Anatomy of sand beach ridges : evidence from severe Tropical Cyclone Yasi and its predecessors, northeast Queensland, Australia

[1] Four well-identified tropical cyclones over the past century have been responsible for depositing distinct units of predominantly quartzose sand and gravel to form the most seaward beach ridge at several locations along the wet tropical coast of northeast Queensland, Australia. These units deposited by tropical cyclones display a key sedimentary signature characterized by a sharp basal erosional contact, a coarser grain size than the underlying facies and a coarse-skewed trend toward the base. Coarse-skewed distributions with minimal change in mean grain size also characterize the upper levels of the high-energy deposited units at locations within the zone of maximum onshore winds during the tropical cyclone. These same coarse skew distributions are not apparent in sediments deposited at locations where predominantly offshore winds occurred during the cyclone, which in the case of northeast Australia is north of the eye-crossing location. These sedimentary signatures, along with the geochemical indicators and the degraded nature of the microfossil assemblages, have proven to be useful proxies to identify storm-deposited units within the study site and can also provide useful proxies in older beach ridges where advanced pedogenesis has obscured visual stratigraphic markers. As a consequence, more detailed long-term histories of storms and tropical cyclones can now be developed.

Numerical investigation of the influence of topography on simulated downburst wind fields

A, dry, non-hydrostatic sub-cloud model is used to simulate an isolated stationary downburst wind event to study the influence topographic features have on the near-ground wind structure of these storms. It was generally found that storm maximum wind speeds could be increased by up to 30% because of the presence of a topographic feature at the location of maximum wind speeds. Comparing predicted velocity profile amplification with that of a steady flow impinging jet, similar results were found despite the simplifications made in the impinging jet model. Comparison of these amplification profiles with those found in the simulated boundary layer winds reveal reductions of up to 30% in the downburst cases. Downburst and boundary layer amplification profiles were shown to become more similar as the topographic feature height was reduced with respect to the outflow depth.

Numerical simulation of idealised three-dimensional downburst wind fields

Convective downburst wind storms generate the peak annual gust wind speed for many parts of the non-cyclonic world at return periods of importance for ultimate limit state design. Despite this there is little clear understanding of how to appropriately design for these wind events given their significant dissimilarities to boundary layer winds upon which most design is based. To enhance the understanding of wind fields associated with these storms a three-dimensional numerical model was developed to simulate a multitude of idealised downburst scenarios and to investigate their near-ground wind characteristics. Stationary and translating downdraft wind events in still and sheared environments were simulated with baseline results showing good agreement with previous numerical work and full-scale observational data. Significant differences are shown in the normalised peak wind speed velocity profiles depending on the environmental wind conditions in the vicinity of the simulated event. When integrated over the height of mid- to high rise structures, all simulated profiles are shown to produce wind loads smaller than an equivalent 10 m height matched open terrain boundary layer profile. This suggests that for these structures the current design approach is conservative from an ultimate loading standpoint. Investigating the influence of topography on the structure of the simulated near-ground downburst wind fields, it is shown that these features amplify wind speeds in a manner similar to that expected for boundary layer winds, but the extent of amplification is reduced. The level of reduction is shown to be dependent on the depth of the simulated downburst outflow.

Synthesis and characterization of titanium sol–gels in varied gravity

Two unique test systems were designed and built to allow the effects of varied gravity (high, normal, reduced) during synthesis of titanium sol–gels to be studied. A centrifuge capable of providing high gravity environments of up to 70 g for extended periods while applying a 100 mbar vacuum and a temperature of 40–50 °C to the reaction chambers was developed. The second system was used in the QUT Microgravity Drop Tower Facility also provided the same thermal and vacuum conditions used in the centrifuge, but was required to operate autonomously during free fall. Through the use of post synthesis instrumental characterization, it was found that increased gravity levels during synthesis, had the greatest effect on the final products. Samples produced in reduced and normal gravity appeared to form amorphous gels containing very small particles with moderate surface areas. Whereas crystalline anatase (TiO2), was found to form in samples synthesized above 5 g with significant increases in crystallinity, particle size and surface area observed when samples were produced at gravity levels up to 70 g. It is proposed that for samples produced in higher gravity, an increased concentration gradient of water is forms at the bottom of the reacting film due to forced convection. The particles formed in higher gravity diffuse downward toward this excess of water, which favors the condensation reaction of remaining sol–gel precursors with the particles promoting increased particle growth. Due to the removal of downward convection in reduced gravity, particle growth due to condensation reaction processes are physically hindered hydrolysis reactions favored instead. Another significant finding from this work was that anatase could be produced at relatively low temperatures of 40–50 °C instead of the conventional method of calcination above 450 °C solely through sol–gel synthesis at higher gravity levels.

