The influence of solute carbon in cold-rolled steels on shear band formation and recrystallization texture

Two experiments were conducted to clarify the roles of grain size, solute carbon and strain in determining the recrystallization textures of cold-rolled and annealed steels. In the first experiment, samples of coarse-grained low-carbon (LC) and interstitial-free (IF) steels were cold-rolled to a 75% reduction in thickness. One sample from each steel was polished and cold-rolled an additional 5%, while the remaining samples were annealed for various times at 650°C. In the second experiment, three samples from a commercial LC steel sheet were rolled 70% at 300°C. Two of the samples were given a further rolling reduction of 5% of the original thickness, with one of the samples being given this additional reduction at 300°C and the other at room temperature. Goss recrystallization textures are strengthened by coarse initial grain sizes, the presence of solute carbon and rolling at a temperature where dynamic strain ageing occurs, but are weakened by additional rolling beyond a reduction of 70%, especially when this extra rolling is conducted at a temperature where dynamic strain ageing does not occur. Characterization of key features of the deformed and recrystallized steels using optical microscopy, scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD) supports a rationale for these effects based on the repeated activation and deactivation of shear bands and the influence of solute carbon and dynamic strain ageing on the operating life of the bands and the accumulation of strain within them.

China's Burra Charter: the formation and implementation of the China principles

In 2000, the China Principles were promulgated by the China ICOMOS as professional guidelines for the conservation of historic sites. In writing the China Principles, China ICOMOS worked in collaboration with heritage experts from the USA and Australia and adopted ideas from Western conservation codes, particularly Australia's Burra Charter. While acknowledging the influence of international trends on the heritage profession in China, the paper identifies the Chinese characteristics of the China Principles by comparing them with the Burra Charter, and raises issues about the application of the China Principles to conservation practice.

Phase formation and physical properties of mechanically alloyed amorphous 55Mg35Ni1OSi

Amorphous 55Mg35Ni10Si alloy powder has been synthesized by mechanical alloying technique using pure Mg, Ni and Si elemental powders. The transformation of the crystalline powders into an amorphous one has been investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and differential scanning calorimetry. The new material produced has a higher thermal stability than reported results, which is beneficial to the fabrication of Mg–Ni–Si bulk amorphous components through powder metallurgy.

Health-related beliefs, explanations and actions of older Anglo-Celtic-Australians

This thesis was an exploration of the health-related understandings and experiences of older Anglo-Celtic-Australians from a disadvantaged metropolitan locality. New insights were gained about the relationship between disadvantage and poor health outcomes; particularly the impact of limited self-care practices in combination with difficulties relating to the health care professionals.

Understanding of hydrogel network formation and its application in the architecture of significantly enhanced hydrogel

An understanding of the physical hydrogel network formation has been obtained by dynamic rheological experiments. The evidence shows that the network formation turns out to be a nucleation-controlled process. It was found that there exists a critical temperature Tc; fiber branching is greatly enhanced when the network formation is performed in the regime of T<Tc (T, the final setting temperature). This finding enables the authors to build significantly enhanced gel networks. So far G′ (elastic modulus) of the hydrogel network has been enhanced by 187% while the formation period can be greatly shortened to only 1/20 of the previous process.

Formation and dissolution of hen egg white lysozyme amyloid fibrils in protic ionic liquids

The formation of amyloid fibrils from non-disease-related proteins demonstrates that any protein can adopt this “rogue” form; we show that it is possible to use protic ionic liquids to fibrilize hen egg white lysozyme, and then subsequently to dissolve the fibrils with up to 72% restoration of enzymatic activity.

An electrochemical impedance study of ionic liquid film formation and aqueous corrosion of magnesium alloy ZE41

Ionic liquid surface treatments are proposed as a method of controlling corrosion processes on magnesium alloys. An important magnesium alloy, ZE41 (nominally 4% Zn and 1% rare earth), was treated with the ionic liquid trihexyl(tetradecyl)phosphonium diphenylphosphate (P₆₆₆₁₄DPP). Impedance spectra were acquired at intervals during the treatment, indicating the development of a film and allowing a measure of the film formation process to be obtained over time. Mechanically polished and electro-polished surfaces were prepared; these surfaces, treated and untreated, were subsequently exposed to 0.1 M NaCl aqueous solutions. The corrosion behavior of the prepared surfaces were assessed using impedance spectroscopy and optical microscopy. The results indicated a significant role for the method of surface preparation used and, in both cases, the ionic liquid treatment produced a more corrosion-resistant surface.

