986 resultados para ELECTRONIC PUBLICATIONS
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Supplements 1941/1942-1945/1946.
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Mode of access: Internet.
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Catalogue of the officers, faculty and students for the academic year 1859-60 / Ypsilanti Union School -- Biennial catalogue and circular of the officers, teachers and pupils of the Ypsilanti Union Seminary : together with the courses of study, rules and regulations for the school year 1868-69 -- Union Lyceum, public, Ypsilanti Seminary, Saturday eve., Feb. 26, '70 [program] : order of exercises -- Ninth annual commencement of the Ypsilanti Union Seminary, Friday evening, June 24, 1870 -- Circular containing organization, courses of study and rules and regulations of the public schools of Ypsilanti, Michigan, 1885 -- Circular of the Ypsilanti high school for the academic year 1885-86 -- Annual report and circular containing courses of study of the public schools of Ypsilanti, Michigan, 1892 -- Announcement, Ypsilanti public schools, 1892-93 -- Circular of information, August, 1895 / Ypsilanti High School -- Catalog of the officers, instructors, and students of the Ypsilanti High School for the school year 1898-99 -- Catalog of the officers, instructors, and students of the Ypsilanti High School, for the school year 1899-1900 -- Catalog of the officers, teachers, and students of the Ypsilanti High School for the school year 1900-1901 -- Commemoration exercises celebrating the close of the nineteenth century high school hall, Thursday evening, Dec. 20, 1900 / Ypsilanti High School -- Annual report of the Superintendent of the public schools of Ypsilanti, Michigan for the school year 1908-1909 -- The public schools, Ypsilanti, Michigan : course of study, rules and regulations, reports for 1910-11 and general information -- Annual catalogue, 1911-12 / high school, Ypsilanti, Michigan.
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ACM Computing Classification System (1998): I.7.4.
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A novel method to fabricate chemically linked conducting polymer–biopolymer composites that are intrinsically flexible and conducting for functional electrode applications is presented. Polypyrrole was synthesised in situ during the cellulose regeneration process using the 1-butyl-3-methylimidazolium chloride ionic liquid as a solvent medium. The obtained polypyrrole–cellulose composite was chemically blended and showed flexible polymer properties while retaining the electronic properties of a conducting polymer. Addition of an ionic liquid such as trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide, enhanced the flexibility of the composite. The functional application of these materials in the electrochemically controlled release of a model drug has been demonstrated. This strategy opens up a new design for a wide spectrum of materials for smart electronic device applications wherein the functionality of doping and de-doping of conducting polymers is retained and their processability issue is addressed by exploiting an ionic liquid route.
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We present a reformulation of the hairy-probe method for introducing electronic open boundaries that is appropriate for steady-state calculations involving nonorthogonal atomic basis sets. As a check on the correctness of the method we investigate a perfect atomic wire of Cu atoms and a perfect nonorthogonal chain of H atoms. For both atom chains we find that the conductance has a value of exactly one quantum unit and that this is rather insensitive to the strength of coupling of the probes to the system, provided values of the coupling are of the same order as the mean interlevel spacing of the system without probes. For the Cu atom chain we find in addition that away from the regions with probes attached, the potential in the wire is uniform, while within them it follows a predicted exponential variation with position. We then apply the method to an initial investigation of the suitability of graphene as a contact material for molecular electronics. We perform calculations on a carbon nanoribbon to determine the correct coupling strength of the probes to the graphene and obtain a conductance of about two quantum units corresponding to two bands crossing the Fermi surface. We then compute the current through a benzene molecule attached to two graphene contacts and find only a very weak current because of the disruption of the π conjugation by the covalent bond between the benzene and the graphene. In all cases we find that very strong or weak probe couplings suppress the current.
