10,061 research outputs found

    Zone leveling and solution growth of complex compound semiconductors in space

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    A research program on complex semiconducting compounds and alloys was completed that addressed the growth of single crystals of CdSe(y)Te(1-y), Zn(x)Cd(1-x)Te, Mn(x)Cd(1-x)Te, InP(y)As(1-y) and CuInSe2 and the measurement of fundamental physico-chemical properties characterizing the above materials. The purpose of this ground based research program was to lay the foundations for further research concerning the growth of complex ternary compound semiconductors in a microgravity environment

    Uncertainties for Pre- and Post-Launch Radiometric Calibration of Imaging Spectrometers for Multi-Sensor Applications

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    An important aspect to using imaging spectrometer data is the radiometric characterization and calibration of the sensors and validation of their data products and doing so with error budgets with known traceability. The radiometric accuracy of a given sensor is important for demonstrating the expected quality of data from the sensor. Known traceability allows data from multiple sensors to be directly comparable as will become more important in the near future with the expected launches of multiple imaging spectrometers from multiple countries, agencies, and commercial entities. The current work describes the state of pre- and post-launch radiometric absolute and relative uncertainties and their role in harmonising on-orbit data. Examples of prelaunch uncertainties based on the calibration of EnMAP and the calibration planned for the CLARREO Pathfinder Mission are presented highlighting recent work in the area of detector-based approaches using tunable laser sources. Post-launch calibration approaches for Pathfinder, EnMAP, CHIME, and DESIS including traditional vicarious calibration methods and the challenges of working with commercial data are presented. The vicarious calibration discussion relies on the example of the recently-available RadCalNet data to describe typical methods and challenges that will be faced when harmonising data between imaging spectrometers as well as with multispectral sensors

    Labour Market Entry Conditions, Wages and Job Mobility

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    Economic conditions at the time of labour market entry can induce wage differentials between workers entering the labour market at different points in time. While the existence and persistence of these entry wage differentials are well documented, little is known about their interaction with employees’ mobility behaviour. This paper contributes to this research area by analyzing the interaction between job mobility and entry wage differentials using German administrative data. The results suggest that labour market entrants earning less than the average starting wage are more likely to change jobs, directly from employer to employer as well as indirectly via an unemployment spell. In addition they are more likely to change occupation. Moreover, job mobility tends to reduce the effects of labour market entry conditions, implying that job mobility operates as an adjustment mechanism that mitigates entry wage differentials. These results hold not only for high-skilled, but also for medium-skilled and unskilled workers.Mobility; job-to-job; wages; labour market entry; initial conditions

    Just war and military morale: a brief reflection on the correlation between the legality of war and the moral repercussions for members of US and UK forces arising from the questionable legality of the campaign Iraqi Freedom of March 2003

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    Does it matter to a member of the military whether the military campaign in which he is taking part is lawful or not? Despite the observation that the crime of aggression (post Kampala 2010) constitutes a ‘leadership crime par excellence,’ which limits any (future) criminal responsibility accordingly, the legality or illegality of any military action under international law can create moral implications for the common foot soldier and mid-level officer and also have a tangible impact on the national legal frameworks under which these forces operate. This short article uses the example of Operation Iraqi Freedom (2003) to discuss the repercussions of a—most likely—illegal military campaign for individual members of democratic armed forces before the background of the present discussion of NATO led action in Libya

    Conformational Mechanics of Polymer Adsorption Transitions at Attractive Substrates

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    Conformational phases of a semiflexible off-lattice homopolymer model near an attractive substrate are investigated by means of multicanonical computer simulations. In our polymer-substrate model, nonbonded pairs of monomers as well as monomers and the substrate interact via attractive van der Waals forces. To characterize conformational phases of this hybrid system, we analyze thermal fluctuations of energetic and structural quantities, as well as adequate docking parameters. Introducing a solvent parameter related to the strength of the surface attraction, we construct and discuss the solubility-temperature phase diagram. Apart from the main phases of adsorbed and desorbed conformations, we identify several other phase transitions such as the freezing transition between energy-dominated crystalline low-temperature structures and globular entropy-dominated conformations.Comment: 13 pages, 15 figure

    Special values of finite multiple harmonic q-series at roots of unity

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    We study special values of finite multiple harmonic q-series at roots of unity. These objects were recently introduced by the authors and it was shown that they have connections to finite and symmetric multiple zeta values and the Kaneko-Zagier conjecture. In this note we give new explicit evaluations for finite multiple harmonic q-series at roots of unity and prove Ohno-Zagier-type relations for them

    NESTMOD: The NetMod-NEST Interface

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    NESTMOD is a combined analytical modeling and simulation tool, based on the existing tools NetMod and NEST. It provides both transient and steady-state response statistics from models of interconnected local area networks that can execute at any level of detail desired. This gives users the potential to model both networks of extremely large scope (hundreds of thousands of nodes), and to look at great detail for any combination of the ISO layers. This paper describes the interface implementation, and presents an example to illustrate the potential power of the tool.http://deepblue.lib.umich.edu/bitstream/2027.42/107970/1/citi-tr-91-7.pd
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