Creeping insulation - Hong Kong green wall

Hong Kong is a densely populated city suffering badly from the urban heat island effect. Green wall offers a means of ameliorating the situation but there are doubts over its suitability in Hong Kong’s unique environment. In this paper, we look at the potential for green walls in Hong Kong first by summarizing some of the Chinese green walling systems and associated vegetation in use, then by an introduction to three existing green walls in Hong Kong, and finally through a small experiment aimed at identifying the likely main effects of green walled housing. The results indicate that green walling in Hong Kong is likely to provide enhanced internal house environment in terms of warm weather temperature reduction, stabilization and damping, with direct energy savings in air-conditioning and indirect district benefits of reduced heat island effect and carbon emissions. The green walling insulation properties also suggest the possibility of warmer homes in winter and/or energy savings in mechanical heating provision.

Small signal stability analysis of power systems with high penetration of wind power

The integration of large amount of wind power into a power system imposes a new challenge for the secure and economic operation of the system. It is necessary to investigate the impacts of wind power generation on the dynamic behavior of the power system concerned. This paper investigates the impacts of large amount of wind power on small signal stability and the corresponding control strategies to mitigate the negative effects. The concepts of different types of wind turbine generators (WTGs) and the principles of the grid-connected structures of wind power generation systems are first briefly introduced. Then, the state-of-the-art of the studies on the impacts of WTGs on small signal stability as well as potential problems to be studied are clarified. Finally, the control strategies on WTGs to enhance power system damping characteristics are presented.

Separating shadows

This practice-led research is in the field of dance creation and performance. The dancer, unlike many artists from different fields, has to contend with the added complexity of being a creative tool. Grove states, ‘..they are the phenomenon of self-creation twice over, being both the artist and the work of art’ (2005, 44). A dancer’s success relies on the quality of their instrument and their ability to reliably employ it in the creative act (Jowitt 2001a). The traditional rehearsal studio is the creative meeting place for dance artists. A liminal space with specific spatial, temporal and personal considerations: a space fraught with uncertainty and vulnerability, ripe with potential. If harnessed, the creative potential inherent in vulnerability, experienced as increased sensitivity and openness (Press 2002), can facilitate new ways of investigating and doing. This research investigated ways in which dancers prepare themselves during the act of creation and rehearsal within the studio, for the public presentation of a site-specific dance work. Navigating the complexities inherent in performing site-specific dance work is best achieved through the development of a connection with the site during the creation of the work. This is achieved through the provision of rehearsals within the site and ensures seamless replication of rehearsal qualities from studio to non-traditional site. This research received funding and support from the Australia Council for the Arts, Arts Queensland, Brisbane Festival, Kelvin Grove Urban Village, Besen Family Foundation, Korean Culture Arts Foundation and the Australia Korea Foundation. It was presented in the Brisbane Festival, 2006. http://www.accentedbody.com/projects/accented-body

Modal flexibility method for structural damage detection in suspension bridges

Suspension bridges meet the steadily growing demand for lighter and longer bridges in today’s infrastructure systems. These bridges are designed to have long life spans, but with age, their main cables and hangers could suffer from corrosion and fatigue. There is a need for a simple and reliable procedure to detect and locate such damage, so that appropriate retrofitting can be carried out to prevent bridge failure. Damage in a structure causes changes in its properties (mass, damping and stiffness) which in turn will cause changes in its vibration characteristics (natural frequencies, modal damping and mode shapes). Methods based on modal flexibility, which depends on both the natural frequencies and mode shapes, have the potential for damage detection. They have been applied successfully to beam and plate elements, trusses and simple structures in reinforced concrete and steel. However very limited applications for damage detection in suspension bridges have been identified to date. This paper examines the potential of modal flexibility methods for damage detection and localization of a suspension bridge under different damage scenarios in the main cables and hangers using numerical simulation techniques. Validated finite element model (FEM) of a suspension bridge is used to acquire mass normalized mode shape vectors and natural frequencies at intact and damaged states. Damage scenarios will be simulated in the validated FE models by varying stiffness of the damaged structural members. The capability of damage index based on modal flexibility to detect and locate damage is evaluated. Results confirm that modal flexibility based methods have the ability to successfully identify damage in suspension bridge main cables and hangers.

