Experimental study on creep and shrinkage of high-performance ultra-lightweight cement composite of 60 MPa

Creep and shrinkage behaviour of an ultra lightweight cement composite (ULCC) up to 450 days was evaluated in comparison with those of a normal weight aggregate concrete (NWAC) and a lightweight aggregate concrete (LWAC) with similar 28-day compressive strength. The ULCC is characterized by low density < 1500 kg/m3 and high compressive strength about 60 MPa. Autogenous shrinkage increased rapidly in the ULCC at early-age and almost 95% occurred prior to the start of creep test at 28 days. Hence, majority of shrinkage of the ULCC during creep test was drying shrinkage. Total shrinkage of the ULCC during the 450-day creep test was the lowest compared to the NWAC and LWAC. However, corresponding total creep in the ULCC was the highest with high proportion attributed to basic creep (≥ ~90%) and limited drying creep. The high creep of the ULCC is likely due to its low elastic modulus. Specific creep of the ULCC was similar to that of the NWAC, but more than 80% higher than the LWAC. Creep coefficient of the ULCC was about 47% lower than that of the NWAC but about 18% higher than that of the LWAC. Among five creep models evaluated which tend to over-estimate the creep coefficient of the ULCC, EC2 model gives acceptable prediction within +25% deviations. The EC2 model may be used as a first approximate for the creep of ULCC in the designs of steel-concrete composites or sandwich structures in the absence of other relevant creep data.

Food security

INTRODUCTION Globally, one-third of food production is lost annually due to negligent authorities. India alone loses some 21 million tonnes of wheat per year even while it has 200 million food-insecure people in the nation. Disturbingly provocative as it may sound, it is amazing how national and international institutions and governments make use of human hunger for their own survival (Raghib 2013). The global food system is increasingly insecure. Challenges to long-term global food security are encapsulated by resource scarcity, environmental degradation, biodiversity loss, climate change, reductions of farm labour and a growing world population. These issues are caused and aggravated by the spread of corporatised and monopolised food systems, dietary change, and urbanisation. These factors have rapidly brought food insecurity under the umbrella of unconventional security threats (Heukelom 2011). For some, humanitarian crises associated with food insecurity, or what has been dubbed ‘the silent tsunami’, is a pending peril, notably for the world’s poorest and most vulnerable people. For others, the food production industry is an emerging market with unprecedented profits. Despite this problem of food scarcity we are witnessing extraordinary ‘food wastage’, notably in North America and Europe, on a scale that would reportedly be capable of feeding the world’s hungry six times over (Stuart 2012). As the opening quotation to this chapter suggests, governments and corporations are deeply involved in the contexts, politics, and resources associated with food related issues. As many economically developed and advanced industrial nations are reporting a rise out of recession, announcements are made by the world’s richest countries that they are to cut $US2 billion per year from food aid. The head of the World Food Aid Programme, Rosette Sheeran, warns that such cuts could result in ‘the loss of a generation’ (Walters 2011). The global food crisis has also reinvigorated debates about agricultural development and genetically modified (GM) food; as well as fuelling debates about poverty, debt and security. This chapter provides a discussion of the political economy of global food debates and explores the threats and opportunities surrounding food production and future food security.

A comparison of mathematical models for phase separation in high-rate LiFePO4 cathodes

We construct a two-scale mathematical model for modern, high-rate LiFePO4cathodes. We attempt to validate against experimental data using two forms of the phase-field model developed recently to represent the concentration of Li+ in nano-sized LiFePO4crystals. We also compare this with the shrinking-core based model we developed previously. Validating against high-rate experimental data, in which electronic and electrolytic resistances have been reduced is an excellent test of the validity of the crystal-scale model used to represent the phase-change that may occur in LiFePO4material. We obtain poor fits with the shrinking-core based model, even with fitting based on “effective” parameter values. Surprisingly, using the more sophisticated phase-field models on the crystal-scale results in poorer fits, though a significant parameter regime could not be investigated due to numerical difficulties. Separate to the fits obtained, using phase-field based models embedded in a two-scale cathodic model results in “many-particle” effects consistent with those reported recently.

