327 research outputs found
Generational Differences in Use of Social Media in Todayâs Workplace
This study examined the use of social media at work. Undergraduate students and professors were surveyed to try to find a generational relationship between the younger generationâs view of using sites such as Facebook while working and how some participants from an older generation perceived it. We also examined the effects of Facebook outside of work and whether or not postings made there could jeopardize a position at work. The results from our survey and research conclude that social media is an increasing problem because it serves as a distraction and predict that with increasing individual use of social media it will become more of a problem at work if it is not properly managed by the employer
BeitrĂ€ge zur Erweiterung der HĂŒckel'schen Theorie der Ï-Elektronensysteme [Pi-Elektronensysteme]
BeitrĂ€ge zur Erweiterung der HĂŒckel'schen Theorie der Pi-Elektronensysteme HĂŒckel entwickelte 1931 ein Verfahren zur quantenmechanischen Berechnung zahlreicher Eigenschaften von zr-Elektronensystemen. Obwohl die Theorie halbtheoretisch ist, hat sie einen wesentlichen Beitrag zum VerstĂ€ndnis solcher Eigenschaften von ungesĂ€ttigten und aromatischen Verbindungen geliefert, die dem Grundzustand der MolekĂŒle zugeschrieben werden können, so z. B. der ResonanzstabilitĂ€t und der ReaktivitĂ€t. Doch ist sie nur in der Lage, die Eigenschaften dieser Verbindungen richtig zu beschreiben, die durch angeregte ZustĂ€nde der MolekĂŒle mitbestimmt werden, wie z. B. die Spektren, wenn man fĂŒr das Resononanzintegral einen entsprechenden Wert verwendet, der von dem fĂŒr den Grundzustand benutzten bedeutend abweichen kan. Im ersten Abschnitt der vorliegenden Arbeit wird die HĂŒckel'schen Theorie der Pi-Elektronensysteme diskutiert. Einen nur annĂ€hernd vollstĂ€ndigen Ăberblick ĂŒber die BeitrĂ€ge zu dieser Theorie zu geben, wĂŒrde den Rahmen der Arbeit ĂŒberschreiten. Daher wurde sich im Wesentlichen darauf beschĂ€nkt, die Grundgedanken und die NĂ€herungen des Verfahrens klar darzustellen und kritisch zu betrachten, sowie die Anwendungsmöglicheiten zu beschreiben. Hartmann hat 1960 eine Erweiterung der HĂŒckel 'schen Theorie vorgeschlagen, die auch solche Eigenschaften ungesĂ€ttigter und aromatischer Verbindunsen richtig erfaĂt, die aur der Beteiligung angeregter ZustĂ€nde beruhen, wie am Beispiel der Spektren gezeigt wurde. Im zweiten Teil dieser Arbeit wird die HĂŒckel-Hartmann'sche Theorie der Pi-Elektronensysteme dargestellt und die Ergebnisse mit denen der HĂŒckel'schen Theorie verglichen. Hartmann selbst hat die Erweiterung nur fĂŒr gleichatomige Pi-Elektronensysteme und unter zahlreichen VernachlĂ€ssigunen durchgefĂŒhrt. Dieser Umstand und die wenigen zu der Theorie erst vorliegenden Arbeiten lieĂen es wĂŒnschensert erscheinen, die HĂŒckel-Hartmannsche Theorie der Pi-Elektronensysteme systematisch und in möglichst allgemeiner Form zu diskutieren. Im dritten Abschnitt der Arbeit wird daher eine Generalisierung der HĂŒckel-Hartmannt'schen Theorie durchgefĂŒhrt. Mit Hilfe des entwickelten Verfahrens wird anschlieĂend der EinfluĂ der Ăberlappungen auf die Ergebnisse untersucht und eine Erweiterung der HĂŒckel-Hartmann'schen Theorie auf heteroatomare Pi-Elektronensysteme angegeben
Demokrati eller demokratisk kontrol? : en kritisk diskursanalyse af politikere og juristers fremstilling af Den EuropĂŠiske Menneskerettighedsdomstol
This paper examines the discourse regarding The Danish Chairmanship of the Committee of Ministers of the Council of Europe. The study is focused around eight articles from 2017 in which the European Court of Human Rights dynamic interpretation of the Euro-pean Convention of Human Rights is either questioned or defended. In choosing these articles the study focuses on including both politicians and lawyers since this discourse represents a continuing battle between democratic control and democracy. In analyzing these articles, the study will use Faircloughâs Critical Discourse Analysis with a theoreti-cal social constructivism perspective. The analysis of this study shows that the discourse regarding the dynamic interpretation is constantly changing and is an example of what happens when making a national problem international. The analysis shows clear repre-sentations of power, hierarchy and status in the public debate for both politicians and law-yers and this study can therefore serve as an example for other discourses where the in-ternational society and human rights are criticized. This study shows the power hierarchy with the Danish Justice Minister, SĂžren Pape Poulsen, at the top followed by the lawyers and then the following politicians. The lawyers never gained more than minimal influence because of the Ministers ability to placate them
Theoretical studies of photoexcitation and ionization in H_2O