Fire management on private conservation lands : knowledge, perceptions and actions of landholders in eastern Australia

Fire is an important natural disturbance process within the Australian landscape, but the complex and hazardous nature of fire creates a conservation management dilemma. For landholders of private conservation lands, management for conservation of biodiversity and risk reduction is complicated. Private conservation landholders in eastern Australia directed far less effort towards fire management than other conservation management actions, despite clearly acknowledging the risk and associated responsibilities of fire management on their lands. Nonetheless, landholders did undertake actions to reduce fuel hazards and prepare for wildfire events on their land. Despite the established role and benefits of fire to many ecosystems in the region, landholder understanding of the ecological role of fire was generally poor. Few landholders were aware of ecologically appropriate fire regimes for the vegetation types on their property, and few undertook fire management actions to achieve ecological outcomes. Site-specific obstacles, lack of fire management knowledge and experience, and legal and containment concerns contributed to the low level of fire management observed. There is a need for property-specific fire management planning across all private conservation lands, to further integrate ecological fire requirements into biodiversity management, and prioritise actions that aim to improve conservation outcomes while safeguarding life and property.

The type II secretion system and its ubiquitous lipoprotein substrate, SsIE are required for biofilm formation and virulence of enteropathogenic escherichia coli

Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrhea in infants in developing countries. We have identified a functional type II secretion system (T2SS) in EPEC that is homologous to the pathway responsible for the secretion of heat-labile enterotoxin by enterotoxigenic E. coli. The wild-type EPEC T2SS was able to secrete a heat-labile enterotoxin reporter, but an isogenic T2SS mutant could not. We showed that the major substrate of the T2SS in EPEC is SslE, an outer membrane lipoprotein (formerly known as YghJ), and that a functional T2SS is essential for biofilm formation by EPEC. T2SS and SslE mutants were arrested at the microcolony stage of biofilm formation, suggesting that the T2SS is involved in the development of mature biofilms and that SslE is a dominant effector of biofilm development. Moreover, the T2SS was required for virulence, as infection of rabbits with a rabbit-specific EPEC strain carrying a mutation in either the T2SS or SslE resulted in significantly reduced intestinal colonization and milder disease.

Oxidative stress is induced by islet amyloid formation and time-dependently mediates amyloid-induced beta cell apoptosis

Aims/hypothesis Islet amyloid in type 2 diabetes contributes to loss of beta cell mass and function. Since islets are susceptible to oxidative stress-induced toxicity, we sought to determine whether islet amyloid formation is associated with induction of oxidative stress.

Methods Human islet amyloid polypeptide transgenic and non-transgenic mouse islets were cultured for 48 or 144 h with or without the antioxidant N-acetyl-l-cysteine (NAC) or the amyloid inhibitor Congo Red. Amyloid deposition, reactive oxygen species (ROS) production, beta cell apoptosis, and insulin secretion, content and mRNA were measured.

Results After 48 h, amyloid deposition was associated with increased ROS levels and increased beta cell apoptosis, but no change in insulin secretion, content or mRNA levels. Antioxidant treatment prevented the rise in ROS, but did not prevent amyloid formation or beta cell apoptosis. In contrast, inhibition of amyloid formation prevented the induction of oxidative stress and beta cell apoptosis. After 144 h, amyloid deposition was further increased and was associated with increased ROS levels, increased beta cell apoptosis and decreased insulin content. At this time-point, antioxidant treatment and inhibition of amyloid formation were effective in reducing ROS levels, amyloid formation and beta cell apoptosis. Inhibition of amyloid formation also increased insulin content.

Conclusions/interpretation Islet amyloid formation induces oxidative stress, which in the short term does not mediate beta cell apoptosis, but in the longer term may feed back to further exacerbate amyloid formation and contribute to beta cell apoptosis.