Jahn-Teller distortions and excitation energies in C60(n+)

Based on previously computed parameters for the electron-phonon couplings and the Coulomb exchange, we compute and classify the static Jahn-Teller distortions, i.e. the minima of the lowest adiabatic potential energy surface, of C60(n+), for all values of charge 1 <= n <= 9 and spin. We compute the intra-band electronic excitation energies in the different optimal geometries in the sudden approximation, and find a spread of the electronic states of roughly 1 eV. We also obtain the leading vibronic quantum corrections to the ground-state energy, equal to zero-point energy lowering due to the softening of the phonons at the adiabatic Jahn-Teller minima: these non-adiabatic corrections are so large that for 4 <= n <= 6 states of different spin symmetry turn lower than the high-spin adiabatic ground state.Comment: 19 pages, proceedings of the XVI Jahn-Teller Conference - Leuven (Be), 26/8 - 1/9 200

Experimental investigation of advanced concepts to increase turbine blade loading. 4 - Performance evaluation of plain rotor blade with plow type vortex generators

Performance evaluation of plain rotor blade with plow type vortex generator

Do companies exploit accounting rules for broad stock opion plans?

Several studies indicate that stock option plans are becoming more and more a substantial part of compensation schemes in U.S. companies. This paper argues that for an employer the attractiveness of stock options arises from the U.S. Generally Accepted Accounting Principles (US-GAAP) which require no charge to earnings for specifically designed stock option plans if a company opts for footnote disclosure. This poses a substantial problem for security analysis since a firm's earnings may be considerably upward biased. Based on a case study of 20 companies out of the S&P 500 which rely heavily on employee stock options we arrive at the conclusion that the amount of hidden compensation cost can be significant. For some of the companies the misrepresentation of stated earnings exceeds usual immateriality limits by far. Therefore, we propose that the fair value method of Statement No. 123 Financial Accounting Standards Board should be made compulsory in order to restore the true and fair view which "income as stated" should provide.

Hund's rule Magnetism in C60 ions?

We investigate the occurrence of Hund's rule magnetism in C60(n+-) molecular ions, by computing the ground-state spin for all charge states n from -3 to +5. The two competing interactions, electron-vibration (e-v, including Jahn Teller, favoring low spin) and electron-electron (e-e, including Hund-rule exchange, favoring high spin), are accounted for based on previously computed ab-initio coupling parameters. Treating the ion coordinates as classical, we first calculate and classify the static Jahn-Teller distorted states for all n, inclusive of both e-v and e-e effects. We then correct the adiabatic result by including the zero-point energy lowering associated with softening of vibrations at the adiabatic Jahn-Teller minima. Our overall result is that while, like in previous investigations, low-spin states prevail in negative ions, Hund's rule high spin dominates all positive C60(n+) ions. This suggests also that Hund-rule magnetism could arise in fullerene cation-based solid state compounds, particularly those involving C60(2+).Comment: 12 pages, 2 figures, epj styl

Update on the CERN Computing and Network Infrastructure for Controls (CNIC)

Over the last few years modern accelerator and experiment control systems have increasingly been based on commercial-off-the-shelf products (VME crates, PLCs, SCADA systems, etc.), on Windows or Linux PCs, and on communication infrastructures using Ethernet and TCP/IP. Despite the benefits coming with this (r)evolution, new vulnerabilities are inherited too: Worms and viruses spread within seconds via the Ethernet cable, and attackers are becoming interested in control systems. Unfortunately, control PCs cannot be patched as fast as office PCs. Even worse, vulnerability scans at CERN using standard IT tools have shown that commercial automation systems lack fundamental security precautions: Some systems crashed during the scan, others could easily be stopped or their process data be altered. During the two years following the presentation of the CNIC Security Policy at ICALEPCS2005, a "Defense-in-Depth" approach has been applied to protect CERN's control systems. This presentation will give a review of its thorough implementation and its deployment. Particularly, measures to secure the controls network and tools for user-driven management of Windows and Linux control PCs will be discusse

On the ferromagnetic character of (LaVO3_3)m_m/SrVO3_3 superlattices

The experimental observation that vanadate superlattices (LaVO$_3$)$_m$/SrVO$_3$ show ferromagnetism up to room temperature [U.\ L\"uders {\it et al.}, Phys.\ Rev.\ B {\bf 80}, 241102R (2009)] is investigated by means of density functional theory. First, the influence of the density functional on the electronic and magnetic structure of bulk ${\rm LaVO_3}$ is discussed. Second, the band structure of a (LaVO$_3$)$_m$/SrVO$_3$ slab for $m=5$ and 6 is calculated. Very different behaviors for odd and even values of $m$ are found: In the odd case lattice relaxation results into a buckling of the interface VO$_2$ layers that leads to spin-polarized interfaces. In the even case a decoupling of the interface VO$_2$ layers from the LaO layers is obtained, confining the interface electrons into a two-dimensional electron gas. The orbital reconstruction at the interface due to the lattice relaxation is discussed.Comment: 8 pages, 7 figure

Balsamic Vinegar Reproducibility Study of Heavy Metal Quantification Method Using Spectral Analysis

This project seeks to examine the reproducibility of a previously established method used to quantify heavy metals in organic and inorganic samples. Balsamic vinegar has the potential to contain traces of heavy metals due to its long aging process involving wooden barrels. Therefore, this study will examine heavy metal concentrations in balsamic vinegar samples using the spectroscopic analyte quantification method. Heavy metal analysis is performed using Graphite Furnace Atomic Absorption Spectroscopy (GFAAS) and Total Reflection X-Ray Fluorescence (TXRF) Spectrometry. The heavy metals copper and magnesium were spiked in balsamic vinegar samples and underwent microwave-assisted acid digestion prior to spectrometric testing

The CERN Detector Safety System for the LHC Experiments

The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four LHC experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC front-end, to which the safety-critical part of the DSS task is delegated. This is then supervised by a PVSS SCADA system via an OPC server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "Configuration Database". Thus, the DSS can easily adapt to the different and constantly evolving requirements of the LHC experiments during their construction, commissioning and exploitation phases.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 5 pages, PDF. PSN THGT00

Social Support and Anorexia Recovery Online

An analysis of an online anorexia recovery message board community was used to develop an understanding of how anorexia patients conceptualize the recovery process, what tangential topics they discuss on the message board, if the community has similar characteristics to those previously marked as effective by previous studies (Barak, Boniel-Nissim, & Suler 2008), and how community members deal with stigma. Through discourse analysis, ideologies were identified from the message board postings collected from the website, eating-disorder.supportgroups.com, over a one month period in 2013. Ideologies are "social systems of ideas, values or prescriptions of groups [and] have the function of organizing or legitimating the actions of the group" (van Dijk, 1998, p. 3). The ideologies identified in the current study demonstrate that recovering anorexics understand recovery as a process and discuss tangential topics in an effort to relate to, and connect with, one another. Also, this study provides evidence that the online community of anorexics dealing with recovery is similar to communities deemed effective by prior research (Barak et al., 2008) and that recovering anorexics make use of various stigma management strategies. Theoretical and practical implications are offered in an effort to improve the anorexia recovery process.