Theoretical studies are reported of the complete dipole excitation and ionization spectrum in H_2O employing FranckâCondon and staticâexchange approximations. Large Cartesian Gaussian basis sets are used to represent the required discrete and continuum electronic eigenfunctions at the groundâstate equilibrium geometry, and previously devised momentâtheory techniques are employed in constructing the continuum oscillatorâstrength densities from the calculated spectra. Detailed comparisons are made of the calculated excitation and ionization profiles with recent experimental photoabsorption studies and corresponding spectral assignments, electron impactâexcitation cross sections, and dipole (e,â2e)/(e,âe+ion) and synchrotronâradiation studies of partialâchannel photoionization cross sections. The various calculated excitation series in the outerâvalence (1b(^â1)_1, 3a(^â1)_1, 1b(^â1)_2) region are found to include contributions from valenceâlike 2b_2â(Ï*) and 4a_1(Îł*) virtual orbitals, as well as appropriate nsa_1, npa_1, nda_1, npb_1, npb_2, ndb_1, ndb_2, and nda_2 Rydberg states. Transition energies and intensities in the âŒ7 to 19 eV interval obtained from the present studies are seen to be in excellent agreement with the measured photoabsorption cross section, and to provide a basis for detailed spectral assignments. The calculated (1b(^â1)_1)X(^â2)B_1, (3a_1(^â1))^2A_1, and (1b_2(^â1))(^2)B_2 partialâchannel cross sections are found to be largely atomicâlike and dominated by 2pâkd components, although the 2b_2(Ï*) orbital gives rise to resonanceâlike contributions just above threshold in the 3a_1âkb_2 and 1b_2âkb_2 channels. It is suggested that the latter transition couples with the underlying 1b_1âkb_1 channel, accounting for a prominent feature in the recent highâresolution synchrotronâradiation measurements. When this feature is taken into account, the calculations of the three outerâvalence channels are in excellent accord with recent synchrotronâradiation and dipole (e,â2e) photoionization crossâsectional measurements. The calculated innerâvalence (2a_1(^â1)) cross section is also in excellent agreement with corresponding measured values, although proper account must be taken of the appropriate finalâstate configurationâmixing effects that give rise to a modest failure of the Koopmans approximation, and to the observed broad PES band, in this case. Finally, the origins of the various spectral features present in the measured 1a_1 oxygen Kâedge electron energyâloss profile in H_2O are seen to be clarified fully by the present calculations
Symmetry-breaking in the independent particle model: nature of the singular behavior of HartreeâFock potentials
Scattering length of the ground state Mg+Mg collision
We have constructed the X 1SIGMAg+ potential for the collision between two
ground state Mg atoms and analyzed the effect of uncertainties in the shape of
the potential on scattering properties at ultra-cold temperatures. This
potential reproduces the experimental term values to 0.2 inverse cm and has a
scattering length of +1.4(5) nm where the error is prodominantly due to the
uncertainty in the dissociation energy and the C6 dispersion coefficient. A
positive sign of the scattering length suggests that a Bose-Einstein condensate
of ground state Mg atoms is stable.Comment: 15 pages, 3 figures, Submitted Phys. Rev.
Unified Treatment of Asymptotic van der Waals Forces
In a framework for long-range density-functional theory we present a unified
full-field treatment of the asymptotic van der Waals interaction for atoms,
molecules, surfaces, and other objects. The only input needed consists of the
electron densities of the interacting fragments and the static polarizability
or the static image plane, which can be easily evaluated in a ground-state
density-functional calculation for each fragment. Results for separated atoms,
molecules, and for atoms/molecules outside surfaces are in agreement with those
of other, more elaborate, calculations.Comment: 6 pages, 5 figure
Reduced sintering of mass-selected Au clusters on SiO2 by alloying with Ti: an aberration-corrected STEM and computational study
Au nanoparticles represent the most remarkable example of a size effect in heterogeneous catalysis. However, a major issue hindering the use of Au nanoparticles in technological applications is their rapid sintering. We explore the potential of stabilizing Au nanoclusters on SiO2 by alloying them with a reactive metal, Ti. Mass-selected Au/Ti clusters (400â000 amu) and Au2057 clusters (405â229 amu) were produced with a magnetron sputtering, gas condensation cluster beam source in conjunction with a lateral time-of-flight mass filter, deposited onto a silica support and characterised by XPS and LEIS. The sintering dynamics of mass-selected Au and Au/Ti alloy nanoclusters were investigated in real space and real time with atomic resolution aberration-corrected HAADF-STEM imaging, supported by model DFT calculations. A strong anchoring effect was revealed in the case of the Au/Ti clusters, because of a much increased local interaction with the support (by a factor 5 in the simulations), which strongly inhibits sintering, especially when the clusters are more than âŒ0.60 nm apart. Heating the clusters at 100 °C for 1 h in a mixture of O2 and CO, to simulate CO oxidation conditions, led to some segregation in the Au/Ti clusters, but in line with the model computational investigation, Au atoms were still present on the surface. Thus size-selected, deposited nanoalloy Au/Ti clusters appear to be promising candidates for sustainable gold-based nanocatalysis
Large multiconfigurational Hartree-Fock calculations on the hyperfine-structure constants of the Li
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