensus on the Court, to this point most of the evidence has been anecdotal. Our main findings are that the structural breaks that we identify coincide with major turning points in the leadership of the Court and that leadership has been important in explaining variations in the proportion of dissenting opinions on the Court.

The high prevalence of vitamin D insufficiency across Australian populations is only partly explained by season and latitude

Background Inadequate sun exposure and dietary vitamin D intake can result in vitamin D insufficiency. However, limited data are available on actual vitamin D status and predictors in healthy individuals in different regions and by season.

Methods We compared vitamin D status [25-hydroxyvitamin D; 25(OH)D] in people < 60 years of age using data from cross-sectional studies of three regions across Australia: southeast Queensland (27°S; 167 females and 211 males), Geelong region (38°S; 561 females), and Tasmania (43°S; 432 females and 298 males).

Results The prevalence of vitamin D insufficiency (≤ 50 nmol/L) in women in winter/spring was 40.5% in southeast Queensland, 37.4% in the Geelong region, and 67.3% in Tasmania. Season, simulated maximum daily duration of vitamin D synthesis, and vitamin D effective daily dose each explained around 14% of the variation in 25(OH)D. Although latitude explained only 3.9% of the variation, a decrease in average 25(OH)D of 1.0 (95% confidence interval, 0.7–1.3) nmol/L for every degree increase in latitude may be clinically relevant. In some months, we found a high insufficiency or even deficiency when sun exposure protection would be recommended on the basis of the simulated ultraviolet index.

Conclusion Vitamin D insufficiency is common over a wide latitude range in Australia. Season appears to be more important than latitude, but both accounted for less than one-fifth of the variation in serum 25(OH)D levels, highlighting the importance of behavioral factors. Current sun exposure guidelines do not seem to fully prevent vitamin D insufficiency, and consideration should be given to their modification or to pursuing other means to achieve vitamin D adequacy.