949 resultados para variable line-space gratings
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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.
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The propagation of Langmuir waves in nonisothermal plasmas contaminated by fine dust particles with variable charge is investigated for a self-consistent closed system. Dust charge relaxation, ionization, recombination, and collisional dissipation are taken into account. It is shown that the otherwise unstable coupling of the Langmuir and dust-charge relaxation modes becomes stable and the Langmuir waves are frequency down-shifted.
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In this paper we provide normative data along multiple cognitive and affective variable dimensions for a set of 110 sounds, including living and manmade stimuli. Environmental sounds are being increasingly utilized as stimuli in the cognitive, neuropsychological and neuroimaging fields, yet there is no comprehensive set of normative information for these type of stimuli available for use across these experimental domains. Experiment 1 collected data from 162 participants in an on-line questionnaire, which included measures of identification and categorization as well as cognitive and affective variables. A subsequent experiment collected response times to these sounds. Sounds were normalized to the same length (1 second) in order to maximize usage across multiple paradigms and experimental fields. These sounds can be freely downloaded for use, and all response data have also been made available in order that researchers can choose one or many of the cognitive and affective dimensions along which they would like to control their stimuli. Our hope is that the availability of such information will assist researchers in the fields of cognitive and clinical psychology and the neuroimaging community in choosing well-controlled environmental sound stimuli, and allow comparison across multiple studies.
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A theory of low-frequency dust-acoustic waves in low-temperature collisional plasmas containing variable-charge impurities is presented. Physical processes such as dust-charge relaxation, ionization-recombination of the electrons and ions, electron and ion elastic collisions with neutrals and dusts, as well as charging collisions with the dusts, are taken into account. Inclusion of these processes allows a balance of the plasma particles and thus a self-consistent determination of the stationary state of the unperturbed plasma. The generalized dispersion relation describing the propagation and damping of the dust acoustic waves is derived and analyzed. © 2000 American Institute of Physics.
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Recent literature credits community art spaces with both enhancing social interaction and engagement and generating economic revitalization. This article argues that the ability of art spaces to realize these outcomes is linked to their role as public spaces and that their community development potential can be expanded with greater attention to this role. An analysis of the public space characteristics is useful because it encourages consideration of sometimes overlooked issues, particularly the effect of the physical environment on outcomes related to community development. I examine the relationship between public space and community development at various types of art spaces including artist cooperatives, ethnic-specific art spaces, and city-sponsored art centers in central city and suburban locations. This study shows that through their programming and other activities, art spaces serve various public space roles related to community development. However, the ability of many to perform as public spaces is hindered by facility design issues and poor physical connections in their surrounding area. This article concludes with proposals for enhancing the community development role of the art spaces through their function as public spaces.
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Interest in the participation of Indigenous peoples in higher education has, in recent times, gained momentum with an increasing number of advocates challenging the global history of culturally inept policies and practices imposed within the western higher education system. To address the challenges being presented by Indigenous communities and other groups (often relegated under the banner of disadvantaged or equity) Western Universities are promoting a shift toward inclusive policies and practices. Frustrated with the offerings of the Western Higher Education system, a global movement of Indigenous academics, Elders and knowledge holders are developing strategies to meet the educational needs of their own communities, in order to find a way forward. The mobilization of Elders and Indigenous academics has resulted in the development of a global higher education network which is proving to be a significant force in changing the position of Indigenous participation in higher education. The World Indigenous Network Higher Education Consortium (WINHEC) has presented a significant challenge to those barriers within the western higher education system that has historically demonstrated an inability to develop culturally inclusive practices within their institutions. This paper examines the development of a world Indigenous higher education movement and its contribution to the history of the “university” within the context of western higher education institutions. Outlined in this examination will be a synopsis of the development of the “University of Excellence” and the creation of an international Indigenous space within higher education.
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While the body, time and space are fundamental to human experience, comparatively little attention has been given to the connections between them. Here scholars from a wide range of disciplines explore important themes of embodied life in time and space across cultures, activities and bodymind states. Motivated by a common desire to deepen and extend our comprehension of these phenomena and the connections and conversations between them, this book emerged from intense inter-disciplinary dialogue during the 1st Global Conferences on Time, Space and the Body and Body Horror. A plenitude of theoretical approaches and media are deployed to investigate assumptions and pose problems, to creatively deconstruct and reconstruct the terms through which experience is rendered meaningful, pleasurable, and functional. These investigations, pursued through various research methods in fields of the arts, social and psychological sciences and humanities, invite readers into a genuinely pluralistic conversation around the most basic and profound aspects of being.