Damage detection in cable structures using vibration characteristics

Cable structures find many applications such as in power transmission, in anchors and especially in bridges. They serve as major load bearing elements in suspension bridges, which are capable of spanning long distances. All bridges, including suspension bridges, are designed to have long service lives. However, during this long life, they become vulnerable to damage due to changes in loadings, deterioration with age and random action such as impacts. The main cables are more vulnerable to corrosion and fatigue, compared to the other bridge components, and consequently reduces the serviceability and ultimate capacity of the bridge. Detecting and locating such damage at the earliest stage is challenging in the current structural health monitoring (SHM) systems of long span suspension bridges. Damage or deterioration of a structure alters its stiffness, mass and damping properties which in turn modify its vibration characteristics. This phenomenon can therefore be used to detect damage in a structure. The modal flexibility, which depends on the vibration characteristics of a structure, has been identified as a successful damage indicator in beam and plate elements, trusses and simple structures in reinforced concrete and steel. Successful application of the modal flexibility phenomenon to detect and locate the damage in suspension bridge main cables has received limited attention in recent research work. This paper, therefore examines the potential of the modal flexibility based Damage Index (DI) for detecting and locating damage in the main cable of a suspension bridge under four different damage scenarios. Towards this end, a numerical model of a suspension bridge cable was developed to extract the modal parameters at both damaged and undamaged states. Damage scenarios considered in this study with varied location and severity were simulated by changing stiffness at particular locations of the cable model. Results confirm that the DI has the potential to successfully detect and locate damage in suspension bridge main cables. This simple method can therefore enable bridge engineers and managers to detect and locate damage in suspension bridges at an early stage, minimize expensive retrofitting and prevent bridge collapse.

Deep dermal burn injury results in scarless wound healing in the ovine fetus

Early to mid-term fetuses heal cutaneous incisional wounds without scars; however, fetal response to burn injury has not been ascertained. We present a fetal model of thermal injury and subsequent analysis of fetal and lamb response to burn injury. A reproducible deep dermal burn injury was created in the fetus by application of water at 66 degrees C for 7 seconds, and at 82 degrees C for 10 seconds to the lamb. Macroscopically, the area of fetal scald was undetectable from day 7 post injury, while all lamb scalds were readily identified and eventually healed with scarring. Using a five-point histopathology scoring system for alteration in tissue morphology, differences were detected between control and scalded skin at all stages in lamb postburn, but no difference was detected in the fetal model after day 7. There were also large differences in content of alpha-smooth muscle actin and transforming growth factor-beta1 between control and scalded lamb and these differences were statistically significant at day 14 (P < 0.01). This novel model of fetal and lamb response to deep dermal injury indicates that the fetus heals a deep burn injury in a scarless fashion. Further elucidation of this specific fetal process of burn injury repair may lead to improved outcome for patients with burn injury.

TEXTA Book Club in the QUT Art Museum

TEXTA runs as a type of book club that we have previously labelled as ‘bespoke’ (Ellison, Holliday and Van Luyn 2012). We visualise TEXTA as a meeting place between the community and the university, as a space for discussion and engagement with both visual art forms and written texts. In today’s presentation, we shall briefly establish the ‘bespoke’ bookclub. We then want to introduce the idea of TEXTA as an example of a book club that negotiates Edward Soja’s Thirdspace (1996) – a space that incorporates and extends concepts of First and Secondspace (or perceived and conceived spaces). In doing so, we showcase two recent sessions of TEXTA as case studies. We will then illustrate some ideas we have for expanding TEXTA beyond the boundaries of Brisbane city, and invite feedback on how to further extend the opportunities for community engagement that TEXTA can offer in regional areas.

Expression, regulation and putative nutrient-sensing function of taste GPCRs in the heart

G protein-coupled receptors (GPCRs) are critical for cardiovascular physiology. Cardiac cells express >100 nonchemosensory GPCRs, indicating that important physiological and potential therapeutic targets remain to be discovered. Moreover, there is a growing appreciation that members of the large, distinct taste and odorant GPCR families have specific functions in tissues beyond the oronasal cavity, including in the brain, gastrointestinal tract and respiratory system. To date, these chemosensory GPCRs have not been systematically studied in the heart. We performed RT-qPCR taste receptor screens in rodent and human heart tissues that revealed discrete subsets of type 2 taste receptors (TAS2/Tas2) as well as Tas1r1 and Tas1r3 (comprising the umami receptor) are expressed. These taste GPCRs are present in cultured cardiac myocytes and fibroblasts, and are enriched in myocytes, which we corroborated using in situ hybridization. Tas1r1 gene-targeted mice (Tas1r1Cre/Rosa26tdRFP) strikingly recapitulated these data. In vivo taste receptor expression levels were developmentally regulated in the postnatal period. Intriguingly, several Tas2rs were upregulated in cultured rat myocytes and in mouse heart in vivo following starvation. The discovery of taste GPCRs in the heart opens an exciting new field of cardiac research. We predict that these taste receptors may function as nutrient sensors in the heart.

Wide-area control of aggregated power systems

This paper proposes a new method for stabilizing disturbed power systems using wide area measurement and FACTS devices. The approach focuses on both first swing and damping stability of power systems following large disturbances. A two step control algorithm based on Lyapunov Theorem is proposed to be applied on the controllers to improve the power systems stability. The proposed approach is simulated on two test systems and the results show significant improvement in the first swing and damping stability of the test systems.