High level of MT-MMP expression is associated with invasiveness of cervical cancer cells

MMP-2 (gelatinase A) has been associated with the invasive potential of many cancer cells both in vitro and in vivo. It is now becoming clear that the activation of this enzyme might be a key step in tumor invasion. This activation process has been shown to be a membrane-associated pathway inducible by various agents such as collagen type I, concanavalin A or TGF-β, but its physiological regulation is still largely unresolved. MT-MMP was recently discovered and described as a potential gelatinase-A activator. In the present study, we investigated the expression of MT-MMP (membrane-type metalloproteinase) in cervical cancer cells both in vitro and in vivo. Comparing several in vitro-transformed cervical cell lines, previously shown to display different invasive potentials, our results showed that the ability of cells to overexpress MT-MMP mRNA following ConA induction correlated with their ability to activate gelatinase A and with a highly invasive behavior. Moreover, using immunohistochemistry and in situ hybridization, we found a higher level of MT-MMP expression in invasive cervical carcinoma and lymphnode metastases compared to its expression in non-invasive CIN III lesions. Our in vivo observations also clearly demonstrated a cooperation between stromal and tumor cells for the production of MT-MMP. Taken together, our results clearly correlated high level MT-MMP expression with invasiveness, and thus suggested that MT-MMP might play a crucial role in cervical tumor invasion.

High-frequency global navigation satellite system’s receivers for airborne gravimetry

The development of global navigation satellite systems (GNSS) provides a solution of many applied problems with increasingly higher quality and accuracy nowadays. Researches that are carried out by the Bavarian Academy of Sciences and Humanities in Munich (BAW) in the field of airborne gravimetry are based on sophisticated data processing from high frequency GNSS receiver for kinematic aircraft positioning. Applied algorithms for inertial acceleration determination are based on the high sampling rate (50Hz) and on reducing of such factors as ionosphere scintillation and multipath at aircraft /antenna near field effects. The quality of the GNSS derived kinematic height are studied also by intercomparison with lift height variations collected by a precise high sampling rate vertical scale [1]. This work is aimed at the ways of more accurate determination of mini-aircraft altitude by means of high frequency GNSS receivers, in particular by considering their dynamic behaviour.

Identifying the key sociocultural influences on drinking behavior in high and moderate binge-drinking countries and the public policy implications

Despite considerable state investment and initiatives, binge drinking is still a major behavioral problem for policy makers and communities in many parts of the world. Furthermore, the practice of bingeing on alcohol seems to be spreading to young people in countries traditionally considered to have moderate drinking behaviors. Using a sociocultural lens and a framework of sociocultural themes from previous literature to develop propositions from their empirical study, the authors examine binge-drinking attitudes and behaviors among young people from high and moderate binge-drinking countries. The authors then make proposals regarding how policy makers can use social marketing more effectively to contribute to behavior change. Qualitative interviews were conducted with 91 respondents from 22 countries who were studying in two high binge-drinking countries at the time. The results show support for three contrasting sociocultural propositions that identify influences on binge drinking across these countries.

Book reviews : "Biosecurity interventions: global health and security in question"

International Relations’ engagement with global health governance has proliferated in the last decade. There are a number of excellent works that seek to understand how the relationship between politics and health shapes and informs people’s lives and governments’ policies. However, the overt securitization of health by the IR field has, Biosecurity interventions argues, remained relatively unproblematized...