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The experiences and constructs of time, space and bodies saturate human discourse—naturally enough, since they are fundamental to existence—yet there has long been a tendency for the terms to be approached somewhat independently, belying the depth of their interconnections. It was a desire to address that apparent shortcoming that inspired this book, and the interdisciplinary meetings from which it was born, the 1st Global Conferences on ‘Time, Space and the Body’ and ‘Body Horror’ held in Sydney in February 2013. Following the lively, often provocative, exchange of ideas throughout those meetings, the writing here crosses conventional boundaries inhabiting everyday life and liminal experiences, across cultures, life circumstances, and bodily states. Through numerous theoretical frameworks and with reference to a variety of media, the authors problematize or deconstruct commonplace assumptions to reveal challenging new perspectives on the diverse cultures and communities which make our world. If there is an overarching theme of this collection it is diversity itself. The writers here come from numerous academic fields, but a good number of them also draw on first-hand cultural production in the arts: photography, sculpture and fine art instillation, for example. Of course, however laudable it might be, there is a potential problem in such diversity: does it produce fruitful dialogue moving toward creative, workable syntheses or simply a cacophony of competing, incomprehensible, barely comprehending voices? To a large degree this depends upon the intellectual, existential ambitions as well as the old-fashioned goodnatured tolerance of both writers and readers. But we hope three unifying characteristics are discernable in the following chapters viewed as a whole: firstly, a genuine concern for the world humans inhabit and the communities they form as bodies in space and time; secondly, an emphasis upon the experience of the human subject, exemplified perhaps by the number of chapters drawing on phenomenology; thirdly, an adventurous, explorative impulse associated with an underlying sense that being, since it is inseparable from the body’s temporality, is always becoming, and here the presence of poststructuralist influences is unmistakable, often explicit. Our challenge as editors has been to present the enormous variety of subjects and views in a way that would render the book coherent and at the same time encourage readers to make explorations themselves into realms they might usually consider beyond their field of interest. To that end we have divided the book into six sections around loosely defined themes, each offering different angles on how time and/or space unfold in and around bodies.
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Corona discharge is responsible for the small ions found near overhead power lines, and these are capable of modifying the ambient electrical environment such as the dc electric field at ground level (Fews, Wilding et al. 2002). Once produced, small ions quickly attach to aerosol particles in the air, producing ‘large ions’ which are roughly 1 nm to 1 µm in diameter. However, very few studies have reported measurements of ions produced by power lines and its impact on particle charge concentrations. In this present study, the measurements were conducted as a function of normal downwind distance from a 275kV power line for investigating the effect of corona ions on air ions, aerosol particle charge concentration and dc e-filed.
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The drive towards high efficiency wind energy conversion systems has resulted in almost all the modern wind turbines to operate in the variable speed mode which inevitably requires back-to-back power electronic converters to decouple generator dynamics from the grid. The aim of this paper is to present an analysis on suitable topologies for the generator-side converter (rectifier) of the back-to-back converter arrangement. Performance of the two most popular rectifier systems, namely, the passive diode bridge rectifier and the active six-switch two-level rectifier are taken as two extremes to evaluate other topologies presented in this paper. The other rectifier systems considered in this study include combinations of a diode bridge rectifier and electronic reactance(s), a combination of a rectifier and a dc-dc converter and a half controlled rectifier. Diode-clamped and capacitor-clamped three-level active rectifier topologies and their possible switch reductions are also discussed in relation to the requirements of modern high power wind energy conversion systems (WECSs). Simulation results are presented to support conclusion derived from this analysis.
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The spatiotemporal dynamics of an alien species invasion across a real landscape are typically complex. While surveillance is an essential part of a management response, planning surveillance in space and time present a difficult challenge due to this complexity. We show here a method for determining the highest probability sites for occupancy across a landscape at an arbitrary point in the future, based on occupancy data from a single slice in time. We apply to the method to the invasion of Giant Hogweed, a serious weed in the Czech republic and throughout Europe.
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This paper presents a new direct integration scheme for supercapacitors that are used to mitigate short term power fluctuations in wind power systems. The idea is to replace ordinary capacitors of a 3-level flying capacitor inverter by supercapacitors and operate them under variable voltage conditions. This approach eliminates the need of interfacing dc-dc converters for supercapacitor integration and thus considerably improves the overall efficiency. However, the major problem of this unique system is the change of supercapacitor voltages. An analysis on the effects of these voltage variations are presented. A space vector modulation method, built from the scratch, is proposed to generate undistorted current even in the presence of dynamic changes in supercapacitor voltages. A supercapacitor voltage equalisation algorithm is also proposed. Furthermore, resistive behavior of supercapacitors at high frequencies and the need for a low pass filter are highlighted. Simulation results are presented to verify the efficacy of the proposed system in suppressing short term wind power fluctuations.
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Design principles for learning spaces for 21st century learning emphasise flexibility and collaboration. Yet it is rare in Australian schools for school leaders to invite students and teachers to collaborate in the design process or to prepare them for the transition into innovative physical learning spaces that are often designed to challenge and change existing learning habits. This article presents a qualitative case study of how one primary school leader led a successful transition for a teacher and her students by inviting them to design their future physical learning space and reconstruct their pedagogic relationships. This article analyses her leadership practices drawing from literature in the learning space, student voice and leadership fields to consider the benefits and challenges experienced by the collaborators when making space to learn.
