1,883 research outputs found
A Public Firm's R&D Policy and Trade Liberalization
This paper studies a public firm's incentive to raise its productive efficiency by undertaking cost-reducing R&D investment when it competes against a foreign private firm. Our focus is to ravel out how a decrease in an importing tariff levied on foreign goods affects this investment level inter alia. We show that when the government imposes non-negative tariffs, a tariff reduction lowers the R&D investment, irrespective of whether the public firm has downward or upward sloping reaction curve. Namely, R&D investment conducted by the public firm is substitutable to an importing tariff. Furthermore, under a linear demand assumption, it is concluded that a tariff reduction necessarily enhances world welfare if both R&D investment and tariffs are set to domestic welfare-maximizing levels. More strict assumptions on marginal cost and R&D cost function make complete trade liberalization desirable from the viewpoint of world welfare.Mixed Oligopoly; R&D; Trade Liberalization
Conduction Effect of Thermal Radiation in a Metal Shield Pipe in a Cryostat for a Cryogenic Interferometric Gravitational Wave Detector
A large heat load caused by thermal radiation through a metal shield pipe was
observed in a cooling test of a cryostat for a prototype of a cryogenic
interferometric gravitational wave detector. The heat load was approximately
1000 times larger than the value calculated by the Stefan-Boltzmann law. We
studied this phenomenon by simulation and experiment and found that it was
caused by the conduction of thermal radiation in a metal shield pipe.Comment: 7 pages, 4 figures, 2 tables, Submitted to Jpn. J. Appl. Phy
An infrared measurement of chemical desorption from interstellar ice analogues
In molecular clouds at temperatures as low as 10 K, all species except
hydrogen and helium should be locked in the heterogeneous ice on dust grain
surfaces. Nevertheless, astronomical observations have detected over 150
different species in the gas phase in these clouds. The mechanism by which
molecules are released from the dust surface below thermal desorption
temperatures to be detectable in the gas phase is crucial for understanding the
chemical evolution in such cold clouds. Chemical desorption, caused by the
excess energy of an exothermic reaction, was first proposed as a key molecular
release mechanism almost 50 years ago. Chemical desorption can, in principle,
take place at any temperature, even below the thermal desorption temperature.
Therefore, astrochemical net- work models commonly include this process.
Although there have been a few previous experimental efforts, no infrared
measurement of the surface (which has a strong advantage to quantify chemical
desorption) has been performed. Here, we report the first infrared in situ
measurement of chemical desorption during the reactions H + H2S -> HS + H2
(reaction 1) and HS + H -> H2S (reaction 2), which are key to interstellar
sulphur chemistry. The present study clearly demonstrates that chemical
desorption is a more efficient process for releasing H2S into the gas phase
than was previously believed. The obtained effective cross-section for chemical
desorption indicates that the chemical desorption rate exceeds the
photodesorption rate in typical interstellar environments
Digital frequency domain multiplexing readout electronics for the next generation of millimeter telescopes
Frequency domain multiplexing (fMux) is an established technique for the
readout of transition-edge sensor (TES) bolometers in millimeter-wavelength
astrophysical instrumentation. In fMux, the signals from multiple detectors are
read out on a single pair of wires reducing the total cryogenic thermal loading
as well as the cold component complexity and cost of a system. The current
digital fMux system, in use by POLARBEAR, EBEX, and the South Pole Telescope,
is limited to a multiplexing factor of 16 by the dynamic range of the
Superconducting Quantum Interference Device pre-amplifier and the total system
bandwidth. Increased multiplexing is key for the next generation of large
format TES cameras, such as SPT-3G and POLARBEAR2, which plan to have on the of
order 15,000 detectors.
Here, we present the next generation fMux readout, focusing on the warm
electronics. In this system, the multiplexing factor increases to 64 channels
per module (2 wires) while maintaining low noise levels and detector stability.
This is achieved by increasing the system bandwidth, reducing the dynamic range
requirements though active feedback, and digital synthesis of voltage biases
with a novel polyphase filter algorithm. In addition, a version of the new fMux
readout includes features such as low power consumption and radiation-hard
components making it viable for future space-based millimeter telescopes such
as the LiteBIRD satellite.Comment: 15 pages, 10 figures. To be published in Proceedings of SPIE Volume
9153. Presented at SPIE Astronomical Telescopes + Instrumentation 2014,
conference 915
Mixed Oligopoly with a Vertical Structure of Government: Implications of Strategic Privatization and Other Policies
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