Density of States in Landau Level Tails of GaAs-AlxGa1-xAs Heterostructures

From an analysis of the thermally activated resistivity as a function of the magnetic field in the quantum Hall regime we deduced the position of the Fermi energy in the mobility gap as a function of the filling factor and therefore the density of states. The measured density of states is best described by a Gaussian like profile superimposed on a constant background

Towards transnational CSR. Corporate social responsibility approaches and governance solutions for multinational corporations

The global environment in which multinational corporations (MNCs) operate dramatically increases the complexity of the governance challenges and ethical dilemmas confronting MNCs and their leaders, as well as the diversity of stakeholders whose interests must be considered. In this context, MNCs face a perennial dilemma: how to balance the need for global consistency in CSR approaches and ethical standards across the organization with the need to be sensitive to the demands and expectations of a diverse set of stakeholders spread across the globe? Building on the framework of “transnational CSR”, we provide a systematic mapping of CSR approaches in MNCs, high¬light the tensions and possible trade-offs between globally integrated and locally adapted CSR strategies, and discuss the constraints that they impose on MNC activities at both headquarters and subsidiary levels. We also highlight the impli¬cations for corporate governance, stakeholder management and corporate social performance. Based on in-depth case studies of 18 MNCs, we conclude that a transnational CSR approach that attempts to strike an appropriate balance between global consistency and local adaptation seems best able to guide managerial decision making and help executives address the CSR challenges in the global arena

Eta Carinae across the 2003.5 Minimum: Analysis in the visible and near infrared spectral region

We present an analysis of the visible through near infrared spectrum of Eta Carinae and its ejecta obtained during the "Eta Carinae Campaign with the UVES at the ESO VLT". This is a part of larger effort to present a complete Eta Carinae spectrum, and extends the previously presented analyses with the HST/STIS in the UV (1240-3159 A) to 10,430 A. The spectrum in the mid and near UV is characterized by the ejecta absorption. At longer wavelengths, stellar wind features from the central source and narrow emission lines from the Weigelt condensations dominate the spectrum. However, narrow absorption lines from the circumstellar shells are present. This paper provides a description of the spectrum between 3060 and 10,430 A, including line identifications of the ejecta absorption spectrum, the emission spectrum from the Weigelt condensations and the P-Cygni stellar wind features. The high spectral resolving power of VLT/UVES enables equivalent width measurements of atomic and molecular absorption lines for elements with no transitions at the shorter wavelengths. However, the ground based seeing and contributions of nebular scattered radiation prevent direct comparison of measured equivalent widths in the VLT/UVES and HST/STIS spectra. Fortunately, HST/STIS and VLT/UVES have a small overlap in wavelength coverage which allows us to compare and adjust for the difference in scattered radiation entering the instruments' apertures. This paper provides a complete online VLT/UVES spectrum with line identifications and a spectral comparison between HST/STIS and VLT/UVES between 3060 and 3160 A.Comment: 13 pages, 11 figures + atlas. The paper accepted for the ApJS and is accompanied with an atlas in the online edition pape

Relational Contracts and Trust in a High-Tech Industry

We study how informal buyer-supplier relationships in the German automotive industry affect procurement. Using unique data from a survey focusing on these, we show that more trust, the belief that the trading partner acts to maintain the mutual relationship, is associated with both higher quality of the automotive parts and more competition among suppliers. Yet both effects hold only for parts involving unsophisticated technology, not when technology is sophisticated. We rationalize these findings within a relational contracting model that critically focuses on changes in the bargaining power, due to differences in the costs of switching suppliers

Compensation device of breakaway torque of reaction wheel assembly

Статья посвящена разработке устройства компенсации момента трогания в управляющихдвигателях-маховиках. В статье анализируются проблемы, связанные с возникновением явления момента трогания в двигателях. Автором предлагаются пути решения данной проблемы, а так же рассматриваются преимущества и недостатки каждого из них. В результате было предложено устройство, которое позволяет снизить момент трогания управляющих двигателей-маховиков и исключить зону нечувствительности к малым управляющим сигналам, описана его структура и представлен краткий алгоритм работы такого устройства. Оценка результатов была произведена на испытательном стенде, представляющем собой имитационную модель управляющего двигателя-маховика.The article is devoted to the development of compensation device of breakaway torque of reaction wheel assembly. The article analyses the problems associated with the emergence of phenomenon of breakaway torque in reaction wheel assembly. The author suggests ways of solving this problem, as well as discusses the advantages anddisadvantages of each of them. As a result, it was suggested the device which reduces breakaway torque of reaction wheel assembly and exclude the dead zone in range of small signals, described its structure and provides an algorithm for such a device. Evaluation of the results was carried out on a test bench, which represent a simulationmodel of reaction wheel assembly

