870 resultados para 240501 Acoustics and Acoustical Devices
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An exhibition of stencil letters from the 18th century to the present day. Co-curated by Eric Kindel and Fred Smeijers, the exhibition featured a wide selection of stencil letters in the context of historical artefacts, documents and ephemera, including stencil plates and stencilling devices, specimens and catalogues and patent inventions. The exhibition also introduced a series of new stencil fonts designed by Maurice Göldner, Pierre Pané-Farré and Fred Smeijers. The design of each font made reference to and was informed by the historical material.
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With the fast development of the Internet, wireless communications and semiconductor devices, home networking has received significant attention. Consumer products can collect and transmit various types of data in the home environment. Typical consumer sensors are often equipped with tiny, irreplaceable batteries and it therefore of the utmost importance to design energy efficient algorithms to prolong the home network lifetime and reduce devices going to landfill. Sink mobility is an important technique to improve home network performance including energy consumption, lifetime and end-to-end delay. Also, it can largely mitigate the hot spots near the sink node. The selection of optimal moving trajectory for sink node(s) is an NP-hard problem jointly optimizing routing algorithms with the mobile sink moving strategy is a significant and challenging research issue. The influence of multiple static sink nodes on energy consumption under different scale networks is first studied and an Energy-efficient Multi-sink Clustering Algorithm (EMCA) is proposed and tested. Then, the influence of mobile sink velocity, position and number on network performance is studied and a Mobile-sink based Energy-efficient Clustering Algorithm (MECA) is proposed. Simulation results validate the performance of the proposed two algorithms which can be deployed in a consumer home network environment.
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This article examines how conventional studio production strategies were active in the construction of political meaning in the 1974 television play 'Absolute Beginners' written by Trevor Griffiths. Produced for the BBC anthology series Fall of Eagles, the play dramatises Lenin's involvement with the Russian Social Democratic Workers Party (RSDWP) and explores the contradictions between personal ethics and political necessity. Through close textual analysis and contextual discussion of other plays in the series, this piece demonstrates how shot patterns and spatial and performative devices in 'Absolute Beginners' supported the drama's socialist-humanist themes. Drawing on existing writing about the studio mode, it argues that the qualities of intimacy and presentational distance that it engendered were highly appropriate for the personal and the political dialectic in 'Absolute Beginners'. While using authorship as a convenient category for referring to the coherence of Griffiths' thematic concerns and dramatic structure during this period, the article complicates notions of the television dramatist as author by arguing for the importance of visual style and showing how 'ordinary' studio form was operational in the play's political meanings.
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The increasing use of patterned neural networks in multielectrode arrays and similar devices drives the constant development and evaluation of new biomaterials. Recently, we presented a promising technique to guide neurons and glia reliably and effectively. Parylene-C, a common hydrophobic polymer, was photolithographically patterned on silicon oxide (SiO2) and subsequently activated via immersion in serum. In this article, we explore the effects of ultraviolet (UV)-induced oxidation on parylene's ability to pattern neurons and glia. We exposed parylene-C stripe patterns to increasing levels of UV radiation and found a dose-dependent reduction in the total mass of patterned cells, as well as a gradual loss of glial and neuronal conformity to the patterns. In contrast, nonirradiated patterns had superior patterning results and increased presence of cells. The reduced cell adhesion and patterning after the formation of aldehyde and carboxyl groups on UV-radiated parylene-C supports our hypothesis that cell adhesion and growth on parylene is facilitated by hydrophobic adsorption of serum proteins. We conclude that unlike other cell patterning schemes, our technique does not rely on photooxidation of the polymer. Nonetheless, the precise control of oxygenated groups on parylene could pave the way for the differential binding of proteins and other molecules on the surface, aiding in the adhesion of alternative cell types. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
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In this article, we review the state-of-the-art techniques in mining data streams for mobile and ubiquitous environments. We start the review with a concise background of data stream processing, presenting the building blocks for mining data streams. In a wide range of applications, data streams are required to be processed on small ubiquitous devices like smartphones and sensor devices. Mobile and ubiquitous data mining target these applications with tailored techniques and approaches addressing scarcity of resources and mobility issues. Two categories can be identified for mobile and ubiquitous mining of streaming data: single-node and distributed. This survey will cover both categories. Mining mobile and ubiquitous data require algorithms with the ability to monitor and adapt the working conditions to the available computational resources. We identify the key characteristics of these algorithms and present illustrative applications. Distributed data stream mining in the mobile environment is then discussed, presenting the Pocket Data Mining framework. Mobility of users stimulates the adoption of context-awareness in this area of research. Context-awareness and collaboration are discussed in the Collaborative Data Stream Mining, where agents share knowledge to learn adaptive accurate models.