Influence of jet inclination on structural loading in an experimentally simulated microburst

Steady and pulsed flow stationary impinging jets have been employed to simulate the wind field produced by a thunderstorm microburst. The effect on the low level wind field due to jet inclination with respect to the impingement surface has been studied. A single point velocity time history has been compared to the full-scale Andrews AFB microburst for model validation. It was found that for steady flow, jet inclination increased the radial extent of high winds but did not increase the magnitude of these winds when compared to the perpendicular impingement case. It was found that for inclined pulsed flow the design wind conditions could increase compared to perpendicular impingement. It was found that the location of peak winds was affected by varying the outlet conditions.

Discussion on the wind climate of Kuwait and Dubai

Historical wind data for Kuwait and Dubai have been analysed to determine the design wind speed for the region. Kuwait and Dubai are located near the northern and southern end of the Persian Gulf respectively. The winds in this region just north of the Tropic of Capricorn are dominated by the Shamal, literally 'north' in Arabic. The winds have traditional Bedouin names such as Al-Haffar (the driller), and Barih Thorayya (morning star). The Al-Dabaran is generally the strongest Shamal in late summer, and can last up to 40 days bringing sand and duststorms.

Experience has no shadow : Bell tower III

I created Experience Has No Shadow (2010) following a successful Ausdance Qld choreographic grant in 2010, which comprised of two solos and a video-dance at the Performance Space at the Judith Wright Centre. The aim of the Bell Tower III residency was to research and construct a Stage One Development that explored choreographic approaches to oral histories. Like many first generation Australians, oral histories are the way memories and experiences of distant homelands often offer the only connection to cultural origins. Consequently, I drew on auto-ethnographic references in the form of family stories – specifically those of my mother’s family - told and retold by my mother and her family as East German refugees during World War II. While working on the video, I explored a way to make a direct connection to the past stories by using a recording of my mother’s voice. She is re-telling a favourite story about Salamo the circus horse that was sold to my great grandfather as a work horse. Rather than representing the text literally, I attempted to capture the intensity of the storytelling which accompanied abstract footage of Avril Huddy filmed through perspex glass producing animal-like shapes that continually blur and morph in and out of focus. Strangely, by tying the story in with the filmed images a whole new story seems to emerge. Two distinct solos were created in collaboration with the performers, Expressions Dance Company’s Elise May and QUT’s Avril Huddy. These were performed at the Judith Wright Centre for Contemporary Arts, Performance Space, 1st April, 2010. The simplicity of its design became a key concept behind the work in terms of sets, spacing requirements, and costumes – almost minimalist. The choreographic process was conceived as highly collaborative, with commissioned music (and eventually lighting features) to act as equal partners in the performance.

The garden of Australian dreams: The moral rights of landscape architects

This article considers the moral rights controversy over plans to redesign the landscape architecture of the National Museum of Australia. This dispute raises issues about the nature and scope of moral rights; the professional standing of landscape architects; and the culture wars taking place in Australia. Part 1 considers the introduction of the Copyright Amendment (Moral Rights) Act 2000 (Cth), with its special regime for architecture and public sculpture. It focuses upon a number of controversies which have arisen in respect of copyright law and architecture - involving the National Gallery of Australia, the National Museum of Australia, the Pig ’n Whistle pub, the South Bank redevelopment, and the new Parliament House. Part 2 examines the dispute over the Garden of Australian Dreams. The controversy is a striking one - as the Australian Government sought to subvert the spirit of its own legislation, the Copyright Amendment (Moral Rights) Act 2000 (Cth). Part 3 engages in a comparative study of how copyright law and architecture are dealt with in other jurisdictions. In particular, it considers the dual operation of the Architectural Works Copyright Act 1990 (US) and the Visual Artists Rights Act 1990 (US) and a number of controversies in the United States - over the Tilted Arc sculpture, a Los Angeles tower block that appeared in the film Batman Forever, a community garden mural, a sculpture park, and the Freedom Tower.