Dust Formation and He II 4686 emission in the Dense Shell of the Peculiar Type Ib Supernova 2006jc

We present evidence for the formation of dust grains in an unusual Type Ib SN based on late-time spectra of SN 2006jc. The progenitor suffered an LBV-like outburst just 2 yr earlier, and we propose that the dust formation is a consequence of the SN blast wave overtaking that LBV-like shell. The key evidence for dust formation is (a) the appearance of a red/near-IR continuum source fit by 1600 K graphite grains, and (b) fading of the redshifted sides of He I emission lines, yielding progressively more asymmetric blueshifted lines as dust obscures receding material. This provides the strongest case yet for dust formation in any SN Ib/c. Both developments occurred between 51 and 75 d after peak, while other SNe observed to form dust did so after a few hundred days. Geometric considerations indicate that dust formed in the dense swept-up shell between the forward and reverse shocks, and not in the freely expanding SN ejecta. Rapid cooling leading to dust formation may have been aided by extremely high shell densities, as indicated by He I line ratios. The brief epoch of dust formation is accompanied by He II 4686 emission and enhanced X-ray emission. These clues suggest that the unusual dust formation in this object was not due to properties of the SN itself, but instead -- like most peculiarities of SN 2006jc -- was a consequence of the dense environment created by an LBV-like eruption 2 yr before the SN.Comment: ApJ, accepted. added some discussion and 2 figures, better title, conclusions same as previous version. 12 pages, 4 color fig

Pilot Study: Measuring Attitudes Toward Ramp Resource Management—The Influence of National Culture

Ramp resource management (RRM) is a highly flight-safety-relevant, but to date widely overlooked, part of the air transportation system. Organizational, national, professional, and safety cultures play an important role in setting up resource management and training. This pilot study evaluates the influence of national culture on attitudes toward RRM, based on Geert Hofstede’s Values Survey Module. A slightly adapted version of this survey module was distributed to ramp personnel in Germany and national cultural indices were generated. A one-way analysis of variance revealed that, while some influence of national culture in RRM could be concluded, the majority of the results were not statistically significant (critical p-value \u3c 0.05). In spite of the broad acceptance of the influence of national culture on crew resource management, the results could indicate weaknesses in current cultural values survey tools. Clearly, this pilot study indicates that further research in the field of RRM and culture is needed for a reliable evaluation of current RRM and training methods

The influence of alfalfa-switchgrass intercropping on microbial community structure and function

The use of nitrogen fertilizer on bioenergy crops such as switchgrass results in increased costs, nitrogen leaching and emissions of N2O, a potent greenhouse gas. Intercropping with nitrogen-fixing alfalfa has been proposed as an environmentally sustainable alternative, but the effects of synthetic fertilizer versus intercropping on soil microbial community functionality remain uncharacterized. We analysed 24 metagenomes from the upper soil layer of agricultural fields from Prosser, WA over two growing seasons and representing three agricultural practices: unfertilized switchgrass (control), fertilized switchgrass and switchgrass intercropped with alfalfa. The synthetic fertilization and intercropping did not result in major shifts of microbial community taxonomic and functional composition compared with the control plots, but a few significant changes were noted. Most notably, mycorrhizal fungi, ammonia-oxidizing archaea and bacteria increased in abundance with intercropping and fertilization. However, only betaproteobacterial ammonia-oxidizing bacteria abundance in fertilized plots significantly correlated to N2O emission and companion qPCR data. Collectively, a short period of intercropping elicits minor but significant changes in the soil microbial community toward nitrogen preservation and that intercropping may be a viable alternative to synthetic fertilization

Calculation of electrostatic fields using quasi-Green's functions: application to the hybrid Penning trap.

Penning traps offer unique possibilities for storing, manipulating and investigating charged particles with high sensitivity and accuracy. The widespread applications of Penning traps in physics and chemistry comprise e.g. mass spectrometry, laser spectroscopy, measurements of electronic and nuclear magnetic moments, chemical sample analysis and reaction studies. We have developed a method, based on the Green's function approach, which allows for the analytical calculation of the electrostatic properties of a Penning trap with arbitrary electrodes. The ansatz features an extension of Dirichlet's problem to nontrivial geometries and leads to an analytical solution of the Laplace equation. As an example we discuss the toroidal hybrid Penning trap designed for our planned measurements of the magnetic moment of the (anti)proton. As in the case of cylindrical Penning traps, it is possible to optimize the properties of the electric trapping fields, which is mandatory for high-precision experiments with single charged particles. Of particular interest are the anharmonicity compensation, orthogonality and optimum adjustment of frequency shifts by the continuous SternGerlach effect in a quantum jump spectrometer. The mathematical formalism developed goes beyond the mere design of novel Penning traps and has potential applications in other fields of physics and engineering