A detailed investigation of nominally 2-D radical-farming scramjet combustion

This paper reports on an investigation of the flow/chemistry coupling inside a nominally two-dimensional inlet-fuelled scramjet configuration. The experiments were conducted at a freestream Mach number of 7.3 and a total flow enthalpy of 4.3MJ/kg corresponding to a Mach 9.7 flight condition. The phenomenon of radical-farming has been studied in detail using two-dimensional OH* chemiluminescence imaging and emission spectroscopy. High signal levels of excited OH (OH*) were detected behind the first shock reflections inside the combustion chamber upstream of any measurable pressure rise from combustion, which occurred towards the rear of the combustor. The production of OH in the first hot pocket initiates the ignition process and then accelerates the combustion process in the next downstream hot pocket. This was confirmed by numerical simulations of premixed hydrogen/air flow through the scramjet. Chemical kinetics analyses reveal that the ignition process is governed by the interaction between various reaction groups leading to a chainbranching explosion for low mean temperature and pressure combustion flowfields.

The SCRAMSPACE I scramjet flight design and construction

The design activities of the development of the SCRAMSPACE I scramjet-powered free-flight experiment are described in this paper. The objectives of this flight are first described together with the definition of the primary, secondary and tertiary experiments. The Scramjet configuration studied is first discussed together with the rocket motor system selected for this flight. The different flight sequences are then explained, highlighting the SCRAMSPACE I free-flyer separation and re-orientation procedures. A design trade-off study is then described considering vehicle stability, packaging, thermo-structural analysis and trajectory, discussing the alignment of the predicted performance with the mission scientific requirements. The global system architecture and instrumentation of the vehicle are then explained. The conclusions of this design phase are that a vehicle design has been produced which is able to meet the mission scientific goals and the procurement & construction of the vehicle are ongoing.

Chemiluminescence imaging in supersonic combustors operating in radical-farming mode

Emission spectroscopy was used to investigate ignition and combustion characteristics of supersonic combustion ramjet engines. Two-dimensional scramjet models with inlet injection, fuelled with hydrogen gas, were used in the study. The scramjet engines were configured to operate in radical farming mode, where combustion radicals are formed behind shock waves reflected at the walls. The chemiluminescence emission signals were recorded in a two-dimensional, time-integrated fashion to give information on the location and distribution of the radical farms in the combustors. High signal levels were detected in localised regions immediately downstream of shock reflections, an indication of localised hydroxyl formation supporting the concept of radical farming. Results are presented for a symmetric as well as an asymmetric scramjet geometry. These data represent the first successful visualisation of radical farms in the hot pockets of a supersonic combustor. Spectrally resolved measurements have been obtained in the ultraviolet wavelength range between 300 and 400 nm. This data shows that the OH! chemiluminescence signal around 306nm is not the most dominant source of radiation observed in the radical farms.

Productivity differences, technology adoption and economic growth : the case of India

When the acronym of ëBRICí was coined in 2001 by Jim OíNeill of Goldman Sachs, it was expected that economic growth rates in India, Brazil and Russia would eventually catch up with that of China. However, China has continued to outperform the other economies in the group, even after it was renamed ëBRICSí to reflect the inclusion of South Africa in 2010. The focus of this chapter is on one of the BRICS economies, namely India. Its aim is to examine from an economic perspective, why Indiaís performance has not lived up to expectations, and comment on the key challenges it faces in meeting them. We begin with some descriptive statistics regarding the progress of the Indian economy since 1990. While it has been growing at a rapid rate since the reforms it introduced in the1990s, there has been a slowdown in its overall GDP growth rates since 2008. The rate of growth experienced in the period 2003ñ07 was an average of 10.5 per cent. However, since the recession following the Global Financial Crisis (GFC) of 2008, the growth rate has fallen. From the period 2008ñ12 it has only registered an average growth rate of 6.5 per cent (World Bank, 2013). This chapter suggests that one of the major factors underpinning this slowdown is the performance of Indiaís agricultural sector. The importance of the agricultural sector is highlighted by the following stylized facts.

Tragedy and assimilation: Occupying the patterned surface

This chapter draws on biographical data about two notable pattern designers of wall surfaces in the interior. Both had personal histories of multiple careers and geographical locations and both their lives ended in mysterious circumstances. One of the pattern designers, Jim Thompson, disappeared in the Malaysian highlands in 1967 and was never found. The other, Florence Broadhurst, was brutally murdered in 1977; her case remains unsolved. This chapter theorizes that the patterned surface attracted Broadhurst and Thompson as a space to occupy and record their divergent pasts, and questions what it is to lose oneself in the surface of the interior, to find freedom (or slavery) in the abdication of control. This notion is further evidenced in creative works, including the Australian film Candy and the work by skin illustrator Emma Hack. What is it to work with the self as a two-dimensional representation in the outside world? Occupying the surface suggests a reflexive relationship with identity, that makes-over and re-shapes truths, lies and re-constructions. The chapter reminds us that the surface is never in stasis.

SCRAMSPACE : Radical-Farming Scramjet for access to space

Scramjet-based launch systems offer considerable promise for safe, reliable and economical access to space. A general Scramjets introduction is first provided, followed by the specifics of Australian Scramjet Research and the recent progress in inlet-injection radical-farming scramjets as part of the SCRAMSPACE program. Through both flight and ground tests, leveraging Australias world leadership in scramjet R&D, the SCRAMSPACE project is designed to answer key scientific and technological questions and build an industry-ready talent pool for a future Australian space industry. An extensive descriptions of all phases of the development of the SCRAMSPACE I scramjet-powered free-flight experiment are described in these lecture notes.

