760 resultados para ELECTRONIC PUBLISHING
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We introduce a spin-charge conductance matrix as a unifying concept underlying charge and spin transport within the framework of the Landauer-Buttiker conductance formula. It turns out that the spin-charge conductance matrix provides a natural and gauge covariant description for electron transport through nanoscale electronic devices. We demonstrate that the charge and spin conductances are gauge invariant observables which characterize transport phenomena arising from spin-dependent scattering. Tunnelling through a single magnetic atom is discussed to illustrate our theory.
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We review the role of strong electronic correlations in quasi-two-dimensional organic charge transfer salts such as (BEDT-TTF)(2)X, (BETS)(2)Y, and beta'-[Pd(dmit)(2)](2)Z. We begin by defining minimal models for these materials. It is necessary to identify two classes of material: the first class is strongly dimerized and is described by a half-filled Hubbard model; the second class is not strongly dimerized and is described by a quarter-filled extended Hubbard model. We argue that these models capture the essential physics of these materials. We explore the phase diagram of the half-filled quasi-two-dimensional organic charge transfer salts, focusing on the metallic and superconducting phases. We review work showing that the metallic phase, which has both Fermi liquid and 'bad metal' regimes, is described both quantitatively and qualitatively by dynamical mean field theory (DMFT). The phenomenology of the superconducting state is still a matter of contention. We critically review the experimental situation, focusing on the key experimental results that may distinguish between rival theories of superconductivity, particularly probes of the pairing symmetry and measurements of the superfluid stiffness. We then discuss some strongly correlated theories of superconductivity, in particular the resonating valence bond (RVB) theory of superconductivity. We conclude by discussing some of the major challenges currently facing the field. These include parameterizing minimal models, the evidence for a pseudogap from nuclear magnetic resonance (NMR) experiments, superconductors with low critical temperatures and extremely small superfluid stiffnesses, the possible spin- liquid states in kappa-(ET)(2)Cu-2(CN)(3) and beta'-[Pd(dmit)(2)](2)Z, and the need for high quality large single crystals.
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With a wide diversity of available technologies, it is extremely problematic for SMEs to identify, plan, prioritize and use the correct strategy. Electronic-manufacturing has been evolving for some time, but currently an effective planning framework to assist managers with implementing electronic-manufacturing planning is still lacking. A framework, built around three elements: the Balanced Scorecard, Quality Function Deployment and Value Chain Analysis, is proposed here to assist SMEs in managing complexity in e-manufacturing planning. A case study, carried out in Singapore, demonstrates the practicality and utility of the framework in the context of a real business environment. © World Scientific Publishing Company.
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The Electronic Patient Record (EPR) is being developed by many hospitals in the UK and across the globe. We class an EPR system as a type of Knowledge Management System (KMS), in that it is a technological tool developed to support the process of knowledge management (KM). Healthcare organisations aim to use these systems to provide a vehicle for more informed and improved clinical decision making thereby delivering reduced errors and risks, enhanced quality and consequently offering enhanced patient safety. Finding an effective way for a healthcare organisation to practically implement these systems is essential. In this study we use the concept of the business process approach to KM as a theoretical lens to analyse and explore how a large NHS teaching hospital developed, executed and practically implemented an EPR system. This theory advocates the importance of taking into account all organizational activities - the business processes - in considering any KM initiatives. Approaching KM through business processes allows for a more holistic view of the requirements across a process: emphasis is placed on how particular activities are performed, how they are structured and what knowledge demanded and not just supplied across each process. This falls in line with the increased emphasis in healthcare on patient-centred approaches to care delivery. We have found in previous research that hospitals are happy with the delivery of patient care being referred to as their 'business'. A qualitative study was conducted over a two and half year period with data collected from semi-structured interviews with eight members of the strategic management team, 12 clinical users and 20 patients in addition to non- participant observation of meetings and documentary data. We believe that the inclusion of patients within the study may well be the first time this has been done in examining the implementation of a KMS. The theoretical propositions strategy was used as the overarching approach for data analysis. Here Initial theoretical research themes and propositions were used to help shape and organise the case study analysis. This paper will present preliminary findings about the hospital's business strategy and its links to the KMS strategy and process.
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Date of Acceptance: 13/04/2015
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Date of Acceptance: 13/04/2015
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Date of Acceptance: 13/04/2015
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Inscriptions: Verso: [stamped] Photograph by Freda Leinwand. [463 West Street, Studio 229G, New York, NY 10014].
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Adobe's Acrobat software, released in June 1993, is based around a new Portable Document Format (PDF) which offers the possibility of being able to view and exchange electronic documents, independent of the originating software, across a wide variety of supported hardware platforms (PC, Macintosh, Sun UNIX etc.). The fact that Acrobat's imageable objects are rendered with full use of Level 2 PostScript means that the most demanding requirements can be met in terms of high-quality typography and device-independent colour. These qualities will be very desirable components in future multimedia and hypermedia systems. The current capabilities of Acrobat and PDF are described; in particular the presence of hypertext links, bookmarks, and yellow sticker annotations (in release 1.0) together with article threads and multi-media plugins in version 2.0, This article also describes the CAJUN project (CD-ROM Acrobat Journals Using Networks) which has been investigating the automated placement of PDF hypertextual features from various front-end text processing systems. CAJUN has also been experimenting with the dissemination of PDF over e-mail, via World Wide Web and on CDROM.
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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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This study describes the sperm morphology of the mayfly Hexagenia (Pseudeatonica) albivitta (Ephemeroptera). Its spermatozoon measures approximately 30 μm of which 9 μm corresponds to the head. The head is composed of an approximately round acrosomal vesicle and a cylindrical nucleus. The nucleus has two concavities, one in the anterior tip, where the acrosomal vesicle is inserted and a deeper one at its base, where the flagellum components are inserted. The flagellum is composed of an axoneme, a mitochondrion and a dense rod adjacent to the mitochondrion. A centriolar adjunct is also observed surrounding the axoneme in the initial portion of the flagellum and extends along the flagellum for at least 2 μm, surrounding the axoneme in a half-moon shape. The axoneme is the longest component of the flagellum, and it follows the 9+9+0 pattern, with no central pair of microtubules. At the posterior region of the flagellum, the mitochondrion has a dumb-bell shape in cross sections that, together with the rectangular mitochondrial-associated rod, is responsible for the flattened shape of the flagellum. An internal membrane is observed surrounding both mitochondrion and its associated structure.
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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.
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The n→π* absorption transition of formaldehyde in water is analyzed using combined and sequential classical Monte Carlo (MC) simulations and quantum mechanics (QM) calculations. MC simulations generate the liquid solute-solvent structures for subsequent QM calculations. Using time-dependent density functional theory in a localized set of gaussian basis functions (TD-DFT/6-311++G(d,p)) calculations are made on statistically relevant configurations to obtain the average solvatochromic shift. All results presented here use the electrostatic embedding of the solvent. The statistically converged average result obtained of 2300 cm-1 is compared to previous theoretical results available. Analysis is made of the effective dipole moment of the hydrogen-bonded shell and how it could be held responsible for the polarization of the solvent molecules in the outer solvation shells.