Understanding past climate variation and environmental change for the future of an iconic landscape – K'gari Fraser Island, Queensland, Australia

The unique combination of landscapes and processes that are present and operate on Fraser Island (K'gari) create a dynamic setting that is capable of recording past environmental events, climate variations and former landscapes. Likewise, its geographic position makes Fraser Island sensitive to those events and processes. Based on optically stimulated luminescence dating, the records archived within the world's largest sand island span a period that has the potential to exceed 750 ka and contain specific records that are of extremely high resolution over the past 40,000 years. This is due to the geographic position of Fraser Island, which lies in the coastal subtropical region of Queensland Australia. Fraser Island is exposed to the open ocean currents of the Coral Sea on the east coast and the waters of Hervey Bay on its western margin and is positioned to receive moisture from the Indo-Australian monsoon, southeast trade winds and experiences occasional tropical and ex-tropical cyclones. We review literature that presents the current level of understanding of sea level change, ecological variation and environmental change on Fraser Island. The previous works illustrate the importance of Fraser Island and may link processes, environments and climates on Fraser Island with global records.

Speed-based diagnostics of aerodynamic and mass imbalance in large wind turbines

Any kind of imbalance in the operation of a wind turbine has adverse effect on the downstream torsional components as well as tower structure. It is crucial to detect imbalance at its very inception. The identification of the type of imbalance is also required so that appropriate measures of fault accommodation can be performed in the control system. In particular, it is important to distinguish between mass and aerodynamic imbalance. While the former is gradually caused by a structural anomaly (e.g. ice deposition, moisture accumulation inside blade), the latter is generally associated to a fault in the pitch control system. This paper proposes a technique for the detection and identification of imbalance fault in large scale wind turbines. Unlike most other existing method it requires only the rotor speed signal which is readily available in existing turbines. Signature frequencies have been proposed in this work to identify imbalance type based on their physical phenomenology. The performance of this technique has been evaluated by simulations using an existing benchmark model. The effectiveness of the proposed method has been confirmed by the simulation results.

A Story of Organized Crime: Constructing Criminality and Building Institutions

This is a narrative about the way in which a category of crime-to-be-combated is constructed through the discipline of criminology and the agents of discipline in criminal justice. The aim was to examine organized crime through the eyes of those whose job it is to fight it (and define it), and in doing so investigate the ways social problems surface as sites for state intervention. A genealogy of organized crime within criminological thought was completed, demonstrating that there are a range of different ways organized crime has been constructed within the social scientific discipline, and each of these were influenced by the social context, political winds and intellectual climate of the time. Following this first finding, in-depth qualitative interviews were conducted with individuals who had worked at the apex of the policing of organized crime in Australia, in order to trace their understandings of organized crime across recent history. It was found that organized crime can be understood as an object of the discourse of the politics of law and order, the discourse of international securitization, new public management in policing business, and involves the forging of outlaw identities. Therefore, there are multiple meanings of organized crime that have arisen from an interconnected set of social, political, moral and bureaucratic discourses. The institutional response to organized crime, including law and policing, was subsequently examined. An extensive legislative framework has been enacted at multiple jurisdictional levels, and the problem of organized crime was found to be deserving of unique institutional powers and configurations to deal with it. The social problem of organized crime, as constituted by the discourses mapped out in this research, has led to a new generation of increasingly preemptive and punitive laws, and the creation of new state agencies with amplified powers. That is, the response to organized crime, with a focus on criminalization and enforcement, has been driven and shaped by the four discourses and the way in which the phenomenon is constructed within them. An appreciation of the nexus between the emergence of the social problem, and the formation of institutions in response to it, is important in developing a more complete understanding of the various dimensions of organized crime.