Results 241 to 250 of about 10,978,845 (289)

Ultra low frequency transducer and loud speaker comprising same

The Journal of the Acoustical Society of America, 2004
An ultra low frequency transducer or subwoofer for automotive speaker systems with a concave diaphragm and a pleated surround. Preferably, the periphery of the diaphragm is square or rectangular and sized to be substantially coextensive with the front of the speaker housing or cabinet.
Steven M. Irby, William O. Doering
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Ultra-low phase noise frequency combs

Frontiers in Optics 2015, 2015
Emerging applications put increasing demands on the short-term stability of frequency combs. We review how ultra-low noise oscillator design combined with improved loop gain and bandwidth continue to enable these most challenging applications to date.
C.-C. Lee, D. Hou, Z. Yang, T. R. Schibli   +3 more
openaire   +1 more source

Ultra-Low Frequency Seismic: Benefits and Solutions

International Petroleum Technology Conference, 2014
Abstract Ultra-low seismic frequencies less than about 7–10 Hz cannot be produced with significant amplitudes by conventional air gun arrays, for any configuration and for any towing depth used during marine seismic surveys.
Andrew Samuel Long, Cyrille Reiser
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Performance of an ultra low-frequency folded pendulum

Physics Letters A, 1994
Abstract A folded pendulum consisting of the sum of a conventional compound pendulum and an inverse pendulum can be tuned to create a pendulum with the dynamic response of a kilometre scale pendulum. Results are presented demonstrating the stability and Q-factor of the system down to a resonant frequency of 17 mHz.
David G. Blair, Jiangfeng Liu, Ehsan F. Moghaddam, Li Ju   +3 more
openaire   +1 more source

Ultra-Low Frequency Waves at Comets

2013
Theory and observational results on ultralow frequency (ULF) waves or turbulence upstream of comets are reviewed. The ULF wave characteristics of comets Giacobini-Zinner and Halley are described and the cyclotron resonance condition is discussed. Theoretical work on the contribution of instabilities to ULF wave excitation is addressed. The quasi-linear
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High-sensitive ultra-low frequency hydrophone

International Conference on Micro- and Nano-Electronics 2018, 2019
In this paper we demonstrate a new prototype of a high-precision ultra-low-frequency hydrophone on the basis of a planar type electrochemical transducer (ECT). We have developed a new planar electrochemical microchip and have invented a mechanical system that allows detecting the alternating pressure at low frequencies up to 0.01 Hz.
Vladimir G. Krishtop, Alexey Y. Belyaev, Alexander S. Zlobin, Pavel V. Dudkin, Sergey V. Kokhanovsky, Dmitry A. Zhevnenko, Tatiana V. Krishtop   +6 more
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Adiabatic calorimeter as an ultra-low frequency spectrometer

Pure and Applied Chemistry, 1989
Abstract
H. Suga, T. Matsuo
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Ultra-low-frequency ride motions and kinetosis

The Journal of the Acoustical Society of America, 1997
Proposed ultra-high-speed ground transportation systems, such as Maglev, may have motion characteristics affecting passenger comfort different from anything previously experienced in ground transportation. These motions not only include isolated vertical maneuvers but also repeated motions.
E. D. Sussman, Robert DiSario, Peter Mengert, John K. Pollard   +3 more
openaire   +1 more source

Characteristics of Vacuo-Thermojunctions at Ultra-Low Frequency

IEEE Transactions on Instrumentation and Measurement, 1985
Characteristics of vacuo-thermo-junctions (VTJ's) at ultra-low frequency are discussed. A method of expansion with series of nonharmonic sine functions has been combined with a method of perturbation to solve the partial differential equation for heat conduction in the heater of a vacuo-thermojunction.
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An ultra-low-frequency acoustic vector sensor.

The Journal of the Acoustical Society of America, 2010
Passive underwater acoustic surveillance and oceanographic studies, for the most, have not been conducted at ultra-low frequencies (ULFs), from 0.01 Hz to a few hertz. One of the primary reasons for neglecting ULF has been the lack of sensitive, and directional, ULF acoustic sensors.
Dimitri M. Donskoy, Benjamin A. Cray
openaire   +1 more source