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Not Available
First-Principles Study of the Electronic and Magnetic Properties of Defects in Carbon Nanostructures
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Understanding the magnetic properties of graphenic nanostructures is instrumental in future spintronics applications. These magnetic properties are known to depend crucially on the presence of defects. Here we review our recent theoretical studies using density functional calculations on two types of defects in carbon nanostructures: Substitutional doping with transition metals, and sp$^3$-type defects created by covalent functionalization with organic and inorganic molecules. We focus on such defects because they can be used to create and control magnetism in graphene-based materials. Our main results are summarized as follows: i)Substitutional metal impurities are fully understood using a model based on the hybridization between the $d$ states of the metal atom and the defect levels associated with an unreconstructed D$_{3h}$ carbon vacancy. We identify three different regimes, associated with the occupation of distinct hybridization levels, which determine the magnetic properties obtained with this type of doping; ii) A spin moment of 1.0 $\mu_B$ is always induced by chemical functionalization when a molecule chemisorbs on a graphene layer via a single C-C (or other weakly polar) covalent bond. The magnetic coupling between adsorbates shows a key dependence on the sublattice adsorption site. This effect is similar to that of H adsorption, however, with universal character; iii) The spin moment of substitutional metal impurities can be controlled using strain. In particular, we show that although Ni substitutionals are non-magnetic in flat and unstrained graphene, the magnetism of these defects can be activated by applying either uniaxial strain or curvature to the graphene layer. All these results provide key information about formation and control of defect-induced magnetism in graphene and related materials.
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L’arbre en ville offre plusieurs bienfaits, et ce, même s’il est souvent confronté à des conditions de vie difficiles. Au cours des années, la foresterie urbaine a suscité plusieurs travaux de recherches. Ce projet visait à faire un recensement des publications scientifiques de recherche en foresterie urbaine, à faire l’état de la situation des municipalités en matière de foresterie urbaine et à identifier les besoins de recherche en foresterie urbaine des municipalités canadiennes de 5 000 habitants et plus. Le premier objectif a été réalisé en utilisant plusieurs bases de données d’articles scientifiques et des mots clefs en foresterie urbaine. Un sondage pancanadien a permis de réaliser les deux autres objectifs. Le recensement que nous avons effectué des publications en foresterie urbaine depuis 1800 a montré, comme pour les publications scientifiques en général, mais de façon encore plus marquée, un accroissement de leur nombre ces dernières années. Ce recensement a aussi permis de révéler que les préoccupations de recherche touchent surtout l’effet des arbres sur la santé humaine et la qualité de l’air. L’identification des besoins de recherche réalisée auprès des responsables des espaces verts a permis de constater qu’il y avait toujours place pour la recherche dans ce domaine. Les municipalités veulent connaître, entre autres, quelles espèces d’arbres sont adaptées à l’environnement urbain, quel est l’effet des arbres sur le ruissellement des eaux de pluie et sur la santé humaine. Nous avons aussi constaté qu’il y avait un manque de transfert de connaissances entre les chercheurs et les responsables d’espaces verts ou que les recherches menées ne répondent pas aux besoins exprimés par les répondants. Le présent mémoire a permis de mieux cerner les besoins de recherche des municipalités canadiennes et permettra aux chercheurs de mieux définir les priorités de recherche en foresterie urbaine.
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This chapter discusses the historical development, current practice and future prospects of the self-archiving of research papers in open-access repositories (so-called 'e-print archives'). It describes how the development of interoperable e-print repositories in a number of subject communities has shown that self-archiving can benefit academic researchers (and potentially others) by enabling quick and easy access to the research literature and therefore maximising the impact potential of papers. Realising that the possible benefits are high and the technical entry barriers low, many organisations such as universities have recently tried to encourage widespread self-archiving by setting up institutional repositories. However, major barriers to self-archiving remain - most of them cultural and managerial. There are concerns about quality control, intellectual property rights, disturbing the publishing status quo, and workload. Ways in which these issues are currently being addressed are discussed in this chapter. A number of self-archiving initiatives in different countries have been set up to address the concerns and to kick-start e-print repository use. However, issues remain which require further investigation; those discussed in this chapter include discipline differences, definitions of 'publication', versioning problems, digital preservation, costing and funding models, and metadata standards. The ways in which these issues are resolved will be important in determining the future of self-archiving. Possible futures are discussed with particular reference to journal publishing and quality control. If widely adopted, self-archiving might come to assume a central place in the scholarly communication process, but a great deal of restructuring of the process needs to take place before this potential can be realised.