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Anuradha Mathur and Dilip da Cunha theorise in their work on cities and flooding that it is not the floodwaters that threaten lives and homes, the real cause of danger in natural disaster is the fixity of modern civilisation. Their work traces the fluidity of the boundaries between 'dry' and 'wet' land challenging the deficiencies of traditional cartography in representing the extents of bodies of water. Mathur and da Cunha propose a process of unthinking to address the redevelopment of communities in the aftermath of natural disaster. By documenting the path of floodwaters in non-Euclidean space they propose a more appropriate response to flooding. This research focuses on the documentation of flooding in the interior of dwellings, which is an extreme condition of damage by external conditions in an environment designed to protect from these very elements. Because the floodwaters don't discriminate between the interior and the exterior, they move between structures with disregard for the systems of space we have in place. With the rapid clean up that follows flood damage, little material evidence is left for post mortem examination. This is especially the case for the flood damaged interior, piles of materials susceptible to the elements, furniture, joinery and personal objects line curbsides awaiting disposal. There is a missed opportunity in examining the interior in the after math of flood, in the way that Mathur and Dilip investigate floods and the design of cities, the flooded interior proffers an undersigned interior to study. In the absence of intact flood damaged interior, this research relies on two artists' documentation of the flooded interior. The first case study is the mimetic scenographic interiors of a flood-damaged office exhibited in the Bangkok art gallery by the group _Proxy in 2011. The second case study is Robert Polidori's photographic exhibition in New Orleans, described by Julianna Preston as, 'a series of interiors undetected by satellite imaging or storm radar. More telling, more dramatic, more unnerving, more alarming, they force a disturbance of what is familiar'.
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The Woods Bagot 2007 refurbishment of the Qantas and British Airways Bangkok Business lounge in the Survarnabhumi Airport features wall finishes designed by wallpaper designer, Florence Broadhurst (1899-1977) and Thai Silk trader, Jim Thompson (1906-1967). This distinctive selection, which is proclaimed on the airport’s website, of patterned wall surfaces side by side draws attention to their striking similarities and their defining differences . Thompson and Broadhurst would appear to be worlds apart, but here in the airport their work brings them together. Thompson, the son of a wealthy cotton family in America, worked as an architect before joining the army. He moved to Bangkok to start The Thai Silk Company in 1948. Broadhurst was born on a farm in Mt. Perry, Queensland. She began her career as a performance artist, as part of an Australian troupe in Shanghai, moving onto pursue a career in fashion design, catering to the middle and upper classes in London. Upon her return to Australia, Broadhurst started a print design company in 1959. Both Broadhurst and Thompson pursued multiple careers, lived many lives, and died under mysterious circumstances. Broadhurst was murdered in 1977 at her Sydney print warehouse, which remains an unsolved crime. Thompson disappeared in Malaysia in 1967 and his body has never been found. This chapter investigates the parallels between Thompson and Broadhurst and what lead them to design such popular patterns for wall surfaces towards the end of their careers. While neither designer was a household name, their work is familiar to most, seen in the costume and set design of films, on the walls of restaurants and cafes and even in family homes. The reason for the popularity of their patterns has not previously been analysed. However, this chapter suggests that the patterns are intriguing because they contain something of their designers’ identities. It suggests that the coloured surface provides a way of camouflaging and hiding its subjects’ histories, such that Broadhurst and Thompson, consciously or unconsciously, used the patterned surface as a plane in which their past lives could be buried. The revealing nature of the stark white wall, compared with the forgiveness provided by the pattern in which to hide, is elaborated by painter and advocate for polychromatic architecture, Fernand Léger in his essay, “The Wall, The Architect, The Painter (1965).” Léger writes that, “the modern architect has gone too far in his magnificent attempts to cleanse through emptiness,” and that the resultant white walls of modernity create ‘an impalpability of air, of slick, brilliant new surfaces where nothing can be hidden any longer …even shadows don’t dare to enter’. To counter the exposure produced by the white wall, Thompson and Broadhurst designed patterned surfaces that could harbour their personal histories. Broadhurst and Thompson’s works share a number of commonalities in their design production, even though their work in print design commenced a decade apart. Both designers opted to work more with traditional methods of pattern making. Broadhurst used hand-operated screens, and Thompson outsourced work to local weavers and refrained from operating out of a factory. Despite humble beginnings, Broadhurst and Thompson enjoyed international success with their wall patterns being featured in a number of renowned international hotels in Bahrain, Singapore, Sydney, and London in the 1970s and 1980s. Their patterns were also transferred to fabric for soft furnishings and clothing. Thompson’s patterns were used for costumes in films including the King and I and Ben Hur. Broadhurst’s patterns were also widely used by fashion designers and artists, such as Akira Isogowa‘s costume design for Salome, a 1998 production by the Sydney Dance Company. Most recently her print designs have been used by skin illustrator Emma Hack, in a series of works painting female bodies into Broadhurst’s patterns. Hack’s works camouflage the models’ bodies into the patterned surface, assimilating subject and surface, hinting at there being something living within the patterned wall. More than four decades after Broadhurst’s murder and five decades since Thompson’s disappearance, their print designs persist as more than just a legacy. They are applied as surface finishes with the same fervour as when the designs were first released. This chapter argues that the reason for the ongoing celebration of their work is that there is the impalpable presence of the creator in the patterns. It suggests that the patterns blur the boundary between subject and surface.