5,422 research outputs found

    Is Employment Globalizing?

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    We investigate the claim that national labor markets have become more globally interconnected in recent decades. We do so by deriving estimates over time of three different notions of interconnection: (i) the share of labor demand that is export induced (i.e., all labor demand created by foreign entities buying products exported by the home country)—we provide estimates for 40 countries; (ii) the share of workers employed in sectors producing tradable goods or services—68 countries; and (iii) the ratio of the number of jobs that are either located in a tradable sector, or that are involved in producing services that are required by these tradable sectors, to all jobs in the economy, which we call the trade-linked employment share—40 countries. Our estimates lead to the conclusion that the evidence of a large increase in the interconnections between national labor markets is far weaker than commonly asserted: levels of interconnectivity, and the direction of changes over time, vary across notions of interconnection and countries. The main reasons for this are labor- displacing productivity growth in tradable sectors of each economy and the diminishing fraction of national labor forces hired into manufacturing jobs worldwide. We also discuss the implications of our results for different policy debates that each of the three measures is associated with: international coordination of macroeconomic policies (export-induced labor demand), currency devaluations (share of workers producing tradables), and education and labor protection (trade-linked share)

    INTEGRATING BIOMASS TO PRODUCE HEAT AND POWER AT ETHANOL PLANTS

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    Published in: Applied Engineering in Agriculture, Vol. 25(2): 227‐244Biomass, Renewable, Sustainable, Model, Gasification, Combustion, Emissions, Ethanol production, Combined heat and power, Resource /Energy Economics and Policy,

    ECONOMICS OF BIOMASS GASIFICATION/COMBUSTION AT FUEL ETHANOL PLANTS

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    Published in Applied Engineering in Agriculture, Vol. 25(3): 391‐400Ethanol, Biomass, Economics, CHP, Emissions, Process heat, Electricity production, Resource /Energy Economics and Policy,

    Few-electron quantum dots in III-V ternary alloys: role of fluctuations

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    We study experimentally the electron transport properties of gated quantum dots formed in InGaAs/InP and InAsP/InP quantum well structures grown by chemical-beam epitaxy. For the case of the InGaAs quantum well, quantum dots form directly underneath narrow gate electrodes due to potential fluctuations. We measure the Coulomb-blockade diamonds in the few-electron regime of a single quantum dot and observe photon-assisted tunneling peaks under microwave irradiation. A singlet-triplet transition at high magnetic field and Coulomb-blockade effects in the quantum Hall regime are also observed. For the InAsP quantum well, an incidental triple quantum dot forms also due to potential fluctuations within a single dot layout. Tunable quadruple points are observed via transport measurements.Comment: 3.3 pages, 3 figures. Added two new subfigures, new references, and improved the tex

    Application of Risk Informed Decision Making to Highly Reliable Three Dimensionally Woven Thermal Protection System for Mars Sample Return

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    The NASA Risk Informed Decision Making process is used to assess a trade space of three dimensionally woven thermal protection systems for application to the Mars Sample Return Earth Entry Vehicle. Candidate architectures are assessed based on mission assurance, technical development, cost, and schedule risk. Assessment methodology differed between the architectures, utilizing a four-point quantitative scale for mission assurance and technical development and highly tailored PERT techniques for cost and schedule. Risk results are presented, in addition to a review of RIDM effectiveness for this application

    Coherent Transport Through a Quadruple Point in a Few Electron Triple Dot

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    A few electron double electrostatic lateral quantum dot can be transformed into a few electron triple quantum dot by applying a different combination of gate voltages. Quadruple points have been achieved at which all three dots are simultaneously on resonance. At these special points in the stability diagram four occupation configurations are possible. Both charge detection and transport experiments have been performed on this device. In this short paper we present data and confirm that transport is coherent by observing a Pi phase shift in magneto-conductance oscillations as one passes through the quadruple point.Comment: To be published in ICPS Conf. Proceedings 200

    An IPMC-Enabled Bio-Inspired bending/twisting Fin for Underwater Applications

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    This paper discusses the design, fabrication, and characterization of an ionic polymer–metal composite (IPMC) actuator-based bio-inspired active fin capable of bending and twisting motion. It is pointed out that IPMC strip actuators are used in the simple cantilever configuration to create simple bending (flapping-like) motion for propulsion in underwater autonomous systems. However, the resulting motion is a simple 1D bending and performance is rather limited. To enable more complex deformation, such as the flapping (pitch and heaving) motion of real pectoral and caudal fish fins, a new approach which involves molding or integrating IPMC actuators into a soft boot material to create an active control surface (called a \u27fin\u27) is presented. The fin can be used to realize complex deformation depending on the orientation and placement of the actuators. In contrast to previously created IPMCs with patterned electrodes for the same purpose, the proposed design avoids (1) the more expensive process of electroless plating platinum all throughout the surface of the actuator and (2) the need for specially patterning the electrodes. Therefore, standard shaped IPMC actuators such as those with rectangular dimensions with varying thicknesses can be used. One unique advantage of the proposed structural design is that custom shaped fins and control surfaces can be easily created without special materials processing. The molding process is cost effective and does not require functionalizing or \u27activating\u27 the boot material similar to creating IPMCs. For a prototype fin (90 mm wide × 60 mm long× 1.5 mm thick), the measured maximum tip displacement was approximately 44 mm and the twist angle of the fin exceeded 10°. Lift and drag measurements in water where the prototype fin with an airfoil profile was dragged through water at a velocity of 21 cm s−1 showed that the lift and drag forces can be affected by controlling the IPMCs embedded into the fin structure. These results suggest that such IPMC-enabled fin designs can be used for developing active propeller blades or control surfaces on underwater vehicles

    The JPL telerobotic Manipulator Control and Mechanization (MCM) subsystem

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    The Manipulator Control and Mechanization (MCM) subsystem of the telerobot system provides the real-time control of the robot manipulators in autonomous and teleoperated modes and real time input/output for a variety of sensors and actuators. Substantial hardware and software are included in this subsystem which interfaces in the hierarchy of the telerobot system with the other subsystems. The other subsystems are: run time control, task planning and reasoning, sensing and perception, and operator control subsystem. The architecture of the MCM subsystem, its capabilities, and details of various hardware and software elements are described. Important improvements in the MCM subsystem over the first version are: dual arm coordinated trajectory generation and control, addition of integrated teleoperation, shared control capability, replacement of the ultimate controllers with motor controllers, and substantial increase in real time processing capability
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