958 resultados para POLYMER INTEGRATED-CIRCUITS
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This special issue of the Journal of Urban Technology brings together five articles that are based on presentations given at the Street Computing Workshop held on 24 November 2009 in Melbourne in conjunction with the Australian Computer- Human Interaction conference (OZCHI 2009). Our own article introduces the Street Computing vision and explores the potential, challenges, and foundations of this research trajectory. In order to do so, we first look at the currently available sources of information and discuss their link to existing research efforts. Section 2 then introduces the notion of Street Computing and our research approach in more detail. Section 3 looks beyond the core concept itself and summarizes related work in this field of interest. We conclude by introducing the papers that have been contributed to this special issue.
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This paper describes a generic and integrated solar powered remote Unmanned Air Vehicles (UAV) and Wireless Sensor Network (WSN) gas sensing system. The system uses a generic gas sensing system for CH4 and CO2 concentrations using metal oxide (MoX) and non-dispersive infrared sensors, and a new solar cell encapsulation method to power the UASs as well as a data management platform to store, analyse and share the information with operators and external users. The system was successfully field tested at ground and low altitudes, collecting, storing and transmitting data in real time to a central node for analysis and 3D mapping. The system can be used in a wide range of outdoor applications, especially in agriculture, bushfires, mining studies, opening the way to a ubiquitous low cost environmental monitoring. A video of the bench and flight test performed can be seen in the following link https://www.youtube.com/watch?v=Bwas7stYIxQ.
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Prior to graduation engineering students are expected to provide evidence of relevant experience in the workplace. This experience is expected to provide opportunities for exposure to the profession and to help students develop confidence, skills and capabilities as emerging professionals. This investigation considers the expectations and challenges in implementing WIL programs in different contexts. While this will inform the next iteration of engineering course development at QUT the issues and interventions described provide useful insights into options available and engineering curriculum design more broadly. This comparative analysis across three phases highlights expectations and challenges including stakeholder responsibilities, expectations, and assessment. The study draws on the findings of a 2005 investigation into the purpose and provision of WIL and findings of a 2012 Faculty review of the current WIL model. The enhancement of WIL through a series of developmental phases highlights strengths and weaknesses of various models. It is anticipated that this investigation will inform course development decisions on a whole-of-course approach to WIL that improves student engagement and learning experience. The importance of WIL is not disputed. However with industry expectations, increasing student numbers and cohort diversity the ways in which students and industry currently engage in WIL are not sustainable and more creative, flexible and engaging approaches are needed.
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A city is the most dramatic manifestation of human activities on the environment. This human dominated organism degrades natural habitats, simplifies species composition, disrupts hydrological systems, and modifies energy flow and nutrient cycling. Sustainable urban development is seen as a panacea to minimise these externalities caused by widespread human activities on the environment. The concept of sustainable urban development has been around over a considerably long-time as the need to adopt environmentally sustainable behaviours made the international community commit to it. However, to date such development has not been achieved in large scales anywhere around the globe. This review paper aims to look at the sustainable urban development concept from the lens of planning and development integration to generate new insights and directions. The paper reports the outcome of the review of the literature on planning and development approaches—i.e., urban planning, ecological planning, urban development, sustainable urban development—and proposes a new process to support the efforts for achieving sustainable urban development—i.e., integrated urban planning and development process. The findings of this review paper highlights that adopting such holistic planning and development process generate a potential to further support the progress towards achieving sustainability agendas of our cities.
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Graphene–polymer nanocomposites have promising properties as new structural and functional materials. The remarkable mechanical property enhancement in these nanocomposites is generally attributed to exceptional mechanical property of graphene and possible load transfer between graphene and polymer matrix. However, the underlying strengthening and toughening mechanisms have not been well understood. In this work, the interfacial behavior of graphene-polyethylene (PE) was investigated using molecular dynamics (MD) method. The interfacial shear force (ISF) and interfacial shear stress (ISS) between graphene and PE matrix were evaluated, taking into account graphene size, the number of graphene layers and the structural defects in graphene. MD results show that the ISS at graphene-PE interface mainly distributes at each end of the graphene nanofiller within the range of 1 nm, and much larger than that at carbon nanotube (CNT)-PE interface. Moreover, it was found that the ISS at graphene-PE interface is sensitive to the layer number.
