Observation of Magnetic Edge State and Dangling Bond State on Nanographene in Activated Carbon Fibers

The electronic structure of nanographene in pristine and fluorinated activated carbon fibers (ACFs) have been investigated with near-edge x-ray absorption fine structure (NEXAFS) and compared with magnetic properties we reported on previously. In pristine ACFs in which magnetic properties are governed by non-bonding edge states of the \pi-electron, a pre-peak assigned to the edge state was observed below the conduction electron {\pi}* peak close to the Fermi level in NEXAFS. Via the fluorination of the ACFs, an extra peak, which was assigned to the \sigma-dangling bond state, was observed between the pre-peak of the edge state and the {\pi}* peak in the NEXAFS profile. The intensities of the extra peak correlate closely with the spin concentration created upon fluorination. The combination of the NEXAFS and magnetic measurement results confirms the coexistence of the magnetic edge states of \pi-electrons and dangling bond states of \sigma-electrons on fluorinated nanographene sheets.Comment: 4 figures, to appear in Phys. Rev.

Carbon nanotube: a low-loss spin-current waveguide

We demonstrate with a quantum-mechanical approach that carbon nanotubes are excellent spin-current waveguides and are able to carry information stored in a precessing magnetic moment for long distances with very little dispersion and with tunable degrees of attenuation. Pulsed magnetic excitations are predicted to travel with the nanotube Fermi velocity and are able to induce similar excitations in remote locations. Such an efficient way of transporting magnetic information suggests that nanotubes are promising candidates for memory devices with fast magnetization switchings

MSIS 2000: Model Curriculum and Guidelines for Graduate Degree Programs in Information Systems

This article contains the official text of the MSIS 2000 model curriculum as approved by both the Association for Computing Machinery and the Association for Information Systems. It is presented here in its original form

Engineering long-range order in supramolecular assemblies on surfaces : the paramount role of internal double bonds in discrete long-chain naphthalenediimides

Achieving long-range order with surface-supported supramolecular assemblies is one of the pressing challenges in the prospering field of non-covalent surface functionalization. Having access to defect-free on-surface molecular assemblies will pave the way for various nanotechnology applications. Here we report the synthesis of two libraries of naphthalenediimides (NDIs) symmetrically functionalized with long aliphatic chains (C28 and C33) and their self-assembly at the 1-phenyloctane/highly oriented pyrolytic graphite (1-PO/HOPG) interface. The two NDI libraries differ by the presence/absence of an internal double bond in each aliphatic chain (unsaturated and saturated compounds, respectively). All molecules assemble into lamellar arrangements, with the NDI cores lying flat and forming 1D rows on the surface, while the carbon chains separate the 1D rows from each other. Importantly, the presence of the unsaturation plays a dominant role in the arrangement of the aliphatic chains, as it exclusively favors interdigitation. The fully saturated tails, instead, self-assemble into a combination of either interdigitated or non-interdigitated diagonal arrangements. This difference in packing is spectacularly amplified at the whole surface level and results in almost defect-free self-assembled monolayers for the unsaturated compounds. In contrast, the monolayers of the saturated counterparts are globally disordered, even though they locally preserve the lamellar arrangements. The experimental observations are supported by computational studies and are rationalized in terms of stronger van der Waals interactions in the case of the unsaturated compounds. Our investigation reveals the paramount role played by internal double bonds on the self-assembly of discrete large molecules at the liquid/solid interface

Inversed linear dichroism in F <em>K</em>-edge NEXAFS spectra of fluorinated planar aromatic molecules

et al.The symmetry and energy distribution of unoccupied molecular orbitals is addressed in this work by means of NEXAFS and density functional theory calculations for planar, fluorinated organic semiconductors (perfluorinated copper phthalocyanines and perfluoropentacene). We demonstrate how molecular orbitals with significant density of states on the fluorine atoms show different symmetry from those mainly located on C and N atoms. As a result, the angle-dependent linear dichroism in NEXAFS F K-edge spectra is inversed with respect to that in the C and N K-edges. In addition, the significant overlap in energy of π * and σ * orbitals throughout the F K-edge spectrum hampers its use for analysis of molecular orientations from angle-dependent NEXAFS measurements. © 2012 American Physical Society.J.E.O. and A.R. acknowledge funding from the Spanish MEC through Grants No. FIS2011-65702-C02-01, No. MAT2010-21156-C03-01, and No. PIB2010US-00652, and from the Basque Government through Grants No. IT-257-07 and No. IT-319-07. A.R. additionally acknowledges that financial support was provided by ACI-Promociona Grant No. ACI2009-1036 and the European Research Council Advanced Grant DYNamo (ERC-2010-AdG, Proposal No. 267374). A.S. acknowledges the support of the Research Funds of the University of Helsinki and the Academy of Finland through Contract No. 1127462, Centers of Excellence Program, and the National Graduate School in Materials Physics. J.M.G.L. acknowledges support from The Lundbeck Foundation’s Center for Atomic-Scale Materials Design and the Danish Center for Scientific Computing.Peer Reviewe

