6,324 research outputs found
The IceCube Neutrino Observatory V: Future Developments
Proposed enhancements of the IceCube observatory. Submitted papers to the
32nd International Cosmic Ray Conference, Beijing 2011.Comment: Papers submitted by the IceCube Collaboration to the 32nd
International Cosmic Ray Conference, Beijing 2011; part
Development and testing of a dual accelerometer vector sensor for AUV acoustic surveys
This paper presents the design, manufacturing and testing of a Dual Accelerometer Vector Sensor (DAVS). The device was built within the activities of theWiMUST project, supported under the Horizon 2020 Framework Programme, which aims to improve the efficiency of the methodologies used to perform geophysical acoustic surveys at sea by the use of Autonomous Underwater Vehicles (AUVs). The DAVS has the potential to contribute to this aim in various ways, for example, owing to its spatial filtering capability, it may reduce the amount of post processing by discriminating the bottom from the surface reflections. Additionally, its compact size allows easier integration with AUVs and hence facilitates the vehicle manoeuvrability compared to the classical towed arrays. The present paper is focused on results related to acoustic wave azimuth estimation as an example of its spatial filtering capabilities. The DAVS device consists of two tri-axial accelerometers and one hydrophone moulded in one unit. Sensitivity and directionality of these three sensors were measured in a tank, whilst the direction estimation capabilities of the accelerometers paired with the hydrophone, forming a vector sensor, were evaluated on a Medusa Class AUV, which was sailing around a deployed sound source. Results of these measurements are presented in this paper.European Union [645141]info:eu-repo/semantics/publishedVersio
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Design of an instrumented smart cutting tool and its implementation and application perspectives
This paper presents an innovative design of a smart cutting tool, using two surface acoustic wave (SAW) strain sensors mounted onto the top and the side surface of the tool shank respectively, and its implementation and application perspectives. This surface acoustic wave-based smart cutting tool is capable of measuring the cutting force and the feed force in a real machining environment, after a calibration process under known cutting conditions. A hybrid dissimilar workpiece is then machined using the SAW-based smart cutting tool. The hybrid dissimilar material is made of two different materials, NiCu alloy (Monel) and steel, welded together to form a single bar; this can be used to simulate an abrupt change in material properties. The property transition zone is successfully detected by the tool; the sensor feedback can then be used to initiate a change in the machining parameters to compensate for the altered material properties.The UK Technology Strategy Board (TSB) for supporting this research (SEEM Project, contract No. BD266E
The TIANSHAN Radio Experiment for Neutrino Detection
An antenna array devoted to the autonomous radio-detection of high energy
cosmic rays is being deployed on the site of the 21 cm array radio telescope in
XinJiang, China. Thanks in particular to the very good electromagnetic
environment of this remote experimental site, self-triggering on extensive air
showers induced by cosmic rays has been achieved with a small scale prototype
of the foreseen antenna array. We give here a detailed description of the
detector and present the first detection of extensive air showers with this
prototype.Comment: 37 pages, 15 figures. Astroparticle Physics (in press
VHF Boundary Layer Radar and RASS
This thesis describes the refinements, modifications and additions to a prototype Very
High Frequency (VHF) Boundary Layer (BL) Spaced Antenna (SA) radar initially
installed at the University of Adelaide's Buckland Park field site in 1997.
Previous radar observations of the lowest few kilometres of the atmosphere, in
particular the Atmospheric Boundary Layer, have used Ultra-High Frequency (UHF)
radars. Unlike VHF radars, UHF radars are extremely sensitive to hydro-meteors
and have difficulty in distinguishing clear-air echoes from precipitation returns. The
advantages and requirements of using a VHF radar to observe the lowest heights is
discussed in conjunction with some of the limitations.
The successful operation of the system over long periods has enabled in-depth
investigation of the performance of the system in a variety of conditions and locations.
Observations were made from as low as 300m and as high as 8 km, dependent upon
conditions. Comparisons between the radar and alternative wind measuring devices
were carried out and examined.
The antenna system of the radar is a critical component which was analysed in
depth and subsequently re-designed. Through the use of numerical models and mea-
surements, evaluation of different designs was accomplished. Further calibration of
the remaining components of the full system has enabled estimations of the absolute
received power. Additional parameters which can be derived with a calibrated radar
were compared with values obtained by other authors, giving favourable results.
Full Correlation Analysis (FCA) is the predominant technique used in this work.
A brief discussion of the background theory and parameters which can be measured
is described. A simple one-dimensional model was developed and combined with a
'radar backscatter model' to investigate potential sources of errors in the parameters
determined using FCA with the VHF Boundary Layer Radar. In particular, underes-
timations in the wind velocity were examined.
The integration of a Radio Acoustic Sounding System (RASS) to obtain tempera-
ture profiles is discussed. The theory of RASS measurements including the limitations
and considerations which are required for the VHF BL radar are given. The difficulties
encountered trying to implement such a system and the subsequent success using a
Stratospheric Tropospheric (ST) Profiler in place of the BL radar is presented.
Taken as a whole this thesis shows the success of the VHF BL to obtain mea-
surements from as low as 300m. The validation of this prototype radar provides an
alternative and, in certain situations, a superior device with which to study the lower
troposphere.Thesis (Ph.D.)--University of Adelaide, Department of Physics and Mathematical Physics, 2001
Calibrating CHIME, A New Radio Interferometer to Probe Dark Energy
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a transit
interferometer currently being built at the Dominion Radio Astrophysical
Observatory (DRAO) in Penticton, BC, Canada. We will use CHIME to map neutral
hydrogen in the frequency range 400 -- 800\,MHz over half of the sky, producing
a measurement of baryon acoustic oscillations (BAO) at redshifts between 0.8 --
2.5 to probe dark energy. We have deployed a pathfinder version of CHIME that
will yield constraints on the BAO power spectrum and provide a test-bed for our
calibration scheme. I will discuss the CHIME calibration requirements and
describe instrumentation we are developing to meet these requirements
3-D printed UWB microwave bodyscope for biomedical measurements
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this letter, a three-dimensional (3-D) printed compact ultrawideband (UWB) extended gap ridge horn (EGRH) antenna designed to be used for biological measurements of the human body is described. The operational frequency covers the microwave band of interest from 0.5 to 3.0 GHz (for an S 11 under -7 dB). The 3-D printed EGRH antenna is dielectrically matched to the permittivity of the human body, and because of its compactness, it can be visualized as a general-purpose microwave probe among the RF biomedical community. The probe has proven its capability as a pass-through propagation sensor for different parts of the human body and as a sensor detecting a 1 cm diameter object placed inside an artificial head phantom.Peer ReviewedPostprint (author's final draft
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