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The term 'big data' has recently emerged to describe a range of technological and commercial trends enabling the storage and analysis of huge amounts of customer data, such as that generated by social networks and mobile devices. Much of the commercial promise of big data is in the ability to generate valuable insights from collecting new types and volumes of data in ways that were not previously economically viable. At the same time a number of questions have been raised about the implications for individual privacy. This paper explores key perspectives underlying the emergence of big data, and considers both the opportunities and ethical challenges raised for market research.
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Mobile devices can enhance undergraduate research projects and students’ research capabilities. The use of mobile devices such as tablet computers will not automatically make undergraduates better researchers, but their use should make investigations, writing, and publishing more effective and may even save students time. We have explored some of the possibilities of using “tablets” and “smartphones” to aid the research and inquiry process in geography and bioscience fieldwork. We provide two case studies as illustration of how students working in small research groups use mobile devices to gather and analyze primary data in field-based inquiry. Since April 2010, Apple’s iPad has changed the way people behave in the digital world and how they access their music, watch videos, or read their email much as the entrepreneurs Steve Jobs and Jonathan Ive intended. Now with “apps” and “the cloud” and the ubiquitous references to them appearing in the press and on TV, academics’ use of tablets is also having an impact on education and research. In our discussion we will refer to use of smartphones such as the iPhone, iPod, and Android devices under the term “tablet”. Android and Microsoft devices may not offer the same facilities as the iPad/iphone, but many app producers now provide versions for several operating systems. Smartphones are becoming more affordable and ubiquitous (Melhuish and Falloon 2010), but a recent study of undergraduate students (Woodcock et al. 2012, 1) found that many students who own smartphones are “largely unaware of their potential to support learning”. Importantly, however, students were found to be “interested in and open to the potential as they become familiar with the possibilities” (Woodcock et al. 2012). Smartphones and iPads could be better utilized than laptops when conducting research in the field because of their portability (Welsh and France 2012). It is imperative for faculty to provide their students with opportunities to discover and employ the potential uses of mobile devices in their learning. However, it is not only the convenience of the iPad or tablet devices or smartphones we wish to promote, but also a way of thinking and behaving digitally. We essentially suggest that making a tablet the center of research increases the connections between related research activities.
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CdS is one of the most important II-VI semiconductors, with applications in solar cells, optoelectronics and electronic devices. CdS nanoparticles were synthesized via microwave-assisted solvothermal technique. Structural and morphological characterization revealed the presence of crystalline structures presenting single phase with different morphologies such as ""nanoflowers"" and nanoplates depending on the solvent used. Optical characterization was made by diffuse reflectance and photoluminescence spectroscopy, revealing the influence of the different solvents on the optical properties due to structural defects generated during synthesis. It is proposed that these defects are related to sulfur vacancies, with higher concentration of defects for the sample synthesized in ethylene glycol in comparison with the one synthesized in ethylene diamine. (C) 2011 Elsevier B.V. All rights reserved.
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A variety of substrates have been used for fabrication of microchips for DNA extraction, PCR amplification, and DNA fragment separation, including the more conventional glass and silicon as well as alternative polymer-based materials. Polyester represents one such polymer, and the laser-printing of toner onto polyester films has been shown to be effective for generating polyester-toner (PeT) microfluidic devices with channel depths on the order of tens of micrometers. Here, we describe a novel and simple process that allows for the production of multilayer, high aspect-ratio PeT microdevices with substantially larger channel depths. This innovative process utilizes a CO(2) laser to create the microchannel in polyester sheets containing a uniform layer of printed toner, and multilayer devices can easily be constructed by sandwiching the channel layer between uncoated cover sheets of polyester containing precut access holes. The process allows the fabrication of deep channels, with similar to 270 mu m, and we demonstrate the effectiveness of multilayer PeT microchips for dynamic solid phase extraction (dSPE) and PCR amplification. With the former, we found that (i) more than 65% of DNA from 0.6 mu L of blood was recovered, (ii) the resultant DNA was concentrated to greater than 3 ng/mu L., (which was better than other chip-based extraction methods), and (iii) the DNA recovered was compatible with downstream microchip-based PCR amplification. Illustrative of the compatibility of PeT microchips with the PCR process, the successful amplification of a 520 bp fragment of lambda-phage DNA in a conventional thermocycler is shown. The ability to handle the diverse chemistries associated with DNA purification and extraction is a testimony to the potential utility of PeT microchips beyond separations and presents a promising new disposable platform for genetic analysis that is low cost and easy to fabricate.