Automated analysis of XANES: A feasibility study of Au reference compounds

With the advent of high-throughput and imaging core level spectroscopies (including X-ray absorption spectroscopy, XAS, as well as electron energy loss spectroscopy, EELS), automated data processing, visualisation and analytics will become a necessity. As a first step towards these objectives we examined the possibilities and limitations of a simple automated XANES peak fitting procedure written in MATLAB, for the parametrisation of XANES features, including ionisation potentials as well as the energies and intensities of electronic transitions. Using a series of Au L3-edge XANES reference spectra we show that most of the relevant information can be captured through a small number of rules applied to constrain the fits. Uncertainty in this strategy arises mostly when the ionisation potential (IP) overlaps with weak electronic transitions or features in the continuum beyond the IP, which can result in ambiguity through multiple equally good fits

Satisfaction of staff of Swiss insurance companies with medical appraisals: a cross sectional study

<p>Abstract</p> <p>Background</p> <p>A high quality of timely delivered medical appraisals is crucial for social and other insurances to judge possible occupational reintegration measures for patients with medical conditions who are in danger to lose their job. However, little is known about the satisfaction of staff of insurance companies with medical appraisals that they have commissioned.</p> <p>Our questionnaire survey prospectively included all medical appraisals arriving at Swiss insurances from FEB to APR 2008. We assessed the satisfaction of the commissioner with medical appraisals performed by medical assessors. In addition, we evaluated the contribution of several factors to overall satisfaction. The unit of sample was the medical appraisal.</p> <p>Findings</p> <p>We analysed 3165 medical appraisals, 2444 (77%) of them from the public disability insurance, 678 (22%) from private accident, liability and loss of income insurances and 43 (1%) from other insurances. Overall satisfaction of staff of insurance companies in Switzerland was high, but satisfaction of the disability insurance with appraisals was generally lower compared to satisfaction of private insurances. The staff of the disability insurance judged time for preparation as too long in 30%. For staff of private insurance companies 20% of appraisals were not "worth its price". Well-grounded and comprehensible conclusions were the single most important factor for high overall satisfaction (OR 10.1; 95%-CI: 1.1-89.3).</p> <p>Conclusions</p> <p>From the viewpoint of staff of insurance companies, a relevant part of medical appraisals arrives too late. Medical assessors have to take the specific needs of insurances into account, to perform more appraisals with sound conclusions in due time.</p

Influence of a Transport Current on Magnetic Anisotropy in Gyrotropic Ferromagnets

Current-induced torques are commonly used to manipulate non-collinear magnetization configurations. In this article we discuss current-induced torques present in a certain class of collinear magnetic systems, relating them to current-induced changes in magnetic anisotropy energy. We present a quantitative estimate of their characteristics in uniform strained ferromagnetic (Ga,Mn)As.Comment: 12 pages, 8 figures; submitted to Phys. Rev.

Profiling a decade of information systems frontiers’ research

This article analyses the first ten years of research published in the Information Systems Frontiers (ISF) from 1999 to 2008. The analysis of the published material includes examining variables such as most productive authors, citation analysis, universities associated with the most publications, geographic diversity, authors’ backgrounds and research methods. The keyword analysis suggests that ISF research has evolved from establishing concepts and domain of information systems (IS), technology and management to contemporary issues such as outsourcing, web services and security. The analysis presented in this paper has identified intellectually significant studies that have contributed to the development and accumulation of intellectual wealth of ISF. The analysis has also identified authors published in other journals whose work largely shaped and guided the researchers published in ISF. This research has implications for researchers, journal editors, and research institutions

Importance of Ethnicity, CYP2B6 and ABCB1 Genotype for Efavirenz Pharmacokinetics and Treatment Outcomes: A Parallel-group Prospective Cohort Study in two sub-Saharan Africa Populations.

We evaluated the importance of ethnicity and pharmacogenetic variations in determining efavirenz pharmacokinetics, auto-induction and immunological outcomes in two African populations. ART naïve HIV patients from Ethiopia (n = 285) and Tanzania (n = 209) were prospectively enrolled in parallel to start efavirenz based HAART. CD4+ cell counts were determined at baseline, 12, 24 and 48 weeks. Plasma and intracellular efavirenz and 8-hydroxyefvairenz concentrations were determined at week 4 and 16. Genotyping for common functional CYP2B6, CYP3A5, ABCB1, UGT2B7 and SLCO1B1 variant alleles were done. Patient country, CYP2B6*6 and ABCB1 c.4036A>G (rs3842A>G) genotype were significant predictors of plasma and intracellular efavirenz concentration. CYP2B6*6 and ABCB1 c.4036A>G (rs3842) genotype were significantly associated with higher plasma efavirenz concentration and their allele frequencies were significantly higher in Tanzanians than Ethiopians. Tanzanians displayed significantly higher efavirenz plasma concentration at week 4 (p<0.0002) and week 16 (p = 0.006) compared to Ethiopians. Efavirenz plasma concentrations remained significantly higher in Tanzanians even after controlling for the effect of CYP2B6*6 and ABCB1 c.4036A>G genotype. Within country analyses indicated a significant decrease in the mean plasma efavirenz concentration by week 16 compared to week 4 in Tanzanians (p = 0.006), whereas no significant differences in plasma concentration over time was observed in Ethiopians (p = 0.84). Intracellular efavirenz concentration and patient country were significant predictors of CD4 gain during HAART. We report substantial differences in efavirenz pharmacokinetics, extent of auto-induction and immunologic recovery between Ethiopian and Tanzanian HIV patients, partly but not solely, due to pharmacogenetic variations. The observed inter-ethnic variations in efavirenz plasma exposure may possibly result in varying clinical treatment outcome or adverse event profiles between populations