Low-cost railway level crossings - breaking down the barriers

Level crossing risk continues to be a significant safety concern for the security of rail operations around the world. Over the last decade or so, a third of railway related fatalities occurred as a direct result of collisions between road and rail vehicles in Australia. Importantly, nearly half of these collisions occurred at railway level crossings with no active protection, such as flashing lights or boom barriers. Current practice is to upgrade level crossings that have no active protection. However, the total number of level crossings found across Australia exceed 23,500, and targeting the proportion of these that are considered high risk (e.g. public crossings with passive controls) would cost in excess of AU$3.25 billion based on equipment, installation and commissioning costs of warning devices that are currently type approved. Level crossing warning devices that are low-cost provide a potentially effective control for reducing risk; however, over the last decade, there have been significant barriers and legal issues in both Australia and the US that have foreshadowed their adoption. These devices are designed to have significantly lower lifecycle costs compared with traditional warning devices. They often make use of use of alternative technologies for train detection, wireless connectivity and solar energy supply. This paper describes the barriers that have been encountered for the adoption of these devices in Australia, including the challenges associated with: (1) determining requisite safety levels for such devices; (2) legal issues relating to duty of care obligations of railway operators; and (3) issues of Tort liability around the use of less than fail-safe equipment. This paper provides an overview of a comprehensive safety justification that was developed as part of a project funded by a collaborative rail research initiative established by the Australian government, and describes the conceptual framework and processes being used to justify its adoption. The paper provides a summary of key points from peer review and discusses prospective barriers that may need to be overcome for future adoption. A successful outcome from this process would result in the development of a guideline for decision-making, providing a precedence for adopting low-cost level crossing warning devices in other parts of the world. The framework described in this paper also provides relevance to the review and adoption of analogous technologies in rail and other safety critical industries.

Security analysis of the non-aggressive challenge response of the DNP3 Protocol using a CPN Model

Distributed Network Protocol Version 3 (DNP3) is the de-facto communication protocol for power grids. Standard-based interoperability among devices has made the protocol useful to other infrastructures such as water, sewage, oil and gas. DNP3 is designed to facilitate interaction between master stations and outstations. In this paper, we apply a formal modelling methodology called Coloured Petri Nets (CPN) to create an executable model representation of DNP3 protocol. The model facilitates the analysis of the protocol to ensure that the protocol will behave as expected. Also, we illustrate how to verify and validate the behaviour of the protocol, using the CPN model and the corresponding state space tool to determine if there are insecure states. With this approach, we were able to identify a Denial of Service (DoS) attack against the DNP3 protocol.

The continuing decline of science and mathematics enrolments in Australian high schools

Is there a crisis in Australian science and mathematics education? Declining enrolments in upper secondary Science and Mathematics courses have gained much attention from the media, politicians and high-profile scientists over the last few years, yet there is no consensus amongst stakeholders about either the nature or the magnitude of the changes. We have collected raw enrolment data from the education departments of each of the Australian states and territories from 1992 to 2012 and analysed the trends for Biology, Chemistry, Physics, two composite subject groups (Earth Sciences and Multidisciplinary Sciences), as well as entry, intermediate and advanced Mathematics. The results of these analyses are discussed in terms of participation rates, raw enrolments and gender balance. We have found that the total number of students in Year 12 increased by around 16% from 1992 to 2012 while the participation rates for most Science and Mathematics subjects, as a proportion of the total Year 12 cohort, fell (Biology (-10%), Chemistry (-5%), Physics (-7%), Multidisciplinary Science (-5%), intermediate Mathematics (-11%), advanced Mathematics (-7%) in the same period. There were increased participation rates in Earth Sciences (+0.3%) and entry Mathematics (+11%). In each case the greatest rates of change occurred prior to 2001 and have been slower and steadier since. We propose that the broadening of curriculum offerings, further driven by students' self-perception of ability and perceptions of subject difficulty and usefulness, are the most likely cause of the changes in participation. While these continuing declines may not amount to a crisis, there is undoubtedly serious cause for concern.

Cryptology and network security

This book constitutes the refereed proceedings of the 11th International Conference on Cryptology and Network Security, CANS 2012, held in Darmstadt, Germany, in December 2012. The 22 revised full papers, presented were carefully reviewed and selected from 99 submissions. The papers are organized in topical sections on cryptanalysis; network security; cryptographic protocols; encryption; and s-box theory.

AISC '11 Proceedings of the Ninth Australasian Information Security Conference

The Australasian Information Security Conference (AISC) 2011 was held on 18th-19th January 2011 in Perth, Australia, as a part of the Australasian Computer Science Week 2011. AISC grew out of the Australasian Information Security Workshop and officially changed the name to Australasian Information Security Conference in 2008. The main aim of the AISC is to provide a venue for Australasian and other researchers to present their work on all aspects of information security and promote collaboration between academic and industrial researchers working in this area.