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