Jacobian-free Newton-Krylov methods with GPU acceleration for computing nonlinear ship wave patterns

The nonlinear problem of steady free-surface flow past a submerged source is considered as a case study for three-dimensional ship wave problems. Of particular interest is the distinctive wedge-shaped wave pattern that forms on the surface of the fluid. By reformulating the governing equations with a standard boundary-integral method, we derive a system of nonlinear algebraic equations that enforce a singular integro-differential equation at each midpoint on a two-dimensional mesh. Our contribution is to solve the system of equations with a Jacobian-free Newton-Krylov method together with a banded preconditioner that is carefully constructed with entries taken from the Jacobian of the linearised problem. Further, we are able to utilise graphics processing unit acceleration to significantly increase the grid refinement and decrease the run-time of our solutions in comparison to schemes that are presently employed in the literature. Our approach provides opportunities to explore the nonlinear features of three-dimensional ship wave patterns, such as the shape of steep waves close to their limiting configuration, in a manner that has been possible in the two-dimensional analogue for some time.

Living City 2013 Workshop

Living City 2013 Workshop, as part of a school term’s design-based curriculum connected to the KGSC/QUT Design Excellence Program and run from 11 February – 1 May, 2013, was essentially a three-day place-based urban design immersion workshop program for 25 Year 11 Visual Art and Design Students and 2 Teachers from Kelvin Grove State College (KGSC) held at both Queensland University of Technology (QUT) Gardens Point Campus and The Edge, State Library of Queensland. Mentored by 4 design professionals, 2 tertiary design academics, 2 public artists, and 12 QUT tertiary design students, the workshop explored youth-inspired public space design solutions for the active Brisbane City Council redevelopment site of Queens Wharf Road precinct. As well as the face-to-face workshops, for Living City 2013, an interactive web environment was introduced to enable students to connect with each other and program mentors throughout the course of the program. The workshop, framed within notions of ecological, economic, social and cultural sustainability, aimed to raise awareness of the layered complexity and perspectives involved in the design of shared city spaces and to encourage young people to voice their own concerns as future citizens about the shape and direction of their city. The program commenced with an introductory student briefing by stakeholders and mentors at KGSC on 11 February, an introduction to site appraisal and site visit held at QUT and Queens Wharf Road on 20 February, and a follow up site analysis session on 6 March. Day 1 Workshop on April 17 at the Edge, State Library of Queensland, as part of the Design Minds partnership (http://designminds.org.au/kelvin-grove-state-college-excellence-in-art-design/), focused on mentoring team development of a concept design for a range of selected sites. Two workshops on April 22 and 23 at QUT, to develop these designs and presentation schemes, followed this. The workshop program culminated in a visual presentation of concept design ideas and discussion with a public audience in the Ideas Gallery on The Deck, King George Square during the Brisbane City Council City Centre Master Plan Ideas Fiesta on 1 May, 2013, as referenced in the Ideas Fiesta Wrap-up Report (http://www.brisbane.qld.gov.au/planning-building/planning-guidelines-tools/city-centre-master-plan/city-centre-master-plan-ideas-fiesta). Students were introduced to design methodology, team thinking strategies, the scope of design practices and professions, presentation skills and post-secondary pathways, while participating teachers acquired content and design learning strategies transferable in many other contexts. The program was fully documented on the Living City website (http://www.livingcity.net.au/LC2013x/index.html) and has been recognised by the Brisbane City Council Youth Strategy 2014-2019 as a best practice model for making Brisbane a well-designed, subtropical city.

Energy-based nonlinear control of ship roll gyro-stabiliser with precession angle constraints

In this paper, we consider a passivity-based approach for the design of a control law of multiple ship-roll gyro-stabiliser units. We extend previous work on control of ship roll gyro-stabilisation by considering the problem within a nonlinear framework. In particular, we derive an energy-based model using the port-Hamiltonian theory and then design an active precession controller using passivity-based control interconnection and damping assignment. The design considers the possibility of having multiple gyro-stabiliser units, and the desired potential energy of the system (in closed loop) is chosen to behave like a barrier function, which allows us to enforce constraints on the precession angle of the gyros.

Regulation and integral control of an underactuated robotic system using IDA-PBC with dynamic extension

This paper proposes a method for design of a set-point regulation controller with integral action for an underactuated robotic system. The robot is described as a port-Hamiltonian system, and the control design is based on a coordinate transformation and a dynamic extension. Both the change of coordinates and the dynamic extension add extra degrees of freedom that facilitate the solution of the matching equation associated with interconnection and damping assignment passivity-based control designs (IDA-PBC). The stability of the controlled system is proved using the closed loop Hamiltonian as a Lyapunov candidate function. The performance of the proposed controller is shown in simulation.