Surface reconstruction of wheat leaf morphology from three-dimensional scanned data

Realistic virtual models of leaf surfaces are important for a number of applications in the plant sciences, such as modelling agrichemical spray droplet movement and spreading on the surface. In this context, the virtual surfaces are required to be sufficiently smooth to facilitate the use of the mathematical equations that govern the motion of the droplet. While an effective approach is to apply discrete smoothing D2-spline algorithms to reconstruct the leaf surfaces from three-dimensional scanned data, difficulties arise when dealing with wheat leaves that tend to twist and bend. To overcome this topological difficulty, we develop a parameterisation technique that rotates and translates the original data, allowing the surface to be fitted using the discrete smoothing D2-spline methods in the new parameter space. Our algorithm uses finite element methods to represent the surface as a linear combination of compactly supported shape functions. Numerical results confirm that the parameterisation, along with the use of discrete smoothing D2-spline techniques, produces realistic virtual representations of wheat leaves.

Unpacking the role of mindfulness on conscientiousness and spirituality

The present study examined relationships between conscientiousness and intrinsic spirituality, with the proposed trait ‘mindfulness’ as mediator. The results from 161 functioning adults within an Australian context revealed that mindfulness was significantly predicted by conscientiousness. This study examined the relationship among conscientiousness, trait mindfulness and intrinsic spirituality. It was hypothesised that trait mindfulness would mediate the relationship between conscientiousness and spirituality. We found this hypothesis partially supported. Practically, these results suggest that conscientious individuals do significantly connect with mindfulness, and it was only the more mindful of conscientious individuals that also displayed high levels of intrinsic spirituality. Additional analyses also suggest that conscientious individuals connect with mindfulness through attending to current actions or regulating impulses (act aware) and have an accepting attitude towards thoughts and feelings (non-judge). Possible explanations and implications of these results are discussed in relation to theory, practice and delivery mechanisms of mindfulness.

AR and gamification concepts to reduce driver boredom and risk taking behaviours

Young males are over-represented in road crashes. Part of the problem is their proneness to boredom, a hardwired personality factor that can lead to risky driving. This paper presents a theoretical understanding of boredom in the driving context and demonstrates convincing arguments to investigate the role of boredom further. Specifically, this paper calls for the design of innovative technologies and applications that make safe driving more pleasurable and stimulating for young males, e.g., by applying gamification techniques. We propose two design concepts through the following questions: A. Can the simulation of risky driving reduce actual risky driving? B. Can the replacement of risky driving stimuli with alternative stimuli reduce risky driving? We argue that considering these questions in the future design of automotive user-interfaces and personal ubiquitous computing devices could effectively reduce risky driving behaviours among young males.

Experience indigenous culture in Arnhem Land, NT

A travel article about a journey to the Cobourg Peninsula, Arnhem Land. "NOW I know I'm back,'' says our guide David McMahon as the scent of wood smoke makes its way into the 4WD. For McMahon, being back means Kakadu and Arnhem Land, and ultimately our final destination in the Northern Territory's Cobourg Peninsula. In the north, one of the first things you need to adjust is your attitude to fire. The indigenous people have long worked with it. The rangers perform controlled burns. The animals have adapted and know how to escape the flames. The smoke trail leads us down the old Jim Jim Rd, our first stretch of dirt track since leaving Darwin. Our destination is the Venture North campsite at Garig Gunak Barlu National Park...

Understanding declining science participation in Australia : a systemic perspective

In this chapter we describe the substantial declines in student participation in senior high school physics, chemistry and biology classes in Australia over the last two decades. We outline some of the explanations commonly offered to account for these declines, focusing on two contrasting positions: first, that they are due to today’s students holding less positive attitudes towards science classes and careers than their predecessors, and second, that the declines are related to policy and structural changes at the upper secondary and tertiary education levels which have affected the relative status of subjects and the dynamics of choice. We describe how the Choosing Science study investigated the extent to which the two hypotheses were supported by empirical evidence, and discuss our findings in the light of a third result from the study concerning the role of self-identity in subject choice. We conclude that the declines in high school science enrolments are most likely related to changes in school and university curriculum options and that within this expanded curriculum marketplace, identity becomes a very important reference point in students’ decisions about whether to take science in the final years of high school.

One-step homogeneous C-reactive protein assay for saliva

Background: Cardiovascular disease is the leading cause of death in the world. Human C-reactive protein (CRP) has been used in the risk assessment of coronary events. Human saliva mirrors the body's health and well-being and is non-invasive, easy to collect and ideal for third world countries as well as for large patient screening. The aim was to establish a saliva CRP reference range and to demonstrate the clinical utility of salivary CRP levels in assessing the coronary events in a primary health care setting. Methods: We have used a homogeneous bead based assay to detect CRP levels in human saliva. We have developed a rapid 15 min (vs 90 min), sequential, one-step assay to detect CRP in saliva. Saliva was collected from healthy volunteers (n = 55, ages 20-70 years) as well as from cardiac patients (n = 28, ages 43-86 years). Results: The assay incubation time was optimised from 90 min to 15 mm and generated a positive correlation (n = 29, range 10-2189 pg/mL, r2 = 0.94; Passing Bablok slope 0.885. Intercept 0, p>0.10), meaning we could decrease the incubation time and produce equivalent results with confidence. The mean CRP level in the saliva of healthy human volunteers was 285 pg/mL and in cardiac patients was 1680 pg/mL (p<0.01). Analysis of CRP concentrations in paired serum and saliva samples from cardiac patients gave a positive correlation (r2 = 0.84, p<0.001) and the salivary CRP concentration capable of distinguishing healthy from diseased patients. Conclusions: The results suggest that this minimally invasive, rapid and sensitive assay will be useful in large patient screening studies for risk assessment of coronary events. (C) 2011 Elsevier B.V. All rights reserved.