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Background The size of the carrier influences the aerosolization of drug from a dry powder inhaler (DPI) formulation. Currently, lactose monohydrate particles in a variety of sizes are preferably used in carrier based DPI formulations of various drugs; however, contradictory reports exist regarding the effect of the size of the carrier on the dispersion of drug. In this study we examined the influence of the intrinsic particle size of the polymeric carrier on the aerosolization of a model drug salbutamol sulphate (SS). Methods Four different sizes (20–150 lm) of polymer carriers were fabricated using solvent evaporation technique and the dispersion of SS particles from these carriers was measured by a Twin Stage Impinger (TSI). The size and morphological properties of polymer carriers were by laser diffraction and SEM, respectively. Results The FPF from these carriers was found to be increasing from 5.6% to 21.3% with increasing the carrier size. The FPF was found to be greater (21%) with the highest particle size of the carrier (150 lm). Conclusions The aerosolization of drug was dependent on the size of polymer carriers. The smaller size of the carrier resulted in lower FPF which was increased with increasing the carrier size. For a fixed mass of drug particles in a formulation, the mass of drug particles per unit area of carriers is higher in formulations containing the larger carriers, which leads to an increase in the dispersion of drug due to the increased mechanical forces occurred between the carriers and the device walls.
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This chapter approaches integrated advertising as a practice that is continuous with advertising history, rather than a phenomenon associated with new technologies. Competition for technology-enabled audiences in expanding media and entertainment markets is nonetheless an important factor in the turn to integrated advertising and marketing strategies in recent years. While integrated advertising provides solutions for advertisers, it is problematic for media consumers because it is not always distinguishable from surrounding program content and clearly identifiable as advertising. It creates opportunities for advertisers to fly below the radar of citizen and consumer awareness of commercial and political influences in media content, and for this reason has been constrained by regulation. Media regulators have come to play an important role in striking a balance between public and private interests in commercial media by setting and adjudicating the limits of integrated advertising practices. This chapter looks at how broadcasting regulators have responded to the challenges of regulating integrated advertising in commercial radio in three different territories (United States, United Kingdom and Australia). It draws attention to the ways in which integrated advertising simultaneously drives innovation in media genres and forms, as well as de-regulation of the influence exercised by advertisers in commercial media content.
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The study of memory in most behavioral paradigms, including emotional memory paradigms, has focused on the feed forward components that underlie Hebb’s first postulate, associative synaptic plasticity. Hebb’s second postulate argues that activated ensembles of neurons reverberate in order to provide temporal coordination of different neural signals, and thereby facilitate coincidence detection. Recent evidence from our groups has suggested that the lateral amygdala (LA) contains recurrent microcircuits and that these may reverberate. Additionally this reverberant activity is precisely timed with latencies that would facilitate coincidence detection between cortical and sub cortical afferents to the LA.Thus, recent data at the microcircuit level in the amygdala provide some physiological evidence in support of the second Hebbian postulate.
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This study reports an action research undertaken at Queensland University of Technology. It evaluates the effectiveness of the integration of GIS within the substantive domains of an existing land use planning course in 2011. Using student performance, learning experience survey, and questionnaire survey data, it also evaluates the impacts of incorporating hybrid instructional methods (e.g., in-class and online instructional videos) in 2012 and 2013. Results show that: students (re)iterated the importance of GIS in the course justifying the integration; the hybrid methods significantly increased student performance; and unlike replacement, the videos are more suitable as a complement to in-class activity.
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A long query provides more useful hints for searching relevant documents, but it is likely to introduce noise which affects retrieval performance. In order to smooth such adverse effect, it is important to reduce noisy terms, introduce and boost additional relevant terms. This paper presents a comprehensive framework, called Aspect Hidden Markov Model (AHMM), which integrates query reduction and expansion, for retrieval with long queries. It optimizes the probability distribution of query terms by utilizing intra-query term dependencies as well as the relationships between query terms and words observed in relevance feedback documents. Empirical evaluation on three large-scale TREC collections demonstrates that our approach, which is automatic, achieves salient improvements over various strong baselines, and also reaches a comparable performance to a state of the art method based on user’s interactive query term reduction and expansion.