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The present Thesis reports on the various research projects to which I have contributed during my PhD period, working with several research groups, and whose results have been communicated in a number of scientific publications. The main focus of my research activity was to learn, test, exploit and extend the recently developed vdW-DFT (van der Waals corrected Density Functional Theory) methods for computing the structural, vibrational and electronic properties of ordered molecular crystals from first principles. A secondary, and more recent, research activity has been the analysis with microelectrostatic methods of Molecular Dynamics (MD) simulations of disordered molecular systems. While only very unreliable methods based on empirical models were practically usable until a few years ago, accurate calculations of the crystal energy are now possible, thanks to very fast modern computers and to the excellent performance of the best vdW-DFT methods. Accurate energies are particularly important for describing organic molecular solids, since they often exhibit several alternative crystal structures (polymorphs), with very different packing arrangements but very small energy differences. Standard DFT methods do not describe the long-range electron correlations which give rise to the vdW interactions. Although weak, these interactions are extremely sensitive to the packing arrangement, and neglecting them used to be a problem. The calculations of reliable crystal structures and vibrational frequencies has been made possible only recently, thanks to development of some good representations of the vdW contribution to the energy (known as “vdW corrections”).
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Two single crystalline surfaces of Au vicinal to the (111) plane were modified with Pt and studied using scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS) in ultra-high vacuum environment. The vicinal surfaces studied are Au(332) and Au(887) and different Pt coverage (θPt) were deposited on each surface. From STM images we determine that Pt deposits on both surfaces as nanoislands with heights ranging from 1 ML to 3 ML depending on θPt. On both surfaces the early growth of Pt ad-islands occurs at the lower part of the step edge, with Pt ad-atoms being incorporated into the steps in some cases. XPS results indicate that partial alloying of Pt occurs at the interface at room temperature and at all coverage, as suggested by the negative chemical shift of Pt 4f core line, indicating an upward shift of the d-band center of the alloyed Pt. Also, the existence of a segregated Pt phase especially at higher coverage is detected by XPS. Sample annealing indicates that the temperature rise promotes a further incorporation of Pt atoms into the Au substrate as supported by STM and XPS results. Additionally, the catalytic activity of different PtAu systems reported in the literature for some electrochemical reactions is discussed considering our findings.
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Universidade Estadual de Campinas . Faculdade de Educação Física
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INTRODUCTION: Open access publishing is becoming increasingly popular within the biomedical sciences. SciELO, the Scientific Electronic Library Online, is a digital library covering a selected collection of Brazilian scientific journals many of which provide open access to full-text articles.This library includes a number of dental journals some of which may include reports of clinical trials in English, Portuguese and/or Spanish. Thus, SciELO could play an important role as a source of evidence for dental healthcare interventions especially if it yields a sizeable number of high quality reports. OBJECTIVE: The aim of this study was to identify reports of clinical trials by handsearching of dental journals that are accessible through SciELO, and to assess the overall quality of these reports. MATERIAL AND METHODS: Electronic versions of six Brazilian dental Journals indexed in SciELO were handsearched at www.scielo.br in September 2008. Reports of clinical trials were identified and classified as controlled clinical trials (CCTs - prospective, experimental studies comparing 2 or more healthcare interventions in human beings) or randomized controlled trials (RCTs - a random allocation method is clearly reported), according to Cochrane eligibility criteria. CRITERIA TO ASSESS METHODOLOGICAL QUALITY INCLUDED: method of randomization, concealment of treatment allocation, blinded outcome assessment, handling of withdrawals and losses and whether an intention-to-treat analysis had been carried out. RESULTS: The search retrieved 33 CCTs and 43 RCTs. A majority of the reports provided no description of either the method of randomization (75.3%) or concealment of the allocation sequence (84.2%). Participants and outcome assessors were reported as blinded in only 31.2% of the reports. Withdrawals and losses were only clearly described in 6.5% of the reports and none mentioned an intention-to-treat analysis or any similar procedure. CONCLUSIONS: The results of this study indicate that a substantial number of reports of trials and systematic reviews are available in the dental journals listed in SciELO, and that these could provide valuable evidence for clinical decision making. However, it is clear that the quality of a number of these reports is of some concern and that improvement in the conduct and reporting of these trials could be achieved if authors adhered to internationally accepted guidelines, e.g. the CONSORT statement.
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The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9% saline solution and 1% sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.