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Linguistic features of business letters have been a research target of both linguists and business writers. In this study, the language of British and Pakistani Business letters was compared and contrasted in terms of concreteness and abstractness. A corpus of 100 business letters from Inner Circle and Outer Circle writers were collected for analysis. The findings of the study revealed that British writers use more specific and concrete nouns, definite determiners, numeral, possessive and demonstrative adjectives, cohesive and rhetorical devices than the Pakistani Writers in order to be become concrete and vivid in their communication. The present findings are rather corpus specific since the data include only two countries; however this study may lead to further cross circle research including Expanding Circle research of business letters in terms of concreteness and abstractness. The issue of concreteness in Cross-circle business English can also be studied from psychological, sociological and anthropological perspectives in future Research.
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OBJECTIVES: There is a growing emphasis on the perspective of individuals living with diabetes and the need for a more person-centred diabetes care. At present, the Swedish National Diabetes Register (NDR) lacks patient-reported outcome measures (PROMs) based on the perspective of the patient. As a basis for a new PROM, the aim of this study was to describe important aspects in life for adult individuals with diabetes. DESIGN: Semistructured qualitative interviews analysed using content analysis. SETTING: Hospital-based outpatient clinics and primary healthcare clinics in Sweden. PARTICIPANTS: 29 adults with type 1 diabetes mellitus (DM) (n=15) and type 2 DM (n=14). INCLUSION CRITERIA: Swedish adults (≥18 years) living with type 1 DM or type 2 DM (duration ≥5 years) able to describe their situation in Swedish. Purposive sampling generated heterogeneous characteristics. RESULTS: To live a good life with diabetes is demanding for the individual, but experienced barriers can be eased by support from others in the personal sphere, and by professional support from diabetes care. Diabetes care was a crucial resource to nurture the individual's ability and knowledge to manage diabetes, and to facilitate life with diabetes by supplying support, guidance, medical treatment and technical devices tailored to individual needs. The analysis resulted in the overarching theme 'To live a good life with diabetes' constituting the two main categories 'How I feel and how things are going with my diabetes' and 'Support from diabetes care in managing diabetes' including five different categories. CONCLUSIONS: Common aspects were identified including the experience of living with diabetes and support from diabetes care. These will be used to establish a basis for a tailored PROM for the NDR.
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This article explores libraries’ technical workflow design and strategic considerations as various e-books business models and mobile devices and their management become a growing part of the information landscape.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Thin films of perovskite-type materials such as PbTiO3, BaTiO3, (Pb,La)TiO3, (Pb, La)(ZrTi)O-3, KNbO3, and Pb(Mg,Nb)03 have been attracting great interest for applications like non-volatile memories, ultrasonic sensors and optical devices. Thin film should be epitaxially grown or at least highly textured since the properties of this anisotropic material depend on the crystallographic orientation. For optical devices, in particular, an epitaxial thin film without defects are essential to reduce optical propagation losses. Pb1-xLaxTiO3 (PLT) where x=0, 13 and 27% thin films were prepared by a chemical method (polymeric precursors method), and deposited by the spin coating technique onto substrates of SrTiO3 (STO) and LaAlO3 (LAO). The films were then beat treated at 500 degrees C in a controlled atmosphere of 0,. The orientation degree of the thin films was obtained from rocking curve technique, by means of X-ray difftaction analysis. A microstructural study revealed that the films were crack-free, homogeneous and have low roughness. (c) 2006 Elsevier B.V. All rights reserved.