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The purpose of this review is to showcase the present capabilities of ambient sampling and ionisation technologies for the analysis of polymers and polymer additives by mass spectrometry (MS) while simultaneously highlighting their advantages and limitations in a critical fashion. To qualify as an ambient ionisation technique, the method must be able to probe the surface of solid or liquid samples while operating in an open environment, allowing a variety of sample sizes, shapes, and substrate materials to be analysed. The main sections of this review will be guided by the underlying principle governing the desorption/extraction step of the analysis; liquid extraction, laser ablation, or thermal desorption, and the major component investigated, either the polymer itself or exogenous compounds (additives and contaminants) present within or on the polymer substrate. The review will conclude by summarising some of the challenges these technologies still face and possible directions that would further enhance the utility of ambient ionisation mass spectrometry as a tool for polymer analysis. (C) 2013 Elsevier B. V. All rights reserved.
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This work is motivated by the need to efficiently machine the edges of ophthalmic polymer lenses for mounting in spectacle or instrument frames. The polymer materials used are required to have suitable optical characteristics such high refractive index and Abbe number, combined with low density and high scratch and impact resistance. Edge surface finish is an important aesthetic consideration; its quality is governed by the material removal operation and the physical properties of the material being processed. The wear behaviour of polymer materials is not as straightforward as for other materials due to their molecular and structural complexity, not to mention their time-dependent properties. Four commercial ophthalmic polymers have been studied in this work using nanoindentation techniques which are evaluated as tools for probing surface mechanical properties in order to better understand the grinding response of polymer materials.
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Graphene has been increasingly used as nano sized fillers to create a broad range of nanocomposites with exceptional properties. The interfaces between fillers and matrix play a critical role in dictating the overall performance of a composite. However, the load transfer mechanism along graphene-polymer interface has not been well understood. In this study, we conducted molecular dynamics simulations to investigate the influence of surface functionalization and layer length on the interfacial load transfer in graphene polymer nanocomposites. The simulation results show that oxygen-functionalized graphene leads to larger interfacial shear force than hydrogen-functionalized and pristine ones during pull-out process. The increase of oxygen coverage and layer length enhances interfacial shear force. Further increase of oxygen coverage to about 7% leads to a saturated interfacial shear force. A model was also established to demonstrate that the mechanism of interfacial load transfer consists of two contributing parts, including the formation of new surface and relative sliding along the interface. These results are believed to be useful in development of new graphene-based nanocomposites with better interfacial properties.
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In this paper, an integrated inter-vehicles wireless communications and positioning system supporting alternate positioning techniques is proposed to meet the requirements of safety applications of Cooperative Intelligent Transportation Systems (C-ITS). Recent advances have repeatedly demonstrated that road safety problems can be to a large extent addressed via a range of technologies including wireless communications and positioning in vehicular environments. The novel communication stack utilizing a dedicated frequency spectrum (e.g. at 5.9 GHz band), known as Dedicated Short-Range Communications (DSRC), has been particularly designed for Wireless Access in Vehicular Environments (WAVE) to support safety applications in highly dynamic environments. Global Navigation Satellite Systems (GNSS) is another essential enabler to support safety on rail and roads. Although current vehicle navigation systems such as single frequency Global Positioning System (GPS) receivers can provide route guidance with 5-10 meters (road-level) position accuracy, positioning systems utilized in C-ITS must provide position solutions with lane-level and even in-lane-level accuracies based on the requirements of safety applications. This article reviews the issues and technical approaches that are involved in designing a vehicular safety communications and positioning architecture; it also provides technological solutions to further improve vehicular safety by integrating the DSRC and GNSS-based positioning technologies.
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Whole System Design is increasingly being seen as one of the most cost effective ways to both increase the productivity and reduce the negative environmental impacts of an engineered system. A focus on design is critical, as the output from this stage of the project locks-in most of the economic and environmental performance of the designed system throughout its life, which can span from a few years to many decades. Indeed, it is now widely acknowledged that all designers – particularly engineers, architects and industrial designers – need to be able to understand and implement a whole system design approach. This book provides a clear design methodology, based on leading efforts in the field, and is supported by worked examples that demonstrate how advances in energy, materials and water productivity can be achieved through applying an integrated approach to sustainable engineering. Chapters 1–5 outline the approach and explain how it can be implemented to enhance the established Systems Engineering framework. Chapters 6–10 demonstrate, through detailed worked examples, the application of the approach to industrial pumping systems, passenger vehicles, electronics and computer systems, temperature control of buildings, and domestic water systems.